Articles de revues : « Metabolism, Cell Cycle, Cancer, Kras »

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Chiu, Ching-Feng, Ming-I. Hsu, Hsiu-Yen Yeh, Ji Min Park, Yu-Shiuan Shen, Te-Hsuan Tung, Jun-Jie Huang, Hung-Tsung Wu et Shih-Yi Huang. « Eicosapentaenoic Acid Inhibits KRAS Mutant Pancreatic Cancer Cell Growth by Suppressing Hepassocin Expression and STAT3 Phosphorylation ». Biomolecules 11, n^o 3 (2 mars 2021) : 370. http://dx.doi.org/10.3390/biom11030370.

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Background: The oncogenic Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation was reported to be the signature genetic event in most cases of pancreatic ductal adenocarcinoma (PDAC). Hepassocin (HPS/FGL1) is involved in regulating lipid metabolism and the progression of several cancer types; however, the underlying mechanism of HPS/FGL1 in the KRAS mutant PDAC cells undergoing eicosapentaenoic acid (EPA) treatment remains unclear. Methods: We measured HPS/FGL1 protein expressions in a human pancreatic ductal epithelial (HPNE) normal pancreas cell line, a KRAS-wild-type PDAC cell line (BxPC-3), and KRAS-mutant PDAC cell lines (PANC-1, MIA PaCa-2, and SUIT-2) by Western blot methods. HEK293T cells were transiently transfected with corresponding KRAS-expressing plasmids to examine the level of HPS expression with KRAS activation. We knocked-down HPS/FGL1 using lentiviral vectors in SUIT-2 cells and measured the cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clonogenicity assays. Furthermore, a lipidomic analysis was performed to profile changes in lipid metabolism after HPS/FGL1 knockdown. Results: We found that the HPS/FGL1 level was significantly upregulated in KRAS-mutated PDAC cells and was involved in KRAS/phosphorylated (p)-signal transduction and activator of transcription 3 (STAT3) signaling, and the knockdown of HPS/FGL1 in SUIT-2 cells decreased cell proliferation through increasing G2/M cell cycle arrest and cyclin B1 expression. In addition, the knockdown of HPS/FGL1 in SUIT-2 cells significantly increased omega-3 polyunsaturated fatty acids (PUFAs) and EPA production but not docosahexaenoic acid (DHA). Moreover, EPA treatment in SUIT-2 cells reduced the expression of de novo lipogenic protein, acetyl coenzyme A carboxylase (ACC)-1, and decreased p-STAT3 and HPS/FGL1 expressions, resulting in the suppression of cell viability. Conclusions: Results of this study indicate that HPS is highly expressed by KRAS-mutated PDAC cells, and HPS/FGL1 plays a crucial role in altering lipid metabolism and increasing cell growth in pancreatic cancer. EPA supplements could potentially inhibit or reduce ACC-1-involved lipogenesis and HPS/FGL1-mediated cell survival in KRAS-mutated pancreatic cancer cells.

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Hatipoglu, Ahmet, Deepak Menon, Talia Levy, Maria A. Frias et David A. Foster. « Inhibiting glutamine utilization creates a synthetic lethality for suppression of ATP citrate lyase in KRas-driven cancer cells ». PLOS ONE 17, n^o 10 (21 octobre 2022) : e0276579. http://dx.doi.org/10.1371/journal.pone.0276579.

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Metabolic reprogramming is now considered a hallmark of cancer cells. KRas-driven cancer cells use glutaminolysis to generate the tricarboxylic acid cycle intermediate α-ketoglutarate via a transamination reaction between glutamate and oxaloacetate. We reported previously that exogenously supplied unsaturated fatty acids could be used to synthesize phosphatidic acid–a lipid second messenger that activates both mammalian target of rapamycin (mTOR) complex 1 (mTORC1) and mTOR complex 2 (mTORC2). A key target of mTORC2 is Akt–a kinase that promotes survival and regulates cell metabolism. We report here that mono-unsaturated oleic acid stimulates the phosphorylation of ATP citrate lyase (ACLY) at the Akt phosphorylation site at S455 in an mTORC2 dependent manner. Inhibition of ACLY in KRas-driven cancer cells in the absence of serum resulted in loss of cell viability. We examined the impact of glutamine (Gln) deprivation in combination with inhibition of ACLY on the viability of KRas-driven cancer cells. While Gln deprivation was somewhat toxic to KRas-driven cancer cells by itself, addition of the ACLY inhibitor SB-204990 increased the loss of cell viability. However, the transaminase inhibitor aminooxyacetate was minimally toxic and the combination of SB-204990 and aminooxtacetate led to significant loss of cell viability and strong cleavage of poly-ADP ribose polymerase–indicating apoptotic cell death. This effect was not observed in MCF7 breast cancer cells that do not have a KRas mutation or in BJ-hTERT human fibroblasts which have no oncogenic mutation. These data reveal a synthetic lethality between inhibition of glutamate oxaloacetate transaminase and ACLY inhibition that is specific for KRas-driven cancer cells and the apparent metabolic reprogramming induced by activating mutations to KRas.

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Conroy, Lindsey R., Susan Dougherty, Traci Kruer, Stephanie Metcalf, Pawel Lorkiewicz, Liqing He, Xinmin Yin et al. « Loss of Rb1 Enhances Glycolytic Metabolism in Kras-Driven Lung Tumors In Vivo ». Cancers 12, n^o 1 (17 janvier 2020) : 237. http://dx.doi.org/10.3390/cancers12010237.

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Dysregulated metabolism is a hallmark of cancer cells and is driven in part by specific genetic alterations in various oncogenes or tumor suppressors. The retinoblastoma protein (pRb) is a tumor suppressor that canonically regulates cell cycle progression; however, recent studies have highlighted a functional role for pRb in controlling cellular metabolism. Here, we report that loss of the gene encoding pRb (Rb1) in a transgenic mutant Kras-driven model of lung cancer results in metabolic reprogramming. Our tracer studies using bolus dosing of [U-13C]-glucose revealed an increase in glucose carbon incorporation into select glycolytic intermediates. Consistent with this result, Rb1-depleted tumors exhibited increased expression of key glycolytic enzymes. Interestingly, loss of Rb1 did not alter mitochondrial pyruvate oxidation compared to lung tumors with intact Rb1. Additional tracer studies using [U-13C,15N]-glutamine and [U-13C]-lactate demonstrated that loss of Rb1 did not alter glutaminolysis or utilization of circulating lactate within the tricarboxylic acid cycle (TCA) in vivo. Taken together, these data suggest that the loss of Rb1 promotes a glycolytic phenotype, while not altering pyruvate oxidative metabolism or glutamine anaplerosis in Kras-driven lung tumors.

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Rana, Manjul, Rita G. Kansal, Jie Fang, Benjamin T. Allen, Jun Yang et Evan S. Glazer. « Abstract B044 : Bromodomain and Extra-Terminal Protein inhibition decreases pancreatic cancer proliferation via MYC-independent pathways ». Cancer Research 82, n^o 22_Supplement (15 novembre 2022) : B044. http://dx.doi.org/10.1158/1538-7445.panca22-b044.

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Abstract Introduction: The bromodomain and extra-terminal (BET) protein family contains proteins which have evolutionarily conserved bromodomains (BRDs) that specifically recognize acetylated lysine residues on the histone tails of chromatin and regulate gene transcription. Deregulation of these BRD-containing proteins has been seen in carcinogenesis as they are also known to play role in the regulation of the cell-cycle and MYC oncogenes. BMS-986158 is an oral BET inhibitor which has been used in the clinical trials for both hematologic and advanced solid tumor cancers. We hypothesized that BET inhibition (BETi) decreases pancreatic ductal adenocarcinoma (PDA) proliferation. Methods: Pancreatic cancer cell lines and patient-derived cell-lines (PDCLs) were treated with 2.5 to 100nM BMS-986158 for 72 hours to study dose-response effect with Incucyte. We performed RNA-seq, qPCR, protein analysis, and flow cytometry to evaluate comprehensive changes and underlying mechanisms/pathways including epithelial to mesenchymal transition (EMT) and the cancer stem cell (CSC) phenotype. Various doses of BMS-986158 were used in PDCL and PDA patient-derived organoids (PDO) in combination with chemotherapy drug to evaluate combinational effects. Results: We found that BETi induced dose-dependent decrease in growth of PDA and PDCLs and induced cancer cell death. BETi demonstrated PDO growth inhibition which was enhanced when combined with gemcitabine and paclitaxel chemotherapy. Next, we found that BETi did not affect MYC expression but decreased expression of the SNAI1 (a mesenchymal marker) protein and increased E-cadherin protein expression in PDA cell line and PDO consistent with decreased activation of an EMT program. BETi also decreased expression of CD133, a marker of CSCs in PDO. BETi also induced G1/S Phase cell cycle arrest in PDA PDCLs. Furthermore, RNA-seq studies revealed that BETi treatment inhibits KRAS pathway and upregulates pathways involved in metabolism of lipids and lysosomal degradation. RNA-seq and qPCR demonstrated that GPX3 (glutathione peroxidase 3, a key protein in reactive oxygen species response) gene expression is upregulated in BETi treated samples. Conclusions: Thus, our data demonstrate that BETi through BMS-986158 is an additional therapy for inhibiting PDA growth through mechanisms that are independent of MYC pathway, inhibition of abnormal lipid metabolism and scavenging of reactive oxygen species. Citation Format: Manjul Rana, Rita G. Kansal, Jie Fang, Benjamin T. Allen, Jun Yang, Evan S. Glazer. Bromodomain and Extra-Terminal Protein inhibition decreases pancreatic cancer proliferation via MYC-independent pathways [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B044.

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Renatino-Canevarolo, Rafael, Mark B. Meads, Maria Silva, Praneeth Reddy Sudalagunta, Christopher Cubitt, Gabriel De Avila, Raghunandan R. Alugubelli et al. « Dynamic Epigenetic Landscapes Define Multiple Myeloma Progression and Drug Resistance ». Blood 136, Supplement 1 (5 novembre 2020) : 32–33. http://dx.doi.org/10.1182/blood-2020-142872.

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Multiple myeloma (MM) is an incurable cancer of bone marrow-resident plasma cells, which evolves from a premalignant state, MGUS, to a form of active disease characterized by an initial response to therapy, followed by cycles of therapeutic successes and failures, culminating in a fatal multi-drug resistant cancer. The molecular mechanisms leading to disease progression and refractory disease in MM remain poorly understood. To address this question, we have generated a new database, consisting of 1,123 MM biopsies from patients treated at the H. Lee Moffitt Cancer Center. These samples ranged from MGUS to late relapsed/refractory (LR) disease, and were comprehensively characterized genetically (844 RNAseq, 870 WES, 7 scRNAseq), epigenetically (10 single-cell chromatin accessibility, scATAC-seq) and phenotypically (537 samples assessed for ex vivo drug resistance). Mutational analysis identified putative driver genes (e.g. NRAS, KRAS) among the highest frequent mutations, as well as a steady increase in mutational load across progression from MGUS to LR samples. However, with the exception of KRAS, these genes did not reach statistical significance according to FISHER's exact test between different disease stages, suggesting that no single mutation is necessary or sufficient to drive MM progression or refractory disease, but rather a common "driver" biology is critical. Pathway analysis of differentially expressed genes identified cell adhesion, inflammatory cytokines and hematopoietic cell identify as under-expressed in active MM vs. MGUS, while cell cycle, metabolism, DNA repair, protein/RNA synthesis and degradation were over-expressed in LR. Using an unsupervised systems biology approach, we reconstructed a gene expression map to identify transcriptomic reprogramming events associated with disease progression and evolution of drug resistance. At an epigenetic regulatory level, these genes were enriched for histone modifications (e.g. H3k27me3 and H3k27ac). Furthermore, scATAC-seq confirmed genome-wide alterations in chromatin accessibility across MM progression, involving shifts in chromatin accessibility of the binding motifs of epigenetic regulator complexes, known to mediate formation of 3D structures (CTCF/YY1) of super enhancers (SE) and cell identity reprograming (POU5F1/SOX2). Additionally, we have identified SE-regulated genes under- (EBF1, RB1, SPI1, KLF6) and over-expressed (PRDM1, IRF4) in MM progression, as well as over-expressed in LR (RFX5, YY1, NBN, CTCF, BCOR). We have found a correlation between cytogenetic abnormalities and mutations with differential gene expression observed in MM progression, suggesting groups of genetic events with equivalent transcriptomic effect: e.g. NRAS, KRAS, DIS3 and del13q are associated with transcriptomic changes observed during MGUS/SMOL=>active MM transition (Figure 1). Taken together, our preliminary data suggests that multiple independent combinations of genetic and epigenetic events (e.g. mutations, cytogenetics, SE dysregulation) alter the balance of master epigenetic regulatory circuitry, leading to genome-wide transcriptional reprogramming, facilitating disease progression and emergence of drug resistance. Figure 1: Topology of transcriptional regulation in MM depicts 16,738 genes whose expression is increased (red) or decreased (green) in presence of genetic abnormality. Differential expression associated with (A) hotspot mutations and (B) cytogenetic abnormalities confirms equivalence of expected pairs (e.g. NRAS and KRAS, BRAF and RAF1), but also proposes novel transcriptomic dysregulation effect of clinically relevant cytogenetic abnormalities, with yet uncharacterized molecular role in MM. Figure 1 Disclosures Kulkarni: M2GEN: Current Employment. Zhang:M2GEN: Current Employment. Hampton:M2GEN: Current Employment. Shain:GlaxoSmithKline: Speakers Bureau; Amgen: Speakers Bureau; Karyopharm: Research Funding, Speakers Bureau; AbbVie: Research Funding; Takeda: Honoraria, Speakers Bureau; Sanofi/Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Adaptive: Consultancy, Honoraria; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Siqueira Silva:AbbVie: Research Funding; Karyopharm: Research Funding; NIH/NCI: Research Funding.

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Liu, Xiaoling, Yichen Jia, Changyuan Shi, Dechen Kong, Yuanming Wu, Tiantian Zhang, Anjie Wei et Dan Wang. « CYP4B1 is a prognostic biomarker and potential therapeutic target in lung adenocarcinoma ». PLOS ONE 16, n^o 2 (16 février 2021) : e0247020. http://dx.doi.org/10.1371/journal.pone.0247020.

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CYP4B1 belongs to the mammalian CYP4 enzyme family and is predominantly expressed in the lungs of humans. It is responsible for the oxidative metabolism of a wide range of endogenous compounds and xenobiotics. In this study, using data from The Cancer Genome Atlas (TCGA) project and the Gene Expression Omnibus (GEO) database, a secondary analysis was performed to explore the expression profile of CYP4B1, as well as its prognostic value in patients with lung adenocarcinoma (LUAD). Based on the obtained results, a significantly decreased CYP4B1 expression was discovered in patients with LUAD when compared with their normal counterparts (p<0.05), and was linked to age younger than 65 years (p = 0.0041), history of pharmaceutical (p = 0.0127) and radiation (p = 0.0340) therapy, mutations in KRAS/EGFR/ALK (p = 0.0239), and living status of dead (p = 0.0026). Survival analysis indicated that the low CYP4B1 expression was an independent prognostic indicator of shorter survival in terms of overall survival (OS) and recurrence-free survival (RFS) in patients with LUAD. The copy number alterations (CNAs) and sites of cg23440155 and cg23414387 hypermethylation might contribute to the decreased CYP4B1 expression. Gene set enrichment analysis (GSEA) suggested that CYP4B1 might act as an oncogene in LUAD by preventing biological metabolism pathways of exogenous and endogenous compounds and enhancing DNA replication and cell cycle activities. In conclusion, CYP4B1 expression may serve as a valuable independent prognostic biomarker and a potential therapeutic target in patients with LUAD.

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Dellinger, Thanh Hue, Xiwei Wu, Hyejin Cho, Winnie S. Liang, Ernest Soyoung Han, Mark Tsuneo Wakabayashi, Stephen Lee et al. « Whole transcriptome changes correlate to exceptional ovarian cancer responders : A sub-analysis of a HIPEC Phase I trial. » Journal of Clinical Oncology 38, n^o 15_suppl (20 mai 2020) : 6060. http://dx.doi.org/10.1200/jco.2020.38.15_suppl.6060.

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6060 Background: Advanced stage ovarian cancer patients benefit from hyperthermic intraperitoneal chemotherapy (HIPEC), prolonging overall survival by nearly 12 months. However, molecular changes triggered by HIPEC are not well characterized, and no molecular signatures of response are known. We analyzed early gene expression changes after HIPEC treatment in ovarian tumors. Methods: This is an interval subgroup analysis of a single institution Phase I trial using HIPEC with cisplatin 75 mg/m2 at time of optimal cytoreduction. Snap-frozen biopsies from tumor and normal peritoneum from 20 patients with ovarian cancer before and after HIPEC underwent whole-transcriptome sequencing using Illumina’s NovaSeq 6000 for paired 100 base-pair reads. Differential expression analysis comparing post and pre-samples was done to identify significantly changed genes, and pathway analysis was conducted using GSEA. Results: Sixty-three genes were differentially expressed (P < 0.05, fold change ≥2) between pre- and post-HIPEC tumors. Hierarchical clustering analysis of these genes confirmed that all tumors and normal tissues clustered based on pre-HIPEC versus post-HIPEC status, and not based on their patient source. Gene set enrichment analysis using a collection of 50 “hallmark” gene sets revealed that post-HIPEC tumors demonstrate significant upregulation in immune pathways (TNFA signaling via NFKB, coagulation, complement), followed by epithelial-mesenchymal transition, inflammation, apoptosis, hypoxia, angiogenesis, KRAS signaling and JAK/STAT3 signaling. In contrast, post-HIPEC normal tissues exhibited upregulation in cell cycle pathways (Myc targets V2, G2M checkpoint). As expected, both post-HIPEC tumor and normal samples shared upregulation of genes related to inflammatory response. Lastly, post-HIPEC normal samples revealed downregulation of growth and metabolism pathways; in contrast, cell cycle or DNA repair pathways were downregulated in post-HIPEC tumors. Two exceptional-responders with recurrent platinum-sensitive disease (ongoing PFS 47 and 12+ months) demonstrated the most substantial changes in gene expression. Conclusions: Exceptional ovarian cancer responders to HIPEC are characterized by extensive gene expression changes; specifically, early HIPEC-induced molecular changes are strongly associated with immune pathways changes, implicating a role for immunotherapy after HIPEC in ovarian cancer. Clinical trial information: NCT01970722.

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Ross, P. M. « Cellular and adenovirus dl312 DNA metabolism in cycling or mitotic human cultures exposed to supralethal gamma radiation. » Journal of Cell Biology 109, n^o 5 (1 novembre 1989) : 1993–2002. http://dx.doi.org/10.1083/jcb.109.5.1993.

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Cellular repair of DNA damage due to lethal gamma irradiation was studied to reveal differences between strains and cell cycle stages that are otherwise difficult to detect. Cycling and metaphase-blocked cultures of normal fibroblasts and carcinoma cells were compared for repair of gamma sites (gamma radiation-induced nicks, breaks, and alkalilabile sites in DNA) at supralethal exposures ranging from 7 to 150 krad 137Cs radiation and at postirradiation incubations of 20-180 min. Fibroblasts from normal human skin or lung repaired gamma sites efficiently when cycling but did not repair them when blocked at mitosis. Bladder (253J) or lung (A549) carcinoma cells, unlike normal fibroblasts, repaired gamma sites efficiently even when blocked at mitosis. HeLa cells degraded their DNA soon after exposure at all doses tested, regardless of mitotic arrest. Whether the above differences in DNA repair between cell cycle stages and between strains result from differences in chromatin structure (cis effects) or from differences in the nuclear enzymatic environment (trans effects) could be resolved by placing an inert, extrachromosomal DNA molecule in the cell nucleus. Specifically, cis effects should be confined to the host chromosomes and would not be detected in the inert probe whereas trans effects should be detected in host chromosomes and inert probe DNA alike. Indeed, we found a suitable DNA molecule in the adenovirus deletion mutant dl312, which does not proliferate in the absence of E1A complementation. Gamma sites in 32P-labeled adenovirus dl312 DNA were repaired efficiently in all hosts, regardless of mitotic arrest. Failure of mitosis-arrested fibroblasts to repair gamma sites was therefore due to a cis effect of chromatin organization rather than to a trans effect such as repair enzyme insufficiency. In sharp contrast, chromosomes of mitotic carcinoma cells remained accessible to repair enzymes and nucleases alike. By means of these new tools, we should get a better understanding of higher-order chromatin management in normal and cancer cells.

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Boda, Akash, Casey Ager, Kimal Rajapakshe, Spencer Lea, Maria Emilia Di Francesco, Philip Jones et Michael Curran. « 758 High-potency synthetic STING agonists rewire the myeloid stroma in the tumour microenvironment to amplify immune checkpoint blockade efficacy in refractory pancreatic ductal adenocarcinoma ». Journal for ImmunoTherapy of Cancer 9, Suppl 2 (novembre 2021) : A793. http://dx.doi.org/10.1136/jitc-2021-sitc2021.758.

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BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and is clinically unresponsive to immune checkpoint blockade (ICB) immunotherapy.1 2 High densities of immunosuppressive myeloid cells,3 a paucity of antigen-presenting cells4–6 and T cell exclusion from tumour microenvironment7 all contribute to the refractory nature of PDAC to immune-based therapies. We and others have shown that innate immune activation of myeloid stroma via engagement of the STING (Stimulator of Interferon Genes) pathway can mediate proinflammatory remodeling and trigger a flood of T cell infiltration into otherwise 'cold' tumours.8–11 To that end, intratumoral injection of cyclic dinucleotide (CDN) agonists of the STING pathway has been shown to foster local and abscopal tumor immunity.8–10 Despite proven therapeutic efficacy in preclinical models, the mechanistic basis at a cellular level of how CDNs reprogram the suppressive myeloid stroma to sensitise tumours to ICB is poorly understood.MethodsUsing RNA sequencing and protein arrays we profiled myeloid-derived suppressor cell (MDSC) and M2 macrophage function following stimulation with CDNs of ascending potency. We describe the effects of CDN STING agonists on cell cycle dynamics, metabolic reprogramming and c-Myc expression in MDSCs. Next, in an orthotopic Kras+/G12DTP53+/R172HPdx1-Cre (KPC)-derived model of PDAC, we determined the ability of intratumorally-administered CDNs to sensitise PDAC to checkpoint blockade using bioluminescent in vivo imaging and multi-parameter flow cytometry of tumor stroma post-therapy.ResultsMulti-omics profiling of MDSCs and M2 Macrophages of human and murine origin show that high-potency synthetic STING agonists rewire these populations from immunosuppressive to immune-permissive phenotypes in part through inhibition of c-Myc signaling, energy metabolic modulation, and antagonism of cell cycle. Intratumoral injection of the STING agonist, IACS-8803 resulted in an amplified therapeutic response to checkpoint blockade that was dependent on T/NK cell infiltration into the tumour. Furthermore, dimensionality reduction analyses of multiparameter flow cytometry data show proinflammatory remodeling of the myeloid stroma and enhanced T cell function as salient features of synthetic agonists versus natural CDNs in orchestrating the in vivo therapeutic benefit.ConclusionsThis study uncovers molecular and cellular mechanisms by which STING agonists drive proinflammatory conversion of tumour myeloid stroma. We are the first to report that synthetic CDN STING agonists affect MDSC and M2 macrophage repolarization through altering energy metabolism and c-Myc signalling. Lastly, we demonstrate the potential for high-potency STING agonists to overcome resistance to checkpoint blockade in an aggressive orthotopic tumour model of PDAC.ReferencesRoyal RE, Levy C, et al. Phase 2 trial of single agent Ipilimumab (anti-CTLA-4) for locally advanced or metastatic pancreatic adenocarcinoma. J Immunother 2010;33(8):828–33.Brahmer JR, Tykodi SS, et al. Safety and activity of anti-PD-L1 antibody in patients with advanced cancer. N Engl J Med 2012;366(26):2455–65.Karakhanova S, Link J. Characterization of myeloid leukocytes and soluble mediators in pancreatic cancer: importance of myeloid-derived suppressor cells. Oncoimmunology 2015;4:e998519.Dallal RM, Christakos P, et al. Paucity of dendritic cells in pancreatic cancer. Surgery 2002;131:135–138.Yamamoto T, Yanagimoto H, et al. Circulating myeloid dendritic cells as prognostic factors in patients with pancreatic cancer who have undergone surgical resection. J Surg Res 2012;173:299–308.Hegde S, Krisnawan V, et al. Dendritic cell paucity leads to dysfunctional immune surveillance in pancreatic cancer. Cancer Cell 2020;37(3):289–307.Beatty GL, Winograd R, et al. Exclusion of T cells from pancreatic carcinomas in mice is regulated by Ly6Clow F4/80+ extratumoral macrophages. Gastroenterology 2015;149(1):201–210.Baird JR, Friedman D, et al. Radiotherapy combined with novel STING-Targeting oligonucleotides results in regression of established tumors. Cancer Res 2016;76(1):50–61.Ager CR, Reilley MJ, et al. Intratumoral STING activation with T-cell checkpoint modulation generates systemic antitumor immunity. Cancer Immunol Res 2017;5(8):676–84.Smith TT, Moffett HF, et al. Biopolymers codelivering engineered T cells and STING agonists can eliminate heterogeneous tumors. J Clin Invest 2017;127(6):2176–91.Jing W, McAllister D, et al. STING agonist inflames the pancreatic cancer immune microenvironment and reduces tumor burden in mouse models. J Immunother Cancer 2019;7(1):115.

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Kalofonos, H. P., A. Antonacopoulou, P. Matsouka et E. Giannopoulou. « Effect of panitumumab on autophagy in colon cancer ». Journal of Clinical Oncology 27, n^o 15_suppl (20 mai 2009) : e22151-e22151. http://dx.doi.org/10.1200/jco.2009.27.15_suppl.e22151.

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e22151 Background: Panitumumab, a human monoclonal antibody raised against EGFR, has been approved by the Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) for the treatment of patients with EGFR-expressing mCRC and wild type kras. The ratio of reduced/oxidised form of glutathione (GSH/GSSG) is an indicator of the redox status in cells. The aim of the current study was to investigate the effect of panitumumab on the redox status of colon cancer cell lines Caco-2, DLD-1 and HT-29 regarding proliferation, apoptosis, necrosis, cell cycle arrest and autophagy. Methods: Cell proliferation was measured by MTT assay. Apoptosis and necrosis were detected by annexin v/propidium iodide assay. Cell cycle arrest was estimated by propidium iodide assay. Autophagy was detected by immunobloting and GSH levels were measured by spectrophotometrical analysis. kras mutations were detected by sequencing analysis. Results: Caco-2, DLD-1 and HT-29 cell lines differ in the expression levels of EGFR and HER-2. Kras mutation analysis in previous studies and in the current study showed that DLD-1 cells express mutated kras while Caco-2 and HT-29 cells express wild type of kras. Panitumumab decreased proliferation only in DLD-1 cells 48 h after its application besides the mutated kras. However, panitumumab did not affect DLD-1 cell apoptosis, necrosis or cell cycle progression 24 and 48 h after cells treatment. Interestingly, panitumumab increased protein levels of beclin 1, an indicator of autophagy, 24 h after its addition in cells. Moreover, an increase in GSH levels was noted 48 h after cells treatment with panitumumab. Conclusions: This is the first study to show that panitumumab, an EGFR inhibitor, affects colon cancer cell proliferation independently of kras mutations and EGFR protein levels through the induction of autophagy. The inhibition in cell proliferation was followed by an increase in GSH levels reflecting an imbalance on the redox status of cells. No significant financial relationships to disclose.

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Leal-Esteban, Lucia C., et Lluis Fajas. « Cell cycle regulators in cancer cell metabolism ». Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease 1866, n^o 5 (mai 2020) : 165715. http://dx.doi.org/10.1016/j.bbadis.2020.165715.

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Song, Jisu, Heejung Seo, Mi-Ryung Kim, Sang-Jae Lee, Sooncheol Ahn et Minjung Song. « Active Compound of Pharbitis Semen (Pharbitis nil Seeds) Suppressed KRAS-Driven Colorectal Cancer and Restored Muscle Cell Function during Cancer Progression ». Molecules 25, n^o 12 (22 juin 2020) : 2864. http://dx.doi.org/10.3390/molecules25122864.

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Kirsten rat sarcoma viral oncogene homolog (KRAS)-driven colorectal cancer (CRC) is notorious to target with drugs and has shown ineffective treatment response. The seeds of Pharbitis nil, also known as morning glory, have been used as traditional medicine in East Asia. We focused on whether Pharbitis nil seeds have a suppressive effect on mutated KRAS-driven CRC as well as reserving muscle cell functions during CRC progression. Seeds of Pharbitis nil (Pharbitis semen) were separated by chromatography and the active compound of Pharbitis semen (PN) was purified by HPLC. The compound PN efficiently suppressed the proliferation of mutated KRAS-driven CRC cells and their clonogenic potentials in a concentration-dependent manner. It also induced apoptosis of SW480 human colon cancer cells and cell cycle arrest at the G2/M phase. The CRC related pathways, including RAS/ERK and AKT/mTOR, were assessed and PN reduced the phosphorylation of AKT and mTOR. Furthermore, PN preserved muscle cell proliferation and myotube formation in cancer conditioned media. In summary, PN significantly suppressed mutated KRAS-driven cell growth and reserved muscle cell function. Based on the current study, PN could be considered as a promising starting point for the development of a nature-derived drug against KRAS-mutated CRC progression.

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Lin, Tsung-Jen, Kuo-Chu Lai, An-Sheng Lee, Chien-Hsin Chang, Chiung-Lin Liu et Ching-Hu Chung. « Novel Antrodia cinnamomea Extract Reduced Cancer Stem-Like Phenotype Changes and Resensitized KRAS-Mutant Colorectal Cancer via a MicroRNA-27a Pathway ». Cancers 11, n^o 11 (26 octobre 2019) : 1657. http://dx.doi.org/10.3390/cancers11111657.

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Colorectal cancer (CRC) is one of the most common causes of death in Taiwan. Previous studies showed that Antrodia cinnamomea (AC) can treat poisoning, diarrhea, and various types of cancer. Therefore, we purified a novel ubiquinone derivative, AC009, and investigated its antitumor effects. Cell viability assays revealed that AC009 reduced the viability of several human CRC cell lines. AC009 treatment resulted in cell-cycle arrest/apoptosis, and these effects may occur via caspase and Bcl-2 signaling pathways. We demonstrated that AC009 could significantly inhibit in vivo tumor growth in xenograft mouse models. Using messenger RNA (mRNA) and microRNA (miRNA) microarrays, we found that KRAS gene expression was also regulated by AC009, possibly through specific miRNAs. AC009 also reduced cancer stem-cell marker CD44+/CD24+ expression and restored the tumor inhibition effect of cetuximab in KRAS-mutant CRC. Moreover, we found that miRNA-27a could restore the tumor inhibition effect of cetuximab in KRAS-mutant CRC cells. Taken together, our results suggest that AC009 has therapeutic potential against human wild-type and KRAS-mutant CRC.

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Mullany, Lisa K., Zhilin Liu, Erin R. King, Kwong-Kwok Wong et JoAnne S. Richards. « Wild-Type Tumor Repressor Protein 53 (TRP53) Promotes Ovarian Cancer Cell Survival ». Endocrinology 153, n^o 4 (6 mars 2012) : 1638–48. http://dx.doi.org/10.1210/en.2011-2131.

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Loss of Pten in the KrasG12D;Amhr2-Cre mutant mice leads to the transformation of ovarian surface epithelial (OSE) cells and rapid development of low-grade, invasive serous adenocarcinomas. Tumors occur with 100% penetrance and express elevated levels of wild-type tumor repressor protein 53 (TRP53). To test the functions of TRP53 in the Pten;Kras (Trp53+) mice, we disrupted the Trp53 gene yielding Pten;Kras(Trp53−) mice. By comparing morphology and gene expression profiles in the Trp53+ and Trp53− OSE cells from these mice, we document that wild-type TRP53 acts as a major promoter of OSE cell survival and differentiation: cells lacking Trp53 are transformed yet are less adherent, migratory, and invasive and exhibit a gene expression profile more like normal OSE cells. These results provide a new paradigm: wild-type TRP53 does not preferentially induce apoptotic or senescent related genes in the Pten;Kras(Trp53+) cancer cells but rather increases genes regulating DNA repair, cell cycle progression, and proliferation and decreases putative tumor suppressor genes. However, if TRP53 activity is forced higher by exposure to nutlin-3a (a mouse double minute-2 antagonist), TRP53 suppresses DNA repair genes and induces the expression of genes that control cell cycle arrest and apoptosis. Thus, in the Pten;Kras(Trp53+) mutant mouse OSE cells and likely in human TP53+ low-grade ovarian cancer cells, wild-type TRP53 controls global molecular changes that are dependent on its activation status. These results suggest that activation of TP53 may provide a promising new therapy for managing low-grade ovarian cancer and other cancers in humans in which wild-type TP53 is expressed.

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Chippalkatti, Rohan, et Daniel Abankwa. « Promotion of cancer cell stemness by Ras ». Biochemical Society Transactions 49, n^o 1 (5 février 2021) : 467–76. http://dx.doi.org/10.1042/bst20200964.

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Cancer stem cells (CSC) may be the most relevant and elusive cancer cell population, as they have the exquisite ability to seed new tumors. It is plausible, that highly mutated cancer genes, such as KRAS, are functionally associated with processes contributing to the emergence of stemness traits. In this review, we will summarize the evidence for a stemness driving activity of oncogenic Ras. This activity appears to differ by Ras isoform, with the highly mutated KRAS having a particularly profound impact. Next to established stemness pathways such as Wnt and Hedgehog (Hh), the precise, cell cycle dependent orchestration of the MAPK-pathway appears to relay Ras activation in this context. We will examine how non-canonical activities of K-Ras4B (hereafter K-Ras) could be enabled by its trafficking chaperones calmodulin and PDE6D/PDEδ. Both dynamically localize to the cellular machinery that is intimately linked to cell fate decisions, such as the primary cilium and the centrosome. Thus, it can be speculated that oncogenic K-Ras disrupts fundamental polarized signaling and asymmetric apportioning processes that are necessary during cell differentiation.

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Oya, Yuko, Katsuhiro Masago, Hirokazu Matsushita et Hiroaki Kuroda. « Association of the KRAS genotype and clinicopathologic findings of resected non–small cell lung cancer. » Journal of Clinical Oncology 40, n^o 16_suppl (1 juin 2022) : 8545. http://dx.doi.org/10.1200/jco.2022.40.16_suppl.8545.

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8545 Background: This study assessed the clinicopathological background of early-stage KRAS-mutated non-small-cell lung cancer and analyzed the biological process of KRAS-mutated tumor using an RNA sequencing procedure. Methods: We used a cohort of consecutive series of 179 surgically resected early-stage non-small-cell lung cancers harboring KRASmutations and analyzed the clinicopathological features, including the KRAS genotypes, affecting the recurrence-free survival and prognosis. Consequently, we performed RNA sequencing to determine the gene expression profiles of nineteen KRAS-mutated non-small-cell cancers. Results: The most common KRAS genotype was p.G12C (57; 31.8%). A high p-stage (hazard ratio [HR], 4.181; P < 0.0001) and solid predominant adenocarcinoma histology (HR, 2.343; P = 0.0076) were significant independent prognostic factors for the recurrence-free survival. A high p-stage (HR, 3.793; P < 0.0001), solid predominant adenocarcinoma histology (HR, 2.373; P = 0.0147), and KRAS p.G12V genotype (HR, 1.975; P = 0.0407) were significant independent prognostic factors for the overall survival. A gene expression analysis of the two factors revealed the p.G12V genotype to be closer to those of stem cells, and the traits of e an enhanced fatty acid and amino acid metabolism as well as a solid predominant phenotype were shown to an acquired a trait that can withstand hypoxia and the effect of prostaglandin-endoperoxide synthase Conclusions: The KRAS p.G12V genotype and solid predominant adenocarcinoma phenotype may be independent predictive factors of a poor clinical course in resected early-stage non-small-cell lung cancers, possibly due to the differentiation tendency observed in stem cells, the trait of an enhanced fatty acid and amino acid metabolism, and the effect of prostaglandin-endoperoxide synthase.

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Oya, Yuko, Katsuhiro Masago, Hirokazu Matsushita et Hiroaki Kuroda. « Association of the KRAS genotype and clinicopathologic findings of resected non–small cell lung cancer. » Journal of Clinical Oncology 40, n^o 16_suppl (1 juin 2022) : 8545. http://dx.doi.org/10.1200/jco.2022.40.16_suppl.8545.

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8545 Background: This study assessed the clinicopathological background of early-stage KRAS-mutated non-small-cell lung cancer and analyzed the biological process of KRAS-mutated tumor using an RNA sequencing procedure. Methods: We used a cohort of consecutive series of 179 surgically resected early-stage non-small-cell lung cancers harboring KRASmutations and analyzed the clinicopathological features, including the KRAS genotypes, affecting the recurrence-free survival and prognosis. Consequently, we performed RNA sequencing to determine the gene expression profiles of nineteen KRAS-mutated non-small-cell cancers. Results: The most common KRAS genotype was p.G12C (57; 31.8%). A high p-stage (hazard ratio [HR], 4.181; P < 0.0001) and solid predominant adenocarcinoma histology (HR, 2.343; P = 0.0076) were significant independent prognostic factors for the recurrence-free survival. A high p-stage (HR, 3.793; P < 0.0001), solid predominant adenocarcinoma histology (HR, 2.373; P = 0.0147), and KRAS p.G12V genotype (HR, 1.975; P = 0.0407) were significant independent prognostic factors for the overall survival. A gene expression analysis of the two factors revealed the p.G12V genotype to be closer to those of stem cells, and the traits of e an enhanced fatty acid and amino acid metabolism as well as a solid predominant phenotype were shown to an acquired a trait that can withstand hypoxia and the effect of prostaglandin-endoperoxide synthase Conclusions: The KRAS p.G12V genotype and solid predominant adenocarcinoma phenotype may be independent predictive factors of a poor clinical course in resected early-stage non-small-cell lung cancers, possibly due to the differentiation tendency observed in stem cells, the trait of an enhanced fatty acid and amino acid metabolism, and the effect of prostaglandin-endoperoxide synthase.

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Saiz-Lopez, Patricia, Raquel Alcaraz-Ortega, Ana Maria Lopez, Beatriz Llorente, Maria Soledad Diez-Ordoñez, Juan Carlos Pérez Álvarez, Maria José Cáceres Porras, Johanna Beatriz Palacios Ball, Celina Echevarria-Iturbe et Guillermo Crespo. « Cell-free KRAS in pancreatic cancer as a rapid prognostic marker. » Journal of Clinical Oncology 38, n^o 15_suppl (20 mai 2020) : e15534-e15534. http://dx.doi.org/10.1200/jco.2020.38.15_suppl.e15534.

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e15534 Background: KRAS mutations are present over 90% of patients with pancreatic cancer (PC). Liquid biopsies provide the opportunity to genotype alterations in a less invasive way and offer a possibility to monitor the molecular characteristics of a cancer through the course of treatment. We aim to establish an association between the mutational levels of KRAS detected in plasma with patient stage and evolution. Methods: Plasma samples were collected from patients with newly diagnosed PC, before any treatment and during one year. Diagnosis of any previous cancer was an exclusion criterion. Samples were frozen (-80ºC) until analysis of KRAS mutations in cell free DNA (cfDNA) by real time PCR. Specifically, Idylla TM technology was used due to the rapid capacity to report up to 21 KRAS mutations in exon 2, 3, and 4 (LOD = < 5%), without necessity of cfDNA isolation. Mutation was considered present (categorical measurement), taking into account cycle quantification values (Cq) established by the commercial test. Cut-off values for Cq were studied by the ROC curve (receiver operating characteristic) with the Youden's J statistic. Paired tissue samples were analyzed when available. Results: A total of 23 patients were enrolled, median age 65 years old, 57% male, 100% adenocarcinoma, 18 (70%) metastatic. Sixteen patients could also be tested in tissue, being 15 (93.8%) positive for KRAS mutation. Plasma basal mutations were detected in 10 patients (43.5%), all in stage IV (p = 0.046), and interestingly, all with liver involvement (p = 0.003). Moreover, these patients also had metastasis in another organ apart from the liver. The most frequent mutation was G12V (5), followed by G12D (4) and G12R (1). Patients with basal KRAS mutations detected in plasma had a survival of 6.1 months (CI 95%, 3.7-8.5), and non-mutated 11.2 months (95% CI, 7.8-14.7) (p = 0.041). The presence of these cell-free KRAS mutations was more informative for survival than stage IV disease vs III (p = 0.054). Paying attention to KRAS wild type detection in plasma samples used as an internal control of the PCR, we could establish a Cq value cut-off of < 21 Cq for mutant samples, with a sensitivity of 100% (95% CI, 75%-100%) and specificity of 50% (95% CI, 19%-81%), area under ROC curve 0.823 (95% CI, 0.649-0.997). Conclusions: Measurement of cell-free KRAS in plasma samples at diagnosis could be used to quickly predict metastasis and survival in patients with pancreatic adenocarcinoma.

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Icard, Philippe, Ludovic Fournel, Zherui Wu, Marco Alifano et Hubert Lincet. « Interconnection between Metabolism and Cell Cycle in Cancer ». Trends in Biochemical Sciences 44, n^o 6 (juin 2019) : 490–501. http://dx.doi.org/10.1016/j.tibs.2018.12.007.

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Sato, Hiromichi, Kazuki Sasaki, Tomoaki Hara, Yoshiko Tsuji, Yasuko Arao, Chihiro Otsuka, Yumiko Hamano et al. « Pancreatic Cancer Research beyond DNA Mutations ». Biomolecules 12, n^o 10 (17 octobre 2022) : 1503. http://dx.doi.org/10.3390/biom12101503.

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Pancreatic ductal adenocarcinoma (PDAC) is caused by genetic mutations in four genes: KRAS proto-oncogene and GTPase (KRAS), tumor protein P53 (TP53), cyclin-dependent kinase inhibitor 2A (CDKN2A), and mothers against decapentaplegic homolog 4 (SMAD4), also called the big 4. The changes in tumors are very complex, making their characterization in the early stages challenging. Therefore, the development of innovative therapeutic approaches is desirable. The key to overcoming PDAC is diagnosing it in the early stages. Therefore, recent studies have investigated the multifaced characteristics of PDAC, which includes cancer cell metabolism, mesenchymal cells including cancer-associated fibroblasts and immune cells, and metagenomics, which extend to characterize various biomolecules including RNAs and volatile organic compounds. Various alterations in the KRAS-dependent as well as KRAS-independent pathways are involved in the refractoriness of PDAC. The optimal combination of these new technologies is expected to help treat intractable pancreatic cancer.

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Kim, Hyeon Jin, Han Na Lee, Mi Suk Jeong et Se Bok Jang. « Oncogenic KRAS : Signaling and Drug Resistance ». Cancers 13, n^o 22 (9 novembre 2021) : 5599. http://dx.doi.org/10.3390/cancers13225599.

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RAS proteins play a role in many physiological signals transduction processes, including cell growth, division, and survival. The Ras protein has amino acids 188-189 and functions as GTPase. These proteins are switch molecules that cycle between inactive GDP-bound and active GTP-bound by guanine nucleotide exchange factors (GEFs). KRAS is one of the Ras superfamily isoforms (N-RAS, H-RAS, and K-RAS) that frequently mutate in cancer. The mutation of KRAS is essentially performing the transformation in humans. Since most RAS proteins belong to GTPase, mutated and GTP-bound active RAS is found in many cancers. Despite KRAS being an important molecule in mostly human cancer, including pancreatic and breast, numerous efforts in years past have persisted in cancer therapy targeting KRAS mutant. This review summarizes the biological characteristics of these proteins and the recent progress in the exploration of KRAS-targeted anticancer, leading to new insight.

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Shifteh, David, Tzuriel Sapir, Moshe Pahmer, Adam Haimowitz, Sanjay Goel et Radhashree Maitra. « Protein Arginine Methyltransferase 5 as a Therapeutic Target for KRAS Mutated Colorectal Cancer ». Cancers 12, n^o 8 (28 juillet 2020) : 2091. http://dx.doi.org/10.3390/cancers12082091.

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Nearly 45% of colorectal cancer (CRC) patients harbor a mutation in their KRAS gene for which, despite many years of research, there are still no targeted therapies available. Protein Arginine Methyltransferase 5 (PRMT5) is a transcription regulator for multiple cellular processes that is currently being tested as a potential target in several cancer types. PRMT5 has been previously shown to be overexpressed in approximately 75% of CRC patient tumor samples, as well as negatively correlated with CRC patient survival. Here, we provide evidence that PRMT5 can act as a surrogate target for mutated KRAS in CRC. Our findings show that PRMT5 expression is upregulated, as well as positively correlated with KRAS expression, in CRC patient datasets. Moreover, our results reveal that PRMT5 is further overexpressed in KRAS mutant CRC cells when compared to KRAS wild type (WT) CRC cells at both the transcriptional and translational levels. Additionally, our data demonstrate that this further overexpression of PRMT5 in the KRAS mutant CRC cells affects an even greater degree of growth inhibition, apoptosis, and cell cycle arrest, following treatment with PRMT5 inhibitor, when compared to the KRAS WT CRC cells. Our research therefore suggests for the first time that PRMT5 and KRAS may crosstalk, and thus, PRMT5 can potentially be used as a surrogate target for mutated KRAS in CRC.

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Unson, Sukanya, Tung-Cheng Chang, Yung-Ning Yang, Shwu-Huey Wang, Chi-Hung Huang, Dana R. Crawford, Haw-Ming Huang et al. « Heteronemin and Tetrac Induce Anti-Proliferation by Blocking EGFR-Mediated Signaling in Colorectal Cancer Cells ». Marine Drugs 20, n^o 8 (27 juillet 2022) : 482. http://dx.doi.org/10.3390/md20080482.

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Overexpressed EGFR and mutant K-Ras play vital roles in therapeutic resistance in colorectal cancer patients. To search for an effective therapeutic protocol is an urgent task. A secondary metabolite in the sponge Hippospongia sp., Heteronemin, has been shown to induce anti-proliferation in several types of cancers. A thyroxine-deaminated analogue, tetrac, binds to integrin αvβ3 to induce anti-proliferation in different cancers. Heteronemin- and in combination with tetrac-induced antiproliferative effects were evaluated. Tetrac enhanced heteronemin-induced anti-proliferation in HT-29 cells (KRAS WT CRC) and HCT-116 cells (KRAS MT CRC). Heteronemin and tetrac arrested cell cycle in different phases. Combined treatment increased the cell accumulation in sub-G1 and S phases. The combined treatment also induced the inactivation of EGFR signaling and downregulated the phosphorylated ERK1/2 protein in both cell lines. Heteronemin and the combination showed the downregulation of the phosphorylated and total PI3K protein in HT-29 cells (KRAS WT CRC). Results by NanoString technology and RT-qPCR revealed that heteronemin and combined treatment suppressed the expression of EGFR and downstream genes in HCT-116 cells (KRAS MT CRC). Heteronemin or combined treatment downregulated genes associated with cancer progression and decreased cell motility. Heteronemin or the combined treatment suppressed PD-L1 expression in both cancer cell lines. However, only tetrac and the combined treatment inhibited PD-L1 protein accumulation in HT-29 cells (KRAS WT CRC) and HCT-116 cells (KRAS MT CRC), respectively. In summary, heteronemin induced anti-proliferation in colorectal cancer cells by blocking the EGFR-dependent signal transduction pathway. The combined treatment further enhanced the anti-proliferative effect via PD-L1 suppression. It can be an alternative strategy to suppress mutant KRAS resistance for anti-EGFR therapy.

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Li, Yuchan, Omar Elakad, Sha Yao, Alexander von Hammerstein-Equord, Marc Hinterthaner, Bernhard C. Danner, Carmelo Ferrai, Philipp Ströbel, Stefan Küffer et Hanibal Bohnenberger. « Regulation and Therapeutic Targeting of MTHFD2 and EZH2 in KRAS-Mutated Human Pulmonary Adenocarcinoma ». Metabolites 12, n^o 7 (15 juillet 2022) : 652. http://dx.doi.org/10.3390/metabo12070652.

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Activating KRAS mutations occur in about 30% of pulmonary adenocarcinoma (AC) cases and the discovery of specific inhibitors of G12C-mutated KRAS has considerably improved the prognosis for a subgroup of about 14% of non-small cell lung cancer (NSCLC) patients. However, even in patients with a KRAS G12C mutation, the overall response rate only reaches about 40% and mutations other than G12C still cannot be targeted. Despite the fact that one-carbon metabolism (1CM) and epigenetic regulation are known to be dysregulated by aberrant KRAS activity, we still lack evidence that co-treatment with drugs that regulate these factors might ameliorate response rates and patient prognosis. In this study, we show a direct dependency of Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) and Enhancer of Zeste Homolog 2 (EZH2) expression on mutationally activated KRAS and their prognostic relevance in KRAS-mutated AC. We show that aberrant KRAS activity generates a vulnerability of AC cancer cell lines to both MTHFD2 and EZH2 inhibitors. Importantly, co-inhibition of both factors was synergistically effective and comparable to KRASG12C inhibition alone, paving the way for their use in a therapeutic approach for NSCLC cancer patients.

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Kim, Seo-Hyun, Ammar Karo, Lela Buckingham, Sanjib Basu, Jeffrey Allen Borgia, Philip Bonomi, Marta Batus et Mary J. Fidler. « Association of KRAS mutations detected via liquid biopsy in metastatic non-small cell lung cancer patients with high levels of FDG-PET SUV. » Journal of Clinical Oncology 35, n^o 15_suppl (20 mai 2017) : e20594-e20594. http://dx.doi.org/10.1200/jco.2017.35.15_suppl.e20594.

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e20594 Background: We had previously evaluated the relationship between FDG-PET SUV with TP53 and KRAS mutations in formalin fixed paraffin embedded tissue (FFPE) in non-small cell lung cancers (NSCLC) in which genomic profiling had been performed. Considering FDG-PET SUV as a surrogate of glycolysis, we found TP53 and KRAS mutations were associated with increased glycolytic activity. The aim for this study was to evaluate KRAS and TP53 in circulating tumor DNA (ctDNA) in relation to FDG-PET SUV in a different cohort of NSCLCs in which genomic profiling was performed on peripheral blood. Methods: All stage IV NSCLC patients with genomic analysis from ctDNA and baseline FDG-PET scans between December 2014 and November 2016 were included. Associations between KRAS and TP53 mutations and maximal standard uptake value (SUVmax) were assessed using the Mann-Whitney and Kruskal-Wallis test. A subset analysis studying all KRAS positive patients from FFPE and ctDNA was performed based on the specific KRAS mutation. Results:122 patients had FDG-PET scans and genomic analyses of their circulating tumor cells. 62 (51%) patients had a TP53 mutation, 20 (17%) patients had a KRAS mutation, and 13 (11%) patients had both TP53 and KRAS mutations. Patients with a KRAS mutation had a higher SUVmax with a mean of 12.32 (p = 0.019). The presence of TP53 alone or concurrent TP53/KRAS was not significantly related to SUVmax. Analyzing 48 patients with KRAS mutation from FFPE and ctDNA assay, 16 patients had mutations of G12C and 9 patients had G12V. The presence of the G12C mutation was particularly highly correlated with higher SUVmax with a mean of 17.68 (p = 0.0006). Conclusions: In analyzing ctDNA, a larger cohort, mutations in KRAS had the strongest correlation with increased SUVmax. Targeting glycolysis and cellular metabolism could be a potential therapeutic strategy for patients with KRAS mutations. Although individual numbers are small, KRAS subtype analysis showed the presence of the G12C mutation might have the strongest relationship with SUV max and increased glycolysis.

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Abdel Hadi, Nadine, Gabriela Reyes-Castellanos et Alice Carrier. « Targeting Redox Metabolism in Pancreatic Cancer ». International Journal of Molecular Sciences 22, n^o 4 (3 février 2021) : 1534. http://dx.doi.org/10.3390/ijms22041534.

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Cell metabolism is reprogrammed in cancer cells to meet their high bioenergetics and biosynthetic demands. This metabolic reprogramming is accompanied by alterations in redox metabolism, characterized by accumulation of reactive oxygen species (ROS). Elevated production of ROS, mostly by mitochondrial respiration, is counteracted by higher production of antioxidant defenses (mainly glutathione and antioxidant enzymes). Cancer cells are adapted to a high concentration of ROS, which contributes to tumorigenesis, metastasis formation, resistance to therapy and relapse. Frequent genetic alterations observed in pancreatic ductal adenocarcinoma (PDAC) affect KRAS and p53 proteins, which have a role in ROS production and control, respectively. These observations led to the proposal of the use of antioxidants to prevent PDAC development and relapse. In this review, we focus on the therapeutic strategies to further increase ROS level to induce PDAC cell death. Combining the promotion of ROS production and inhibition of antioxidant capacity is a promising avenue for pancreatic cancer therapy in the clinic.

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Hobbs, Guy Aaron, Rachel Burge, Amanda Linke, Kamala Sundararaj et John P. O'Bryan. « Abstract B057 : KRAS mutant-specific protein interactions reveal mechanisms in pancreatic cancer tumorigenesis and metabolic regulation ». Cancer Research 82, n^o 22_Supplement (15 novembre 2022) : B057. http://dx.doi.org/10.1158/1538-7445.panca22-b057.

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Abstract Pancreatic ductal adenocarcinoma (PDAC) is the third most deadly human cancer in the US with a five-year survival rate of 11%. KRAS is mutated in over 95% of PDAC patients and is a key driver of tumorigenesis. Despite the promise of targeted inhibition of the RAF-MEK-ERK MAPK signaling pathway, arguably the most critical KRAS-mediated signaling pathway, clinical trials targeting MEK/ERK signaling as a single-agent therapy have been unsuccessful, indicating the role of additional KRAS-specific signaling pathways. The most frequent KRAS mutations in PDAC are KRAS G12D (40%), KRAS G12V (33%) and KRAS G12R (17%). However, the KRAS G12R mutation is rare in lung and colorectal cancers (<1%), suggesting the presence of KRAS mutant-specific signaling, which remains poorly understood. While mutagenic processes may drive the observed mutation frequency data, many studies have demonstrated that mutant KRAS protein signaling drives the overall observed mutational frequencies. In agreement with this observation, the KRAS Q61L mutant is predicted to occur in PDAC but is rarely detected in the patient population. Therein, we hypothesize that mutation-specific signaling promotes tumorigenesis and that determination of the KRAS mutant-specific interactomes that promote pancreatic tumorigenesis in KRAS G12R yet hinder oncogenic fitness in KRAS Q61L will provide insight into the development of KRAS mutation-selective therapies in PDAC. Thus, we used doxycycline-inducible KRAS constructs combined with BioID proximity labeling to determine the mutant-selective interactomes of four KRAS mutant proteins in an isogenic immortalized pancreatic cell line. While we detected significant overlap in effector signaling, numerous mutant-selective differences were detected, including pathways regulating endocytosis and autophagy. Interestingly, the PDAC tumor microenvironment has been shown to have limited nutrient availability, which promotes macropinocytosis, the nonselective uptake of proteins and molecules from extracellular spaces, and autophagy, a mode of cellular recycling, to promote tumor proliferation. To replicate this environment in cell culture, we utilized a minimal glucose medium supplemented with albumin, a large protein that is absorbed via macropinocytosis. We show that this altered cell culture medium preferentially drives increased macropinocytosis and resistance to MEK MAPK and autophagy inhibition in KRAS G12R-mutant PDAC. Furthermore, while KRAS G12R PDAC cell lines continue to proliferate in the absence of glucose, many KRAS G12D mutant PDAC cell lines fail to sustain proliferation. To determine alternative potential therapeutic vulnerabilities, we have performed an RNA sequencing screen in high and low glucose medium, which has exposed an increase in receptor tyrosine kinase signaling and a reprogramming of metabolic processes in the tricarboxylic acid cycle. These studies provide a rationale for the limited success of MEK/ERK therapies in the clinic and we propose novel treatment strategies for KRAS G12R PDAC patients with elevated macropinocytosis. Citation Format: Guy Aaron Hobbs, Rachel Burge, Amanda Linke, Kamala Sundararaj, John P. O'Bryan. KRAS mutant-specific protein interactions reveal mechanisms in pancreatic cancer tumorigenesis and metabolic regulation [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B057.

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Hwang, Elizabeth E., Alex Lee, Stanley Leung, Marcus Breese et Alejandro Sweet-Cordero. « Abstract 1107 : Notch activation drives resistance to Kras(G12C) inhibition in lung adenocarcinoma ». Cancer Research 82, n^o 12_Supplement (15 juin 2022) : 1107. http://dx.doi.org/10.1158/1538-7445.am2022-1107.

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Abstract Approximately one-third of lung adenocarcinoma (LUAD) tumors contain driver mutations in the Kras GTPase, most commonly occurring as Kras(G12C) activating mutations. Despite the promising development of covalent G12C small molecule inhibitors, early-phase clinical trial data indicate most patients will likely demonstrate disease progression through either intrinsic or acquired resistance. Thus, there is an urgent need to identify such resistance mechanisms to targeting Kras. Our lab previously discovered a unique requirement for Notch3 in tumor-propagating cells from the KrasLSL-G12D p53fl/fl LUAD mouse model as well as in patient-derived xenografts. Here we report activated Notch3 as a novel driver of resistance to Kras(G12C) inhibition in LUAD cell lines. Aiming to study the Notch3 transcriptional signature in LUAD, we developed an inducible model of Notch3 intracellular domain (NICD) expression in Kras-mutant LUAD cell lines. Our data demonstrate that activated NICD modulates downstream RTK signaling pathways to suppress both cell cycle arrest and apoptosis in response to G12C inhibitor treatment. We subsequently performed RNA-sequencing to identify Notch-dependent genes driving resistance and in parallel, used Cut&Run technology to interrogate the global chromatin binding profiles of Notch3 and associated histone marks in NICD-expressing cell lines. We integrate our transcriptomic and epigenomic data to reveal that NICD acts as a key regulator of Rho family genes, which in turn support cell survival upon Kras inhibition. We additionally find enrichment of cell division and morphological signatures in inhibitor treated NICD cell lines and we elucidate the mechanism of direct Notch target genes in mediating the apoptotic response. Finally, we conduct a focused in vitro CRISPRi screen in the H358 LUAD cell line to identify the subset of Notch target genes required for NICD-induced resistance. Our results define a Notch3 transcriptional landscape in LUAD and demonstrate a role for Notch signaling in promoting resistance to small molecule Kras inhibitors. Citation Format: Elizabeth E. Hwang, Alex Lee, Stanley Leung, Marcus Breese, Alejandro Sweet-Cordero. Notch activation drives resistance to Kras(G12C) inhibition in lung adenocarcinoma [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 1107.

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Gao, Shuai, Fangxia Zou, Lixia Zheng, Yunjie Wang, Xinyu Feng, Deshuai Liu, Yutong Mao, Liang Ye et Jingwei Tian. « Efficacy and mechanism of KRAS G12C PROTAC in inhibiting the proliferation of pancreatic cancer cells ». Journal of Pharmaceutical and Biopharmaceutical Research 3, n^o 1 (2022) : 176–84. http://dx.doi.org/10.25082/jpbr.2021.01.002.

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Pancreatic cancer is a rare but highly malignant cancer with few effective treatments available. Targeting cancers bearing specific genetic mutations offers a new approach for cancer therapy. PROTAC (proteolysis-targeting chimeras) is an emerging technique to design targeted therapy and increasing evidence supports its utility. This study examined the in vitro pharmacodynamics and mechanism of PROTAC K-Ras Degrader-1 (PKD-1), a PROTAC molecule, in inhibiting the proliferation of pancreatic cancer cells. We used a pancreatic cancer cell line, MIA PaCa-2 cells, to examined the binding and degradation-promoting capabilities of PKD-1 on KRAS G12C protein and further evaluated the effects of PKD-1 on cell viability, cell cycle and apoptosis. PKD-1 was able to bind to KRAS G12C protein, promoted its degradation for up to 72 h, reduced cell viability, increased cell cycle arrest and promoted cell apoptosis. Mechanistic study found that the efficacy of PKD-1 was at least partially mediated by promoting 26S proteasome degradation process. Combined, these results extended previous findings and support the potential utility of PROTAC molecules such as PKD-1 as a new treatment strategy against pancreatic cancer.

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Baldelli, Elisa, Emna El Gazzah, John Conor Moran, Kimberley A. Hodge, Zarko Manojlovic, Rania Bassiouni, John D. Carpten et al. « Wild-Type KRAS Allele Effects on Druggable Targets in KRAS Mutant Lung Adenocarcinomas ». Genes 12, n^o 9 (11 septembre 2021) : 1402. http://dx.doi.org/10.3390/genes12091402.

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KRAS mutations are one of the most common oncogenic drivers in non-small cell lung cancer (NSCLC) and in lung adenocarcinomas in particular. Development of therapeutics targeting KRAS has been incredibly challenging, prompting indirect inhibition of downstream targets such as MEK and ERK. Such inhibitors, unfortunately, come with limited clinical efficacy, and therefore the demand for developing novel therapeutic strategies remains an urgent need for these patients. Exploring the influence of wild-type (WT) KRAS on druggable targets can uncover new vulnerabilities for the treatment of KRAS mutant lung adenocarcinomas. Using commercially available KRAS mutant lung adenocarcinoma cell lines, we explored the influence of WT KRAS on signaling networks and druggable targets. Expression and/or activation of 183 signaling proteins, most of which are targets of FDA-approved drugs, were captured by reverse-phase protein microarray (RPPA). Selected findings were validated on a cohort of 23 surgical biospecimens using the RPPA. Kinase-driven signatures associated with the presence of the KRAS WT allele were detected along the MAPK and AKT/mTOR signaling pathway and alterations of cell cycle regulators. FoxM1 emerged as a potential vulnerability of tumors retaining the KRAS WT allele both in cell lines and in the clinical samples. Our findings suggest that loss of WT KRAS impacts on signaling events and druggable targets in KRAS mutant lung adenocarcinomas.

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Ferreira, Anabela, Flávia Pereira, Celso Reis, Maria José Oliveira, Maria João Sousa et Ana Preto. « Crucial Role of Oncogenic KRAS Mutations in Apoptosis and Autophagy Regulation : Therapeutic Implications ». Cells 11, n^o 14 (13 juillet 2022) : 2183. http://dx.doi.org/10.3390/cells11142183.

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KRAS, one of the RAS protein family members, plays an important role in autophagy and apoptosis, through the regulation of several downstream effectors. In cancer cells, KRAS mutations confer the constitutive activation of this oncogene, stimulating cell proliferation, inducing autophagy, suppressing apoptosis, altering cell metabolism, changing cell motility and invasion and modulating the tumor microenvironment. In order to inhibit apoptosis, these oncogenic mutations were reported to upregulate anti-apoptotic proteins, including Bcl-xL and survivin, and to downregulate proteins related to apoptosis induction, including thymine-DNA glycosylase (TDG) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). In addition, KRAS mutations are known to induce autophagy in order to promote cell survival and tumor progression through MAPK and PI3K regulation. Thus, these mutations confer resistance to anti-cancer drug treatment and, consequently, result in poor prognosis. Several therapies have been developed in order to overcome KRAS-induced cell death resistance and the downstream signaling pathways blockade, especially by combining MAPK and PI3K inhibitors, which demonstrated promising results. Understanding the involvement of KRAS mutations in apoptosis and autophagy regulation, might bring new avenues to the discovery of therapeutic approaches for CRCs harboring KRAS mutations.

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Lenz, Heinz-Josef, Daniel H. Ahn, Maya Ridinger, Mark G. Erlander et Afsaneh Barzi. « A phase Ib/II study of onvansertib (PCM-075) in combination with FOLFIRI and bevacizumab for second-line treatment of metastatic colorectal cancer (mCRC) in patients with a KRAS mutation. » Journal of Clinical Oncology 38, n^o 4_suppl (1 février 2020) : TPS265. http://dx.doi.org/10.1200/jco.2020.38.4_suppl.tps265.

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TPS265 Background: FOLFOX (5-flourouracil, leucovorin, oxaliplatin) and FOLFIRI (fluorouracil, leucovorin, irinotecan) in combination with targeted agents are standard-of-care options for patients for mCRC with response rates >50% in first line. In the second line setting, efficacy of chemotherapy and targeted agents are much lower with response rates of 4% for FOLFIRI + bevacizumab and treatment options are limited in particular for the 50% of patients harboring a RAS mutation. Polo-like kinase 1 (PLK1) is a serine/threonine kinase, master regulator of G2/M cell-cycle progression and genome wide RNAi screens identified PLK1 to be synthetic lethal for KRAS mutated tumor cells inducing cell cycle arrest and apoptosis. Onvansertib is an oral, highly selective PLK1 inhibitor that demonstrated single agent activity and synergistic activity with irinotecan in preclinical CRC models. Additionally, KRAS mutated cells showed higher sensitivity to onvansertib than isogenic KRAS wild-type cells. PLK1 inhibition is a potential target in KRAS-mutated mCRC and onvansertib + FOLFIRI may provide a new second-line treatment option. Methods: The primary objective of this single-arm Phase 1b/2 study (NCT03829410) is to assess the safety and preliminary efficacy of onvansertib in combination with FOLFIRI and bevacizumab in the second line setting for KRAS-mutated mCRC patients. The phase 1b will determine the MTD or RP2D using a traditional 3+3 design, with onvansertib initial dose at 12 mg/m2. The phase 2 will enroll 26 patients at the RP2D to further assess the safety of the combination and to evaluate preliminary anti-tumor activity measured by objective response rate (ORR, RECIST v1.1). Based on a one-sided one sample log-rank test with 10% Type I error, there will be at least 90% power to detect an improvement in ORR from 5% to 20% with 26 patients. Exploratory studies include quantitation of KRAS circulating tumor DNA (ctDNA) and genomic studies of circulating tumor cells and ctDNA to determine altered pathways associated with patient response. Clinical trial information: NCT03829410.

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Muyinda, Isaac James, Jae-Gwang Park, Eun-Jung Jang et Byong-Chul Yoo. « KRAS, A Prime Mediator in Pancreatic Lipid Synthesis through Extra Mitochondrial Glutamine and Citrate Metabolism ». International Journal of Molecular Sciences 22, n^o 10 (11 mai 2021) : 5070. http://dx.doi.org/10.3390/ijms22105070.

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Kirsten rat sarcoma viral oncogene homolog (KRAS)-driven pancreatic cancer is very lethal, with a five-year survival rate of <9%, irrespective of therapeutic advances. Different treatment modalities including chemotherapy, radiotherapy, and immunotherapy demonstrated only marginal efficacies because of pancreatic tumor specificities. Surgery at the early stage of the disease remains the only curative option, although only in 20% of patients with early stage disease. Clinical trials targeting the main oncogenic driver, KRAS, have largely been unsuccessful. Recently, global metabolic reprogramming has been identified in patients with pancreatic cancer and oncogenic KRAS mouse models. The newly reprogrammed metabolic pathways and oncometabolites affect the tumorigenic environment. The development of methods modulating metabolic reprogramming in pancreatic cancer cells might constitute a new approach to its therapy. In this review, we describe the major metabolic pathways providing acetyl-CoA and NADPH essential to sustain lipid synthesis and cell proliferation in pancreatic cancer cells.

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Redding, Alexandra, Guillaume Fonteneau et Elda Grabocka. « Abstract B079 : Unfolding the role of cell state on stress granule heterogeneity and function in pancreatic cancer ». Cancer Research 82, n^o 22_Supplement (15 novembre 2022) : B079. http://dx.doi.org/10.1158/1538-7445.panca22-b079.

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Abstract Phenotypic and functional heterogeneity is a common feature of cancer cells that poses as a major therapeutic challenge. Previous work has implicated the phase-separation organelles, stress granules (SGs), as important mediators of tumorigenesis that function as a mutant KRAS-driven stress-adaptive mechanism to enhance cellular fitness. We have found that mutant KRAS pancreatic cancer cells show a high degree of intra-cellular heterogeneity in SG formation, ranging from no SGs to markedly high levels. Given the function of SGs in cancer cell fitness and the role of cancer cell heterogeneity in tumor progression and therapeutic response, we sought to understand the determinants of SG heterogeneity and its role in KRAS-driven tumorigenesis. Here, we show that the capability of KRAS mutant pancreatic cancer cells to form SGs is dependent on the cell cycle state, with cells in G2 phase showing markedly enhanced SG formation. We demonstrate that this heterogeneity in SG formation is determined by a cell cycle specific interplay between the activator of cell death, Caspase 3, and the SG regulator molecule 15-deoxy-delta-12,14-prostaglandin J2 (15-d-PGJ2). We show that 15-d-PGJ2 production in G2 is driven by calcium-dependent phospholipase A2 (cPLA2) activity and is subject to regulation by Caspase 3. Our results show that the capacity of Caspase 3 to cleave and inactivate the cPLA2 protein is specifically suppressed in G2, thus leading to upregulation of cPLA2 activity and 15-d-PGJ2 levels. As such, we find that 15d-PGJ2 levels are highest in G2 and that the inhibition of cPLA2 blocks SG formation in G2 specifically. Accordingly, exogenous 15d-PGJ2 rescues SG formation in cPLA2-inhibited G2 cells. In addition, we demonstrate that Caspase 3 inhibition increases 15-d-PGJ2 levels and stimulates SG formation in asynchronous cells, mirroring the natural suppression of Caspase 3 seen in G2. Importantly, we show that heterogeneity in SG levels translates into a functional heterogeneity whereby SG inhibition preferentially sensitizes cells in G2 to stress stimuli. Altogether these data support a model whereby SG formation integrates cues from cell death and proliferative signals and indicate that SG levels may be critical to achieve a clear signal for cell cycle progression at the G2/M border. Furthermore, our findings suggest that cancer cells may show differential sensitivity to anti-SG therapy as they progress through the cell cycle, and pairing such therapy with G2-synchronizing chemotherapeutics may increase susceptibility and thus treatment efficacy. Citation Format: Alexandra Redding, Guillaume Fonteneau, Elda Grabocka. Unfolding the role of cell state on stress granule heterogeneity and function in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B079.

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Kano, Yoshihito, Teklab Gebregiworgis, Christopher B. Marshall, Nikolina Radulovich, Betty P. Poon, Zhong-Yin Zhang, Ming-Sound Tsao, Mitsuhiko Ikura et Michael Ohh. « 833 - Tyrosyl Phosphorylation of Kras Disrupts the Gtpase Cycle and Inhibits Pancreatic Cancer Cell Growth ». Gastroenterology 154, n^o 6 (mai 2018) : S—173. http://dx.doi.org/10.1016/s0016-5085(18)30991-0.

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Rozeveld, Cody N., Katherine M. Johnson, Lizhi Zhang et Gina L. Razidlo. « KRAS Controls Pancreatic Cancer Cell Lipid Metabolism and Invasive Potential through the Lipase HSL ». Cancer Research 80, n^o 22 (19 août 2020) : 4932–45. http://dx.doi.org/10.1158/0008-5472.can-20-1255.

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Kalvala, Arjun, Pierre Wallet, Lu Yang, Chongkai Wang, Haiqing Li, Arin Nam, Anusha Nathan et al. « Phenotypic Switching of Naïve T Cells to Immune-Suppressive Treg-Like Cells by Mutant KRAS ». Journal of Clinical Medicine 8, n^o 10 (18 octobre 2019) : 1726. http://dx.doi.org/10.3390/jcm8101726.

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Oncogenic (mutant) Ras protein Kirsten rat sarcoma viral oncogene homolog (KRAS) promotes uncontrolled proliferation, altered metabolism, and loss of genome integrity in a cell-intrinsic manner. Here, we demonstrate that CD4+ T cells when incubated with tumor-derived exosomes from mutant (MT) KRAS non-small-cell lung cancer (NSCLC) cells, patient sera, or a mouse xenograft model, induce phenotypic conversion to FOXP3+ Treg-like cells that are immune-suppressive. Furthermore, transfecting T cells with MT KRAS cDNA alone induced phenotypic switching and mathematical modeling supported this conclusion. Single-cell sequencing identified the interferon pathway as the mechanism underlying the phenotypic switch. These observations highlight a novel cytokine-independent, cell-extrinsic role for KRAS in T cell phenotypic switching. Thus, targeting this new class of Tregs represents a unique therapeutic approach for NSCLC. Since KRAS is the most frequently mutated oncogene in a wide variety of cancers, the findings of this investigation are likely to be of broad interest and have a large scientific impact.

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O'Hara, Mark H., Christine Edmonds, Michael Farwell, Rodolfo F. Perini, Daniel A. Pryma, Ursina R. Teitelbaum, Bruce J. Giantonio et al. « Phase II pharmacodynamic trial of palbociclib in patients with KRAS mutant colorectal cancer. » Journal of Clinical Oncology 33, n^o 3_suppl (20 janvier 2015) : 626. http://dx.doi.org/10.1200/jco.2015.33.3_suppl.626.

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626 Background: Cell cycle dysregulation is a hallmark of most cancers. At the G1/S transition, cyclin dependent kinase (CDK) 4 and CDK 6 proteins associate with cyclin D proteins to allow cell cycle progression. Tumor cells that are driven by abnormalities of the cell cycle through activation of the cdk4/6-cyclin D axis showed increased phosphorylation of retinoblastoma protein (Rb), the major substrate for CDKs at the G1/S transition. Palbociclib is a potent specific inhibitor of cdk 4/6, with preclinical data showing G1 arrest in Rb-positive cells. Since activation of the MAP kinase pathway impacts directly on cdk-cyclin activation, we performed a phase II trial of palbociclib in patients with metastatic, KRAS-mutant colorectal cancer (mCRC). Methods: We screened 36 patients with KRAS mutant mCRC for Rb expression and 35 (97%) were Rb positive. We enrolled 15 patients, 9 (60%) of which were male and 6 (40%) female, median age was 62, 10 (67%) colon, 4 (27%) rectal (27%) rectal, and 1 (7%) appendiceal malignancy. Patients received 125mg daily of palbociclib for 21 days of a 28-day cycle, the recommended phase II dose. Results: Six patients (33%) experienced grade 3 neutropenia, 1 patient had grade 3 neutropenic fever (6%), and 2 patients (11%) had grade 3 AST/ALT elevation. There were no responses, but 5 patients (33%) had stable disease by RECIST criteria after 2 cycles of treatment, and 1 patient had stable disease for 8 cycles. The median number of cycles was two. As a pharmacodynamic marker of activity, 9 patients underwent FLT-PET at baseline and after 1 cycle of therapy. FLT-PET uses the tracer 3’-deoxy-3’[18F]-fluorothymidine, uptake of which is proportional to cellular proliferation. Six of the 9 patients (67%) had a decrease in uptake in target lesions, with an average 20% decrease in uptake in target lesions. FLT uptake in the bone marrow decreased by an average 4.85% and this correlated with a decrease in absolute neutrophil count of 62.3% (r2 0.59). Conclusions: While palbociclib has limited activity in KRAS mutant mCRC as a single agent, there is a clear pharmacodynamic effect as determined by FLT-PET imaging. Given the limited toxicity profile, combinations with non-myelosuppressive agents hold great promise. Clinical trial information: NCT01037790.

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Subhi Ramadhan, Rehab, et Rebah Najah Jabbar AL-Gafari. « New Finding in KRAS Mutated Structure Detected in Colorectal Cancer CRC Tumors Causing Uncontrolled Cell Proliferation in Iraqi Patients ». International Journal of Engineering & ; Technology 7, n^o 4.37 (13 décembre 2018) : 1. http://dx.doi.org/10.14419/ijet.v7i4.37.23603.

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A total 200 tumor samples were collected from patients suffering from colorectal CRC at Al-Amal hospital. Their ages ranged from 40 – 70 years old and distributed according to gender as 130 male and 70 female. We found that CRC was more common in male than female, and more frequent in elderly persons especially in age group of 61 – 70 years old. From 12 specifically designed primers that were able to amplify KRAS gene in those patients’ blood samples, only 2 gave a specific band when tumor sample was used. Molecular analysis of the sequence obtained from those two primers showed the presence of 83 missense mutations in both of them, 20 in the first sequence were associated with pathogenic effect on KRAS gene, 3 frame shift, and 3 insertions, while in the second sequence obtained from primer PK2 4 frame shift mutations, and 4 insertions were identified. The impact finding is that in both sequences, open reading frames (ORFs) were developed that affected cell proliferation dramatically and produced truncated functionless proteins causing KRAS to cease control over cell cycle.

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Ma, Yu, Sunkai Ling, Yuan Li, Mingyue Hu, Bo Kong, Peilin Huang et Hui Liu. « Loss of Heterozygosity for KrasG12D Promotes Malignant Phenotype of Pancreatic Ductal Adenocarcinoma by Activating HIF-2α-c-Myc-Regulated Glutamine Metabolism ». International Journal of Molecular Sciences 23, n^o 12 (15 juin 2022) : 6697. http://dx.doi.org/10.3390/ijms23126697.

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Loss of heterozygosity (LOH) for KRAS, in which a wild-type KRAS allele is progressively lost, promotes invasive and migratory abilities of pancreatic ductal adenocarcinoma (PDAC) cells and tissues. Moreover, the occurrence of KrasG12D-LOH activates nonclassical glutamine metabolism, which is related to the malignant behavior of PDAC cells. Herein, we aim to demonstrate the regulatory link between hypoxia-inducible factor-2α (HIF-2α) and glutamine metabolism that mediates malignant phenotypes in KrasG12D-LOH PDAC cells. HIF-2α-shRNA knockdown lentivirus transfection and metabolite analysis were performed in KrasG12D-LOH and KrasG12D cell lines, respectively. Cell proliferation, migration, and invasion were examined using Cell Counting Kit-8, colony formation, and Transwell assays. Cell cycle phase and apoptosis were determined using flow cytometry. Western blotting and real-time quantitative PCR were also performed. Additionally, a subcutaneous xenograft mouse model was established. LOH stimulated HIF-2α activity and transactivated c-Myc, which has a central regulatory effect on glutamine metabolism independent of hypoxia. Meanwhile, HIF-2α silencing repressed KrasG12D-LOH PDAC cell proliferation, invasion, and migration. HIF-2α knockdown inhibited glutamine uptake and GOT1 expression via a c-Myc-dependent pathway. Collectively, KrasG12D-LOH can activate HIF-2α to regulate c-Myc-mediated glutamine metabolism and promote malignant phenotypes. Moreover, targeting HIF-2α-c-Myc regulated nonclassical glutamine metabolism, providing a new therapeutic perspective for KrasG12D-LOH PDAC.

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Rulli, Eliana, Mara Serena Serafini, Mirko Marabese, Elisa Caiola, Gabriella Sozzi, Massimo Moro, Emilio Bria et al. « Co-existance of KRAS and LKB1 mutation as predictor of resistance to Erlotinib : Customized next-generation sequencing (NGS) of TAILOR trial. » Journal of Clinical Oncology 35, n^o 15_suppl (20 mai 2017) : e20631-e20631. http://dx.doi.org/10.1200/jco.2017.35.15_suppl.e20631.

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e20631 Background: The prognostic and predictive value of KRAS mutation in advanced NSCLC is still debatable. In TAILOR (NCT00637910) trial EGFR wild-type patients were randomized to receive 2nd line erlotinib versus docetaxel, and no interaction was detected according to KRAS mutational status. Recent evidences indicate that the concurrent mutation of KRAS and LKB1 (key factor for cell metabolism) may be associated with worse prognosis. Methods: Availableformalin-fixed embeddedtissue samples with annotated clinical data from TAILOR were gathered. Customized deep sequencing (Ion proton Technology) of 111 genes most frequently associated with cancer, was performed; 5% of frequency was used to identify mutations. Association between genes and clinical features was performed with non-parametric tests; Cox regression analysis was used to assess the prognostic and predictive value of LKB1. Results: 123 out of 222 (55%) randomized patients had available tissue and were successfully sequenced. 42/123 (34%) patients had a KRAS mutation. KRAS and LKB1 mutations were found in 11/42 (26%) KRAS patients, while only 6 patients had a LKB1 mutation without KRAS. The presence of a concurrent KRAS-LKB1 mutation did not adversely influence progression-free (PFS) or overall (OS) survival [hazard ratio (HR) PFS 1.08, 95% confidence interval (CI) 0.57-2.05, P = 0.81; OS 1.09, 95% CI 0.56-2.14, P = 0.78]. Patients receiving docetaxel experienced longer survival regardless of the KRAS-LKB1 mutational status (mutated KRAS-LKB1 HR 0.42, 95% CI 0.08-2.29; wild-type KRAS-LKB1 HR 1.16, 95% CI 0.72-1.87, P = 0.55; interaction P = 0.10). Conclusions: Although the significant attrition and the limited number, these data generate the hypothesis that the concurrent mutation of KRAS and LKB1 may potentially be associated with resistance to erlotinib. Overall, the coexistence of mutation in KRAS and LKB1 is not associated with worse prognosis in NSCLC. For these patients refractory to EGFR targeting, metabolic strategies represent a future research opportunity.

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Hood, Fiona E., Bertram Klinger, Anna U. Newlaczyl, Anja Sieber, Mathurin Dorel, Simon P. Oliver, Judy M. Coulson, Nils Blüthgen et Ian A. Prior. « Isoform-specific Ras signaling is growth factor dependent ». Molecular Biology of the Cell 30, n^o 9 (15 avril 2019) : 1108–17. http://dx.doi.org/10.1091/mbc.e18-10-0676.

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HRAS, NRAS, and KRAS isoforms are almost identical proteins that are ubiquitously expressed and activate a common set of effectors. In vivo studies have revealed that they are not biologically redundant; however, the isoform specificity of Ras signaling remains poorly understood. Using a novel panel of isogenic SW48 cell lines endogenously expressing wild-type or G12V-mutated activated Ras isoforms, we have performed a detailed characterization of endogenous isoform-specific mutant Ras signaling. We find that despite displaying significant Ras activation, the downstream outputs of oncogenic Ras mutants are minimal in the absence of growth factor inputs. The lack of mutant KRAS-induced effector activation observed in SW48 cells appears to be representative of a broad panel of colon cancer cell lines harboring mutant KRAS. For MAP kinase pathway activation in KRAS-mutant cells, the requirement for coincident growth factor stimulation occurs at an early point in the Raf activation cycle. Finally, we find that Ras isoform-specific signaling was highly context dependent and did not conform to the dogma derived from ectopic expression studies.

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Maertin, Sandrina, Jason M. Elperin, Ethan Lotshaw, Matthias Sendler, Steven D. Speakman, Kazuki Takakura, Benjamin M. Reicher et al. « Roles of autophagy and metabolism in pancreatic cancer cell adaptation to environmental challenges ». American Journal of Physiology-Gastrointestinal and Liver Physiology 313, n^o 5 (1 novembre 2017) : G524—G536. http://dx.doi.org/10.1152/ajpgi.00138.2017.

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Pancreatic ductal adenocarcinoma (PDAC) displays extensive and poorly vascularized desmoplastic stromal reaction, and therefore, pancreatic cancer (PaCa) cells are confronted with nutrient deprivation and hypoxia. Here, we investigate the roles of autophagy and metabolism in PaCa cell adaptation to environmental stresses, amino acid (AA) depletion, and hypoxia. It is known that in healthy cells, basal autophagy is at a low level, but it is greatly activated by environmental stresses. By contrast, we find that in PaCa cells, basal autophagic activity is relatively high, but AA depletion and hypoxia activate autophagy only weakly or not at all, due to their failure to inhibit mechanistic target of rapamycin. Basal, but not stress-induced, autophagy is necessary for PaCa cell proliferation, and AA supply is even more critical to maintain PaCa cell growth. To gain insight into the underlying mechanisms, we analyzed the effects of autophagy inhibition and AA depletion on PaCa cell metabolism. PaCa cells display mixed oxidative/glycolytic metabolism, with oxidative phosphorylation (OXPHOS) predominant. Both autophagy inhibition and AA depletion dramatically decreased OXPHOS; furthermore, pharmacologic inhibitors of OXPHOS suppressed PaCa cell proliferation. The data indicate that the maintenance of OXPHOS is a key mechanism through which autophagy and AA supply support PaCa cell growth. We find that the expression of oncogenic activation mutation in GTPase Kras markedly promotes basal autophagy and stimulates OXPHOS through an autophagy-dependent mechanism. The results suggest that approaches aimed to suppress OXPHOS, particularly through limiting AA supply, could be beneficial in treating PDAC. NEW & NOTEWORTHY Cancer cells in the highly desmoplastic pancreatic ductal adenocarcinoma confront nutrient [i.e., amino acids (AA)] deprivation and hypoxia, but how pancreatic cancer (PaCa) cells adapt to these conditions is poorly understood. This study provides evidence that the maintenance of mitochondrial function, in particular, oxidative phosphorylation (OXPHOS), is a key mechanism that supports PaCa cell growth, both in normal conditions and under the environmental stresses. OXPHOS in PaCa cells critically depends on autophagy and AA supply. Furthermore, the oncogenic activation mutation in GTPase Kras upregulates OXPHOS through an autophagy-dependent mechanism.

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Lindholm, Heléne, Katarina Ejeskär et Ferenc Szekeres. « Digitoxin Affects Metabolism, ROS Production and Proliferation in Pancreatic Cancer Cells Differently Depending on the Cell Phenotype ». International Journal of Molecular Sciences 23, n^o 15 (26 juillet 2022) : 8237. http://dx.doi.org/10.3390/ijms23158237.

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Digitoxin has repeatedly shown to have negative effects on cancer cell viability; however, the actual mechanism is still unknown. In this study, we investigated the effects of digitoxin (1–100 nM) in four pancreatic cancer cell lines, BxPC-3, CFPAC-1, Panc-1, and AsPC-1. The cell lines differ in their KRAS/BRAF mutational status and primary tumor or metastasis origin. We could detect differences in the basal rates of cell proliferation, glycolysis, and ROS production, giving the cell lines different phenotypes. Digitoxin treatment induced apoptosis in all four cell lines, but to different degrees. Cells derived from primary tumors (Panc-1 and BxPC-3) were highly proliferating with a high proportion of cells in the S/G2 phase, and were more sensitive to digitoxin treatment than the cell lines derived from metastases (CFPAC-1 and AsPC-1), with a high proportion of cells in G0/G1. In addition, the effects of digitoxin on the rate of glycolysis, ROS production, and proliferation were dependent on the basal metabolism and origin of the cells. The KRAS downstream signaling pathways were not altered by digitoxin treatment, thus the effects exerted by digitoxin were probably disconnected from these signaling pathways. We conclude that digitoxin is a promising treatment in highly proliferating pancreatic tumors.

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Nishio, Kazuto, Kazuko Sakai, Takashi Seto, Makoto Nishio, Edward B. Garon, Martin Reck, Koichi Goto et al. « RELAY study of erlotinib (ERL) + ramucirumab (RAM) or placebo (PL) in EGFR-mutated metastatic non-small cell lung cancer (NSCLC) : Biomarker analysis using circulating tumor DNA (ctDNA) in Japanese patients (pts). » Journal of Clinical Oncology 38, n^o 15_suppl (20 mai 2020) : 9527. http://dx.doi.org/10.1200/jco.2020.38.15_suppl.9527.

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9527 Background: The phase III RELAY study (NCT02411448) showed significantly improved progression-free survival (PFS) for RAM+ERL vs PL+ERL in 449 pts with previously untreated EGFR mutation-positive metastatic NSCLC (median PFS 19.4 vs 12.4 mo, HR 0.591 [95% CI 0.461–0.760], p<.0001). To understand baseline genetic mutations and treatment-emergent (TE) resistance mechanisms, this exploratory liquid biopsy substudy examined biomarkers in ctDNA from participating Japanese pts by next-generation sequencing (NGS) and droplet digital PCR (ddPCR). Methods: Plasma samples were collected at baseline, during treatment (Cycle 4, 13, and every 6 cycles to Cycle 53) and post-study treatment discontinuation (30-day follow-up [30d FU]). Mutations were assessed at baseline and 30d FU by NGS (Ion AmpliSeq Colon and Lung Cancer panel). EGFR mutations and MET and ERBB2 copy number (CN) were assessed at all time points by ddPCR. Baseline markers were analyzed in pts with any detectable baseline mutation (to confirm ctDNA presence; NGS N=84, ddPCR N=74). TE mutations were analyzed in pts with any detectable mutation at baseline and 30d FU (NGS N=26, ddPCR N=28). Among these pts, 81% and 57% for NGS and ddPCR, respectively, had progressed by 30d FU. Results: By plasma NGS, baseline EGFR activating mutations (exon 19 deletion or exon 21 [L858R] mutation) were detected in 83.3% of pts. Common co-occurring baseline mutations were TP53 (42.9%), PTEN (7.1%) and KRAS (6.0%). Baseline TP53 mutation rate was higher in men vs women (p=.02). No difference in PFS was detected by baseline TP53 status (interaction predictive p=.45, prognostic p=.33). TE mutations were detected in EGFR (including T790M), FGFR3, KRAS and TP53. Slightly higher rates of TE KRAS (p=.03) and TP53 (p=.07) mutations were detected in RAM+ERL than in PL+ERL. TE total EGFR mutations (p=.65) or TE T790M (p=.69) did not differ by arm. By ddPCR, baseline EGFR activating mutations were detected in all pts. T790M was detected at baseline in 2/37 pts/arm (5.4%) and was TE in 6/11 (55%) RAM+ERL pts and 7/17 (41%) PL+ERL pts. There was a trend (p=.054) for greater ERBB2 CN in RAM+ERL vs PL+ERL at Cycle 4. MET CN decreased slightly at Cycle 4 in both arms (significant in PL+ERL, p=.003). Biomarker levels by ddPCR across all time points will be presented. Conclusions: Though limited by sample size and likely inconsistent tumor shedding, this exploratory study identified potential differences in TP53, KRAS, ERBB2 and MET by demographics, treatment and/or time. Clinical trial information: NCT02411448 .

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Huang, Ching-Wen, Yen-Cheng Chen, Tzu-Chieh Yin, Po-Jung Chen, Tsung-Kun Chang, Wei-Chih Su, Cheng-Jen Ma, Ching-Chun Li, Hsiang-Lin Tsai et Jaw-Yuan Wang. « Low-Molecular-Weight Fucoidan as Complementary Therapy of Fluoropyrimidine-Based Chemotherapy in Colorectal Cancer ». International Journal of Molecular Sciences 22, n^o 15 (27 juillet 2021) : 8041. http://dx.doi.org/10.3390/ijms22158041.

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This study investigated the roles of low-molecular-weight fucoidan (LMWF) in enhancing the anti-cancer effects of fluoropyrimidine-based chemotherapy. HCT116 and Caco-2 cells were treated with LMWF and 5-FU. Cell viability, cell cycle, apoptosis, and migration were analyzed in both cell types. Potential mechanisms underlying how LMWF enhances the anti-cancer effects of fluoropyrimidine-based chemotherapy were also explored. The cell viability of HCT116 and Caco-2 cells was significantly reduced after treatment with a LMWF-–5FU combination. In HCT116 cells, LMWF enhanced the suppressive effects of 5-FU on cell viability through the (1) induction of cell cycle arrest in the S phase and (2) late apoptosis mediated by the Jun-N-terminal kinase (JNK) signaling pathway. In Caco-2 cells, LMWF enhanced the suppressive effects of 5-FU on cell viability through both the c-mesenchymal–epithelial transition (MET)/Kirsten rat sarcoma virus (KRAS)/extracellular signal-regulated kinase (ERK) and the c-MET/phosphatidyl-inositol 3-kinases (PI3K)/protein kinase B (AKT) signaling pathways. Moreover, LMWF enhanced the suppressive effects of 5-FU on tumor cell migration through the c-MET/matrix metalloproteinase (MMP)-2 signaling pathway in both HCT116 and Caco-2 cells. Our results demonstrated that LMWF is a potential complementary therapy for enhancing the efficacies of fluoropyrimidine-based chemotherapy in colorectal cancers (CRCs) with the wild-type or mutated KRAS gene through different mechanisms. However, in vivo studies and in clinical trials are required in order to validate the results of the present study.

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Kim, Daniel Myung, Francesca Paola Aguirre, Alexandra Gangi, Rocio Alvarez, Lisa Zhou, Johanna ten Hoeve, Yi Jou Liao et al. « Plasma central carbon metabolite changes associated with KRAS mutation and circulating tumor DNA (ctDNA) status in colorectal cancer (CRC). » Journal of Clinical Oncology 41, n^o 4_suppl (1 février 2023) : 181. http://dx.doi.org/10.1200/jco.2023.41.4_suppl.181.

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181 Background: KRAS mutations have been widely characterized as markers of poor prognosis in CRC. In stage IV CRC, KRAS mutations are predictive of benefit to anti-EGFR therapy. ctDNA has increasingly been recognized as a prognostic biomarker in CRC as well. We evaluated the association between plasma metabolites and KRAS mutation or ctDNA status in a longitudinal, observational cohort of patients with stage I-IV CRC. Methods: This was a retrospective analysis of prospectively collected blood samples from a single-institute cohort of patients with stage I-IV CRC. All blood samples were collected at pre-chemotherapy baseline. A modified Epi proColon 2.0 CE (Epigenomics AG) assay was used for plasma ctDNA testing on the methylated SEPTIN9 gene (mSEPT9). ctDNA positivity was defined as a mSEPT9 percentage of methylation reference (PMR) value greater than zero. Up to 150 metabolites of central carbon metabolism were analyzed by mass spectrometry and high-performance liquid chromatography. Analytes were compared by relative area under the curve (AUC) and differences evaluated by ANOVA. The mean AUC was used in patients with metabolites measured from > 1 timepoint of collection. Patients were stratified by ctDNA status (positive or negative) and KRAS mutant (MT) or wildtype (WT) status. Results: A total of 32 patients were included with median age 65 years (range 20-90). The majority were female (53%) and had stage IV disease (78%). Of 25 patients with stage IV CRC, 88% had pre-chemotherapy blood samples collected in the first-line setting. Most patients were KRAS MT (44%) compared to KRAS WT (37%) or unknown KRAS status (19%). The most common KRAS MT subtypes were G12D (29%), G12V (29%), G13D (21%), and G12C (14%). The mean overall survival in this cohort was 27.4 months while the mean mSEPT9 PMR value was 2553.6. When stratified by ctDNA status, ctDNA positivity was associated with decreased levels of essential amino acids (lysine, methionine, threonine) and the non-essential amino acid arginine (all p < 0.05). Compared to KRAS WT tumors, KRAS MT tumors were associated with increased levels of proline, phenylalanine, and intermediates of glycolysis (lactate), MTA cycle (SAM, 5-Methioadenosine), and O-GlcNAcylation (GlcNac, all p < 0.05). Conclusions: We are the first to demonstrate the feasibility of associating central carbon metabolites with ctDNA and KRAS mutation status. As ctDNA positivity and KRAS MT status have evolving prognostic potential in CRC, associated metabolic signatures may identify metabolic pathways for novel biomarker development. Our findings also show that KRAS MT CRC appears to be enriched in intermediates of glycolytic, methyl donor, and O-GlcNAcylation pathways.

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Du, Juan, Yangang Liu, Lixuan Tan, Juinn Cherng Lo, Jinyong Wang, Myung-Joem Ryu, Jingfang Zhang et Jing Zhang. « Role of CD44 in Endogenous Kras G12D-mediated Myeloproliferative Neoplasm ». Blood 118, n^o 21 (18 novembre 2011) : 1398. http://dx.doi.org/10.1182/blood.v118.21.1398.1398.

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Abstract Abstract 1398 Abstract Oncogenic KRAS mutations are identified in virtually all the cancer types, making KRAS one of the most frequently mutated genes in human cancers. Our lab established a mouse model of myeloproliferative neoplasm (MPN) initiated by oncogenic Kras mutation (Kras G12D) expressed from its endogenous locus. Because CD44, a cell adhesion molecule and a cell signaling regulator, was found to involve in regulating leukemic stem cells in chronic myeloid leukemia (Krause, Lazarides et al. 2006) and acute myeloid leukemia (Jin, Hope et al. 2006), we have generated compound mice expressing oncogenic Kras but deficient for CD44 (Kras G12D; CD44−/−) to examine the role of CD44 in endogenous oncogenic Kras- mediated MPN. Our preliminary data show that loss of CD44 prolonged survival of compound Kras G12D; CD44−/− mice and greatly downregulated GM-CSF signaling in hematopoietic stem/progenitor cells. However, CD44 deficiency did not significantly affect the development of MPN, suggesting that GM-CSF signaling is not essential for Kras G12D-initiated MPN and CD44 deficiency might not affect other cytokine signaling. We are currently investigating this issue. Because Kras G12D hematopoietic stem cells (HSCs) are required to initiate MPN phenotypes, we then examined whether loss of CD44 would affect the behavior of Kras G12D HSCs. Our preliminary results demonstrate that CD44 deficiency did not significantly alter HSC frequencies in bone marrow and spleen, nor their cell cycle profile and apoptosis status. When Kras G12D; CD44−/− bone marrow cells were transplanted into lethally irradiated mice by retro-orbital injection, ∼19% of recipient mice developed MPN, similarly to recipient mice transplanted with same number of Kras G12D cells (∼14%). These MPN mice simultaneously developed acute T-cell lymphoblastic leukemia/lymphoma. Our results suggest that CD44 is dispensable for the homing and engraftment of Kras G12D HSCs. We are currently investigating whether CD44 function is essential for the homing and engraftment of leukemic initiating cells of MPN. Disclosures: No relevant conflicts of interest to declare.

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Cooper, Alissa Jamie, Alona Muzikansky, Jochen K. Lennerz, Mari Mino-Kenudson, Yin P. Hung, Zofia Piotrowska, Ibiayi Dagogo-Jack et al. « Clinicopathologic characteristics and outcomes for patients with KRAS G12D-mutant non-small cell lung cancer (NSCLC). » Journal of Clinical Oncology 40, n^o 16_suppl (1 juin 2022) : e21024-e21024. http://dx.doi.org/10.1200/jco.2022.40.16_suppl.e21024.

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e21024 Background: Co-occurring mutations in KRAS-mutant NSCLC are associated with discrete biological properties and modulate therapeutic susceptibilities. As G12D-specific inhibitors are expected to enter the clinic, we sought to define the clinicopathologic characteristics and outcomes of patients (pts) with KRAS G12D-mutant NSCLC. Methods: This was a retrospective single-institution study. Pts with NSCLC and KRAS G12D mutations detected by the Massachusetts General Hospital SNaPshot next-generation sequencing assay were identified. Clinical and pathologic characteristics, including co-mutation status and survival outcomes, were collected by chart review. Results: Among pts who underwent SNaPshot testing between May 2014 and August 2021, 665 had cancers that were positive for KRAS G12D, of whom 107 (16.1%) had NSCLC. Most common histology was adenocarcinoma (93, 86.9%). PD-L1 level was < 1% in 24 (22.4%), 1-49% in 19 (17.8%), > 50% in 13 (12.2%), and not assessed in 51 (47.7%). Co-occurring mutations were frequent: 17 NSCLCs had co-occurring STK11 mutations (15.9%), 36 (33.6%) TP53 mutations, and 11 (10.3%) SMARCA4 mutations, of which 2 were truncating. Genetic alterations were detected in a variety of other genes including in the RTK/RAS/MAPK (20, 18.7%), PI3K/AKT/mTOR (12, 11.2%), cell-cycle (17, 15.9%), and WNT (11, 10.3%) pathways. Among 58 tumors with KEAP1 mutation testing, 10 (17.2%) were positive. 75 (70.1%) pts had metastatic disease, including 51 pts who had metastatic disease at initial diagnosis. CNS metastases were present in 27 (36.0%) pts, including 14 pts with CNS metastases at initial diagnosis. Among the 57 pts with metastatic disease who received first-line therapy, 28 (49.1%) received platinum-based chemotherapy, 17 (29.8%) immunotherapy alone, and 12 (21.1%) platinum chemotherapy plus immunotherapy. Median PFS in pts treated with first-line therapy was 4.0 months (95% CI 2.1– 5.7) and median OS 14.3 months (95% CI 8.1 – 27.4). When stratified by co-mutation status, pts with STK11 mutations had significantly worse outcomes than STK11-wild-type (median PFS: 1.2 months vs 4.8 months, p = 0.0165; median OS: 4.3 months vs 21.6 months, p = 0.0015), whereas TP53 exerted no influence. Conclusions: Co-occurring mutations were common in pts with KRAS G12D-mutant NSCLC. Outcomes were poorer for KRAS G12D/ STK11 pts, whereas co-occurring TP53 did not impact survival. Clinical trials examining G12D inhibitors should stratify by STK11.

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Nayak, Kasturi, Yeonjoo Hwang, LeeAnn Wang, Danielle L. Swaney, Nevan J. Krogan et John D. Gordan. « Abstract B016 : Inhibition of KRASG12C in colon cancer illustrates a link between beta-catenin, WNK, and the GID complex ». Cancer Research 82, n^o 23_Supplement_1 (1 décembre 2022) : B016. http://dx.doi.org/10.1158/1538-7445.crc22-b016.

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Abstract KRAS is mutated in 35%-45% of colorectal cancers (CRC), and KRAS mutational status determines the prognosis and therapeutic options available to patients with advanced CRC. Direct KRASG12C inhibitors have proven to be highly effective for patients with non-small cell lung cancers, but unfortunately are relatively ineffective in the treatment of CRC. Thus, we have investigated tissue-specific mechanisms of resistance to direct KRAS inhibition. We used multiplex inhibitor bead kinome profiling (MIBs) and global phosphoproteomic analysis to determine the signaling response to the KRASG12C inhibitor ARS-1620 in four human colon cancer cell lines. Analyzing the kinome revealed a profound reprogramming beyond the Ras/MAPK pathway. We used network propagation to integrate analysis across these lines and define essential signaling nodes modified by direct KRAS inhibition, including two distinct signaling nodes containing RAS/MAPK and WNT-regulating kinases. Two additional smaller nodes contained WNK kinases and their effectors, followed by Hippo and a number of cell cycle-related kinases. The WNK kinases have been identified to modulate beta-catenin, a major driver of CRC biology, via the GID E3 ubiquitin ligase complex. Thus, to understand the signaling that links KRAS and beta-catenin, we used small molecule inhibitors of these kinases along with ARS-1620, we tested how they affected the transcription of beta-catenin targets. Additionally, we assessed the correlation between WNK/GID complex, and beta-catenin transcriptional output using western blot and quantitative real time PCR and observe that inhibition of KRASG12C also modulates beta-catenin transcriptional output. Our results identify new families of possible kinase targets in CRCs expressing KRAS mutations and shed light on the relationship of KRAS, beta-catenin, and WNK/GID in CRC maintenance. By dissecting these signaling relationships, we hope to identify potential drug combinations to overcome primary resistance KRASG12C inhibition in CRC. Citation Format: Kasturi Nayak, Yeonjoo Hwang, LeeAnn Wang, Danielle L. Swaney, Nevan J. Krogan, John D. Gordan. Inhibition of KRASG12C in colon cancer illustrates a link between beta-catenin, WNK, and the GID complex [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr B016.

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