Auswahl der wissenschaftlichen Literatur zum Thema „Jak2-Stat3“

Background. Acute pancreatitis (AP) is a common acute abdomen inflammation, characterized by the dysregulation of digestive enzyme production and secretion. Many studies have shown that Da Cheng Qi Decoction (DCQD) is a secure, effective prescription on AP. In this study, cerulein-stimulated AR42J cells damage model was established to further explore the feasibility and underlying mechanism of DCQD as a potential inhibitor of JAK2/STAT3 pathway for the treatment of AP. Methods. Cell viability of DCQD was measured using a cell counting Kit-8 assay. Pancreatic biochemical markers such as amylase, lipase, and C-reactive protein production were measured by assay kits, respectively. Cytokines (TNF-α, IL-6, IL-10, and IL-1β) were assayed by ELISA. Protein location and protein expression were detected by immunofluorescence staining and Western blotting, respectively. Gene expression was assessed by real-time PCR. For mechanistic analysis of the effect of DCQD on JAK2/STAT3 signaling pathway, selective JAK2 inhibitor (Fedratinib) and STAT3 inhibitor (Stattic) as well as STAT3 activator (Garcinone D) were used. Results. DCQD protected cells by regulating cerulein-induced inflammation and reducing the secretion of pancreatic biochemical markers. Moreover, DCQD could not only inhibit the nuclear translocation of p-STAT3, but also decrease the mRNA expression of JAK2 and STAT3 as well as the ratio of p-JAK2/JAK2 and p-STAT3/STAT3 in protein level. Additionally, DCQD could regulate the mRNA and protein expression of JAK2/STAT3 downstream effectors, Bax and Bcl-XL. The activated effect of cerulein on JAK2/STAT3 pathway was also reversed by JAK2 inhibitor Fedratinib or STAT3 inhibitor Stattic. And the overexpression of JAK2/STAT3 pathway, via STAT3 activator Garcinone D, did exert damage on cells, which bore a resemblance to cerulein. Conclusion. The activation of JAK2/STAT3 pathway may play a key role in the pathogenesis of cerulein-stimulated AR42J pancreatic acinar cell injury. DCQD could improve inflammatory cytokines and cell injury, which might be mediated by suppressing the activation of JAK2/STAT3 signaling pathway.

Objective. To investigate the effect of Da-Cheng-Qi decoction (DCQD) on treating intestinal injury in rats with severe acute pancreatitis (SAP), based on the Janus kinase 2 (JAK2)/signal transducers and transcription 3 (STAT3) signaling pathway. Methods. Rats were randomly divided into the SAP group, SAP + ruxolitinib (JAK2 inhibitor) group, SAP + Stattic (STAT3 inhibitor) group, SAP + DCQD group, and sham operation group. They were further divided into 3-hour, 6-hour, 12-hour, and 18-hour subgroups. Levels of amylase and the inflammatory cytokines tumor necrosis factor-α, interleukin 6, interleukin 10, and interleukin 4 in plasma were tested. The messenger ribonucleic acid (mRNA) expression of JAK2 and STAT3 and the protein expression of phosphorylated JAK2 (p-JAK2) and phosphorylated STAT3 (p-STAT3) in the pancreas and terminal ileum tissues were examined. Results. Rats with SAP had severe changes in plasma levels of amylase and inflammatory cytokines and showed an overexpression of JAK2 mRNA, STAT3 mRNA, p-JAK2 protein, and p-STAT3 protein in the pancreas and terminal ileum. The events could be downregulated by treatment with DCQD, JAK2 inhibitor, and STAT3 inhibitor. Conclusions. In rats with SAP, DCQD ameliorated inflammatory cytokines and intestinal injury, which may be closely associated with the inhibition of the JAK2/STAT3 signaling pathway.

Janus tyrosine kinase 2 (JAK2)−signal transducer and activator of transcription 3 (STAT3) signaling pathway is essential for modulating cellular development, differentiation, and homeostasis. Thus, dysregulation of JAK2−STAT3 signaling pathway is frequently associated with human malignancies. Here, we provide evidence that lysine-specific demethylase 3A (KDM3A) functions as an essential epigenetic enzyme for the activation of JAK2−STAT3 signaling pathway. KDM3A is tyrosine-phosphorylated by JAK2 in the nucleus and functions as a STAT3-dependent transcriptional coactivator. JAK2−KDM3A signaling cascade induced by IL-6 leads to alteration of histone H3K9 methylation as a predominant epigenetic event, thereby providing the functional and mechanistic link between activation of JAK2−STAT3 signaling pathway and its epigenetic control. Together, our findings demonstrate that inhibition of KDM3A phosphorylation could be a potent therapeutic strategy to control oncogenic effect of JAK2−STAT3 signaling pathway.

Triple-negative breast cancer (TNBC) is a highly aggressive disease with invasive and metastasizing properties associated with a poor prognosis. The STAT3 signaling pathway has shown a pivotal role in cancer cell migration, invasion, metastasis and drug resistance of TNBC cells. IL-6 is a main upstream activator of the JAK2/STAT3 pathway. In the present study we examined the impact of the NO-donor glyceryl trinitrate (GTN) on the activation of the JAK2/STAT3 signaling pathway and subsequent migration, invasion and metastasis ability of TNBC cells through in vitro and in vivo experiments. We used a subtoxic dose of carboplatin and/or recombinant IL-6 to activate the JAK2/STAT3 signaling pathway and its functional outcomes. We found an inhibitory effect of GTN on the activation of the JAK2/STAT3 signaling, migration and invasion of TNBC cells. We discovered that GTN inhibits the activation of JAK2, the upstream activator of STAT3, and mediates the S-nitrosylation of JAK2. Finally, the effect of GTN (Nitronal) on lung metastasis was investigated to assess its antitumor activity in vivo.

Abstract Increased STAT3 signalling is a factor in driving ~50% of diffuse large B-cell lymphoma. In some cases increased cytokine production by the lymphoma is responsible for activation of JAK2 and STAT3 but the regulation of signalling through this pathway is not clear. We constructed a conditional BCL6 deficient cell line through disruption of the endogenous BCL6 loci of a genetically tractable human B-cell lymphoma by homologous recombination, and insertion of a tetracycline regulatable BCL6 transgene. On induction of BCL6 deficiency growth of the cell line slowed by 3 to 4-fold. A synthetic lethal screen employing a library of small molecule inhibitors in genetically BCL6 deficient lymphoma cells showed that lestaurtinib, a JAK2 inhibitor, enhanced loss of viability. We investigated the hypothesis that JAK2 is a direct BCL6 target gene. JAK2 mRNA and protein expression were induced by BCL6 deficiency. Inspection of the JAK2 proximal promoter region demonstrated a potential BCL6 binding site. BCL6 bound to this sequence in vitro and mutagenesis of the binding site relieved BCL6 mediated transcriptional repression in luciferase reporter assays. Analysis of ChIP-seq data showed a binding peak in the JAK2 proximal promoter region confirming in vivo BCL6 binding. Data from a large and publicly available gene expression dataset confirmed an inverse correlation between BCL6 and JAK2 mRNA whilst there was a positive correlation between JAK2 and STAT3 mRNA. STAT3 is a known target of BCL6 transcriptional repression. We suggest that BCL6 represses both JAK2 and STAT3 and that relatively high BCL6 levels will tend to reduce JAK2-STAT3 signalling whereas lower BCL6 levels will amplify this pathway. Mouse xenografts utilising our conditional BCL6 deficient cell line showed that lestaurtinib alone caused minimum reduction to tumour size but the combination of BCL6 deficiency and JAK2 inhibitor caused growth reduction with central necrosis. In summary we identify JAK2 as a BCL6 target gene and propose that BCL6 has an important role in regulation of JAK2-STAT3 signalling in DLBCL. BCL6 mRNA expression may be a biomarker to enable the rational use of JAK2 inhibitors in DLBCL. Disclosures No relevant conflicts of interest to declare.

Background: Previous theories considered that the main cause of painful diabetic neuropathy (PDN) was due to hyperglycemia. However, recent evidence indicated that hyperinsulinemia plays a greater role in type 2 diabetic metabolisms (T2DM). Objectives: Our aim was to explore insulin signaling to determine the molecular mechanism involved in the pathogenesis of PDN in T2DM. Study Design: A randomized, double blind, controlled animal trial. Methods: We observed the localization of insulin receptor (IR) and phosphorylated insulin receptor substrate 1 (IRS-1) in the spinal cord using in situ hybridization and immunohistochemistry. Then we investigated the alternations of IR and pIRS-1 and the activity of the JAK2/STAT3 pathway by immunohistochemistry, Western Blotting, and cell culture. Finally, we detected the influence of intrathecal JAK2/STAT3 inhibitor (AG490) on nociceptive behavior and insulin signaling in ob/ob mice using Western Blotting. Results: We found that IR and pIRS-1 are mainly located in neurons in the superficial layer of the spinal dorsal horn. The expressions of IR and pIRS-1 decreased and the JAK2/STAT3 pathway activated in the spinal dorsal horn in ob/ob mice with mechanical hyperalgesia. Next, our in vitro results indicated that hyperinsulinemia and hyperglycemia impaired insulin signaling along with the activated JAK2/STAT3 pathway in differentiated human neuronal cells (SH-SY5Y). Treatment through intrathecal injection of AG490, an inhibitor of the JAK2/STAT3 pathway, alleviated mechanical hyperalgesia in ob/ob mice and prevented impaired insulin signaling in the spinal cord. Limitations: The activation of the JAK2/STAT3 pathway could not explain the mechanism of PDN in T1DM. Conclusions: We demonstrate that insulin signaling impairment in the spinal dorsal horn is associated with the activated JAK2/STAT3 pathway, which contributes to the progressive PDN in T2DM. Key words: Painful diabetic neuropathy, mouse, insulin receptor, insulin receptor substance 1, JAK2, STAT3

Abstract Backgroud: The MLAA-34 gene (GenBank no. AY288977.2) was first discovered in acute monocytic leukemia (M5) in an effort to identify monocytic leukemia-associated antigens by serologic analysis of a recombinant cDNA expression library (SEREX). Previous study showed that high MLAA-34 levels were independently associated with a poorer relapse-free survival and overall survival in AML patients. The MLAA-34 is located on 13q14.2 and has been confirmed to be a novel splice variant of CAB39L (calcium binding protein 39-like). Both mRNA and protein levels of MLAA-34 were found to be higher in U937 cells and M5 patients. The study confirmed that MLAA-34 plays a role in the antiapoptosis of U937 cells, and has the function of oncogenes. Objective: This study is to explore the relationship of MLAA-34 and JAK2/STAT3 signaling pathway so as to further clarify antiapoptotic mechanisms of MLAA-34. Method: Potential binding sites for STAT3 was identified by computer-assisted analysis of the core promoter of MLAA-34 gene. We analyzed the role of STAT3 in the regulation of MLAA-34 gene expression in U937 cells by site-specific mutation, chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). The expression of MLAA-34 was detected by RT-PCR and western blot after over-expressing and interfering STAT3. Through the different concentrations of AG490 (JAK2 inhibitors) and different concentrations of IL- 6 (JAK2 activator) study JAK2/STAT3 signaling pathway upregulated MLAA-34 expression. The gene chip and co-IP were applied to study the MLAA-34-induced JAK2/STAT3 activation. Peripheral blood mononuclear cells and bone marrow (BM) cells of M5 patients were obtained. In M5 patients, mRNA and protein expression of JAK-2, STAT3, p-STAT3 and MLAA-34 were determined by quantitative RT-PCR and western blot respectively to verify the forward feedback regulation pathway. Result: The reporter assay showed that the activity of reporter gene was downregulated after the mutation of STAT3 binding sites. ChIP assay and EMSA showed that STAT3 can directly bind to MLAA-34 gene promoter. The expression vectors of MLAA-34 as well as siRNA eukaryotic expression vectors respectively targeting STAT3 were successfully constructed. RT-PCR and western blot results showed that STAT3 can increase the level of MLAA-34. Research of administration of different concentrations of AG490 and different concentrations of IL-6 showed that JAK2/STAT3 signaling pathway could upregulate MLAA-34 expression. AML-M5 NOD / SCID mice leukemia model was successfully constructed,.Konckdown of MLAA-34 gene can promote apoptosis of leukemia cells, inhibit tumor growth and prolong survival time. Total RNA from shRNA-MLAA-34/U937 and Vec/U937 cells were analyzed by Human Genome U133 chip. Heat-map showed reduced expression of JAK2/STAT3 pathway genes. The result was verified by qPCR and western blot. CO-IP showed that MLAA-34 could form a complex with endogenous JAK2 under the enhanced role of IL-6. Thereby activating JAK2 may directly or indirectly dependent on the presence of MLAA-34. Furthermore, we detected JAK-2, STAT3, P-STAT3 and MLAA-34 gene and protein level in M5 patients, the results showed that they have a positive correlation. Conclusion: JAK2/STAT3 pathway up-regulates MLAA-34 transcription, and MLAA-34 enhances JAK2/STAT3 pathway activation. The forward feedback regulation may have profound therapeutic implications for M5 and could help invent novel approaches in treatment for acute monocytic leukemia. Disclosures No relevant conflicts of interest to declare.

Dexmedetomidine (Dex) works as a crucial agent for the treatment of intestinal ischemia/reperfusion (I/R), but its mechanism remains unclear. Recent articles demonstrated the pivotal role of Janus kinase/signal transducer and activator of transcription (JAK2/STAT3) signalling in I/R. Therefore, it is reasonable to explore the associated mechanism of JAK2/STAT3 signalling in Dex treatment. The study purpose was to evaluate the JAK2/STAT3 signalling regulatory mechanisms of Dex in preventing I/R. Anaesthetized rats were subjected to superior mesenteric artery occlusion consisting of 1 h of ischemia and 2 h of reperfusion while served as controls. Animals received subcutaneous administration of 50 μg/kg Dex, JAK1 and JAK2 inhibitor, Ruxolitinib, selective JAK2 inhibitor, 10 mg/kg AG490 or STAT inhibitor and 0.4 mg/kg rapamycin; or Dex-treatment in the presence of α2-adrenoceptor antagonists Atip or Dex-treatment alone after I/R. Injury was scored histologically, apoptosis was detected via the apoptotic mediators caspase-3 and Bcl-2/Bax and the degree of activation of the JAK/STAT pathway was evaluated. Dex inhibited I/R injury by decreasing apoptosis significantly with rescue of cleaved caspase-3 and the Bcl-2/Bax ratio. Furthermore, phosphorylation of JAK2, STAT1 and STAT3 was affected, suggesting the involvement of activated JAK/STAT in response to Dex. Meanwhile, the JAK2 or STAT inhibitors AG490 and rapamycin, but not Ruxolitinib, exhibited a similar but even greater JAK2 and STAT3 regulatory effect, thus leading to a greater benefit. JAK2/STAT3 activation is crucial to the diminishing effect of Dex on mesenteric I/R injury; however, the efficacy and timing of Dex administration should be considered in clinical practice.

Squamous cell carcinoma of the head and neck (SCCHN) frequently involves metastasis at diagnosis. Our previous research has demonstrated that CCR7 plays a key role in regulating SCCHN metastasis, and this process involves several molecules, such as PI3K/cdc42, pyk2, and Src. In this study, the goals are to identify whether JAK2/STAT3 also participates in CCR7’s signal network, its relationship with other signal pathways, and its role in SCCHN cell invasion and migration. The results showed that stimulation of CCL19 could induce JAK2/STAT3 phosphorylation, which can be blocked by Src and pyk2 inhibitors. After activation, STAT3 was able to promote low expression of E-cadherin and had no effect on vimentin. This JAk2/STAT3 pathway not only mediated CCR7-induced cell migration but also mediated invasion speed. The immunohistochemistry results also showed that the phosphorylation of STAT3 was correlated with CCR7 expression in SCCHN, and CCR7 and STAT3 phosphorylation were all associated with lymph node metastasis. In conclusion, JAk2/STAT3 plays a key role in CCR7 regulating SCCHN metastasis.

Background: Ovarian cancer is the most lethal gynaecological malignancy, accounting for an estimated 140,000 deaths per year worldwide. Five year survival rates have not increased significantly in the last 10 years and the acquisition of resistance to chemotherapy remains a significant barrier to improving patient survival. Isogenic cell line models of in vivo acquired resistance to chemotherapy were used to examine cellular responses to cisplatin and identify differences between sensitive and resistant pairs that might be exploited to sensitise cells to treatment. Results: Microarray analysis of the isogenic paired sensitive/resistant high grade serous ovarian cell lines PEO1 and PEO4 revealed IL6 expression is induced by cisplatin exposure. This result was replicated by QRT-PCR and validated in the additional isogenic pair PEA1/PEA2. Western blotting demonstrated the lack of a correlation between IL6 expression and phosphorylation of either Y1007/1008 JAK2 or Y705 STAT3 levels, suggesting IL6 is not driving the constitutive activation of these proteins. Cells did however display dose dependant changes in STAT3, JAK2 and ERBB2 activation in response to cisplatin that differed between sensitive and resistant isogenic pairs. Both sensitive clones increased their activation of JAK2 and ERBB2 when exposed to low dose, 2μM, cisplatin but reversed these increases at higher concentrations. Resistant clones, PEO4 and PEA2, experienced no low dose increases in ERBB2 JAK2 or STAT3 activation instead reducing the activation of these proteins with greater sensitivity to cisplatin dose. Common to all cell lines was a high degree of correlation in the levels of activated JAK2 and ERBB2. Interfering with cisplatin dependent STAT3 deactivation using IL6 treatment was able to both sensitise cells and reduce cisplatin IC50, suggesting a functional role for STAT3 in both response, and acquired resistance, to cisplatin. Overexpression and knockdown of STAT3 demonstrated it promotes proliferation and the expression of cyclin D1 and BCL xL/S. STAT3 knockdown increased cisplatin resistance as quantified by IC50 whereas STAT3 overexpression was able to potentiate cisplatin induced apoptosis and decrease cisplatin IC50. Similarly the overexpression and knockdown of JAK2 demonstrated it also promotes proliferation, in part by regulating the activity of STAT3. The inhibition of JAK2 activity also increased resistance to cisplatin; small molecule inhibition of JAK2 both lowered background levels of apoptosis as well as attenuating cisplatin induced apoptosis. In common with STAT3 ablation JAK2 knockdown also increased cisplatin IC50. Surprisingly knockdown, overexpression and inhibition of JAK2 were all associated with changes in the activation of ERBB2. Knockdown and inhibition were associated with decreases in Y1248 phosphorylated ERBB2 whereas overexpression was associated with an increase, changes in activation appear to be driven by changes at the level of total protein. GP130 was investigated for due to its role in IL6 signalling and STAT3 activation, mRNA overexpressed was detected in the resistant pair of 2/3 isogenic cell lines. GP130 overexpression was associated with growth promotion and cisplatin resistance as revealed by siRNA knockdowns, which had no effect in cisplatin sensitive non overexpressing cells lines. Knockdown also revealed different pathways to constitutive STAT3 activation, in each high grade serous line assessed there was no effect on pSTAT3 levels, which were almost completely abolished in SKOV3. RNAi of GP130 was also associated with an increase in ERK1/2 activation which was recapitulated by JAK2 knockdown, inhibition as well as cisplatin and doxorubicin exposure. Treatment with a MEK1/2 inhibitor was able to reverse cisplatin and doxorubicin dependent activation and attenuate cytotoxic induced apoptosis. MEK1/2 inhibition was associated with an increase in JAK2, pSTAT3 and pERBB2 which was capable of reversing cisplatin dependent down regulation of these protein, highlighting a mutual feedback mechanism between the GP130/JAK2 and MAPK pathways. Central Conclusion Transcriptional regulation of JAK2 in response to cisplatin exposure drives differential behaviour of paired isogenic cell lines. Greater sensitivity of cisplatin resistant cells lines, in their deactivation of STAT3 and ERBB2 is regulated by their greater extent of JAK2 downregulation upon cisplatin exposure. Downregulation of JAK2 and its commensurate reduction in STAT3 activation were associated with reduced proliferation rates, rendering cells in a state refractory to cisplatin toxicity. This may be due to either or both of reducing the accumulation of DNA double stranded breaks associated with cell division and allowing more time for the repair of single stranded DNA adducts before cell division. While STAT3 has been suggested as a target for adjuvant chemotherapy, data presented here suggests that in combination with cisplatin STAT3 abrogation might actually reduce the effectiveness of treatment.

La maladie d'Alzheimer (MA) est une maladie neurodégénérative et la première cause de démence à travers le monde. Au cours de la MA, les astrocytes développent un phénotype réactif et présentent des changements moléculaires, morphologiques et fonctionnels, pouvant induire des effets délétères et/ou bénéfiques sur le fonctionnement des neurones. Récemment, des données de séquençage ARN (RNAseq) de cellules/noyaux uniques ont révélé l'existence de sous-populations distinctes d'astrocytes dans des cerveaux de patients atteints de la MA et dans les modèles murins. Cependant, les cascades de signalisation contrôlant ces sous-populations, leurs caractéristiques fonctionnelles et leurs impacts sur le fonctionnement du cortex préfrontal (PFC) restent inconnus. Les voies de signalisation JAK2-STAT3 et NF-kB sont connues pour être activées au cours de la MA et contrôler l'état réactif des astrocytes. Notre équipe a développé des lentivirus astrocyte-spécifiques rapporteurs de ces deux voies de signalisation, dans lesquels l'expression de CFP ou de GFP est contrôlée par des séquences promotrices NF-kB et STAT3-dépendantes, respectivement. Ces rapporteurs nous ont permis de mettre en évidence trois sous-populations astrocytaires selon leurs cascades activées, NF-kB+, STAT3+ et NF-κB+/STAT3+ dans le PFC de souris modèle de la MA, les souris APP/PS1dE9, mais aussi les souris APPNL-F/NL-F. Tout d'abord, nous avons observé que les populations ne sont topographiquement pas déterminées par leur proximité aux plaques amyloïdes. Ces observations nous ont ensuite permis de constater que celles-ci sont aussi présentes dans les souris WT, nous guidant vers l'hypothèse que les sous-populations sont probablement innées. Nous observons ensuite que la surface du territoire astrocytaire en 2 dimensions des astrocytes NF-κB+ est plus grande que celle des astrocytes STAT3+ et STAT3+/NF-κB+. Après analyse RNAseq des trois sous-populations, nous avons pu identifier des gènes différentiellement exprimés entre les trois sous-populations, associés à des fonctions spécifiques d'intérêt dans le contexte de la MA (protéostasie, régulation synaptique, métabolisme des lipides). Nous avons confirmé que les sous-populations STAT3+ et NF-κB+ présentent des activités du protéasome et du lysosome significativement différentes dans le PFC de souris APP/PS1dE9. Ayant observé une expression plus élevée des transcrits de Cx30 et 43 dans les astrocytes STAT3+, nous avons aussi étudié le couplage astrocytaire par les jonctions gap et l'activité des hémicanaux. Nous avons montré par redistribution de fluorescence après photoblanchiment (FRAP), que les sous-populations sont couplées de façon équivalente via les jonctions gap, mais que la population STAT3+ présente une augmentation de l'activité des hémicanaux par rapport aux deux autres. Enfin, à l'aide de nouveaux vecteurs lentiviraux, nous avons inhibé spécifiquement les sous-populations STAT3+ ou NF-κB+ en inhibant les voies de signalisation correspondantes chez les souris APP/PS1dE9. Nous observons que ces populations ont un impact sur l'anxiété et la préférence et mémoire sociale des souris APP/PS1dE9. Les autres caractéristiques de la MA (plaques amyloïdes, neurites dystrophiques, inflammation) sont en cours d'étude. Ce projet a permis de mettre en évidence que l'hétérogénéité astrocytaire est contrôlée par différentes voies de signalisation, et que ces sous-populations présentent différents profils morphologiques, moléculaires et fonctionnels, avec potentiellement des impacts différentiels au cours de la MA qui restent à caractériser
Alzheimer's disease (AD) is a neurodegenerative disease and the leading cause of dementia worldwide. During AD, astrocytes develop a reactive phenotype and exhibit molecular, morphological, and functional changes, which can induce deleterious and/or beneficial effects on neuronal function. Recently, single-cell/nucleus RNA sequencing (RNAseq) data have revealed the existence of distinct subpopulations of astrocytes in the brains of AD patients and in mouse models. However, the signaling cascades controlling these subpopulations, their functional characteristics, and their impacts on the functioning of the prefrontal cortex (PFC) remain unknown. The JAK2-STAT3 and NF-kB signaling pathways are known to be activated during AD and control the reactive state of astrocytes. Our team has developed astrocyte-specific lentivirus reporters for these two signaling pathways, in which the expression of CFP or GFP is controlled by NF-κB- and STAT3-dependent promoter sequences, respectively. These reporters allowed us to identify three astrocytic subpopulations based on their activated cascades, NF-kB+, STAT3+, and NF-kB+/STAT3+, in the PFC of AD model mice, APP/PS1dE9 mice, as well as APPNL-F/NL-F mice. First, we observed that the subpopulations are not topographically determined by their proximity to amyloid plaques. These observations subsequently led us to note that these subpopulations are also present in WT mice, suggesting that the subpopulations are probably innate. We then observed that the 2D territory area of NF-kB+ astrocytes is larger than that of STAT3+ and STAT3+/NF-kB+ astrocytes. After RNAseq analysis of the three subpopulations, we identified differentially expressed genes between the three subpopulations associated with specific functions of interest in the context of AD (proteostasis, synaptic regulation, lipid metabolism). We confirmed that STAT3+ and NF-κB+ subpopulations exhibit significantly different proteasome and lysosome activities in the PFC of APP/PS1dE9 mice. Observing higher expression of Cx30 and 43 transcripts in STAT3+ astrocytes, we also studied astrocytic coupling via gap junctions and hemichannel activity. We demonstrated through fluorescence recovery after photobleaching (FRAP) that the subpopulations are equivalently coupled via gap junctions, but the STAT3+ population shows increased hemichannel activity compared to the other two. Finally, using new lentiviral vectors, we specifically inhibited the STAT3+ or NF-kB+ subpopulations by inhibiting the corresponding signaling pathways in APP/PS1dE9 mice. We observed that these populations impact anxiety and social preference and memory in APP/PS1dE9 mice. Other characteristics of AD (amyloid plaques, dystrophic neurites, inflammation) are under study. This project has highlighted that astrocytic heterogeneity is controlled by different signaling pathways, and that these subpopulations exhibit different morphological, molecular, and functional profiles, potentially with differential impacts during AD that remain to be characterized

[EN] Idiopathic pulmonary fibrosis (IPF) is the pulmonary disease with higher incidence and worse prognosis. Recent evidence suggests that cucurbitaceae, selective inhibitors of the JAK2/STAT3 pathway, may improve the pathogenesis of IPF, as anti-inflammatory and antioxidative properties have been confirmed in other diseases. However the role in IPF is unknown. Two pharmacological models were investigated in the present study. In the preventive model, Wistar rats were instilled intratracheally with a single dose of bleomycin (BLM)(3.75 U/kg; n=12) to induce lung injury. CuI (20mg/kg/day; n=6) or CuI vehicle (control and IPF group) was administered intraperitoneally daily for 21 days. The therapeutic model was exactly the same starting CuI administration on day 7 until day 21. Animal evolution together with the ventilation-perfusion ratio was controlled through CT/SPECT imaging. Cellular count and characterization was performed in broncoalveolar lavage (BAL) together with the total protein content and the IL-6 and IL-13 concentration in BAL and lung tissue. Hematoxilin-eosin and masson trichrome stains allowed the study of the lung's tissue histology. TGF-ß1, CTGF, COL1A and ET-1 gene and protein expression were both measured by real time PCR and WB as pulmonary vascular remodeling markers. P-STAT3, P-SMAD3 and P-JAK2 proteins were determined by protein and immunohistochemistry quantification. Finally, JAK2 and STAT3 expression and distribution was studied in lung tissue of fibrotic patients with pulmonary hypertension. CT/SPECT quantification showed reduction of the fibrotic areas in the CuI treated group by reestablishing the air space in the lungs back to day 0 levels for the preventive and the therapeutic model. Furthermore, ventilation/perfusion correlation was restored in the therapeutic model after administrating CuI during 14 days. Hematoxilin-eosine stains demonstrated how the group treated pharmacologically presented an improvement in the lung tissue architecture, reversing vascular remodeling and right heart hypertrophy. Masson trichrome stain revealed a reduction of the collagen deposits. Ashcroft score, used to determine the severity of pulmonary fibrosis, was measured and diminished significantly in the CuI treated group. The results showed a gene and protein overexpression of TGF-ß1, CTGF, COL1A and ET-1 in BLM relative to Control rats. This was counteracted with CuI treatment which reduced the expression back to control. In terms of immunohistochemistry, the results demonstrated a decrease in the COL1A deposits in the treated group versus the absence of treatment group. Protein and immunohistochemistry analysis of JAK2, STAT3 and SMAD3 demonstrated an overexpression in bleomycin rats while the protein expression was inhibited in the CuI treated group. In accordance to the results obtained, the immunohistochemistry analysis of the lung parenchyma in patients with pulmonary hypertension related to pulmonary fibrosis showed and overexpression of the phosphorylated forms of JAK2 and STAT3, lacking its expression in healthy lung tissue. The preventive and therapeutic administration of JAK2/STAT3 inhibitor can be a potential treatment for pulmonary fibrosis, as it improves the parameters related to the disease.
[ES] La fibrosis pulmonar idiopática (FPI) es la enfermedad pulmonar con mayor incidencia y peor pronóstico. Estudios recientes sugieren que la familia de las cucurbitaceae, inhibidores selectivos de la ruta JAK2/STAT3, pueden mejorar la patogénesis de la enfermedad, al haberse confirmado sus propiedades antinflamatorias y antioxidantes en otras enfermedades. Sin embargo se desconoce su papel en FPI. En el presente trabajo se estudiaron dos modelos farmacológicos. En el modelo preventivo las ratas Wistar fueron instiladas con una dosis única de bleomicina intratraqueal (BLM)(3.75 U/kg; n=12) para inducir las lesión pulmonar. Durante 21 días se administró CuI (20mg/kg/día; n=6) o vehículo de CuI (control y grupo FPI) por vía intraperitoneal. El modelo curativo se diferencia del preventivo en el comienzo de la administración farmacológica a los 7 días de inducir la enfermedad. El seguimiento de la evolución animal y el ratio de ventilación-perfusión se realizó mediante las técnicas de imagen TC/SPECT. Se realizó el recuento y caracterización de las células totales extravasadas en lavado broncoalveolar (LBA) así como el contenido de proteína total y la concentración de IL- 6 e IL-13 en LBA y tejido pulmonar. Las tinciones de hematoxilina-eosina y masson tricrómico permitieron el estudio de la histología del tejido pulmonar. Se determinó la expresión génica y proteica de TGF-ß1, CTGF, COL1A y ET-1 mediante las técnicas de real time PCR y WB como marcadores de remodelado vascular. Las proteínas P-STAT3, P-SMAD3 y P-JAK2, fueron determinadas mediante cuantificación proteica e inmunohistoquimia. Por último se estudió la expresión y distribución de JAK2 y STAT3 en tejido de pacientes con fibrosis pulmonar e hipertensión pulmonar. La cuantificación de las imágenes TC/SPECT mostraron una reducción de las áreas fibróticas en el grupo tratado con CuI. El tratamiento farmacológico permitió el restablecimiento del espacio aéreo pulmonar hasta valores control en ambos modelos estudiados. El grupo con tratamiento farmacológico restauró el ratio de ventilación/perfusión tras administrar CuI durante 14 días. Las tinciones de hematoxilina eosina revelaron como el grupo animal tratado farmacológicamente presenta una mejora de la histología pulmonar, revirtiendo el remodelado vascular y la hipertrofia del ventrículo derecho. La tinción de masson tricrómico mostró una disminución de los depósitos de colágeno. Se determinó el valor de Ashcroft, evaluador del grado de fibrosis pulmonar, que descendió significativamente en el grupo tratado con CuI. Los resultados presentan una sobrexpresión génica y proteica de TGF-ß1, CTGF, COL1A y ET-1 en los grupos de bleomicina frente a las ratas control. Dicha condición fue revertida mediante el tratamiento con CuI que restableció los valores a niveles control. Los análisis proteicos e inmunohistoquíimicos de JAK2, STAT3 y SMAD3 revelaron una sobreexpresión en las ratas con bleomicina mientras que la expresión proteica fue inhibida en el grupo tratado con CuI. En consonancia con los resultados obtenidos, el análisis inmunohistoquímico del parénquima pulmonar de pacientes con FPI e HP asociada muestran una sobreeexpresión de las formas fosforiladas de JAK2 y STAT3 frente a la ausencia de expresión en tejido pulmonar sano. La administración curativa y preventiva de un inhibidor de la ruta JAK2/STAT3 puede ser un potencial tratamiento para la fibrosis pulmonar, ya que mejora parámetros indicativos de la patología.
[CAT] La fibrosi pulmonar idiopàtica (FPI) és la enfermetat pulmonar amb major incidència i pitjor pronostic. Estudis recents suggereixen que la família de les cucurbitàcies, Inhibidors selectius de la ruta JAK2 / STAT3, poden millorar la patogènesi de la malaltia, en haver-se confirmat les seues propietats antiinflamatòries i antioxidants En altres patologies. No obstant això es desconeix el seu paper en FPI. En el present treball es van estudiar 2 models farmacològics. En el model preventiu les rates Wistar foren instilades amb una dosi única de bleomicina intratraqueal (BLM) (3,75 U / kg; n = 12) per a induir les lesions pulmonars. Durant 21 dies es va administrar CuI (20 mg / kg / dia, n = 6) o Vehicle de CuI (control i grup FPI) per vía intraperitoneal. El model curatiu es diferència del preventiu en el començament de l'administració farmacológica als 7 dies d'induir l'enfermetat. El seguiment de l'evoluciò dels animals i el ratio de Ventilació-perfusió es va realitzar mitjançant tècniques d'imatge TC/SPECT. Es realitzà el recompte i caracterització de les cèl·lules totals extravasades en el llavat broncoalveolar (LBA). Així com el contingut de proteina total i la concentració d'IL-6 i IL-13 en LBA i teixit pulmonar. Les tincions d'hematoxilina-eosina i tricròmic de Masson van permetre l'estudi de la histologia del teixit pulmonar. Es va determinar l'expressió gènica i proteica de TGF-ß1, CTGF, COL1A i Et-1 mitjançant tècniques de PCR en temps real i WB com marcadors de remodelat vascular. Les proteïnes P-STAT3, P-SMAD3 i P-JAK2, varen ser determinades mitjançant quantificació proteica i inmunohistoquimia. Per últim se estudià l'expressió i distribució de JAK2 i STAT3 en teixit de pacients amb fibrosi pulmonar e hipertensió pulmonar. La quantificació de les imatges TC/SPECT mostraren una reducció de les àrees fibrótiques en el grup tractat amb CuI. El tractament farmacològic permet el restabliment de l'espai aeri pulmonar fins valors de control en els dos models estudiats. El grup amb tractament farmacològic va restaurar el ratio de ventilació/perfusió tras administrar Cul durant 14 dies. Les tincions d'hematoxilina eosina van revelar com el grup animal tractat farmacològicament presenta una Millora de la histologia pulmonar, revertint el remodelat vascular i la hipertròfia del ventricle dret. La tinció de tricròmic de Masson va mostrar una disminució dels dipòsits de col·lagen. Es va determinar el valor d'Ashcroft, avaluador del grau de fibrosi pulmonar, que va baixar significativament a el grup tractat amb CuI. Els resultats presenten una sobreexpressió gènica i proteica de TGF-ß1, CTGF, COL1A i Et-1 en els grups de bleomicina en comparacióa les rates control. Aquesta condició va ser revertida mitjançant el tractament amb CuI que va restablir els valors fins a nivel dels control. A nivell immunohistoquímic els resultats mostren una disminució dels dipòsits de COL1A en el grup tractat comparativament al grup sense tractament. Els anàlisi proteics i inmunohistoquíimics de JAK2, STAT3 i SMAD3 van revelar una sobreexpressió en les rates amb bleomicina mentre que l'expressió proteica va ser inhibida en el grup tractat amb CuI. D'acord amb els resultats obtinguts, l'anàlisi immunohistoquímic del parènquima pulmonar de pacients amb FPI i HP associada mostren sobreeexpresió de les formes fosforilades de JAK2 i STAT3 davant l'absència d'expressió en teixit pulmonar sa. La administració curativa i preventiva d'un inhibidor de la ruta JAK2 / STAT3 pot ser un potencial tractament per la fibrosi pulmonar, ja que millora paràmetres indicatius de la patologia.
Hernández Ribes, G. (2016). ESTUDIO DE LA RUTA CELULAR JAK2/STAT3 COMO POTENCIAL INHIBIDOR EN EL MODELO DE FIBROSIS PULMONAR [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/64087
TESIS

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A via Janus Kinase (JAK) e do transdutor de sinal e ativador de transcrição (STAT) desempenham papéis importantes na patogênese de neoplasias hematopoiéticas. A ativação da via JAK2/STAT3 promove o crescimento e sobrevivência celular em uma variedade de linfomas humanos. Há uma necessidade de compreender a participação da via JAK2/STAT3 em linfomas caninos difusos de grandes células B e do potencial terapêutico dos inibidores de JAK no tratamento dessa doença. O objetivo do presente estudo foi avaliar a expressão de JAK2-STAT3 em linfomas difusos de grandes células B e o impacto do uso de inibidores de JAK2 como AZD1480 e CYT387 no crescimento in vitro dessa linhagem tumoral. Foi realizada técnica de imuno-histoquímica com os anticorpos anti-STAT3 e anti-STAT3 fosforilado (p-STAT3) em linfonodos acometidos por linfoma difuso de grandes células B e comparado à linfonodos normais e reativos. Para avaliação do efeito terapêutico dos inibidores de JAK2 (AZD1480 e CYT387) foi realizado ensaio de viabilidade celular pelo método de azul de tripan utilizando linhagens celulares de linfoma difuso de grandes células B (CLBL-1) e análise de apoptose por citometria de fluxo utilizando o sistema Annexin V. Houve aumento significativo na expressão de STAT3 e p-STAT3 em linfomas difusos de grandes células B em comparação com linfonodos normais. Ambos os fármacos inibiram o crescimento celular em proporções dependentes da dose administrada e houve um aumento significativo nas taxas de apoptose das células tratadas com inibidores de JAK-2 em comparação ao grupo controle tratado com DMSO. Este é o primeiro estudo a avaliar a via JAK2/STAT3 em linfomas difusos de grandes céluslas B canino e esses dados permitem compreender e explorar o potencial terapêutico dos inibidores de JAK permitindo estudos futuros da eficácia clínica desses fármacos na oncologia veterinária
The Janus Kinase (JAK) and signal transducer and activator of transcription (STAT) pathway play important roles in the pathogenesis of hematologic malignancies. Activated JAK2-STAT3 signaling pathway promotes the growth and survival of a variety of lymphomas in human. There is a great demand for understanding JAK-STAT pathway in canine diffuse large B cell lymphoma (DLBCLs) and evaluating the therapeutic potential of JAK inhibitors. Our study aims to evaluate the expression of JAK2-STAT3 pathway in canine DLBCLs and to assess the impact of AZD1480 and CYT387, two novel JAK inhibitors, on canine DLBCL cell growth. Immunohistochemistry was performed in canine DLBCLs, normal and reactive lymph nodes with primary antibodies against STAT3 and phosphorylated STAT3 (p-STAT3). To evaluate the therapeutic effect of novel JAK inhibitors, canine DLBCL cell line CLBL-1 was treated with either AZD1480 or CYT387 and trypan blue viability assay was performed post treatment. There was a significant increase in expression of STAT3 and pSTAT3 in canine DLBCLs compared with the normal lymph node. Both AZD1480 and CYT387 inhibited canine DLBCL cells in a dose dependent manner. This is the first study to evaluate the JAK2/STAT3 pathway in canine DLBCLs. The knowledge of JAK2-STAT3 activity in canine DLBCLs enables us to understand and explore the therapeutic potential of JAK inhibitors. The dose dependent cell growth inhibition by novel JAK inhibitors in this study will lead into the future studies of the underlying mechanism

Orientador: Mirela Tinucci Costa
Banca: Felipe Augusto Ruiz Sueiro
Banca: Lucas Campos de Sá Rodrigues
Banca: Andrigo Barboza De Nardi
Banca: Letícia Abrahão Anai
Resumo: A via Janus Kinase (JAK) e do transdutor de sinal e ativador de transcrição (STAT) desempenham papéis importantes na patogênese de neoplasias hematopoiéticas. A ativação da via JAK2/STAT3 promove o crescimento e sobrevivência celular em uma variedade de linfomas humanos. Há uma necessidade de compreender a participação da via JAK2/STAT3 em linfomas caninos difusos de grandes células B e do potencial terapêutico dos inibidores de JAK no tratamento dessa doença. O objetivo do presente estudo foi avaliar a expressão de JAK2-STAT3 em linfomas difusos de grandes células B e o impacto do uso de inibidores de JAK2 como AZD1480 e CYT387 no crescimento in vitro dessa linhagem tumoral. Foi realizada técnica de imuno-histoquímica com os anticorpos anti-STAT3 e anti-STAT3 fosforilado (p-STAT3) em linfonodos acometidos por linfoma difuso de grandes células B e comparado à linfonodos normais e reativos. Para avaliação do efeito terapêutico dos inibidores de JAK2 (AZD1480 e CYT387) foi realizado ensaio de viabilidade celular pelo método de azul de tripan utilizando linhagens celulares de linfoma difuso de grandes células B (CLBL-1) e análise de apoptose por citometria de fluxo utilizando o sistema Annexin V. Houve aumento significativo na expressão de STAT3 e p-STAT3 em linfomas difusos de grandes células B em comparação com linfonodos normais. Ambos os fármacos inibiram o crescimento celular em proporções dependentes da dose administrada e houve um aumento significativo nas taxas de apopto... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The Janus Kinase (JAK) and signal transducer and activator of transcription (STAT) pathway play important roles in the pathogenesis of hematologic malignancies. Activated JAK2-STAT3 signaling pathway promotes the growth and survival of a variety of lymphomas in human. There is a great demand for understanding JAK-STAT pathway in canine diffuse large B cell lymphoma (DLBCLs) and evaluating the therapeutic potential of JAK inhibitors. Our study aims to evaluate the expression of JAK2-STAT3 pathway in canine DLBCLs and to assess the impact of AZD1480 and CYT387, two novel JAK inhibitors, on canine DLBCL cell growth. Immunohistochemistry was performed in canine DLBCLs, normal and reactive lymph nodes with primary antibodies against STAT3 and phosphorylated STAT3 (p-STAT3). To evaluate the therapeutic effect of novel JAK inhibitors, canine DLBCL cell line CLBL-1 was treated with either AZD1480 or CYT387 and trypan blue viability assay was performed post treatment. There was a significant increase in expression of STAT3 and pSTAT3 in canine DLBCLs compared with the normal lymph node. Both AZD1480 and CYT387 inhibited canine DLBCL cells in a dose dependent manner. This is the first study to evaluate the JAK2/STAT3 pathway in canine DLBCLs. The knowledge of JAK2-STAT3 activity in canine DLBCLs enables us to understand and explore the therapeutic potential of JAK inhibitors. The dose dependent cell growth inhibition by novel JAK inhibitors in this study will lead into the future studies of the underlying mechanism
Doutor

Les astrocytes deviennent réactifs dans les maladies neurodégénératives (MND) comme la maladie d’Alzheimer (MA) et de Huntington (MH) mais les conséquences fonctionnelles de cette réactivité sont peu connues. Dans cette étude, nous avons évalué 1) les voies de signalisation impliquées dans la réactivité astrocytaire, 2) la contribution des astrocyte réactifs (AR) à la dysfonction neuronale dans des modèles de MND et 3) les caractéristiques fonctionnelles des AR.Nous avons montré que la voie JAK2/STAT3 est responsable de la réactivité astrocytaire dans des modèles murins de la MA et la MH. Nous avons développé de nouveaux vecteurs viraux ciblant cette voie dans les astrocytes, in vivo. Grâce à ces outils, nous avons étudié la contribution des AR à la dysfonction neuronale dans deux modèles murins de la MH. Nos résultats suggèrent que les AR ne jouent pas un rôle central dans ces modèles de pathologie. En ciblant la voie JAK2/STAT3, nous avons induit la réactivité astrocytaire chez la souris sauvage et avons montré que cette voie régule la transcription de gènes impliqués dans des fonctions cellulaires importantes. De plus, nous avons observé que l’activation des astrocytes conduit à une diminution de la plasticité synaptique dans le cerveau de souris.En conclusion, nous avons montré que la voie JAK2/STAT3 est une voie centrale dans les AR. Nous avons développé des vecteurs viraux innovants pour évaluer 1) la contribution des AR à la dysfonction neuronale dans des modèles de MND et 2) les propriétés fonctionnelles des AR in vivo. L’étude des AR permettra d’identifier de nouvelles cibles moléculaires pour manipuler ces cellules pléiotropes à des fins thérapeutiques
Astrocyte reactivity is a hallmark of pathological conditions in the CNS including neurodegenerative diseases (ND) such as Alzheimer’s (AD) and Huntington’s (HD) diseases. Reactive astrocytes (RA) are identified by morphological changes but their functional features and influence on neurons are poorly understood, especially in ND. Therefore, we aimed at 1) identifying the signaling cascades involved in astrocyte reactivity in ND, 2) evaluating RA contribution to disease phenotype in ND models and 3) deciphering RA functional features. The JAK2/STAT3 pathway is a known trigger of astrocyte reactivity in CNS injuries. Here, we show that this pathway is a common inducer of astrocyte reactivity in AD and HD models. We developed new viral vectors to target this cascade in astrocytes and manipulate astrocyte reactivity in vivo. We used these vectors to determine the contribution of RA to neuronal dysfunction in HD mouse models. We found that RA do not primarily influence disease phenotype in HD. Last, we targeted the JAK2/STAT3 pathway in WT mice to characterize RA functional features in vivo. We show RA undergo transcriptional changes of numerous genes involved in metabolism, protein degradation pathways and immune response. Moreover, we show that astrocyte reactivity alters synaptic plasticity in the mouse hippocampus. Our results identify the JAK2/STAT3 pathway as a central cascade for astrocyte reactivity. The viral vectors developed in this project represent powerful tools to decipher the roles of RA in various ND models and to characterize RA functional features in vivo. Better understanding RA functions may lead to the identification of new therapeutic targets for ND

Les astrocytes sont des éléments clés de la physiologie cérébrale. Dans les maladies neurodégénératives comme la maladie d’Alzheimer (MA), les astrocytes deviennent réactifs. Cette réactivité astrocytaire (RA) est essentiellement caractérisée par des changements morphologiques. En revanche, les effets de la réactivité sur les fonctions de support des astrocytes sont mal connus. De plus, les cascades de signalisation qui conduisent à la RA restent à déterminer. Les objectifs de ce projet étaient de : 1/ démontrer que la voie JAK2-STAT3 (Janus Kinase 2 - Signal Transducer and Activator of Transcription 3) joue un rôle central dans le contrôle de la RA au cours des maladies neurodégénératives ; 2/ comprendre quelle est l’implication de la RA dans les altérations moléculaires, cellulaires et fonctionnelles observées dans la MA. Nous avons montré que la voie JAK2-STAT3 est une cascade de signalisation centrale dans la RA (Ben Haim et al., 2015). Dans ce projet, nous démontrons en utilisant de nouveaux outils moléculaires basés sur des vecteurs viraux, que cette voie est nécessaire et suffisante à la RA. Nos résultats montrent également que la modulation de la RA dans deux modèles murins de la MA (souris APP/PS1dE9 et 3xTg-AD) influence certains index pathologiques, mais de façon contexte-dépendante. L’ensemble de ce travail a permis de valider de nouveaux outils pour étudier les astrocytes réactifs in situ et souligne l’importance et la complexité de leur fonctions au cours des maladies neurodégénératives
Astrocytes are emerging as key players in brain physiology. In Alzheimer’s disease (AD), astrocytes become reactive. Astrocyte reactivity (AR) is essentially characterized by morphological changes. But how the normal supportive functions of astrocytes are changed by their reactive state is unclear. Moreover, signaling cascades leading to AR are not yet determined. In this study, we aim to: 1/ demonstrate the JAK2-STAT3 pathway (Janus Kinase 2 - Signal Transducer and Activator of Transcription 3) is responsible for AR in neurodegenerative diseases ; 2/ understand the contribution of reactive astrocytes to molecular, cellular and functional alterations in AD. We already reported that the JAK2- STAT3 pathway is a central cascade for AR (Ben Haim et al., 2015). Here, we demonstrate, with new molecular tools based on viral vectors, that this pathway is necessary and sufficient to AR. Our results also show that the modulation of AR in two AD mouse models (APP/PS1dE9 and 3xTg-AD mice) influence several pathological hallmarks, but in a context-dependent manner. Overall, this work has generated new original tools to study reactive astrocytes in situ and it underlines the importance and complexity of their functions in neurodegenerative diseases

Stat proteins, transcription factors that convert extracellular stimuli into appropriate biological responses, are involved in many normal physiological cell processes, including proliferation, differentiation, apoptosis, angiogenesis, and immune system regulation. Irregular Stat activation is often associated with tumorigenesis. This situation has made the Stat pathway an interesting target for drug development studies in cancer treatment and has led to the development of various inhibitors targeting this pathway. Stat signal inhibitors are divided into two main groups as inhibitors with direct and indirect effects. Direct inhibitors target the SH domain, DNA binding domain, or N-terminal domain of the Stat3 protein; indirect inhibitors target upstream components of the Stat3 pathway, such as JAK2 and EGFR. It is known that Stat3 has a strong relationship with the formation of breast cancer and its permanent activation is most pronounced in breast cancer. In this study, primarily the components of the Stat signaling pathway, activation/inactivation and the functions of Stat3 were emphasized, the inhibitors that act by directly inhibiting the SH2 domain of Stat3 proteins in breast cancer cells were focused, and the results of the research examining the effects of these inhibitors on breast cancer cells were compiled.

Adipocytokines have gained significant attention in the scientific community over the past few decades. They are a family of enzymes, hormones, growth factors, proteins, and other bioactive molecules that are important regulators of many processes. Adipocytokines are predominantly produced by preadipocytes and mature adipocytes to act through a network of autocrine, paracrine, and endocrine pathways. Leptin (LEP) is the first adipocytokine discovered that has a role in modulating adiposity and has been shown to exert pleiotropic effects on many metabolic pathways through the leptin receptors (LEPRs). LEP has pro-tumoral roles; it promotes angiogenesis, proliferation, survival of tumor cells, and inhibits apoptosis. To exercise its role in tumorigenesis, LEP-LEPR signaling and epithelial-mesenchymal transitions (EMTs) play a significant role. LEP is an oncogenic factor mainly due to its proinflammatory and proangiogenic effects. In angiogenesis, LEP acts directly as an endothelial growth factor or indirectly through cellular pathways, such as STAT3/ERK1/2, JAK2/STAT3, MAPK/ERK, PI3K/AKT, p38, p53, MAPK, and Wnt/β-catenin.

Neuroblastoma, the most common extra-cranial pediatric solid tumor, is responsible for 9–15% of all pediatric cancer deaths. Its intrinsic heterogeneity makes it difficult to successfully treat, resulting in overall survival of 50% for half of the patients. Here we analyze the role in neuroblastoma of the adaptor protein p140Cap, encoded by the SRCIN1 gene. RNA-Seq profiles of a large cohort of neuroblastoma patients show that SRCIN1 mRNA levels are an independent risk factor inversely correlated to disease aggressiveness. In high-risk patients, SRCIN1 was frequently altered by hemizygous deletion, copy-neutral loss of heterozygosity, or disruption. Functional assays demonstrated that p140Cap is causal in dampening both Src and Jak2 kinase activation and STAT3 phosphorylation. Moreover, p140Cap expression decreases in vitro migration and anchorage-independent cell growth, and impairs in vivo tumor progression, in terms of tumor volume and number of spontaneous lung metastasis. p140Cap also contributes to an increased sensitivity of neuroblastoma cells to chemotherapy drugs and to the combined usage of doxorubicin and etoposide with Src inhibitors. Overall, we provide the first evidence that SRCIN1/p140Cap is a new independent prognostic marker for patient outcome and treatment, with a causal role in curbing the aggressiveness of neuroblastoma. We highlight the potential clinical impact of SRCIN1/p140Cap expression in neuroblastoma tumors, in terms of reducing cytotoxic effects of chemotherapy, one of the main issues for pediatric tumor treatment.