Articles de revues : « TAM, miR-155, tumor microenvironment »

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Szebeni, Gabor J., Csaba Vizler, Klara Kitajka et Laszlo G. Puskas. « Inflammation and Cancer : Extra- and Intracellular Determinants of Tumor-Associated Macrophages as Tumor Promoters ». Mediators of Inflammation 2017 (2017) : 1–13. http://dx.doi.org/10.1155/2017/9294018.

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One of the hallmarks of cancer-related inflammation is the recruitment of monocyte-macrophage lineage cells to the tumor microenvironment. These tumor infiltrating myeloid cells are educated by the tumor milieu, rich in cancer cells and stroma components, to exert functions such as promotion of tumor growth, immunosuppression, angiogenesis, and cancer cell dissemination. Our review highlights the ontogenetic diversity of tumor-associated macrophages (TAMs) and describes their main phenotypic markers. We cover fundamental molecular players in the tumor microenvironment including extra- (CCL2, CSF-1, CXCL12, IL-4, IL-13, semaphorins, WNT5A, and WNT7B) and intracellular signals. We discuss how these factors converge on intracellular determinants (STAT3, STAT6, STAT1, NF-κB, RORC1, and HIF-1α) of cell functions and drive the recruitment and polarization of TAMs. Since microRNAs (miRNAs) modulate macrophage polarization key miRNAs (miR-146a, miR-155, miR-125a, miR-511, and miR-223) are also discussed in the context of the inflammatory myeloid tumor compartment. Accumulating evidence suggests that high TAM infiltration correlates with disease progression and overall poor survival of cancer patients. Identification of molecular targets to develop new therapeutic interventions targeting these harmful tumor infiltrating myeloid cells is emerging nowadays.

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Husain, Kazim, Krystal Villalobos-Ayala, Valentina Laverde, Oscar A. Vazquez, Bradley Miller, Samra Kazim, George Blanck et al. « Apigenin Targets MicroRNA-155, Enhances SHIP-1 Expression, and Augments Anti-Tumor Responses in Pancreatic Cancer ». Cancers 14, n^o 15 (25 juillet 2022) : 3613. http://dx.doi.org/10.3390/cancers14153613.

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Pancreatic cancer (PC) is a deadly disease with a grim prognosis. Pancreatic tumor derived factors (TDF) contribute to the induction of an immunosuppressive tumor microenvironment (TME) that impedes the effectiveness of immunotherapy. PC-induced microRNA-155 (miRNA-155) represses expression of Src homology 2 (SH2) domain-containing Inositol 5′-phosphatase-1 (SHIP-1), a regulator of myeloid cell development and function, thus impacting anti-tumor immunity. We recently reported that the bioflavonoid apigenin (API) increased SHIP-1 expression which correlated with the expansion of tumoricidal macrophages (TAM) and improved anti-tumor immune responses in the TME of mice with PC. We now show that API transcriptionally regulates SHIP-1 expression via the suppression of miRNA-155, impacting anti-tumor immune responses in the bone marrow (BM) and TME of mice with PC. We discovered that API reduced miRNA-155 in the PC milieu, which induced SHIP-1 expression. This promoted the restoration of myelopoiesis and increased anti-tumor immune responses in the TME of heterotopic, orthotopic and transgenic SHIP-1 knockout preclinical mouse models of PC. Our results suggest that manipulating SHIP-1 through miR-155 may assist in augmenting anti-tumor immune responses and aid in the therapeutic intervention of PC.

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Gerloff, Dennis, Jana Lützkendorf, Rose K. C. Moritz, Tom Wersig, Karsten Mäder, Lutz P. Müller et Cord Sunderkötter. « Melanoma-Derived Exosomal miR-125b-5p Educates Tumor Associated Macrophages (TAMs) by Targeting Lysosomal Acid Lipase A (LIPA) ». Cancers 12, n^o 2 (17 février 2020) : 464. http://dx.doi.org/10.3390/cancers12020464.

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Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment, promoting tumor initiation, growth, progression, metastasis, and immune evasion. Recently it was shown that cancer cell-derived exosomes induce a tumor-promoting phenotype in TAMs. Exosome-loaded proteins, DNA, and RNAs may contribute to the macrophage reprogramming. However, the exact mediators and mechanisms, particularly in melanoma, are not known. In this study we examined the effects of cutaneous melanoma-derived exosomes on macrophage function and the underlying mechanisms. First, we showed that exposure to melanoma exosomes induces a tumor-promoting TAM phenotype in macrophages. Sequencing revealed enrichment for several miRNAs including miR-125b-5p in cutaneous melanoma exosomes. We showed that miR-125b-5p is delivered to macrophages by melanoma exosomes and partially induces the observed tumor-promoting TAM phenotype. Finally, we showed that miR-125b-5p targets the lysosomal acid lipase A (LIPA) in macrophages, which in turn contributes to their phenotype switch and promotes macrophage survival. Thus, our data show for the first time that miR-125b-5p transferred by cutaneous melanoma-derived exosomes induces a tumor-promoting TAM phenotype in macrophages.

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Gajeton, Jasmine, Irene Krukovets, Santoshi Muppala, Dmitriy Verbovetskiy, Jessica Zhang et Olga Stenina-Adognravi. « Hyperglycemia-Induced miR-467 Drives Tumor Inflammation and Growth in Breast Cancer ». Cancers 13, n^o 6 (16 mars 2021) : 1346. http://dx.doi.org/10.3390/cancers13061346.

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The tumor microenvironment contains the parenchyma, blood vessels, and infiltrating immune cells, including tumor-associated macrophages (TAMs). TAMs affect the developing tumor and drive cancer inflammation. We used mouse models of hyperglycemia and cancer and specimens from hyperglycemic breast cancer (BC) patients to demonstrate that miR-467 mediates the effects of high blood glucose on cancer inflammation and growth. Hyperglycemic patients have a higher risk of developing breast cancer. We have identified a novel miRNA-dependent pathway activated by hyperglycemia that promotes BC angiogenesis and inflammation supporting BC growth. miR-467 is upregulated in endothelial cells (EC), macrophages, BC cells, and in BC tumors. A target of miR-467, thrombospondin-1 (TSP-1), inhibits angiogenesis and promotes resolution of inflammation. Systemic injections of a miR-467 antagonist in mouse models of hyperglycemia resulted in decreased BC growth (p < 0.001). Tumors from hyperglycemic mice had a two-fold increase in macrophage accumulation compared to normoglycemic controls (p < 0.001), and TAM infiltration was prevented by the miR-467 antagonist (p < 0.001). BC specimens from hyperglycemic patients had increased miR-467 levels, increased angiogenesis, decreased levels of TSP-1, and increased TAM infiltration in malignant breast tissue in hyperglycemic vs. normoglycemic patients (2.17-fold, p = 0.002) and even in normal breast tissue from hyperglycemic patients (2.18-fold increase, p = 0.04). In malignant BC tissue, miR-467 levels were upregulated 258-fold in hyperglycemic patients compared to normoglycemic patients (p < 0.001) and increased 56-fold in adjacent normal tissue (p = 0.008). Our results suggest that miR-467 accelerates tumor growth by inducing angiogenesis and promoting the recruitment of TAMs to drive hyperglycemia-induced cancer inflammation.

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Arora, Shweta, Prithvi Singh, Shaniya Ahmad, Tanveer Ahmad, Ravins Dohare, Saleh A. Almatroodi, Faris Alrumaihi, Arshad Husain Rahmani et Mansoor Ali Syed. « Comprehensive Integrative Analysis Reveals the Association of KLF4 with Macrophage Infiltration and Polarization in Lung Cancer Microenvironment ». Cells 10, n^o 8 (14 août 2021) : 2091. http://dx.doi.org/10.3390/cells10082091.

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Macrophage polarization and infiltration to the tumor microenvironment (TME) is a critical determining factor for tumor progression. Macrophages are polarized into two states—M1 (pro-inflammatory, anti-tumorigenic and stimulated by LPS or IFN-γ) and M2 (anti-inflammatory pro-tumorigenic and stimulated by IL-4) phenotypes. Specifically, M2 macrophages enhance tumor cell growth and survival. Recent evidences suggest the pivotal role of microRNAs in macrophage polarization during the development of Non-small cell lung cancer (NSCLC), thus proposing a new therapeutic option to target lung cancer. In silico analysis determined cogent upregulation of KLF4, downregulation of IL-1β and miR-34a-5p in NSCLC tissues, consequently worsening the overall survival of NSCLC patients. We observed a significant association of KLF4 with macrophage infiltration and polarization in NSCLC. We found that KLF4 is critically implicated in M2 polarization of macrophages, which, in turn, promotes tumorigenesis. KLF4 expression correlated with miR-34a-5p and IL-1β in a feed-forward loop (FFL), both of which are implicated in immune regulation. Mechanistic overexpression of miR-34a-5p in macrophages (IL-4 stimulated) inhibits KLF4, along with downregulation of ARG1, REL-1MB (M2 macrophage specific markers), and upregulation of IL-1β, IL-6, (M1 macrophage specific markers), demonstrating macrophage polarization switch from M2 to M1 phenotype. Moreover, co-culture of these macrophages with NSCLC cells reduces their proliferation, wound healing, clonogenic capacity and enhanced NO-mediated apoptosis. Further, transfection of miR-34a-5p in NSCLC cells, also degrades KLF4, but enhances the expression of KLF4 regulated genes—IL-1β, IL-6 (pro-inflammatory mediators), which is further enhanced upon co-culture with IL-4 stimulated macrophages. Additionally, we observed a significant increase in i-NOS/NO content upon co-culture, suggesting polarization reversion of macrophages from M2 to M1, and eventually leading to anti-tumor effects. Our findings thus show a significant role of KLF4 in tumorigenesis and TAM polarization of NSCLC. However, miR-34a-5p mediated targeting of these molecular networks will provide a better therapeutic intervention for NSCLC.

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Banerjee, Hirendra, Christopher Krauss, Myla Worthington, Narendra Banerjee, Ray Shawn Walker, Sasha Hodges, Lin Chen et al. « Differential expression of efferocytosis and phagocytosis associated genes in tumor associated macrophages exposed to African American patient derived prostate cancer microenvironment ». Journal of Solid Tumors 9, n^o 2 (27 juin 2019) : 22. http://dx.doi.org/10.5430/jst.v9n2p22.

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Macrophages are the first line of defense in the cellular environment in response to any antigenic or foreign invasion. Since cancer cells express antigenic molecules and create a tumor microenvironment quite different from the normal cellular environment, macrophages will attack this cancer cells as foreign Invaders. However, the cancer cells adept their ability to suppress macrophage activity by secreting compounds/proteins through unknown mechanisms and train these macrophages to aid in tumorigenesis. These macrophages are commonly known as tumor associated macrophages (TAM). In this study, our goal was to find out key regulatory molecules involved in this conversion of cancer-fighting macrophages to cancer friendly macrophages. We used African American(AA) patient derived established human prostate cancer cells along with the human derived macrophages followed by Affymetrix cDNA microarray analysis. Microarray analysis of the PCa cell exposed macrophages revealed appreciable decrease in mRNA expression of several genes associated with phagocytosis process. Aberrant expression of several noncoding RNAs that control the expression of such phagocytosis associated molecules were also evident. Increased expression of oncogenic miR such as, miR-148, 615, 515, 130, 139 and markedly decreased expression of tumor suppressive miR’s MiR-3130, let7c,101,103, 383 were noted. Further, TARGET SCAN analysis demonstrated these differential expression of non-coding RNA’s causing down regulation of phagocytosis promoting genes elf5A, Meg3, Tubb5, Sparcl-1, Uch-1, Bsg(CD147), Ube2v, GULP, Stabilin 1 and Pamr1. There is an increase of RAP1GAP gene that causes concomitant decrease in the expression of tubulin genes that promote cytoskeletal assembly in forming phagosomes. In addition Ingenuity pathway analysis of the gene expression data also showed upregulation of antiphagocytic genes IL-10, CD16, IL-18 and MMP-9. Some core canonical pathways showing physiology of cellular signaling obtained by data analyzed by the Ingenuity software is confirmed a very complex mechanism still to be deciphered involved in the biology of TAM formation by which the rogue cancer cells tame their enemies, the macrophages and actually make them their helper cells to survive and propagate in the tumor microenvironment and thus prepare for epithelial mesenchymal transition for future metastasis and cancer stem cell formation and progression.

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Chen, Hao, Chao Tang, Chun Tan, Fei Wu, Zhenhan Li, Wenyan Ji, Linming Lu, Chongjun Xu, Zhengchao Shen et Yanqiang Huang. « IL-2 Modulates TAMs Derived Exosomal MiRNAs to Ameliorate Hepatocellular Carcinoma Development and Progression ». Journal of Oncology 2022 (21 février 2022) : 1–11. http://dx.doi.org/10.1155/2022/3445350.

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Background. Interleukin-2 (IL-2) is proved to play an irreplaceable role in antitumor regulation in numerous experimental and clinical trials. Tumor-associated macrophages (TAMs) are able to release exosomes to promote the development and progression of hepatocellular carcinoma (HCC) as essential component of microenvironment. In this study, our intention is to explore the effects of the exosomes from TAMs with IL-2 treatment on HCC development. TAMs were collected and cultured from HCC tissues. The exosomes from the TAMs treated with IL-2 (ExoIL2-TAM) or not (ExoTAM) were identified and used to treat HCC cells in vivo and in vitro. The proliferation, apoptosis, and metastasis of HCC cells were measured. The changes of miRNAs in exosomes were explored to clarify the possible mechanisms. Both decrease of cell proliferation and metastasis and increase of apoptosis were observed with ExoIL2-TAM treatment compared with ExoTAMin vivo and in vitro. miR-375 was obviously augmented in ExoIL2-TAM and HCC cells treated with ExoIL2-TAM. Taken together, IL-2 may modulate exosomal miRNAs from TAMs to ameliorate hepatocellular carcinoma development. This study provides a new perspective to explain the mechanism by which IL-2 inhibits hepatocellular carcinoma and implies the potential clinical value of exosomal miRNAs released by TAMs.

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Yu, Haiyang, Jing Pan, Siyue Zheng, Deyang Cai, Aixiang Luo, Zanxian Xia et Jufang Huang. « Hepatocellular Carcinoma Cell-Derived Exosomal miR-21-5p Induces Macrophage M2 Polarization by Targeting RhoB ». International Journal of Molecular Sciences 24, n^o 5 (27 février 2023) : 4593. http://dx.doi.org/10.3390/ijms24054593.

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M2-like polarized tumor-associated macrophages (TAMs) are the major component of infiltrating immune cells in hepatocellular carcinoma (HCC), which have been proved to exhibit significant immunosuppressive and pro-tumoral effects. However, the underlying mechanism of the tumor microenvironment (TME) educating TAMs to express M2-like phenotypes is still not fully understood. Here, we report that HCC-derived exosomes are involved in intercellular communications and exhibit a greater capacity to mediate TAMs’ phenotypic differentiation. In our study, HCC cell-derived exosomes were collected and used to treat THP-1 cells in vitro. Quantitative polymerase chain reaction (qPCR) results showed that the exosomes significantly promoted THP-1 macrophages to differentiate into M2-like macrophages, which have a high production of transforming growth factor-β (TGF-β) and interleukin (IL)-10. The analysis of bioinformatics indicated that exosomal miR-21-5p is closely related to TAM differentiation and is associated with unfavorable prognosis in HCC. Overexpressing miR-21-5p in human monocyte-derived leukemia (THP-1) cells induced down-regulation of IL-1β levels; however, it enhanced production of IL-10 and promoted the malignant growth of HCC cells in vitro. A reporter assay confirmed that miR-21-5p directly targeted Ras homolog family member B (RhoB) 3′-untranslatedregion (UTR) in THP-1 cells. Downregulated RhoB levels in THP-1 cells would weaken mitogen-activated protein kinase (MAPK) axis signaling pathways. Taken together, tumor-derived miR-21-5p promote the malignant advance of HCC, which mediated intercellular crosstalk between tumor cells and macrophages. Targeting M2-like TAMs and intercepting their associated signaling pathways would provide potentially specific and novel therapeutic approaches for HCC treatment.

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Miura, Yuji, Takanobu Motoshima, Nanako Wakigami, Natsuki Kusada, Toshikazu Okaneya, Naoko Inoshita, Toshimi Takano, Tomomi Kamba et Yoshihiro Komohara. « Phenotypic differences in tumor-associated macrophages between metastatic and primary sites of clear cell renal cell carcinoma. » Journal of Clinical Oncology 36, n^o 5_suppl (10 février 2018) : 105. http://dx.doi.org/10.1200/jco.2018.36.5_suppl.105.

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105 Background: Tumor-associated macrophages (TAMs) are one of the key contributors to the tumor microenvironment and are phenotypically differentiated into M1 and M2 macrophages. M1 macrophages stimulate anti-tumor immune responses, whereas M2 macrophages promote immunosuppression and are associated with tumor progression in clear cell renal cell carcinoma (ccRCC). However, little information is available regarding the difference in TAM polarization between primary and metastatic lesions of ccRCC. Methods: We collected paired samples of primary and matched metastatic sites from the first recurrence in 41 metastatic ccRCC patients. Immunohistochemistry (IHC) for Iba1, which is a common pan-macrophage marker, and CD163 and CD204, which are considered to be M2 macrophage markers, was performed on all paired samples. Results: Thirty-three paired primary and metastatic samples were available for IHC assessment in this analysis. The most common metastatic sites were lung (N = 26, 78.8 %) and lymph node (N = 3, 9.1 %). The mean (± standard deviation) cell density of Iba1+ TAMs was higher in metastatic lesions than in primary lesions (756 ± 267 mm2 vs. 581 ± 155 mm2, P = 0.0012). By contrast, the ratio of CD163+ and CD204+ to Iba1+ TAMs was significantly lower in metastatic lesions than in primary lesions (0.76 ± 0.30 vs. 0.90 ± 0.24, P = 0.0067 and 0.39 ± 0.27 vs. 0.67 ± 0.29, P = 0.0001, respectively). The median overall survival of patients with high- vs. low-density Iba1+, CD163+, and CD204+ TAMs in metastatic lesions was 120 vs. 92 months (log-rank P = 0.67), 120 vs. 58 months (log-rank P = 0.056), and 120 vs. 92 months (log-rank P = 0.35), respectively. Conclusions: TAMs in the metastatic lesions of ccRCC polarized towards an M1-like phenotype, although the total number of TAMs was greater in metastatic compared with primary lesions. The cell density of Iba1+, CD163+, and CD204+ TAMs in metastatic sites was not associated with overall survival in patients with ccRCC.

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Feng, Zhengzhe, Xiaoxi Zhang, Li Li, Chuanchuan Wang, Mingtao Feng, Kaijun Zhao, Rui Zhao, Jianmin Liu et Yibin Fang. « Tumor-associated macrophage-derived exosomal microRNA-155-5p stimulates intracranial aneurysm formation and macrophage infiltration ». Clinical Science 133, n^o 22 (novembre 2019) : 2265–82. http://dx.doi.org/10.1042/cs20190680.

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Abstract Tumor-associated macrophages (TAMs) play a regulatory role in inflammation and cancer. Exosomes derived from macrophages carrying microRNAs (miRNAs or miRs) are of great value for cancer therapy. Gremlin 1 (GREM1), a member of the antagonists of secreted bone morphogenetic protein, has been implicated in the pathophysiology of multiple diseases or cancers. Based on the predictions of miRNA–mRNA interaction, GREM1 was found to be a target gene of miR-155-5p. Here, the present study aims to explore the role of TAM-derived exosomal miR-155-5p by regulating GREM1 in intracranial aneurysm (IA). The collected results showed that GREM1 was down-regulated in IA, while miR-155-5p was up-regulated in TAM-derived exosomes. Smooth muscle cells (SMCs) were co-cultured with TAMs or exposed to exosomes derived from TAMs transfected with either miR-155-5p mimic or miR-155-5p inhibitor for exploring their roles in proliferation and migration of SMCs in vitro. Accordingly, in vitro experiments showed that TAM-derived exosomal miR-155-5p could promote proliferation and migration of SMCs by targeting GREM1. The effects of TAM-derived exosomal miR-155-5p on IA formation and TAM activation and infiltration by regulation of GREM1 in vivo were measured in IA rats injected with exosomes or those from TAMs transfected with miR-155-5p inhibitor. In vivo experimental results consistently confirmed that TAM-derived exosomes carrying miR-155-5p promoted IA formation and TAM activation and infiltration. In conclusion, TAM-derived exosomal miR-155-5p promotes IA formation via GREM1, which points to miR-155-5p as a possible therapeutic target for IA.

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Huffaker, Thomas, et Ryan O’Connell. « Single cell sequencing reveals regulatory role for T cell expressed microRNA-155 within the tumor microenvironment. » Journal of Immunology 200, n^o 1_Supplement (1 mai 2018) : 178.4. http://dx.doi.org/10.4049/jimmunol.200.supp.178.4.

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Abstract MicroRNA-155 (miR-155) is a pro-inflammatory miRNA that has been shown to regulate antitumor immunity. We recently demonstrated, utilizing miR-155 T cell conditional knockout mice (TCKO), that miR-155 is required by T cells to inhibit the growth of transplanted B16f10 melanoma tumors. To further understand the role of miR-155 expression within tumor infiltrating T cells and their impact upon the tumor microenvironment, we performed 10× single cell RNA-sequencing on tumor infiltrating immune cells from miR-155 TCKO mice and controls. At 12 days post administration of B16f10 OVA syngeneic tumors, CD45+ cells from the tumors of miR-155 TCKO mice and control mice were sorted via flow cytometry and single cell sequencing was performed. Results indicate that the immune cell landscape within these tumors consists of at least 11 distinct populations. This included an expanded population of Arg1 and Ym1 expressing cells of the myeloid lineage in tumors from miR-155 TCKO mice. Tumors from these mice were also deficient in a specific subset of CD8+ T cells that highly express interferon gamma, granzyme B, and perforin. miR-155 host gene was expressed by this population of effector CD8+ T cells in Wt control mice. These results demonstrate the utility of using single cell RNA-Seq to comprehensively profile immune cells that are responding to solid tumors. Further, the data clearly indicate that miR-155 expression by T cells is necessary for their recruitment and production of antitumor molecules, while at the same time preventing the accumulation of myeloid populations with known roles in suppressing tumor immunity. These data have implications for manipulating miR-155 in the clinic as a means to bolster tumor immunotherapy.

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Fan, Daping, et Junfeng Wang. « microRNA-155 is a master regulator of dendritic cell function in breast cancer ». Journal of Immunology 196, n^o 1_Supplement (1 mai 2016) : 75.12. http://dx.doi.org/10.4049/jimmunol.196.supp.75.12.

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Abstract In anti-tumor immunity, dendritic cells (DCs) capture, process and present tumor antigens to T cells, and initiate a tumoricidal response. However, DCs are often found dysfunctional due to their exposure to the tumor microenvironment (TME), leading to tumor escape from immune surveillance. The mechanisms underlying the regulation or dysregulation of DC function in the context of tumor has not been well elucidated. Here a vital role of microRNA-155 (miR-155) in regulating the function of DCs in breast cancer is reported. miR-155 expression is closely correlated with the maturation status, migration ability and cytokine production of DCs, as well as their ability to activate T cells. We further demonstrate that miR-155 regulates DC migration through epigenetic modulation of CCR7 expression. Moreover, IL-6 and IL-10, two cytokines abundant in the TME, are found to impair DC maturation by suppressing miR-155 expression. Animal studies show that lack of miR-155 diminishes, while forced expression of miR-155 enhances, the effectiveness of DC-based immunotherapy for breast cancer. These findings suggest miR-155 is a master regulator of DC function in breast cancer, and boosting the expression of a single microRNA, miR-155, may significantly improve the efficacy of DC-based immunotherapies for breast cancer.

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Velázquez, Kandy T., Reilly T. Enos, Jamie L. McClellan, Taryn L. Cranford, Ioulia Chatzistamou, Udai P. Singh, Mitzi Nagarkatti, Prakash S. Nagarkatti, Daping Fan et E. Angela Murphy. « MicroRNA-155 deletion promotes tumorigenesis in the azoxymethane-dextran sulfate sodium model of colon cancer ». American Journal of Physiology-Gastrointestinal and Liver Physiology 310, n^o 6 (15 mars 2016) : G347—G358. http://dx.doi.org/10.1152/ajpgi.00326.2015.

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Clinical studies have linked microRNA-155 (miR-155) expression in the tumor microenvironment to poor prognosis. However, whether miR-155 upregulation is predictive of a pro- or antitumorigenic response is unclear, as the limited preclinical data available remain controversial. We examined miR-155 expression in tumor tissue from colon cancer patients. Furthermore, we investigated the role of this microRNA in proliferation and apoptosis, inflammatory processes, immune cell populations, and transforming growth factor-β/SMAD signaling in a chemically induced (azoxymethane-dextran sulfate sodium) mouse model of colitis-associated colon cancer. We found a higher expression of miR-155 in the tumor region than in nontumor colon tissue of patients with colon cancer. Deletion of miR-155 in mice resulted in a greater number of polyps/adenomas, an increased symptom severity score, a higher grade of epithelial dysplasia, and a decrease in survival. Surprisingly, these findings were associated with an increase in apoptosis in the normal mucosa, but there was no change in proliferation. The protumorigenic effects of miR-155 deletion do not appear to be driven solely by dysregulation of inflammation, as both genotypes had relatively similar levels of inflammatory mediators. The enhanced tumorigenic response in miR-155−/− mice was associated with alterations in macrophages and neutrophils, as markers for these populations were decreased and increased, respectively. Furthermore, we demonstrated a greater activation of the transforming growth factor-β/SMAD pathway in miR-155−/− mice, which was correlated with the increased tumorigenesis. Given the multiple targets of miR-155, careful evaluation of its role in tumorigenesis is necessary prior to any consideration of its potential as a biomarker and/or therapeutic target in colon cancer.

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Kalkusova, Katerina, Pavla Taborska, Dmitry Stakheev et Daniel Smrz. « The Role of miR-155 in Antitumor Immunity ». Cancers 14, n^o 21 (3 novembre 2022) : 5414. http://dx.doi.org/10.3390/cancers14215414.

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MicroRNAs belong to a group of short non-coding RNA molecules that are involved in the regulation of gene expression at multiple levels. Their function was described two decades ago, and, since then, microRNAs have become a rapidly developing field of research. Their participation in the regulation of cellular processes, such as proliferation, apoptosis, cell growth, and migration, made microRNAs attractive for cancer research. Moreover, as a single microRNA can simultaneously target multiple molecules, microRNAs offer a unique advantage in regulating multiple cellular processes in different cell types. Many of these cell types are tumor cells and the cells of the immune system. One of the most studied microRNAs in the context of cancer and the immune system is miR-155. MiR-155 plays a role in modulating innate and adaptive immune mechanisms in distinct immune cell types. As such, miR-155 can be part of the communication between the tumor and immune cells and thus impact the process of tumor immunoediting. Several studies have already revealed its effect on antitumor immune responses, and the targeting of this molecule is increasingly implemented in cancer immunotherapy. In this review, we discuss the current knowledge of miR-155 in the regulation of antitumor immunity and the shaping of the tumor microenvironment, and the plausible implementation of miR-155 targeting in cancer therapy.

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Majewska, Aleksandra, Klaudia Brodaczewska, Aleksandra Filipiak-Duliban, Arkadiusz Kajdasz et Claudine Kieda. « miRNA Pattern in Hypoxic Microenvironment of Kidney Cancer—Role of PTEN ». Biomolecules 12, n^o 5 (11 mai 2022) : 686. http://dx.doi.org/10.3390/biom12050686.

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MicroRNAs are post-transcriptional regulators of gene expression, and disturbances of their expression are the basis of many pathological states, including cancers. The miRNA pattern in the context of tumor microenvironment explains mechanisms related to cancer progression and provides a potential target of modern therapies. Here we show the miRNA pattern in renal cancer focusing on hypoxia as a characteristic feature of the tumor microenvironment and dysregulation of PTEN, being a major tumor suppressor. Methods comprised the CRSPR/Cas9 mediated PTEN knockout in the Renca kidney cancer cell line and global miRNA expression analysis in both in vivo and in vitro (in normoxic and hypoxic conditions). The results were validated on human cancer models with distinct PTEN status. The increase in miR-210-3p in hypoxia was universal; however, the hypoxia-induced decrease in PTEN was associated with an increase in miR-221-3p, the loss of PTEN affected the response to hypoxia differently by decreasing miR-10b-5p and increasing miR-206-3p. In turn, the complete loss of PTEN induces miR-155-5p, miR-100-5p. Upregulation of miR-342-3p in knockout PTEN occurred in the context of the whole tumor microenvironment. Thus, effective identification of miRNA patterns in cancers must consider the specificity of the tumor microenvironment together with the mutations of key suppressors.

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Zhang, Yong, Christopher P. Rombaoa, Aldo M. Roccaro, Susanna Obad, Oliver Broom, Stacey M. Fernandes, Ranjit Banwait et al. « LNA Anti-MicroRNA-155 : A Novel Therapeutic Strategy in Waldenstrom Macroglobulinemia and Chronic Lymphocytic Leukemia ». Blood 118, n^o 21 (18 novembre 2011) : 2728. http://dx.doi.org/10.1182/blood.v118.21.2728.2728.

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Abstract Abstract 2728 Background. We and others have previously demonstrated that primary Waldenstrom's Macroglobulinemia (WM) and Chronic lymphocytic leukemia (CLL) cells show increased expression of microRNA-155 (miR-155), suggesting a role in regulating pathogenesis and tumor progression of these diseases. However, developing therapeutic agents that specifically target miRNAs has been hampered by the lack of appropriate delivery of small RNA inhibitors into tumor cells. We tested the effect of a novel LNA (locked nucleic acid)-modified anti-miR-155 in WM and CLL. Methods. WM and CLL cells, both cell lines (BCWM.1; MEC.1) and primary tumor cells; BCWM.1 Luc+ cells; and primary WM bone marrow (BM) stromal cells were used. WM and CLL cells were treated with antisense LNA anti-miR-155 or LNA scramble oligonucleotide. Efficiency of delivering FAM-labeled LNA into cells was determined by flow cytometry. Survival and cell proliferation were assessed by MTT and thymidine uptake assay, respectively. Synergistic effects of LNA with bortezomib were detected on BCWM.1 or MEC1 cells. Co-culture of BCWM.1 or MEC1 cells with WM bone marrow stromal cells was performed to better define the effect of the LNA-anti-miR155 in the context of the bone marrow microenvironment. miR-155 levels were detected in stromal cells from WM patients by qPCR. Co-culture of BCWM.1 or MEC1 cells with either wild-type or miR155−/− mice BM stromal cells was examined after LNA treatment. Gene expression profiling analysis was performed on BCWM.1 cells treated with either LNA anti-miR-155 or scramble control. miR-155 target gene candidates were predicted by TargetScan software. mRNA levels of miR-155, and its known target genes or gene candidates were detected by qRT-PCR. A microRNA luciferase reporter assay was used to determine whether miR-155 target candidates could be directly regulated by miR-155. mRNA levels of miR-155 targets were detected by qRT-PCR from primary WM or CLL cells treated with LNA. The activity of the LNA-anti-miR-155 was also detected in vivo using bioluminescence imaging and mRNA levels of miR-155 targets were detected by qRT-PCR ex vivo. Efficiency of introducing the FAM-labeled LNA into mice BM cells was determined by flow cytometry 1 week or 2 weeks after intravenous injection. Results. The efficiency of delivering LNA oligos into both WM and CLL-derived cell lines and primary samples was higher than 90%. LNA antimiR-155 reduced proliferation of WM and CLL-derived cell lines by 30–50%, as compared to LNA scramble control. In contrast, LNA antimiR-155 didn't exert significant cytotoxicity in BCWM.1 or MEC.1. LNA synergistically decreased BCWM.1 or MEC1 cell growth co-treated with bortezomib and decreased BCWM.1 or MEC1 cell growth co-cultured with WM BM stromal cells in vitro. A higher level of miR-155 was found in WM BM stromal cells compared to normal ones. LNA decreased BCWM.1 or MEC1 cell growth when co-cultured with BM stromal cells from miR155−/− mice compared with wild-type. We demonstrated increased expression of miR-155-known targeted genes, including CEBPβ, SOCS1, SMAD5, and several novel target candidates including MAFB, SH3PXD2A, and SHANK2, in WM cells upon LNA anti-miR-155 treatment. These target candidates were confirmed to be directly regulated by miR-155 using a luciferase reporter assay. mRNA levels of miR-155 targets were upregulated by 1.5–2 fold at 48 hr after direct incubation of the LNA with primary WM or CLL samples, indicating efficient delivery and biologic effect of the LNA in cells. Moreover, this LNA showed significant in vivo activity by inhibiting WM cell proliferation in a disseminated xenograft mouse model. Upregulation of miR-155 targeted genes were confirmed ex vivo, in WM cells isolated from the BM of treated mice compared to control. Mice BM cells were FAM positive 1 or 2 weeks after injection indicating efficient delivery of FAM-labeled LNA into cells in vivo. Summary. A novel LNA (locked nucleic acid)-modified anti-miR against miR-155 could be highly efficiently delivered into tumor cells in vivo in the bone marrow microenvironment. Anti-WM activity of LNA anti-miR-155 was confirmed both in vitro and in vivo and anti-CLL activity was confirmed in vitro. Novel miR-155 direct target genes including MAFB, SH3PXD2A, and SHANK2 were identified. These findings will help to design individualized clinical trials for WM and CLL patients with elevated levels of miR-155 in their tumor cells. Disclosures: Roccaro: Roche:. Obad:Santaris Pharma: Employment. Broom:Electroporation: Employment. Kauppinen:Santaris Pharma: Employment. Brown:Calistoga: Consultancy, Research Funding; Celgene: Honoraria, Research Funding; Genzyme: Research Funding; GSK: Research Funding. Ghobrial:Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Noxxon: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium: Research Funding; Bristol-Myers Squibb: Research Funding; Noxxon: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees.

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Abdulla, Osama Azeldeen, Prakash S. Nagarkatti et Mitzi Nagarkatti. « Regulation of macrophages in tumor microenvironment by microRNA in T cell lymphoma-bearing mice ». Journal of Immunology 204, n^o 1_Supplement (1 mai 2020) : 164.18. http://dx.doi.org/10.4049/jimmunol.204.supp.164.18.

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Abstract The tumor microenvironment is a complex niche created by cancer cells to survive and evade the immune system. Macrophages (Mϕs) are considered to be one of the most abundant cells in the cancer microenvironment. Studies have shown that cancer cells have predilection for the M2 cell phenotype compared to M1 in the microenvironment, because M2 Mϕs promote immunosuppression and subsequently enhance tumor cell proliferation and angiogenesis. The aim of this study was to compare the gene expression profile of tumor-associated Mϕs (TAMs) and splenic Mϕs from tumor-bearing hosts (TBHs) and determine the epigenetic regulation of altered genes. For this purpose, C57BL/6 mice were injected with 1×106 EL4 cancer cells subcutaneous to induce tumor growth and 10 days later, TAMs and splenic Mϕs were isolated. Cell phenotyping by flow cytometry showed that there was an increase in M2 cells in TAMs when compared to splenic Mϕs in TBHs. TAMs also exhibited increase in IL-10, IL-6, VEGFA, and ARG-1 whereas there was a decrease in the expression of MYD88, PTEN, TGFβ3 and P53 when compared to splenic Mϕs in TBHs. Analysis of the microRNA profile of the Mϕs showed differential regulation and using ingenuity pathway analysis (IPA), we found various miRs (miR-21a, miR-30a, miR-30c, miR-125b, miR-155) were upregulated. These miRs targeted MYD88, PTEN and P53, which leads to the overexpression of IL10, known to skew Mϕ polarization to an M2 phenotype. In summary, these studies demonstrate that several miRs regulate IL10 to polarize TAMs from an M1 to M2 phenotype in the tumor microenvironment. (Supported by NIH P01AT003961, P20GM103641, R01AI129788, R01 ES030144 and R01AI123947)

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Renrick, Ariana N., Menaka C. Thounaojam, Portia L. Thomas et Anil Shanker. « Bortezomib impacts Notch—miR-155 mediated augmentation of CD8+T Cell antitumor immunity ». Journal of Immunology 200, n^o 1_Supplement (1 mai 2018) : 57.2. http://dx.doi.org/10.4049/jimmunol.200.supp.57.2.

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Abstract The immunosuppressive tumor microenvironment dampens host antitumor immunity by multiple mechanisms including interference with the Notch system, which is important for various cell fate decisions and hematopoietic cell differentiation and function. We observed that treatment with bortezomib, a proteasome inhibitor, in mice bearing subcutaneous tumors resulted in an upregulated expression of various Notch signaling components in lymphoid tissues and increased CD8+T lymphocyte IFNγ secretion and expression of effector molecules, perforin and granzyme-B, as well as the T-box transcription factor eomesodermin. Of note, bortezomib reversed tumor-induced downregulation of Notch receptors, Notch1 and Notch2, as well as increased the levels of cleaved Notch intracellular domain (NICD) and downstream targets Hes1 and Hey1 in tumor-draining CD8+T cells. These data suggest that bortezomib can reverse tumor-induced dysfunction of CD8+T cells by its intrinsic stimulatory effects. Our preliminary data also suggest that bortezomib can positively regulate miR-155 expression in CD8+ T cells from mice bearing tumor. Further, miR-155 suppression was found to downregulate bortezomib-induced increase in Notch target genes in T cells. We are currently elucidating how bortezomib affects the expression of miR-155 and its target genes, such as suppressor of cytokine signaling 1 (SOCS1) and inositol polyphosphate-5-phosphatase (SHIP1) that are associated with T cell function. These data provide novel insights on using bortezomib not only as an agent to sensitize tumors to cell death, but also to provide lymphocyte-stimulatory effects, thereby overcoming immunosuppressive actions of tumor on antitumor T cell functions.

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Renrick, Ariana N., Menaka Thounaojam, Evan Chaudhuri, Chandravanu Dash et Anil Shanker. « Bortezomib improves antitumor CD8+ T cell function by modulating miR-155 and its targets ». Journal of Immunology 202, n^o 1_Supplement (1 mai 2019) : 136.18. http://dx.doi.org/10.4049/jimmunol.202.supp.136.18.

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Abstract The immunosuppressive tumor microenvironment dampens host antitumor immunity by multiple mechanisms including interfering with various cell signaling pathways that aid in the differentiation and function of immune cells. We have taken an immunotherapeutic approach in order to strengthen antitumor immunity in mice bearing solid tumors, specifically breast tumors. In doing so, we observed that treatment with bortezomib, an FDA-approved proteasome inhibitor, has the ability to increase CD8+T lymphocyte IFNγ secretion and expression of effector molecules, perforin, granzyme-B and the T-box transcription factor eomesodermin. In order to understand the molecular mechanism(s) of how bortezomib works to improve antitumor immunity we sought to explore its effects on miRNA expression as well as function. We found that treatment of wild-type or tumor-bearing BALB/c mice with bortezomib modulated the expression of various miRNAs in CD8+T cells. From miRNA array data, we identified miR-155 as one prominent modulator of antitumor CD8+T cell immune functions. miR-155 has been accredited to controlling CD8+T cell responses by regulating interferon signaling in viral infections and cancer. We are currently elucidating the mechanisms of bortezomib-mediated effects on miR-155 and its targets, such as suppressor of cytokine signaling 1 (SOCS1) and inositol polyphosphate-5-phosphatase (SHIP1) that are associated with T cell function. These data provide novel insights on using bortezomib not only as an agent to sensitize tumors to cell death, but also to provide lymphocyte-stimulatory effects that could overcome immunosuppressive actions of tumor on antitumor T cell function.

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Carlesso, Nadia. « Reacting to Inflammatory Signals ». Blood 126, n^o 23 (3 décembre 2015) : SCI—30—SCI—30. http://dx.doi.org/10.1182/blood.v126.23.sci-30.sci-30.

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Specialized cellular niches in the bone marrow (BM) modulate critical functions of the hematopoietic stem and progenitor cells, such as self-renewal, cell-fate decisions and the balance between proliferation and differentiation. Constituents of the BM niche, such as osteoblasts, endothelial cells and macrophages, respond to inflammation with secretion of pro-inflammatory cytokines, and serve as effectors of the inflammatory circuitry; thus their excessive activation can potentially impact on the regulation of hematopoietic cells, and on the initiation and progression of myeloid malignancies. Our current understanding of the mechanisms for Bcr/Ab-negative myeloproliferative neoplasia (MPN) involves recognition of driver mutations (targeting i.e. Tet2, Jak2, Mpl, or Asxl) and of an inflammatory microenvironment. However, despite accumulating evidences on the role of inflammation and of the microenvironment in the maintenance and progression of myeloid malignancies, it is still unclear how the inflamed BM niche contributes to disease establishment and progression. Similarly, the causes leading to an inflammatory microenvironment in MPN are not fully understood. We use genetically-controlled animal model of BM inflammation to study the contribution of the inflammatory microenvironment to MPN. We found that loss of Notch signaling in the BM microenvironment results in an inflammatory state of the BM niche promoting myeloproliferation and marrow fibrosis. Using this model, we discovered that loss of Notch/RBPJ signaling leads to transcriptional upregulation of the pro-inflammatory microRNA miR-155, especially in BM endothelial and mesenchymal cells, resulting in miR-155-dependent inhibition of the NF-κB inhibitor κB-Ras1. Decreased levels of kB-Ras1 resulted in the heightened and persistent activation of NF-κB and in the increased production of NF-kB dependent pro-inflammatory cytokines, leading to uncontrolled myeloproliferation. Deletion of miR-155 in the stroma of RBPJ-/- mice prevented the development of the myeloproliferative disease, and patients affected by MPN exhibit elevated expression of miR155 in their BM. Therefore, we hypothesize that the Notch/miR155/NF-kB axis regulates the level of the inflammatory tonus in the BM niche, and that persistent deregulation of this pathway may contribute to the establishment and progression of MPN. In this presentation, we will discuss our findings and ongoing studies in the context of other recent insights on the crosstalk between tumor cells and the BM niche, and their implications for disease initiation, progression and therapeutic approaches. Disclosures No relevant conflicts of interest to declare.

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Sharma, Sonali, Gabriela Mladonicka Pavlasova, Vaclav Seda, Katerina Amruz Cerna, Eva Vojackova, Daniel Filip, Laura Ondrisova et al. « miR-29 modulates CD40 signaling in chronic lymphocytic leukemia by targeting TRAF4 : an axis affected by BCR inhibitors ». Blood 137, n^o 18 (6 mai 2021) : 2481–94. http://dx.doi.org/10.1182/blood.2020005627.

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Abstract B-cell receptor (BCR) signaling and T-cell interactions play a pivotal role in chronic lymphocytic leukemia (CLL) pathogenesis and disease aggressiveness. CLL cells can use microRNAs (miRNAs) and their targets to modulate microenvironmental interactions in the lymph node niches. To identify miRNA expression changes in the CLL microenvironment, we performed complex profiling of short noncoding RNAs in this context by comparing CXCR4/CD5 intraclonal cell subpopulations (CXCR4dimCD5bright vs CXCR4brightCD5dim cells). This identified dozens of differentially expressed miRNAs, including several that have previously been shown to modulate BCR signaling (miR-155, miR-150, and miR-22) but also other candidates for a role in microenvironmental interactions. Notably, all 3 miR-29 family members (miR-29a, miR-29b, miR-29c) were consistently down-modulated in the immune niches, and lower miR-29(a/b/c) levels associated with an increased relative responsiveness of CLL cells to BCR ligation and significantly shorter overall survival of CLL patients. We identified tumor necrosis factor receptor–associated factor 4 (TRAF4) as a novel direct target of miR-29s and revealed that higher TRAF4 levels increase CLL responsiveness to CD40 activation and downstream nuclear factor-κB (NF-κB) signaling. In CLL, BCR represses miR-29 expression via MYC, allowing for concurrent TRAF4 upregulation and stronger CD40–NF-κB signaling. This regulatory loop is disrupted by BCR inhibitors (bruton tyrosine kinase [BTK] inhibitor ibrutinib or phosphatidylinositol 3-kinase [PI3K] inhibitor idelalisib). In summary, we showed for the first time that a miRNA-dependent mechanism acts to activate CD40 signaling/T-cell interactions in a CLL microenvironment and described a novel miR-29–TRAF4–CD40 signaling axis modulated by BCR activity.

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Chen, Xiaomei, Fang Liu, Wei Xiong, Xiangjun Chen, Cong Lu, Shiang Huang et Huiyu Li. « Comparison of miRNA Expression Profiles in Leukemia-Derived Microvesicles and Corresponding Leukemia Cells and Analysis of Their Roles in Leukemia ». Blood 118, n^o 21 (18 novembre 2011) : 1388. http://dx.doi.org/10.1182/blood.v118.21.1388.1388.

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Abstract Abstract 1388 Microvesicles(MVs) are small exosomes of endocytic origin released by normal healthy or damaged cell types, including leukemic cells. MVs have been considered as cell dust, however, recent data bring evidences that MVs generated during cell activation or apoptosis can transfer biologic messages between different cell types. MicroRNAs (miRNAs) have been demonstrated to be aberrantly expressed in leukemia and the overall miRNA expression could differentiate normal versus leukemia. The MVs expressing miRNAs were found in the primary tumors. However it is currently unknown whether miRNA content changes in MVs derived from leukemic cells. Here we compared the miRNA expression in leukemia-derived MVs to corresponding leukemia cells and analysed their roles in leukemia. K562 cells were cultured and collected. MVs derived from K562 cells were also isolated. The presence and levels of specific miRNAs from both MVs derived from K562 cells and K562 cells were determined by Agilent miRNA microarray analysis probing for 888 miRNAs. Some selected miRNAs were verified by real time qRT-PCR. Bioinformatic software tools were used to predict the target genes of identified miRNAs and define their function. Our results showed that 77 and 122 miRNAs were only expressed in MVs and K562 cells, respectively. There were significant differences in miRNA expression profiles between MVs and K562 cells. We also found that 112 miRNAs were co-expressed in MVs and K562 cells. This observaton may suggest that compartmentalization of miRNAs from cells into to MVs, for at least some miRNAs, is an active (selective) process. Among those abnormally expressed miRNAs, some have been proposed oncomiRNAs or tumor suppressors. For example, miR-155, has been proposed as oncomiRNA, was abnormally expressed only in MVs in our study, suggesting that oncomiRNA was present in MVs. Further analysis revealed that 39 potential target genes regulated by miR-155. Among them, 4 genes involed in oncogenes and the signal genes. OncomiRNAs such as miR-27a and miR-21 expressed in both MVs and corresponding cells, indicating that MVs bear miRNA characteristic of the cell origin. MVs, released into the leukemia microenvironment, play an important role in leukemia. In contrast to oncomiRNAs, if miRNA is associated with tumor suppressive activity, it is regarded as a tumor suppressor (oncosuppressor). The aberrantly expressed miR-125a-3p, miR-125-5p,miR-27b, which have implicated as tumor suppressors, appear in both cellular and MVs of leukemia in our study. MiR-125a-3p, miR-125-5p and miR-27b regulated 308 potential target genes. To our knowledge, 10 of them are tumor suppression genes. It is possible that these aberrantly expressed tumor suppressor miRNAs decreased or lost their roles of tumor suppression, which led to decrease or loss their roles of regulating their target genes including oncogenes, consequently resulted in leukemia. Since K562 cells presented t(9;22), we further examined the predicted function of the 6 expressed miRNAs located in chrosome 9 (hsa-miR-188-5p,hsa-miR-602)and 22(hsa-let-7b,hsa-miR-1249,hsa-miR-130b,hsa-miR-185), which expressed both in the MVs and K562 cells. Using the TargetScan, we found 442 predicted targets regulated by 6 miRNAs. Those miRNAs may play roles in leukemia via these 422 genes. This study is the first to identify and define miRNA expression between K562 cells presented t(9;22), derived from K562 cells and their corresponding cells. We found significant differences in miRNA expression between MVs and corresponding leukemia. K562 cells released MVs riched in miRNAs including oncomiRNAs or tumor suppressor miRNAs into leukemia microenvironment, which play a role in leukemia via regulating their targer genes including oncogenes, consequently resulted in leukemia. Disclosures: No relevant conflicts of interest to declare.

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Seiffert, Martina, Franziska Haderk, Laura Llao Cid, Maria Göbel, Jan Dürig et Peter Lichter. « Chronic Lymphocytic Leukemia-Derived Extracellular Vesicles Mediate NFκB Signaling and Pro-Inflammatory Cytokine Release in Monocytes ». Journal of Immunology 196, n^o 1_Supplement (1 mai 2016) : 73.6. http://dx.doi.org/10.4049/jimmunol.196.supp.73.6.

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Abstract Chronic lymphocytic leukemia (CLL)is a B-cell malignancy associated with an inflammatory milieu and impairedanti-tumor immunity. This study aimed at characterizing CLL-derived extracellularvesicles (EVs) and their role in the tumor microenvironment. EVs were isolated from blood plasma or culture supernatant of the CLL cell line MEC-1 by a serialcentrifugation protocol. Characterization of EVs by electron microscopy, Nanoparticle Tracking Analysis (NTA) and Western blotting revealed vesicles 30to 350 nm in size, which were positive for various EV marker proteins. Quantificationof EVs by NTA and ELISA indicated an enrichment of B-cell derived EVs in plasmaof CLL patients compared to healthy controls, although absolute EV counts were not different. As we observed an accumulation of small RNAs in EVs, small RNAsequencing was performed which revealed a unique microRNA signature of MEC-1 EVs, with CLL-relevant miRNAs such as miR-21, miR-155 and miR-146a being the mostabundant. Moreover, full length and 5′ end fragment forms of Y RNAs, another class of small non-coding RNAs, were enriched in MEC-1 and CLL plasma EVs. In vitro and in mice, CLL EVs were rapidly taken up by monocytes and macrophages which resulted in NFκB signaling and the release of multiple pro-inflammatory cytokines such as CCL2, CCL3, IL-6 andIL-8, proteins known to be elevated in CLL plasma. Moreover, several surface markers on monocytes were altered upon EV uptake, including an increase of the immune checkpoint molecule PD-L1 as well as downregulation of the chemokine receptorCCR2. Of interest, liposomes containing Y RNA transcripts induced a similar response in respective assays suggesting a novel role for these molecules in the tumor microenvironment of CLL.

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Navarro, Alfons, Antonio Martinez, Olga Balagué, Anna Gaya, Aina Pons, Alvaro Urbano-Ispizua, Emili Montserrat et Mariano Monzo. « MicroRNA Analysis by In Situ Hibridization in Hodgkin Lymphoma. » Blood 110, n^o 11 (16 novembre 2007) : 2271. http://dx.doi.org/10.1182/blood.v110.11.2271.2271.

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Abstract Hodgkin lymphoma (HL) is a neoplasm characterized by the presence of relatively few tumoral cells, Hodgkin and Reed-Sternberg cells in an important non-neoplastic environment. The mature microRNAs (miRNAs) are small RNA molecules (20–25 nt), that act inhibiting the mRNA translation to protein by binding to 3′ UTR region of mRNA. In a previous work we detect a 25 miRNA signature of HL. Some of them inhibit the expression of key genes related to B lymphomagenesis. The aim of the study was to determine if the differential expression of miRNAs in tumoral tissue versus reactive lymph nodes, is due to genetic alterations in the Hodgkin/Reed Sternberg cells or alterations in the non-tumoral microenvironment. Fluorescein (FITC) 5′ labelled locked-nuclei-acid-incorporated (LNA) miRNA ribo probes for miR-21, 134, 138, 155 (miRCURY™ LNA detection, Exiqon) were used in 20 cases of HL formalin-fixed paraffin embedded tissue sections on silane coated slides (Vision BioSystem). Chromogenic in situ hybridization was done in an automated platform Bond Max (Vision Biosystems) with minor modifications. Pre-treatment of the slides was performed with Protease 1 for 10 min at 37°C. A total amount of 300 microliter of 25nM probe was hybridized in 1x sodium chloride-sodium citrate hybridization buffer (SSC) (Innogenetics) up to 50° C for 2 hours. We used a pre-diluted mouse anti-FITC antibody (Vision BioSystems) for 20–60 minutes followed by a goat anti-mouse linked to thousands of horse radish peroxidase (HRP) sites (Refine Detection System, Vision BioSystems). DAB was used as a chromogen reacting for 10 minutes and hematoxilyn was used as a counterstain. By functional and target analysis, we selected three miRNAs, miR-21 (PTEN), miR-134 (J-Chain) and miR-138 (PU.1), from the cHL signature that seemed to have a role in tumorigenesis process and analyzed them by CISH. In all cases a cytoplasmic signal was demonstrated in Hodgkin and Reed-Sternberg cells. Moreover, a nuclear signal was identified in reactive tumor infiltrating lymphocytes for miR-21 and miR-138. This nuclear signal may be due to crossreactivity with primary miRNA in these cells. We analyzed miR-155 as positive control of in situ hibridization and we demonstrated a cytoplasmic signal in Hodgkin and Reed Sternberg cells, as well as in scattered reactive lymphocytes and activated histiocytes as previously reported. In conclusion, miR-21, miR-134 and miR-138 play a role in HL lymphomagenesis since their expression is preferentially localized in Hodgkin/Reed Sternberg cells. The study of the other miRNAs of our signature can help explain the changes that appear in the atypical cells as well in the reactive cellular microenvironment in HL.

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Jiang, Yi-Xin, Yan Chen, Yue Yang, Xiao-Xia Chen et Dan-Dan Zhang. « Screening Five Qi-Tonifying Herbs on M2 Phenotype Macrophages ». Evidence-Based Complementary and Alternative Medicine 2019 (15 janvier 2019) : 1–8. http://dx.doi.org/10.1155/2019/9549315.

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Tumor-associated macrophages (TAMs) with M2 phenotype play an essential role in tumor microenvironment (TME) during the progression and development of numerous cancers and associated with poor prognosis. Thus, regulation of TAMs polarization emerged as a new strategy for tumor immune therapy. According to Traditional Chinese Medicine (TCM) theory, herbs with Qi-tonifying character are involved in improving the defense capacity of immune system. In this study, we screened extracts and ingredients from five Qi-tonifying herbs exhibiting an inhibitory effect on M2 polarization of murine macrophages RAW264.7 induced by IL-4 and IL-13. Among these candidates, total flavonoids from Glycyrrhiza Radix et Rhizoma (TFRG) and ethanol extract of Ginseng Radix et Rhizoma significantly inhibited the expression of Arginase-1 (Arg-1) (above 90% at 100μg/mL), one of the phenotype markers of M2 macrophages. The inhibition of total saponins of Ginseng Radix et Rhizoma, ethanol extract of Cordyceps, ethanol extract of Acanthopanacis senticosi Radix et Rhizoma Seu caulis, and ethanol extract of Astragali Radix reached above 50% at 100μg/mL. The inhibition of ingredients including glabridin, isoliquiritin apioside, lysionotin, cordycepin, astragaloside IV, and calycosin reached above 50% at 50μM. Then, we investigated the molecular mechanisms of TFRG. TFRG abolished the migration of murine breast cancer 4T1 stimulated by the conditioned medium from M2 macrophages (M2-CM). In addition to Arg-1, TFRG also antagonized the IL-4/13-mediated mRNA upregulation of the M2 markers including found in inflammatory zone 1 (FIZZ1), chitinase-3-like protein 3 (YM1), and mannose receptor (CD206) and upregulated the expression of inducible nitric oxide synthase (iNOS), one of the M1 markers. The further exploration showed that TFRG decreased the phosphorylation of STAT6 and increased the expression of miR-155. Our study provides a series of potential immune regulating natural products from five Qi-tonifying herbs on M2 phenotype. For instance, TFRG suppressed M2 polarization of macrophages partly by inactivating STAT6 pathway and enhanced the level of miR-155 to regulate the expressions of M1 and M2 markers.

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Lone, Waseem, Alyssa Bouska, Tyler Herek, Catalina Amador, Mallick Saumyaranajn, Yu Jiayu, Tayla Heavican et al. « Genome-Wide microRNA Expression Profiling in Molecular Subgroups of Peripheral T-Cell Lymphoma Identified Role of Mir-126 in T-Cell Lymphomagenesis ». Blood 134, Supplement_1 (13 novembre 2019) : 2767. http://dx.doi.org/10.1182/blood-2019-129327.

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Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of non-Hodgkin lymphomas and approximately 30% of PTCLs are designated as not-otherwise specified (PTCL-NOS). Gene expression profiling (GEP) identified molecular classifiers for PTCL entities and identified 2 novel biological subgroups within PTCL-NOS (PTCL-GATA3 and PTCL-TBX21), associated with T-cell differentiation subsets. To further investigate molecular oncogenesis, we performed microRNA expression profiling (miR-EP) in several molecular subtypes of PTCL including angioimmunoblastic T-cell lymphoma (AITL), PTCL-GATA3 and PTCL-TBX21 using formalin fixed paraffin embedded tissues. We also performed miR-EP of normal T-cell subsets polarized to represent different differentiation stages (TFH, TH1 and TH2). We performed miR-EP on 102 PTCL cases using either quantitative real time PCR (ABI, Biosystem) or ultra-sensitive direct miRNA counting (nCounter, NanoString). Corresponding GEP (mRNA) were available for 67 PTCL cases. Normal T-cells were polarized in-vitro with different cytokine milieu and examined by flow cytometry. We observed distinct miRNA profiles, with miRNA being uniquely expressed in TFH polarized cells (miR-26a-5p, miR-17-5p, miR-30d-5p, miR-22-3p, miR-222-3p, miR-142-3p, let-7i-5p and miR-29b-3p). In contrast, the TH1 lineage was enriched for expression of miR-155-5p, miR-146a-5p, miR-1246, miR-93-5p, miR-16-5p, miR-21-5p, miR-363-3p, miR-1260a, miR-186-5p, miR-148a-3p and miR-579-3p, whereas TH2 polarized cells expressed miR-181a-5p, let-7a-5p, miR-191-5p, miR-15b-5p, let-7d-5p, let-7b-5p, miR-140-5p, miR-98-5p, miR-423-5p and miR-630. Several of these miRNA expressed in the T-cells subsets showed corresponding expression in their respective PTCL entity such as miR-142-3p, let7i-5p, miR-21-5p and miR-29b-3p with AITL, miR-146-5p, miR-155-5p and miR-16-5p in PTCL-TBX21 and miR-181a-5p, miR-630 and let7a-5p in PTCL-GATA3. We also performed the MiRNA Enrichment Analysis and Annotation (miEAA) for miRNA signatures and observed an enrichment of miRNA regulating epigenetic modifications in TFH cells (p=0.028), whereas TH1 showed an enrichment of miRNA regulating IFN-g signaling (p=0.0024), and miRNA signatures in TH2 showed negative regulation of TGF-b signaling (p=0.023). Supervised analysis (p=0.05) of the miRNA profiles identified significant association of miR-126, miR-145, and let-7c-5p with AITL, when compared to other PTCLs. Similarly, miR-92a, miR-25, miR-636, miR-210, miR-222 and miR-491-5p significantly associated with PTCL-GATA3 and miRNA 126-3p, 145-5p, miR-26a-5p and miR-34a-5p associated with PTCL-TBX21. The miEAA for tumor miRNA signatures revealed enrichment of miRNAs regulating histone methylation (h3 k4 methylation) and chemokine receptor signaling in AITL, whereas miRNA regulating T-cell receptor were enriched in PTCL-TBX21 and TP53 signaling pathway in PTCL-GATA3. We validated the expression of miR-126 in AITL by qRT-PCR and also observed its increased expression in IL21 stimulated CD4+ T-cells. Ectopic expression of miR-126 resulted in a ~3 fold increased expression in T-cell lines and led to reduced proliferation and increased apoptosis with expression of T-cell exhaustion makers PD1 and TIM3. Computational algorithmic programs identified relevant biological targets of miR-126, including p85/PIK3R2, S1PR2 and DNMT3A that were further validated in-vitro. We observed an inverse correlation of miR-126 expression with S1PR2 expression (r=-0.64). S1PR2 is a crucial G protein-coupled receptor regulating B and T-cell migration in the germinal center (GC) reaction. Migration assays demonstrated significant decreases in T to B-cell migration, when B-cells (Raji) were co-cultured with Jurkat cells with ectopic expression of miR-126. With the GC reaction holding an important role in AITL, we investigated the biological significance of miRNA-126 in the context of the AITL microenvironment. High expression of miRNA-126 significantly associated with inferior survival in AITL (p=0.008) and significant differences in tumor microenvironment signatures. We identified distinct miRNA signatures for AITL and molecular subgroups of PTCL-NOS. Furthermore, elevated expression of miR-126 may contribute to the dysregulation and the homing of TFH cells in GC reaction through S1PR2 and warrants further mechanistic investigation. Disclosures No relevant conflicts of interest to declare.

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Cheleschi, Sara, Sara Tenti, Sauro Lorenzini, Iole Seccafico, Stefano Barbagli, Elena Frati et Antonella Fioravanti. « Synovial Fluid Regulates the Gene Expression of a Pattern of microRNA via the NF-κB Pathway : An In Vitro Study on Human Osteoarthritic Chondrocytes ». International Journal of Molecular Sciences 23, n^o 15 (28 juillet 2022) : 8334. http://dx.doi.org/10.3390/ijms23158334.

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Synovial fluid (SF) represents the primary source of nutrients of articular cartilage and is implicated in maintaining cartilage metabolism. We investigated the effects of SF, from patients with osteoarthritis (OA), rheumatoid arthritis (RA), and controls, on a pattern of microRNA (miRNA) in human OA chondrocytes. Cells were stimulated with 50% or 100% SF for 24 h and 48 h. Apoptosis and superoxide anion production were detected by cytometry; miRNA (34a, 146a, 155, 181a), cytokines, metalloproteinases (MMPs), type II collagen (Col2a1), antioxidant enzymes, B-cell lymphoma (BCL)2, and nuclear factor (NF)-κB by real-time PCR. The implication of the NF-κB pathway was assessed by the use of NF-κB inhibitor (BAY-11-7082). RA and OA SF up-regulated miR-34a, -146a, -155, -181a, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, MMP-1, MMP-13, and ADAMTs-5 gene expression, while it down-regulated Col2a1. Pathological SF also induced apoptosis, reduced viability, and decreased BCL2 mRNA, whereas it increased superoxide anions, the expression of antioxidant enzymes, p65 and p50 NF-κB. Opposite and positive results were obtained with 100% control SF. Pre-incubation with BAY-11-7082 counteracted SF effects on miRNA. We highlight the role of the SF microenvironment in regulating some miRNA involved in inflammation and cartilage degradation during OA and RA, via the NF-κB pathway.

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McClanahan, Fabienne, Federica Calore, Nicola Zanesi, John G. Gribben et Carlo M. Croce. « Aberrant PD-L1 Expression in CLL As a Result of Adaptive Immune Resistance Mediated By Tumor-Secreted Circulating miRNA Binding to Toll-like Receptor 7 ». Blood 124, n^o 21 (6 décembre 2014) : 716. http://dx.doi.org/10.1182/blood.v124.21.716.716.

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Abstract Background: Chronic lymphocytic leukaemia (CLL) is a model cancer to study immune evasion via PD-L1/PD-1 signalling: aberrantly expressed PD-L1 on CLL and PD-1 on CD8 T cells are key mediators of poor anti-tumor immune responses, which are a major hallmark of CLL. Several preclinical studies suggest that aberrant PD-L1 expression is a result of adaptive immune resistance and is induced during immune responses within the tumor microenvironment. It has recently been proposed that specific circulating microRNAs (miRNAs) shed by malignant cells participate in the complex crosstalk between cancer cells and microenvironment, and that they activate immune cells via Toll-Like Receptor (TLR) 7 due to their structural similarity to its natural ligand. In addition, TLR signaling has been demonstrated to result in the upregulation of costimulatory molecules such as CD80, CD86 and PD-L1/2. In CLL, aberrant circulating miRNA and TLR expression patterns have been well characterized. Therefore, we hypothesized that aberrant PD-L1 expression in CLL is a result of continuous TLR7 signaling mediated by circulating miRNAs. Our aims were to demonstrate that (1) specific circulating miRNAs induce PD-L1 expression and have functional consequences, (2) miRNA/PD-L1 associations are mediated via TLR7, and (3) miR/TLR/PD-L1 interactions are subject to the dynamics of CLL development. Methods and Materials: Mononuclear cells from spleen cell suspensions from 3 month old TCL1 transgenic, wild-type (WT) or TLR7-/- mice (total n=13) were treated ex vivo for 18hours with liposomal formulations of synthetic scrambled miRNA or miRNAs -16 (negative control), -21, -29, -150 and -155, which are reported to have an effect on immune cells and to be released by CLL cells. Specific TLR7 and TLR9 agonists were included for comparison. Primary human CLL cells and healthy B cells were treated with specific TLR2/6, TLR7 and TLR9 agonists. In adoptive transfer experiments, young WT mice (n=15) were injected with 4x107CLL cells from TCL1 transgenic mice. Mice were sacrificed at days 3, 6, 9, 12 and 15, and spleen cells were treated ex vivo as above. Changes in surface PD-L1, CD69 and CD86 expression on DAPI-negative CD19+ B cells/CLL cells were determined by flow cytometry. Supernatant cytokines were screened by multiplex ELISA. Results: PD-L1 surface expression on spleen B cells from both WT and non-leukemic TCL1 mice was strongly induced by miRs -21 and -29, and moderately by -150 and -155, but not by miR-16 negative control. The degree of PD-L1 upregulation by miRs -21 and -29 was comparable to the effect of direct TLR7 and TLR9 binding by specific agonists. Similar patterns were seen for CD69 and CD86 expression. Across treatment conditions, PD-L1 expression was highly correlated with the expression of CD69 (r .7777, p<.0001) and CD86 (r .7516, p<.0001). This observation strongly suggests that PD-L1 expression after TLR engagement is a marker of activation/costimulation, and therefore a physiological adaptive immune response to TLR binding in healthy B cells. Functionally, miR treatments resulted in increased IL-6, IL-10 and TNFα, with miR-29 having the strongest effect. PD-L1, CD69 and CD86 could also be induced by TLR engagement in healthy B cells, but not in CLL patient cells, where PD-L1 was confirmed to be already aberrantly expressed. To elucidate when in the course of CLL development PD-L1 expression becomes aberrant and if it ceases to be inducible by miR treatment, we sacrificed adoptively transferred mice every 3 days to simulate tumor development. With increasing CLL the magnitude of the fold-change of PD-L1 expression following miR treatment decreased substantially, and the baseline expression of miR-untreated B cells increased consistently until day 15. Interestingly, although the PD-L1 response was substantially decreased with tumor load, it was not completely abrogated, even on day 15 when mice had a median CLL load of 71%. Importantly, miR treatment did not result in increased PD-L1, CD69 or CD86 expression in B cells from TLR7-/- mice, indicating that the miR/PD-L1 interactions are indeed mediated by TLR7. Conclusions: Our findings support that PD-L1 expression on B cells can be induced by specific miRNAs known to be produced by CLL cells, and that this effect is mediated via TLR7. Therefore, aberrant PD-L1 expression on CLL is likely to be a result of adaptive immune resistance mediated by tumor cell-produced circulating miRNAs. Disclosures Gribben: Celgene: Research Funding; Pharmacyclics: Honoraria; Roche: Honoraria.

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Youness, R. A., et A. Abdelmotaal. « 13P A mitigation of breast cancer-induced immune-suppressive tumor microenvironment through curbing miR-155/IL-10/TNF-α loop using a novel quercetin derivative ». Annals of Oncology 31 (mars 2020) : S4. http://dx.doi.org/10.1016/j.annonc.2020.01.061.

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Tsukamoto, Shokichi, Karma Salem, Salomon Manier, Michaela R. Reagan, Daisy Huynh, Adriana Perilla-Glen, Antonio Sacco et al. « Microrna-138 Regulates Osteogenic Differentiation and Its Inhibition Presents a Novel Therapeutic Line to Prevent Bone Lytic Lesions in Multiple Myeloma ». Blood 128, n^o 22 (2 décembre 2016) : 4483. http://dx.doi.org/10.1182/blood.v128.22.4483.4483.

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Abstract Introduction The bone marrow (BM) microenvironment in multiple myeloma (MM) plays a pivotal role in tumor growth and bone destructive process. Mesenchymal stromal cells (MSCs) in MM exhibit different genomic and cytokine secretion profiles that ultimately impair their osteogenic differentiation abilities compared to normal MSCs. However, the underlying molecular mechanisms are not fully understood. In the present study, we explored the role of miR-138 in MSCs derived from MM patients (MM-MSCs) and the potential for anti-miR-138 treatment to rescue impaired osteogenic differentiation in MM, both in vitro and in vivo using a human xenograft MM model. Materials and methods Primary BM aspirates were obtained from MM patients and normal healthy donors, after obtaining informed consent in accordance with the Declaration of Helsinki. MiR-138 expression in MM-MSCs was measured by quantitative real-time PCR. Publicly available microarray data sets (GSE17306 and E-TABM-508) were analyzed for miR-138 expression in MM cells compared to normal plasma cells. To test the effect of inhibiting miR-138 function, a high-affinity 15-mer locked nucleic acid (LNA)-modified anti-miR oligonucleotide and a corresponding scramble sequence control oligonucleotide were used (In collaboration with Dr. Kauppinen, Denmark). Anti-miR-138 oligonucleotides were transfected into MM-MSCs or normal MSCs co-cultured with MM cell lines and osteogenic differentiation in MSCs was assessed by alizarin red staining. For the in vivo studies, 6-week-old female SCID-beige mice (n=6, each group) were injected intravenously with anti-miR-138 or scramble control oligonucleotides (15 mg/kg) 2 times a week. 3 weeks later, GFP+Luc+ MM.1S cells (3 × 106) were injected into mice. Anti-miR-138 or control oligonucleotides were continued until day 28 after injection of myeloma cells. At day 28, the effect of anti-miR138 was assessed by the number of osteoblastic lineage cell (OBC: Lin-/CD45-/CD31-/CD51+/Sca-1-) from hematopoietic cell-depleted, collagenase-treated crushed bones of mice by flow cytometry. Results MiR-138 expression in MSCs from MM patients (n=10) was significantly higher than MSCs from normal donors (n = 4) (P<0.05). In addition, miR-138 expression was significantly higher in MM patient tumor cells compared to normal plasma cells using two independent data sets (GSE17306 and E-TABM-508), (P<0.01 and P<0.01, respectively). In three-dimensional co-culture system of MSCs from normal donors (n=6) with MM.1S cells for 2 weeks (GSE60423), miR-138 expression was increased in 4 out of 6 donors compared to MSCs cultured alone (P<0.05). MM-MSCs (n≥3) transfected in vitro with anti-miR-138 oligonucleotides showed significantly increased osteogenic differentiation after 3-4 weeks compared to MSCs with scramble control oligonucleotides (P<0.01). Under in vitro two-dimensional co-culture conditions with MM cell lines, normal MSCs transfected with anti-miR-138 oligonucleotides showed significantly increased osteogenic differentiation compared to MSCs with scramble control oligonucleotides (P<0.001). In an in vivo human xenograft MM model, treatment of anti-miR-138 significantly increased the number of OBCs in the endosteal (Lin-/CD45-) BM stromal fraction of MM bearing SCID-beige mice at day 28 compared to scramble control oligonucleotides (P<0.05). Conclusions These findings indicate that miR-138 plays an important role in impaired osteogenic differentiation in MSCs in MM. Inhibition of miR-138 promotes osteogenic differentiation of MSCs in MM and anti-miR-138 treatment holds the potential to prevent MM induced bone loss and lytic lesions. Additional studies are ongoing to further understand the connection between MM cells and MSCs mediated by miR-138. Disclosures Roccaro: Takeda Pharmaceutical Company Limited: Honoraria. Ghobrial:Novartis: Honoraria; Noxxon: Honoraria; Celgene: Honoraria, Research Funding; Takeda: Honoraria; Amgen: Honoraria; BMS: Honoraria, Research Funding.

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Abdelhamed, Sherif, Noah I. Hornick et Peter Kurre. « Residual HSPC in the Leukemia Microenvironment Are Reprogrammed Via Extracellular Vesicle Trafficking ». Blood 128, n^o 22 (2 décembre 2016) : 888. http://dx.doi.org/10.1182/blood.v128.22.888.888.

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Several groups have shown that leukemic cells create a self-reinforcing bone marrow (BM) niche that functionally impairs normal hematopoietic stem and progenitor cells (HSPC) indirectly through stroma-secreted factors. We recently demonstrated an alternative mechanism whereby extracellular vesicles (EVs) from acute myeloid leukemia (AML) patients and cell lines, but not BM CD34 controls, suppress their clonogenicity through EV trafficking of microRNA that directly downregulate critical transcription factors (c-Myb and HoxA9). Here, we aimed to clarify the fate of residual HSPC in in vivo AML xenografts, as well as ex vivo intrafemural (IF) injection and in vitro exposure of EVs experiments. Among KSL cells we observed a significant increase in the frequency of the long-term hematopoietic stem cell (SLAM, CD150+CD48−) subpopulation, but not the multipotent progenitors even at low levels of AML infiltration or direct IF injection of EVs. The HSPC pool redistribution was accompanied by cell cycle alterations in residual HSPC that showed AML EVs consistently induced quiescence (G0) in KSL (cKit+Sca1+Lin−) HSPC populations. When we assessed their DNA damage, residual HSPC showed a distinct increase in the gH2AX foci relative to control non-engrafted mice as well as the transcriptional upregulation of Rad51 and P21 genes along with gains in phosphorylation of the tumor suppressor p53. Yet, the reprogrammed KSL showed no evidence of apoptosis indicated by the lack of upregulation of the p53 target, Puma, and Annexin V staining, nor evidence of senescence (P16 and Sparc transcripts). To gain additional insight, we performed a tandem mass tag (TMT) proteomic profiling of AML-EV exposed HSPC with or without exposure to EVs derived from AML cells. The results showed significant enrichment of DNA methylation regulatory pathway such as DNMT1, HELLS and UHRF1 as well as inflammatory pathways including IL1b, NOS, CEBPB and NFkB pathway-targets, confirmed by transcriptional profiling of KSL from xeno-transplanted mice. Based on our recent report that miR-1246 is one of the most highly enriched miRNA in AML derived EVs and proceeded to determine its target transcripts using an attenuated RISC complex (RISC-Trap), followed by high-throughput sequencing. Bioinformatics analysis identified a set of 27 miR-1246-specific targets relative to control microRNAs. Strikingly, the target set was selectively enriched for a panel of negative cell-cycle regulator genes (CDK1, CDK7, CDK11, CCNF, HDAC2 and GATA3) as well as the DNA methylation regulators (DNMT1 and HELLS).Collectively, our results demonstrated that residual HSPC in the AML BM are phenotypically reprogrammed and suppressed in their proliferation along with DNA damage accumulation via paracrine EV microRNA trafficking. Our study provides insight into HSPC fates in the AML niche and echoes observations of cell competition, as a mode of non-cell autonomous regulation where p53 activation in the reprogrammed cells leads to a progressive decline in proliferation and fitness. We propose that AML EV trafficking of miR-1246 specifically may contribute to the altered fate of residual HSPC via transcriptional regulation of proliferation-related genes. Disclosures No relevant conflicts of interest to declare.

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Haderk, Franziska, Etienne Moussay, Jerome Paggetti, Maria Göbel, Jan Dürig, Thorsten Zenz, Stephan Stilgenbauer, Peter Lichter et Martina Seiffert. « Chronic Lymphocytic Leukemia-Derived Extracellular Vesicles Contain a Distinctive Proteome, As Well As Specific Micro RNAs and Y RNAs ». Blood 124, n^o 21 (6 décembre 2014) : 1968. http://dx.doi.org/10.1182/blood.v124.21.1968.1968.

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Abstract The pathogenesis of chronic lymphocytic leukemia (CLL) is stringently associated with a tumor-supportive microenvironment and a dysfunctional immune system. Of note, CLL cells themselves induce changes in surrounding cells, and extracellular vesicles (EVs) released by CLL cells represent a newly discovered mechanism of cell-cell communication. EVs are membrane enclosed nanoparticles 30 to 1000 nm in size and are able to reprogram recipient cells by transferring proteins and RNA molecules from their cell of origin. Thus, we aimed to analyze CLL cell-derived EVs present in blood plasma of CLL patients as well as those released by the CLL cell line MEC-1, in order to understand their role within the microenvironment. EVs were isolated from blood plasma of CLL patients and healthy donors, as well as from MEC-1 cell culture supernatant by serial centrifugation and density-based separation. Characterization of EVs by electron microscopy and immunoblot analysis revealed vesicles 20 to 300 nm in size, which are positive for various EV marker proteins such as Rab5a and Hsp70. Proteome analysis via mass spectrometry indicated differences in the composition of plasma derived EVs and peripheral blood mononuclear cells (PBMCs) from the respective patient, as well as between plasma derived EVs from healthy donors compared to CLL patients. Regarding the later, CLL EVs were specifically enriched for proteins involved in antigen presentation, endocytosis signaling as well as integrin mediated signaling and leukocyte extravasation. RNA analysis by BioAnalyzer profiling indicated an enrichment of small RNAs in EVs compared to cells. Subsequent small RNA sequencing revealed a unique microRNA signature of MEC-1 EVs with the 5 most abundant miRNAs encompassing about 60% of all detected miRNAs. Among them, the CLL-relevant miR-21 and miR-155, as well as miR-146a were selectively enriched in EVs. Moreover, Y RNAs, another class of small non-coding, regulatory RNAs, were highly enriched in MEC-1 EVs and their presence was also observed in plasma EVs of CLL patients. We uncovered a rapid uptake of CLL cell-derived EVs by human monocytes and macrophages. Whether the identified proteins and RNA transcripts shown to be enriched in CLL EVs induce phenotypic changes in targeted cells is being investigated. Further, quantification of plasma EVs in a large cohort of CLL patients is currently conducted and differences in the amount of EVs in correlation to disease outcome are analyzed. Harboring a distinct RNA and protein profile, EVs are potent vehicles for shuttling RNA and proteins to recipient cells and might be involved in the establishment of a supportive microenvironment in CLL. Functional analyses regarding possible effects of CLL EVs on target cells will broaden the knowledge of CLL pathogenesis and might help to identify new therapeutic options for CLL. Disclosures No relevant conflicts of interest to declare.

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Hasan, Humna, Nadia A. Lanman, Sagar Utturkar et Andrea L. Kasinski. « Abstract 1537 : Understanding role of uniquely enriched RNAs carried in non-small cell lung cancer derived extracellular vesicles and dynamics of their selective export ». Cancer Research 82, n^o 12_Supplement (15 juin 2022) : 1537. http://dx.doi.org/10.1158/1538-7445.am2022-1537.

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Abstract The dynamic interaction mediated by extracellular vesicles (EVs) between cancer cells and microenvironment has been shown to regulate cancer progression. Specifically, tumor derived EVs alter the phenotypes of recipient cells by delivering functional biomolecules including RNAs (EV-RNA). Studies from our lab reveal the impact of NSCLC derived EVs (Calu6 and H358) in promoting invasion of non-tumorigenic cells (BEAS-2B) and disruption of an epithelial barrier. We further determined that of all the major macromolecules contained in EVs, EV-RNA is a significant contributor to the observed phenotypes. Additionally, our data supports dysregulation of RNA subsets enclosed in NSCLC cell-derived EVs in comparison with non-tumorigenic EVs. Interestingly, RNA sequencing analysis revealed preferential enrichment of several small RNAs (<200nt), especially miRNAs, in EVs isolated from NSCLC cell lines which suggest the presence of precise mechanisms involved in loading and export of RNAs into EVs. We shortlisted a cohort of uniquely enriched miRNAs in EVs derived from Calu6 and H358 cell lines to understand their combinatorial effects on non-tumorigenic recipient cells. Amongst the shortlisted candidates miR-100, miR-10b, miR-21, miR-155 and miR-486 stand out as potential contributors to NSCLC-EV mediated function. To understand the dynamics of export of miRNAs into EVs, we transfected Calu6 cells with one of the uniquely enriched fluorescently labelled candidate miRNA (miR-451) and tracked its export into EVs. We first verified that inclusion of a fluorophore to the RNA does not impair RNA loading into EVs. To set the experiment up, one EV-enriched RNA and one Cell-enriched RNA (as a control) conjugated with different fluorophores were transfected into cells, and cellular and EV fluorescence were monitored. Interestingly, cellular fluorescence corresponding to the EV-enriched RNA diminished, while fluorescence corresponding to the Cell-enriched RNA was retained. Fluorescence signal for EV-enriched RNA showed retention in EVs isolated 48 hours after transfection. Validation of release of candidate miRNA into EVs was performed by inhibiting biosynthesis of EVs after treatment with nSMase inhibitor Gw4869. Inhibition of EV release caused EV-enriched RNA to be retained by the cells which was confirmed following flow cytometry analysis of treated cells. Despite clear evidence that dysregulated EV-RNA subsets enclosed in cancer cell-derived EVs can modulate the cellular microenvironment, research showing dynamics and mechanisms of their export is limiting. Hence, there is a critical need to reveal mechanistic details of RNA export into EVs. Resulting data from this study is expected to not only reveal functional EV-RNA subsets and dynamics of their loading but will ultimately point to novel targets for future therapeutic intervention. Citation Format: Humna Hasan, Nadia A. Lanman, Sagar Utturkar, Andrea L. Kasinski. Understanding role of uniquely enriched RNAs carried in non-small cell lung cancer derived extracellular vesicles and dynamics of their selective export [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1537.

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Reagan, Michaela R., Yuji Mishima, Yong Zhang, Patricia Maiso, Salomon Manier, Yu-Tzu Tai, Priya Dhir et al. « Microrna-Dependent Modulation Of Osteogenesis In a 3D In Vitro Bone Marrow Model System Of Multiple Myeloma ». Blood 122, n^o 21 (15 novembre 2013) : 3093. http://dx.doi.org/10.1182/blood.v122.21.3093.3093.

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Abstract Introduction Recent evidence indicates that tumor cells are not only influenced by their microenvironment, but are also able to drastically alter their surroundings leading to cancer progression. Multiple Myeloma (MM) involves clonal proliferation of malignant plasma cells within the bone marrow, inhibition of osteoblast function, and increased osteoclast activity leading to osteolytic lesions. Our work aims to understand the bi-directional interactions between MM cells and mesenchymal stromal cells (MSCs), using both 2D and 3D in vitro co-culture bone marrow models. Methods We developed a 3D in vitro model system to better mimic myeloma growth within the bone marrow using human MSCs (hMSCs) and fluorescent-, luciferase-labeled MM cell lines seeded into porous, autofluorescent silk scaffolds. Proliferation and osteogenic differentiation of myeloma patient (MM-) and normal donor (ND-) MSCs cultured with or without MM.1S cells were characterized in 2D culture and 3D scaffolds. Non-destructive bioluminescent imaging and fluorescent confocal imaging were used to observe cell growth and cell-cell interactions within scaffolds. Histology was performed to confirm changes in extracellular matrix (ECM) production and bone tissue formation. microRNA (miRNA) profiling was performed on primary ND- (n=3) and MM-MSCs (n=7) using Nanostring technologies. We analyzed 800 human miRNAs from miRBase v.18 and 230 human cancer-related genes using the nCounter® Human Cancer Reference Kit. Gain-of function studies (miRvana mimics) were performed for miRNAs that were down-modulated in MM vs ND-MSCs, and in the 3D model MSCs co-cultured with MM.1S vs MSCs alone, using lipofectamine. Modulation of osteogenesis was evaluated using alizarin red staining and qRT-PCR for the osteogenic markers: IBSP (integrin-binding sialoprotein), Col1a1 (collagen, type I, alpha 1), RUNX2 (runt related transcription factor 2), ALPL (alkaline phosphatase), OPN (secreted phosphoprotein 1), and BGLAP (bone gamma-carboxyglutamate (gla) protein). Results MM-MSCs presented with a lower proliferation rate compared to ND-MSCs and this phenotype was also observed in ND-MSCs co-cultured in the presence of MM.1S cells compared to ND-MSCs alone. Moreover, significant inhibition of MSC growth was evident when co-cultured with MM.1S cells, using a 3D model (Figure 1), where inhibition of osteogenesis, and ECM production were also documented. Alizarin red staining demonstrated inhibited ability for MM-MSCs to undergo osteogenic differentiation. In addition, MM-MSCs differed from ND-MSCs at the gene and miRNA level. Specifically, CDKN1A and CDKN2A were over-expressed in MM vs. ND-MSCs, (P<0.05; fold change >1.2), thus explaining, at least in part, the decreased proliferation of MM-MSCs vs ND-MSCs. Moreover, down-regulation of specific miRNAs (miRNA-199a, -24-3p, -199a, -15a-5p, -16-5p) was demonstrated in MM- vs ND-MSCs, as well as in ND-MSCs vs ND-MSCs co-cultured with MM.1S, using the 3D model. By over-expressing miRNA-199a, -15a-5p and -16-5p, we were able to increase the osteogenic potential, thus suggesting their role in modulating osteogenesis in MM-MSCs. Conclusions Our 3D platform provides a simple, non-destructive, flexible, and clinically relevant tool to spatially and temporally model myeloma growth within bone. It recapitulates decreased bone formation as seen in MM patients and suggests miR-199a-3p, 15a-5p and 16-5p as novel bone anabolic targets. Disclosures: Tai: Onyx: Consultancy. Ghobrial:Onyx: Advisoryboard Other; BMS: Advisory board, Advisory board Other, Research Funding; Noxxon: Research Funding; Sanofi: Research Funding.

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Gu, Wenyu, Linjing Gong, Xu Wu et Xudong Yao. « Hypoxic TAM-derived exosomal miR-155-5p promotes RCC progression through HuR-dependent IGF1R/AKT/PI3K pathway ». Cell Death Discovery 7, n^o 1 (juin 2021). http://dx.doi.org/10.1038/s41420-021-00525-w.

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AbstractHypoxic tumor-associated macrophages (TAMs) are related to poor prognosis of patients with clear cell renal cell carcinoma (ccRCC). Exosomes are small lipid-bilayer vesicles that implicated in tumor progression and metastasis. However, whether hypoxic TAM-derived exosomes affect RCC progression within the hypoxic tumor microenvironment has not been elucidated. GSE analysis identified miR-155-5p was upregulated in RCC. Moreover, we quantified levels of miR-155-5p using RT-qPCR, performed immunohistochemical staining in 79 pairs of primary RCC specimens and related them to clinicopathological parameters. Higher miR-155-5p levels were related to more CD163 + TAM infiltration and elevated HIF-1a expression in our cohort. In the in vitro studies, we initially purified and characterized the exosomes from the supernatant of TAMs subjected to normoxia or hypoxia, and then transfected antagomiR-155-5p or control into these TAMs to produce corresponding exosomes. Gain and loss-of-function studies further investigated the effect of transferred hypoxic exosomal miR-155-5p on the cross-talk between TAMs and RCC cells in xenograft model and in vitro co-culture experiments. The results of RNA immunoprecipitation analyses elucidated that miR-155-5p could directly interact with human antigen R (HuR), thus increasing IGF1R mRNA stability. Mechanistically, hypoxic TAM-Exo transferred miR-155-5p promoted RCC progression partially through activating IGF1R/PI3K/AKT cascades. Taken together, transfer of miR-155-5p from hypoxic TAMs by exosomes to renal cancer cells explains the oncogenic manner, in which M2 macrophages confer the malignant phenotype to RCC cells by enhancing HuR-mediated mRNA stability of IGF1R.

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Zhao, Junlong, Huichen Li, Shoujie Zhao, Enxin Wang, Jun Zhu, Dayun Feng, Yejing Zhu et al. « Epigenetic silencing of miR-144/451a cluster contributes to HCC progression via paracrine HGF/MIF-mediated TAM remodeling ». Molecular Cancer 20, n^o 1 (3 mars 2021). http://dx.doi.org/10.1186/s12943-021-01343-5.

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Abstract Background & Aims Hepatocellular carcinoma (HCC) is among the malignancies with the highest mortality. The key regulators and their interactive network in HCC pathogenesis remain unclear. Along with genetic mutations, aberrant epigenetic paradigms, including deregulated microRNAs (miRNAs), exert profound impacts on hepatocyte transformation and tumor microenvironment remodeling; however, the underlying mechanisms are largely uncharacterized. Methods We performed RNA sequencing on HCC specimens and bioinformatic analyses to identify tumor-associated miRNAs. The miRNA functional targets and their effects on tumor-infiltrating immune cells were investigated. The upstream events, particularly the epigenetic mechanisms responsible for miRNA deregulation in HCC, were explored. Results The miR-144/miR-451a cluster was downregulated in HCC and predicted a better HCC patient prognosis. These miRNAs promoted macrophage M1 polarization and antitumor activity by targeting hepatocyte growth factor (HGF) and macrophage migration inhibitory factor (MIF). The miR-144/miR-451a cluster and EZH2, the catalytic subunit of polycomb repressive complex (PRC2), formed a feedback circuit in which miR-144 targeted EZH2 and PRC2 epigenetically repressed the miRNA genes via histone H3K27 methylation of the promoter. The miRNA cluster was coordinately silenced by distal enhancer hypermethylation, disrupting chromatin loop formation and enhancer-promoter interactions. Clinical examinations indicated that methylation of this chromatin region is a potential HCC biomarker. Conclusions Our study revealed novel mechanisms underlying miR-144/miR-451a cluster deregulation and the crosstalk between malignant cells and tumor-associated macrophages (TAMs) in HCC, providing new insights into HCC pathogenesis and diagnostic strategies.

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Chen, Shaoyi, Zuxiao Chen, Zongyan Li, Shiying Li, Zilong Wen, Liangqi Cao, Yubin Chen, Ping Xue, Haiyan Li et Dawei Zhang. « Tumor-associated macrophages promote cholangiocarcinoma progression via exosomal Circ_0020256 ». Cell Death & ; Disease 13, n^o 1 (janvier 2022). http://dx.doi.org/10.1038/s41419-022-04534-0.

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AbstractThis study investigated the exosomal circular RNAs (CircRNAs) produced by tumor-associated macrophages and delivered into the microenvironment of cholangiocarcinoma cells in order to use them as molecular targets for clinical therapy. Tumor-associated M2 macrophages (TAMs) were induced from THP-1 cells and identified by flow cytometry. The TAM-secreted exosomes were isolated from conditioned medium and a CircRNA microarray assay was performed to identify CircRNAs that were uniquely expressed in the isolated exosomes. Circ_0020256 was especially identified based on having the highest differential expression level among all of the CircRNA candidates. In vitro and in vivo experiments were performed to assess the effects of TAMs, exosomes, and Circ_0020256 on the growth and migration of cholangiocarcinoma (CCA) cells. The induced TAMs promoted the proliferation, migration, and invasion of CCA cells and those effects were mediated by exosomes secreted by the TAMs. In CCA cells (RBE and HCCC-9810), Circ_0020256 significantly promoted cellular activity by interacting with its intra-cellular microRNA target, miR-432-5p. In contrast, overexpression of transcription factor E2F3 in CCA cells restored the CCA cellular activities that were inhibited by miR-432-5p. On the other hand, treatment with small interference RNA (siRNA) for Circ_0020256 inhibited CCA cell proliferation, migration, and invasion both in vitro and in vivo. In conclusion, Circ_0020256 in TAM-secreted exosomes promoted the proliferation, migration, and invasion of CCA cells, and that promotional activity was regulated via a Circ_0020256/miR-432-5p/E2F3 axis.

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Zhang, Lei, Kai Zhang, Shasha Liu, Ruizhe Zhang, Yang Yang, Qi Wang, Song Zhao, Li Yang, Yi Zhang et Jiaxiang Wang. « Identification of a ceRNA Network in Lung Adenocarcinoma Based on Integration Analysis of Tumor-Associated Macrophage Signature Genes ». Frontiers in Cell and Developmental Biology 9 (2 mars 2021). http://dx.doi.org/10.3389/fcell.2021.629941.

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As research into tumor-immune interactions progresses, immunotherapy is becoming the most promising treatment against cancers. The tumor microenvironment (TME) plays the key role influencing the efficacy of anti-tumor immunotherapy, in which tumor-associated macrophages (TAMs) are the most important component. Although evidences have emerged revealing that competing endogenous RNAs (ceRNAs) were involved in infiltration, differentiation and function of immune cells by regulating interactions among different varieties of RNAs, limited comprehensive investigation focused on the regulatory mechanism between ceRNA networks and TAMs. In this study, we aimed to utilize bioinformatic approaches to explore how TAMs potentially influence the prognosis and immunotherapy of lung adenocarcinoma (LUAD) patients. Firstly, according to TAM signature genes, we constructed a TAM prognostic risk model by the least absolute shrinkage and selection operator (LASSO) cox regression in LUAD patients. Then, differential gene expression was analyzed between high- and low-risk patients. Weighted gene correlation network analysis (WGCNA) was utilized to identify relevant gene modules correlated with clinical characteristics and prognostic risk score. Moreover, ceRNA networks were built up based on predicting regulatory pairs in differentially expressed genes. Ultimately, by synthesizing information of protein-protein interactions (PPI) analysis and survival analysis, we have successfully identified a core regulatory axis: LINC00324/miR-9-5p (miR-33b-5p)/GAB3 (IKZF1) which may play a pivotal role in regulating TAM risk and prognosis in LUAD patients. The present study contributes to a better understanding of TAMs associated immunosuppression in the TME and provides novel targets and regulatory pathway for anti-tumor immunotherapy.

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Zhao, Senlin, Yushuai Mi, Bingjie Guan, Binbin Zheng, Ping Wei, Yanzi Gu, Zhengxiang Zhang et al. « Tumor-derived exosomal miR-934 induces macrophage M2 polarization to promote liver metastasis of colorectal cancer ». Journal of Hematology & ; Oncology 13, n^o 1 (19 novembre 2020). http://dx.doi.org/10.1186/s13045-020-00991-2.

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Abstract Background Mounting evidence has demonstrated the vital importance of tumor-associated macrophages (TAMs) and exosomes in the formation of the premetastatic niche. However, the molecular mechanisms by which tumor-derived exosomal miRNAs interact with TAMs underlying premetastatic niche formation and colorectal cancer liver metastasis (CRLM) remain largely unknown. Methods Transmission electron microscopy and differential ultracentrifugation were used to verify the existence of exosomes. In vivo and in vitro assays were used to identify roles of exosomal miR-934. RNA pull-down assay, dual-luciferase reporter assay, etc. were applied to clarify the mechanism of exosomal miR-934 regulated the crosstalk between CRC cells and M2 macrophages. Results In the present study, we first demonstrated the aberrant overexpression of miR-934 in colorectal cancer (CRC), especially in CRLM, and its correlation with the poor prognosis of CRC patients. Then, we verified that CRC cell-derived exosomal miR-934 induced M2 macrophage polarization by downregulating PTEN expression and activating the PI3K/AKT signaling pathway. Moreover, we revealed that hnRNPA2B1 mediated miR-934 packaging into exosomes of CRC cells and then transferred exosomal miR-934 into macrophages. Interestingly, polarized M2 macrophages could induce premetastatic niche formation and promote CRLM by secreting CXCL13, which activated a CXCL13/CXCR5/NFκB/p65/miR-934 positive feedback loop in CRC cells. Conclusions These findings indicate that tumor-derived exosomal miR-934 can promote CRLM by regulating the crosstalk between CRC cells and TAMs. These findings reveal a tumor and TAM interaction in the metastatic microenvironment mediated by tumor-derived exosomes that affects CRLM. The present study also provides a theoretical basis for secondary liver cancer.

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Li, Xiang, Shaomin Wang, Wei Mu, Jennifer Barry, Anna Han, Richard L. Carpenter, Bing-Hua Jiang et al. « Reactive oxygen species reprogram macrophages to suppress antitumor immune response through the exosomal miR-155-5p/PD-L1 pathway ». Journal of Experimental & ; Clinical Cancer Research 41, n^o 1 (27 janvier 2022). http://dx.doi.org/10.1186/s13046-022-02244-1.

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Abstract Background Cancer cells have an imbalance in oxidation-reduction (redox) homeostasis. Understanding the precise mechanisms and the impact of the altered redox microenvironment on the immunologic reaction to tumors is limited. Methods We isolated exosomes from ovarian cancer cells through ultracentrifuge and characterized by Western-blots and Nanoparticle Tracking Analysis. 2D, 3D-coculture tumor model, and 3D live cell imaging were used to study the interactions between tumor cells, macrophages and CD3 T cells in vitro. The role of exosomal miR-155-5p in tumor growth was evaluated in xenograft nude mice models and immune-competent mice models. Flow cytometry and flow sorting were used to determine the expression levels of miR-155-5p and PD-L1 in ascites and splenic macrophages, and the percentages of CD3 T cells subpopulations. Results The elevation of reactive oxygen species (ROS) greatly downregulated exosomal miR-155-5p expression in tumor cells. Neutralization of ROS with N-acetyl-L-cysteine (NAC) increased the levels of miR-155-5p in tumor exosomes that were taken up by macrophages, leading to reduction of macrophage migration and tumor spheroid infiltration. We further found that programmed death ligand 1 (PD-L1) is a functional target of miR-155-5p. Co-culture of macrophages pre-treated with NAC-derived tumor exosomes or exosomal miR-155-5p with T-lymphocytes leading to an increased percentage of CD8+ T-lymphocyte and a decreased CD3+ T cell apoptosis through PD-L1 downregulation. Tumor growth in nude mice was delayed by treatment with NAC-derived tumor exosomes. Delivery of tumor exo-miR-155-5p in immune-intact mice suppressed ovarian cancer progression and macrophage infiltration, and activated CD8+ T cell function. It is of note that exo-miR-155-5p inhibited tumor growth more potently than the PD-L1 antibody, suggesting that in addition to PD-L1, other pathways may also be targeted by this approach. Conclusions Our findings demonstrate a novel mechanism, ROS-induced down-regulation of miR-155-5p, by which tumors modulate the microenvironment that favors tumor growth. Understanding of the negative impact of ROS on the tumor immune response will improve current therapeutic strategies. Targeting miR-155-5p can be an alternative approach to prevent formation of an immunosuppressive TME through downregulation of PD-L1 and other immunosuppressive factors. Graphical Abstract

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Xu, Jianye, Jian Zhang, Zongpu Zhang, Zijie Gao, Yanhua Qi, Wei Qiu, Ziwen Pan et al. « Hypoxic glioma-derived exosomes promote M2-like macrophage polarization by enhancing autophagy induction ». Cell Death & ; Disease 12, n^o 4 (avril 2021). http://dx.doi.org/10.1038/s41419-021-03664-1.

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AbstractExosomes participate in intercellular communication and glioma microenvironment modulation, but the exact mechanisms by which glioma-derived exosomes (GDEs) promote the generation of the immunosuppressive microenvironment are still unclear. Here, we investigated the effects of GDEs on autophagy, the polarization of tumor-associated macrophages (TAMs), and glioma progression. Compared with normoxic glioma-derived exosomes (N-GDEs), hypoxic glioma-derived exosomes (H-GDEs) markedly facilitated autophagy and M2-like macrophage polarization, which subsequently promoted glioma proliferation and migration in vitro and in vivo. Western blot and qRT-PCR analyses indicated that interleukin 6 (IL-6) and miR-155-3p were highly expressed in H-GDEs. Further experiments showed that IL-6 and miR-155-3p induced M2-like macrophage polarization via the IL-6-pSTAT3-miR-155-3p-autophagy-pSTAT3 positive feedback loop, which promotes glioma progression. Our study clarifies a mechanism by which hypoxia and glioma influence autophagy and M2-like macrophage polarization via exosomes, which could advance the formation of the immunosuppressive microenvironment. Our findings suggest that IL-6 and miR-155-3p may be novel biomarkers for diagnosing glioma and that treatments targeting autophagy and the STAT3 pathway may contribute to antitumor immunotherapy.

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Bao, Zixu, Ning Zhang, Wanxiang Niu, Maolin Mu, Xiaoming Zhang, Shanshan Hu et Chaoshi Niu. « Exosomal miR-155-5p derived from glioma stem-like cells promotes mesenchymal transition via targeting ACOT12 ». Cell Death & ; Disease 13, n^o 8 (19 août 2022). http://dx.doi.org/10.1038/s41419-022-05097-w.

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AbstractTumor-associated exosomes play essential roles in intercellular communication and the foundation of cancer microenvironment in glioma. Many mRNAs, microRNAs (miRNAs) and proteins contained in tumor-associated exosomes can be transferred to recipient cells and contribute to the progression of tumor. Nevertheless, the cellular communication between malignant cells with different heterogeneities or characteristics and resultant tumor progression are still unclear in glioma. Here, we show that exosomes released from glioma stem-like cells (GSCs) contain a significant increasing level of miR-155-5p and could be horizontally transferred to surrounding glioma cells. High expression of miR-155-5p in plasma exosomes from patients was associated with glioma diagnosis and grading. Mechanically, we found that miR-155-5p markedly reduced the expression of acetyl-CoA thioesterase 12 (ACOT12), which played as a tumor suppressor in glioma. Furthermore, mesenchymal transition was significantly promoted in glioma cells treated with GSCs-derived exosomes. In conclusion, GSCs-derived exosomal miR-155-5p play a critical role in glioma progression and facilitating tumor aggressive growth by targeting ACOT12 and promoting mesenchymal transition. Exosomal miR-155-5p is also a potential predictive biomarker for glioma, which may provoke the development of novel diagnostic and therapeutic strategies against glioma.

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Renrick, Ariana N., Menaka C. Thounaojam, Maria Teresa P. de Aquino, Evan Chaudhuri, Jui Pandhare, Chandravanu Dash et Anil Shanker. « Bortezomib Sustains T Cell Function by Inducing miR-155-Mediated Downregulation of SOCS1 and SHIP1 ». Frontiers in Immunology 12 (25 février 2021). http://dx.doi.org/10.3389/fimmu.2021.607044.

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Suppressive mechanisms operating within T cells are linked to immune dysfunction in the tumor microenvironment. We have previously reported using adoptive T cell immunotherapy models that tumor–bearing mice treated with a regimen of proteasome inhibitor, bortezomib - a dipeptidyl boronate, show increased antitumor lymphocyte effector function and survival. Here, we identify a mechanism for the improved antitumor CD8+ T cell function following bortezomib treatment. Intravenous administration of bortezomib at a low dose (1 mg/kg body weight) in wild-type or tumor-bearing mice altered the expression of a number of miRNAs in CD8+ T cells. Specifically, the effect of bortezomib was prominent on miR-155 - a key cellular miRNA involved in T cell function. Importantly, bortezomib–induced upregulation of miR-155 was associated with the downregulation of its targets, the suppressor of cytokine signaling 1 (SOCS1) and inositol polyphosphate-5-phosphatase (SHIP1). Genetic and biochemical analysis confirmed a functional link between miR-155 and these targets. Moreover, activated CD8+ T cells treated with bortezomib exhibited a significant reduction in programmed cell death-1 (PD-1) expressing SHIP1+ phenotype. These data underscore a mechanism of action by which bortezomib induces miR-155–dependent downregulation of SOCS1 and SHIP1 negative regulatory proteins, leading to a suppressed PD-1–mediated T cell exhaustion. Collectively, data provide novel molecular insights into bortezomib–mediated lymphocyte–stimulatory effects that could overcome immunosuppressive actions of tumor on antitumor T cell functions. The findings support the approach that bortezomib combined with other immunotherapies would lead to improved therapeutic outcomes by overcoming T cell exhaustion in the tumor microenvironment.

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Iranparast, Sara, Maryam Tahmasebi-Birgani, Azim Motamedfar, Afshin Amari et Mehri Ghafourian. « Altered Expression Levels of MicroRNA-155 and SOCS-1 in Peripheral Blood Mononuclear Cells of Newly Diagnosed Breast Cancer Patients ». Iranian Journal of Allergy, Asthma and Immunology, 8 février 2022. http://dx.doi.org/10.18502/ijaai.v21i1.8608.

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MicroRNA-155 (miR-155) has a critical role in pro-inflammatory activation and tumor progression. In addition, miR-155 has various oncogenic effects in the tumor microenvironment by targeting the suppressor gene of cytokine signaling-1(SOCS-1) and interleukin-6 (IL-6). This study investigated the association of inflammatory changes with the variations of miR-155 expression in newly diagnosed breast cancer (NDBC) patients. Seventy NDBC patients were categorized as lobular and ductal subgroups and forty healthy individuals participated in this study. The expression rate of miR-155 and its downstream target gene, SOCS-1, as well as the plasma levels of IL-6, were evaluated in peripheral blood mononuclear cells of NDBC patients; using real-time PCR and enzyme-linked immunosorbent assay, respectively. Our results indicated an over-expression of miR-155 in the PBMCs of NDBC patients which was significantly associated with the tumor grade and the type of ductal carcinoma. In contrast, a significant downregulation of SOCS-1 was observed in NDBC patients compared to the control group, however, there was no significant difference between the two subtypes of BC. Furthermore, a higher concentration of plasma IL-6 was detected in NDBC patients compared to the healthy control group which had an inverse correlation with the SOCS-1 levels. According to the potential effects of miR-155 on regulating the expression of SOCS-1 and IL-6, we suggest this small transcript as a promising diagnostic marker for various types of BC patients.

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Guo, Jie, Mengfan Liao et Jun Wang. « TLR4 signaling in the development of colitis-associated cancer and its possible interplay with microRNA-155 ». Cell Communication and Signaling 19, n^o 1 (3 septembre 2021). http://dx.doi.org/10.1186/s12964-021-00771-6.

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AbstractUlcerative colitis (UC) has closely been associated with an increased risk of colorectal cancer. However, the exact mechanisms underlying colitis-associated cancer (CAC) development remain unclear. As a classic pattern-recognition receptor, Toll like receptor (TLR)4 is a canonical receptor for lipopolysaccharide of Gram-negative bacteria (including two CAC-associated pathogens Fusobacterium nucleatum and Salmonella), and functions as a key bridge molecule linking oncogenic infection to colonic inflammatory and malignant processes. Accumulating studies verified the overexpression of TLR4 in colitis and CAC, and the over-expressed TLR4 might promote colitis-associated tumorigenesis via facilitating cell proliferation, protecting malignant cells against apoptosis, accelerating invasion and metastasis, as well as contributing to the creation of tumor-favouring cellular microenvironment. In recent years, considerable attention has been focused on the regulation of TLR4 signaling in the context of colitis-associated tumorigenesis. MicroRNA (miR)-155 and TLR4 exhibited a similar dynamic expression change during CAC development and shared similar CAC-promoting properties. The available data demonstrated an interplay between TLR4 and miR-155 in the context of different disorders or cell lines. miR-155 could augment TLR4 signaling through targeting negative regulators SOCS1 and SHIP1; and TLR4 activation would induce miR-155 expression via transcriptional and post-transcriptional mechanisms. This possible TLR4-miR-155 positive feedback loop might result in the synergistic accelerating effect of TLR4 and miR-155 on CAC development.

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Zhang, Wenwen, Xingchen Li, Mengmeng Jiang, Chenyan Ji, Guidong Chen, Qiaoling Zhang, Pengpeng Liu et al. « SOCS3 deficiency-dependent autophagy repression promote the survival of early-stage myeloid-derived suppressor cells in breast cancer by activating the Wnt/mTOR pathway ». Journal of Leukocyte Biology, 20 février 2023. http://dx.doi.org/10.1093/jleuko/qiad020.

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Abstract Early-stage myeloid-derived suppressor cells (eMDSCs) are a newly defined subset of MDSCs in breast cancer tissues, and was related to poor prognosis of breast cancer patients. Compared with classical MDSCs, eMDSCs display exceptional immunosuppressive ability and accumulate in the tumor microenvironment to suppress innate and adaptive immunity. Previously, we demonstrated that eMDSCs was SOCS3 deficiency-dependent and correlated with differentiation arrest in the myeloid lineage. Autophagy is a major regulator of myeloid differentiation, however, the mechanism by which autophagy regulate the development of eMDSCs has not been elucidated. Here, we constructed EO771 mammary tumor-bearing conditional myeloid SOCS3 knockout mice (SOCS3MyeKO) characterized by abundant tumor-infiltrating eMDSCs and exacerbated immunosuppression in vitro and in vivo. We found that eMDSCs isolated from SOCS3MyeKO mice showed differentiation arrest in the myeloid lineage, which was caused by limited autophagy activation in an Wnt/mTOR-dependent manner. RNA sequencing and miRNA microarray assays revealed that miR-155-induced C/EBPβ downregulation activated the Wnt/mTOR pathway, and promoted autophagy repression and differentiation arrest in eMDSCs. Furthermore, inhibition of Wnt/mTOR signaling suppressed both tumor growth and the immunosuppressive functions of eMDSCs. Thus, SOCS3 deficiency-dependent autophagy repression and their regulatory mechanisms could contribute to the immunosuppressive tumor microenvironment. Our study proposes a novel mechanism for promoting eMDSCs survival, which might shed new light on a potential target of oncologic therapy.

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Yan, Yue-Mei, Ji-Na Zheng, Li-Wei Wu, Qian-Wen Rao, Qiao-Rong Yang, Di Gao et Qiang Wang. « Prediction of a Competing Endogenous RNA Co-expression Network by Comprehensive Methods in Systemic Sclerosis-Related Interstitial Lung Disease ». Frontiers in Genetics 12 (5 juillet 2021). http://dx.doi.org/10.3389/fgene.2021.633059.

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Systemic sclerosis (SSc) is an immune-mediated connective tissue disease characterized by fibrosis of multi-organs, and SSc-related interstitial lung disease (SSc-ILD) is a leading cause of morbidity and mortality. To explore molecular biological mechanisms of SSc-ILD, we constructed a competing endogenous RNA (ceRNA) network for prediction. Expression profiling data were obtained from the Gene Expression Omnibus (GEO) database, and differential expressed mRNAs and miRNAs analysis was further conducted between normal lung tissue and SSc lung tissue. Also, the interactions of miRNA–lncRNA, miRNA–mRNA, and lncRNA–mRNA were predicted by online databases including starBase, LncBase, miRTarBase, and LncACTdb. The ceRNA network containing 11 lncRNAs, 7 miRNAs, and 20 mRNAs were constructed. Based on hub genes and miRNAs identified by weighted correlation network analysis (WGCNA) method, three core sub-networks—SNHG16, LIN01128, RP11-834C11.4(LINC02381)/hsa-let-7f-5p/IL6, LINC01128/has-miR-21-5p/PTX3, and LINC00665/hsa-miR-155-5p/PLS1—were obtained. Combined with previous studies and enrichment analyses, the lncRNA-mediated network affected LPS-induced inflammatory and immune processes, fibrosis development, and tumor microenvironment variations. The ceRNA network, especially three core sub-networks, may be served as early biomarkers and potential targets for SSc, which also provides further insights into the occurrence, progression, and accurate treatment of SSc at the molecular level.

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McDonald, Sierra J., Taryn L. Cranford, Brandon N. VanderVeen, Thomas D. Cardaci, Kandy T. Velazquez, Reilly T. Enos, Ioulia Chatzistamou, Daping Fan et E. Angela Murphy. « miR155 deficiency reduces breast tumor burden in the MMTV-PyMT mouse model ». Physiological Genomics, 19 septembre 2022. http://dx.doi.org/10.1152/physiolgenomics.00057.2022.

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miR155 has emerged as an important regulator of breast cancer (BrCa) development. Studies have consistently noted an increase in miR155 levels in serum and/or tissues in BrCa patients. However, what is less clear is whether this increase in miR155 is a reflection of oncogenic or tumor suppressive properties. To study the effects of miR155 in a transgenic model of BrCA, we developed an MMTV-PyMT mouse deficient in miR155 (miR155-/- PyMT). miR155-/- mice (n=11) exhibited reduced tumor number and volume palpations at ~14-18 weeks of age compared to miR155 sufficient littermates (n=12). At 19 weeks, mammary glands were excised from tumors for RT-PCR, and tumors were counted, measured, and weighed. miR155-/- PyMT mice exhibited reduced tumor volume, number, and weight, which was confirmed by histopathological analysis. There was an increase in apoptosis with miR155 deficiency and a decrease in proliferation. As expected, miR155 deficiency resulted in upregulated gene expression of suppressor of cytokine signaling 1 (Socs1) - its direct target. There was a reduction in gene expression of macrophage markers (CD68, Adgre1, Itgax, Mrc1) with miR-155-/- and this was confirmed with immunofluorescence staining for F4/80. miR155-/- increased expression of M1 macrophage marker Nos2 and reduced expression of M2 macrophage markers IL-10, IL-4, Arg1, and MMP9. Overall, miR155 deficiency reduced BrCA and improved the tumor microenvironment through the reduction of genes associated with pro-tumorigenic processes. However, given the inconsistencies in the literature, additional studies are needed before any attempts are made to harness miR155 as a potential oncogenic or tumor suppressive miRNA.

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