Downregulation Of p-STAT3 Research Articles

Selumetinib overcomes gefitinib primary and acquired resistance by regulating MIG6/STAT3 in NSCLC.

Gefitinib, as the first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has achieved great advances in the treatment of non-small cell lung cancer (NSCLC), but drug resistance will inevitably occur. Therefore, exploring the resistance mechanism of gefitinib and developing new combination treatment strategies are of great importance. In our study, the results showed that selumetinib (AZD6244) synergistically inhibited the proliferation of NSCLC with gefitinib. Selumetinib also enhanced gefitinib-induced apoptosis and migration inhibition ability in gefitinib-resistant lung cancer cell lines. Subsequently, the negative regulation between MIG6 and STAT3 was observed and verified through the STRING database and western blotting assays. Sustained activation of STAT3 was significantly downregulated when co-treatment with selumetinib in gefitinib-resistant cells. However, the downregulation of p-STAT3, resulting from the combination of selumetinib and gefitinib was counteracted by the deletion of MIG6, suggesting that selumetinib enhanced gefitinib sensitivity by regulating MIG6/STAT3 in NSCLC. In contrast, p-STAT3 was further inhibited after treatment with gefitinib and selumetinib when MIG6 was overexpressed. Furthermore, the combined administration of selumetinib and gefitinib effectively promoted the sensitivity of lung cancer xenografts to gefitinib in vivo, and the tumor inhibition rate reached 81.49%, while the tumor inhibition rate of the gefitinib monotherapy group was only 31.95%. Overall, MIG6/STAT3 negative regulation plays an important role in the sustained activation of STAT3 and the resistance to EGFR-TKIs. Our study also suggests that EGFR-TKIs combined with MEK1/2 inhibitors, such as selumetinib, may be beneficial to those NSCLC patients who develop a primary or acquired resistance to EGFR-TKIs, providing theoretical support for combining TKIs and selumetinib in clinical cancer treatment.

Ginkgetin suppresses ovarian cancer growth through inhibition of JAK2/STAT3 and MAPKs signaling pathways

BackgroundGinkgo biloba L., a kind of traditional Chinese medicine, is always used to treat various diseases. Ginkgetin is an active biflavonoid isolated from leaves of Ginkgo biloba L., which exhibits diverse biological activities, including anti-tumor, anti-microbial, anti-cardiovascular and cerebrovascular diseases, and anti-inflammatory effects. However, there are few reports on the effects of ginkgetin on ovarian cancer (OC). Hypothesis/PurposeOC is one of the most common cancers with high mortality in women. The purpose of this study was to find out how ginkgetin inhibited OC and which signal transduction pathways was involved to suppress OC. MethodsThe OC cell lines, A2780, SK-OV-3 and CP70, were used for in vitro experiments. MTT assay, colony formation, apoptosis assay, scratch wound assay and cell invasion assay were used to determine the inhibitory effect of ginkgetin. BALB/c nude female mice were injected with A2780 cells subcutaneously, then treated with ginkgetin by intragastric administration. Western blot experiment was used to verify the inhibitory mechanism of OC in vitro and in vivo. ResultsWe found that ginkgetin inhibited the proliferation and induced apoptosis in OC cells. In addition, ginkgetin reduced migration and invasion of OC cells. In vivo study showed that ginkgetin significantly reduced tumor volume in the xenograft mouse model. Furthermore, the anti-tumor effects of ginkgetin were associated with a down regulation of p-STAT3, p-ERK and SIRT1 both in vitro and in vivo. ConclusionOur results suggest that ginkgetin exhibits anti-tumor activity in OC cells via inhibiting the JAK2/STAT3 and MAPK pathways and SIRT1 protein. Ginkgetin could be a potential candidate for the treatment of OC.

Transcriptional and Metabolic Profiling Reveals Alpha-Ketoglutarate As a Novel Mediator of Aberrant Platelet Activity and Inflammation in Myeloproliferative Neoplasms

Prior studies by our group and others have demonstrated that platelets from patients with myeloproliferative neoplasms (MPNs) exhibit a hyperreactive phenotype. However, a complete understanding of platelet alterations in MPNs remains lacking, and the mechanisms by which platelets contribute to MPN-related thrombosis, as well as other MPN disease features, are incompletely understood. In this study, utilizing multiomic approaches to interrogate platelet phenotypes in patient samples, in conjunction with relevant MPN animal models (Figure 1A), we aim to investigate mechanisms of dysregulated platelet activity in MPNs, and explore how these findings may be leveraged to uncover novel therapeutic strategies. We initially studied platelet activation in peripheral blood from patients with essential thromobocythemia (ET) and compared to age-, sex-matched healthy controls. We found significantly increased P-selectin exposure in conjunction with increased platelet-leukocyte aggregates indicating activation of platelets from ET patients. To investigate the transcriptional signature of PBMCs and platelets at the single cell level, we performed single cell RNA-seq (scRNA-seq) in PBMCs from ET patients and healthy controls. Monocytes were increased in ET patients and displayed the highest inflammation index, implicating monocytes as the primary source of inflammation in ET. GSEA analysis revealed enrichment of platelet activation and oxidative phosphorylation (OXPHOS) genes in platelets from ET patients. Liquid chromatography-mass spectrometry (LC-MS) metabolomics analysis showed distinct metabolic phenotypes consisting of elevated tricarboxylic acid (TCA) cycle components, ATP generation and lower alpha-ketoglutarate (α-KG), in platelets from ET patients, all consistent with increased OXPHOS. α-KG is a key TCA cycle intermediate, which inhibits ATP generation via the suppression of ATP synthase. Extracellular flux analysis by Seahorse analysis confirmed bioenergetic alterations in MPN patient platelets. Enhanced mitochondrial respiration at both baseline and after ex vivo stimulation with the platelet agonist thrombin receptor activator peptide (TRAP6) was also observed from MPN patient platelets. Notably, α-KG supplementation drastically reduced oxygen consumption and ATP generation in platelets from MPN patients. We further investigated the effects of α-KG on MPN platelet activation. Ex vivo incubation of platelets from both MPN patients and Jak2 V617F knock-in mice with α-KG significantly reduced platelet surface P-selectin and integrin a2bb3 activation. Additionally, α-KG inhibited the spreading and adhesion of platelets from Jak2 V617F knock-in mice to fibrinogen-coated surfaces. Platelet phosphoblots demonstrated significant downregulation of p-STAT3, p-AKT and p-ERK after treatment with α-KG, suggesting these signaling pathways may be responsible for the inhibitory effects of α-KG on platelet activation. Thus, α-KG inhibited platelet activities in both human and mouse MPN samples. To test the therapeutic impact of α-KG on MPN disease features, we treated Jak2 V617F knock-in mice with α-KG for 6 weeks. Oral α-KG supplementation decreased splenomegaly and reduced elevated platelets and hematocrit. Additionally, monocytes were significantly decreased as early as 2 weeks after α-KG treatment in Jak2 V617F knock-in mice. In ex vivo studies with MPN patient CD34+ cells, α-KG treatment for 10 days led to a decrease in CD41+ CD61+ cells, suggesting decreased megakaryocyte commitment. We further observed that α-KG incubation significantly decreased the secretion of proinflammatory cytokines from sorted CD14+ human monocytes. Mass cytometry analysis of whole blood from MPN patients demonstrated inhibition of MAPK pathway signaling after α-KG treatment. Taken together, these results suggest that α-KG supplementation may exert therapeutic effects through both direct inhibition of MPN platelet activity and via quenching of monocyte hyper-inflammation (Figure 1B). In summary, these studies reveal a previously unrecognized metabolic disorder in platelets from MPN patients and highlight a prominent role for α-KG in aberrant MPN platelet activity and monocyte-driven inflammation. These findings have potential relevance for novel therapeutic approaches for MPN patients. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Effect of baricitinib in regulating programmed death 1 and ligand programmed cell death ligand 1 through JAK/STAT pathway in psoriasis.

OBJECTIVES:Psoriasis is a chronic infectious skin disease triggered by an autoimmune process involving T-cell-mediated hyper-proliferation of keratinocytes. The objective of this study is to assess the modulation of programmed death 1 (PD-1) and its ligand programmed cell death ligand 1 (PD-L1) through JAK/STAT pathway during the development of a psoriasis-like disease by both in vitro and in vivo model. Baricitinib, a known inhibitor of JAK1 and JAK2, was used to study the impact on PD-1 and PD-L1.MATERIALS AND METHODS:Human peripheral blood mononuclear cells (PBMC) were stimulated with either anti-CD3/CD28 or PMA/Ionomycin, to modulate level of PD-1 and PD-L1 under psoriasis-like condition. Interferon-gamma (IFNγ) was used to treat HaCaT cells to mimic the diseased keratinocytes found in Psoriatic patients. Psoriasis was induced with Imiquimod (IMQ) in animal model to study the cross-talk between different cell types and pathways.RESULTS:Expression levels of PD-1 and PD-L1 in PBMC, and secretion of cytokines, namely tumor necrosis factor-α (TNFα), IFNγ, interleukin (IL)-6, and IL-1 β, were down-regulated on treatment with baricitinib. Further, in IFNγ-treated HaCaT cells (keratinocytes) mRNA levels of KRT-17 and PD-L1 were up-regulated.). Interestingly, in IFNγ-treated HaCat cells baricitinib decreased the levels of inflammatory cytokines such as IL-1 β, IL-6, and TNFα along with KRT-17 and PD-L1. On IFNγ-treatment. Data from both PBMC and HaCaT suggest an anti-inflammatory role for this compound. Accordingly, baricitinib was able to alleviate disease symptom in IMQ induce mice model of psoriasis. As a consequence of baricitinib treatment down-regulation of p-STAT3, PD- and PD-L1 expression levels were observed.CONCLUSION:This study demonstrates a crosstalk between JAK/STAT and PD-1/PD-L1 pathways. It also demonstrates that cytokines such as IFNγ and IL-17 are down-regulated by baricitinib. We believe decreased expressions of PD-1 and PD-L1 may be a consequence of baricitinib-induced down-regulation of IFNγ and IL-17. More importantly, our data from the acute model of psoriasis indicates that PD-L1 behaves as a T-cell-associated T-cell-associated surrogate activation marker rather than immunosuppressive marker in early phase of psoriasis. Therefore it does not exhibit a causal relationship to disease.

RBM8A Promotes Glioblastoma Growth and Invasion Through the Notch/STAT3 Pathway.

BackgroundGlioblastoma (GBM) is a prevalent brain malignancy with an extremely poor prognosis, which is attributable to its invasive biological behavior. The RNA-binding motif protein 8A (RBM8A) has different effects on various human cancers. However, the role of RBM8A in GBM progression remains unclear.MethodsWe investigated the expression levels of RBM8A in 94 GBM patients and explored the correlation between RBM8A expression and patient prognosis. Using in vitro and in vivo assays, combined with GBM sequencing data from the Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA), we examined whether and how RBM8A contributes to GBM progression.ResultsRBM8A was up-regulated in GBM tissues, and its higher expression correlated with worse prognosis. Knockdown of RBM8A inhibited GBM progression and invasion ability both in vitro and in vivo. On the contrary, overexpression of RBM8A promoted GBM progression and invasion ability. Enrichment analysis of differentially expressed genes in GBM data identified the Notch1/STAT3 network as a potential downstream target of RBM8A, and this was supported by molecular docking studies. Furthermore, we demonstrated that RBM8A regulates the transcriptional activity of CBF1. The γ-secretase inhibitor DAPT significantly reversed RBM8A-enhanced GBM cell proliferation and invasion, and was associated with down-regulation of p-STAT3 and Notch1 protein. Finally, the gene set variance analysis score of genes involved in regulation of the Notch1/STAT3 network by RBM8A showed good diagnostic and prognostic value for GBM.ConclusionsRBM8A may promote GBM cell proliferation and migration by activating the Notch/STAT3 pathway in GBM cells, suggesting that RBM8A may serve as a potential therapeutic target for the treatment of GBM.

Everolimus Shows Synergistic Anti-Myeloma Effects with Bortezomib Via the AKT/mTOR Pathway

Introduction: Multiple myeloma (MM) is characterized by the proliferation of malignant plasma cells and a subsequent overabundance of monoclonal paraprotein (M protein). Everolimus ,as an oral mammalian target of rapamycin (mTOR) inhibitor, plays an important role in multiple myeloma. In the phase I trial explored the use of everolimus in relapsed and/or refractory multiple myeloma patients ,the median time to progression was 90 days (range, 13 to 278 days),and no dose-limiting toxicity was observed at daily dose of 10 mg. At the same time, the observed responses are promising in some testing combination strategies. The pre-clinical activity of pan-histone deacetylase inhibitor LBH589 in combination with everolimus caused potent G0/G1 arrest and induced pronounced apoptosis, the combination led to down regulation of pStat3, cyclins, CDKs and XIAP and up regulation of pro-apoptotic Bcl-2 family proteins. Everolimus enhances the cytotoxicity of bendamustine in multiple myeloma cells through a network of pro-apoptotic and cell-cycle-progression regulatory proteins.Down regulation of vascular endothelial cell growth factor and everolimus synergistic antitumor activity in multiple myeloma cells. Furthermore, In a phase I study of everolimus in combination with lenalidomide in relapsed or refractory multiple myeloma patients, the overall response rate was 65% and median progression-free survival was 5.5 months. Bortezomib was the first therapeutic proteasome inhibitor to be tested in humans with MM. However, the combination of bortezomib and everolimus for the treatment of MM is still less reported.Methods: To evaluate the in vitro and in vivo anti-tumor activity of the combination of everolimus with bortezomib.CCK-8 was used to explore the proliferation of MM cells. Flow cytometry was used to determine the effect on apoptosis of cells.Western blot and Immunohistochemical staining was used to determine the epression of proteins.Results: In our study, the experimental results demonstrated that everolimus combined with bortezomib suppressed cell proliferation. Treatment with 20 nM everolimus in combination with 10 nM bortezomib for 72h achieved the lowest cell survival rate in both U266 and LP-1 MM cell lines. The combination of everolimus and bortezomib was synergistic in both cell lines indicated by combination index (CI) values of <0.8.Flow cytometry was used to determine the effect on apoptosis of bortezomib in combination with everolimus. everolimus alone and bortezomib alone induced approximately 22.5% and 17.2% apoptosis, combination treatment induced28.8% apoptosis in U266 cells, and the results were 15.6%,10.0% and 16.7% in LP-1 cells. Western blot was used to explore the mechanisms. The expression of AKT1, mTOR, p70S6K1, 4EBP1 and NF-kB was significantly down regulated while the expression of Caspase-3was significantly up regulated in combination group than other alone group. Furthermore, Synergistic antitumor effect of everolimus and bortezomib was observed in the animal model carrying the myeloma xenograft on the 25th day after tumor implantation . The results of immunohistochemical staining further demonstrated that the expression of AKT1, mTOR, p70S6K1, 4EBP1 and NF-kB was significantly down regulated and the expression of Caspase-3 was significantly up regulated in combination group.Conclusion:Our results shows synergistic antitumor effects of the combination therapy of bortezomib and everolimus induced myeloma cell apoptosis in vitro and in vivo xenograft mouse model ,which mainly through the inhibition of the AKT/mTOR pathway. Our results provided provide a rationale application for the combinatorial treatment of MM with proteasome inhibitor agents and mTOR inhibitors in future clinical practice. DisclosuresNo relevant conflicts of interest to declare.

Generation and Application of T-Cell Lymphoma Patient Derived Tumor Xenograft Models

Introduction:Although pivotal “driver mutations” have been described in T-cell lymphomas (T-NHL), targetable dependences are lacking for many entities. As result, T-NHL patients experience dismal therapeutic responses and have a poor survival. Therapeutic improvements have been hindered by the lack of informative models. Patient-Derived-Tumor-Xenografts (PDTX), recapitulating many of the biological features of primary cancers, represent a novel and powerful platform. Here, we constructed a library of T-NHL PDTX to foster drug discovery programs and new patient-tailored approaches.Methods:Fresh and/or viable cryopreserved samples from primary T-NHL were obtained from Turin, WCM, and MSKCC hospitals. For the initial tumorgraft implants, lymphoma fragments, PBMC or bone marrow cells were implanted in NSG-B2m mice. Seeds from arising tumors were then serially transplanted. MRI was used to follow tumor growth and dissemination. The lymphoma phenotype was assessed by multi-channel flow cytometry and immunohistochemistry. We used TCR gene rearrangement analyses, whole exome sequencing (WES), total RNAseq, and CHIP-Seq (STAT3, methylation marks) to annotate primary and PDTX samples. For the in vitro studies, PDTX were digested and stromal cells were excluded by panning. Enriched Patient-Derived Tumor Cells (PDTC) were cultured in either RPMI/20% FBS or StemSpan/10% KSR media. High-throughput drug screening was performed using a library of 432 compounds (1 µM for 72hrs). Cell titer glo/blue, trypan blue cell count, and annexin-V/7AAD were used to assess cell viability, apoptosis, and proliferation.Results:We implanted 123 fresh T-NHL samples, resulting in the generation of 41 PDTX lines (Fig.1). In addition, 14 implants led to the growth of lymphoblastoid EBV+ populations. All PDTX lines were successfully propagated (5-26 serial passages) with the exception of angioimmunoblastic T-cell lymphoma (AITL) PDTX, which displayed a delay in engraftment over time, and eventually ceased growing (passage 3-7). Serially propagated PDTX showed distinct immunophenotypic profiles, which closely reflected their corresponding primary samples. TCR gene rearrangement studies confirmed the faithful correspondence between donor and PDTX over different generations. WES and total RNA-Seq on primary and serially propagated PDTX (at least T1-T5) yielded a rich landscape of mutations shared by primary tumors and PDTX derivatives. On going mutations were also defined along propagations. CHIP-Seq assay defined a STAT3 classifier in STAT+ PDTC.In vitro, all PDTC were shortly maintained (<7days), with some surviving for 6-8 weeks. To overcome their limited growth in vitro, we tested whether stromal cells (i.e. E4-Endothelial cells, E4-EC) could enhance their survival and/or growth. Indeed, co-culturing of PDTC with E4-ECs rescued cell death induced by ex vivo long-term propagation (peripheral T-cell lymphoma not otherwise specified and NK/T-Cell Lymphoma, PTCL-NOS and NK) or starvation (anaplastic large cell lymphoma, ALCL).PDTC were also used to perform a drug screening targeting major signaling pathways (>3x replicates of 8 ALCL, 1 NK, and 2 PTCL-NOS), demonstrating that each PDTX exhibited a unique drug sensitivity profile, mostly dictated by its genomic landscape. This was epitomized by two PDTC (IL-2 and IL-19) derived from the same PTCL-NOS patient bearing an activating V658F JAK1 somatic mutation. These two PDTC, once exposed to JAK inhibitors, displayed down-regulation of pSTAT3 (24hr) and massive cell death (T3-T6, >95% at 72hrs). Similar results were seen with ALK inhibitors in ALK+ ALCL PDTC (n=5). Moreover, specific drugs were identified to bypass refractory phenotypes in selective PDTC (i.e. proteasome and topoisomerase inhibitors).Conclusions:We built up a large and representative PDTX library from major T-NHL entities. Immunophenotyping, genomics and functional studies showed a close correspondence between primary samples and correspondent PDTX derivatives. Our in vitro models provide a starting point for elucidating stromal:tumor cell interactions that contribute to lymphoma growth and survival in vivo, and evidence that a drug screening can be successfully executed on PDTCs. We predict that this cohort may be a valuable tool for testing novel therapeutic compounds and fostering personalized therapeutic approaches in T-NHL patients. [Display omitted] DisclosuresThompson:Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Other: Founder; Merck: Membership on an entity's Board of Directors or advisory committees; Charles River Laboratories: Membership on an entity's Board of Directors or advisory committees. Aster:Eli Lilly and Company: Membership on an entity's Board of Directors or advisory committees. Ruan:Cell Medica: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Dogan:Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Peer Review Institute: Consultancy; Celgene: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche Pharmaceuticals: Consultancy. Cerchietti:Celgene: Research Funding; Lymphoma Research Foundation: Research Funding; Leukemia and Lymphoma Society: Research Funding; Weill Cornell Medicine - New York Presbyterian Hospital: Employment. Horwitz:Celgene: Consultancy, Research Funding; Kyowa-Hakka-Kirin: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; BMS: Consultancy; HUYA: Consultancy; Aileron Therapeutics: Research Funding; ADCT Therapeutics: Research Funding; Millenium/Takeda: Consultancy, Research Funding; Mundipharma: Consultancy; Forty-Seven: Consultancy, Research Funding.

CD44 Targeted Nanomaterials for Treatment of Triple-Negative Breast Cancer

Simple SummaryTriple-negative breast cancer (TNBC) is one of the most challenging tumors with aggressive behavior, low recovery rate, poor prognosis, high metastatic potential, and rapid relapse compared to other breast cancer subtypes. Conventional therapies currently have minimal effect on TNBC; thus, using combination therapies is a valid strategy to enhance drug activity and minimize the overall adverse effect. Therefore, combining drugs with a different mechanism of actions such as apoptosis inducers and JAK/STAT3 inhibitors improved TNBC cell lines killing activity in vitro and in vivo. To further improve the hydrophobic drug activity, CD44 targeted polymeric nanoparticles (CD44-T-PNPs) were utilized by encapsulating hydrophobic drug (CFM-4.16) in CD44-T-PNPs to enhance the drug solubility, tumor accumulation, and most importantly, enhance drug potency. Tagging our PNPs with Hyaluronic acid (HA) enhanced tumor accumulation, reduced off-target distribution, and improved therapeutic efficacy.Identified as the second leading cause of cancer-related deaths among American women after lung cancer, breast cancer of all types has been the focus of numerous research studies. Even though triple-negative breast cancer (TNBC) represents 15–20% of the number of breast cancer cases worldwide, its existing therapeutic options are fairly limited. Due to the pivotal role of the presence/absence of specific receptors to luminal A, luminal B, HER-2+, and TNBC in the molecular classification of breast cancer, the lack of these receptors has accounted for the aforementioned limitation. Thereupon, in an attempt to participate in the ongoing research endeavors to overcome such a limitation, the conducted study adopts a combination strategy as a therapeutic paradigm for TNBC, which has proven notable results with respect to both: improving patient outcomes and survivability rates. The study hinges upon an investigation of a promising NPs platform for CD44 mediated theranostic that can be combined with JAK/STAT inhibitors for the treatment of TNBC. The ability of momelotinib (MMB), which is a JAK/STAT inhibitor, to sensitize the TNBC to apoptosis inducer (CFM-4.16) has been evaluated in MDA-MB-231 and MDA-MB-468. MMB + CFM-4.16 combination with a combination index (CI) ≤0.5, has been selected for in vitro and in vivo studies. MMB has been combined with CD44 directed polymeric nanoparticles (PNPs) loaded with CFM-4.16, namely CD44-T-PNPs, which selectively delivered the payload to CD44 overexpressing TNBC with a significant decrease in cell viability associated with a high dose reduction index (DRI). The mechanism underlying their synergism is based on the simultaneous downregulation of P-STAT3 and the up-regulation of CARP-1, which has induced ROS-dependent apoptosis leading to caspase 3/7 elevation, cell shrinkage, DNA damage, and suppressed migration. CD44-T-PNPs showed a remarkable cellular internalization, demonstrated by uptake of a Rhodamine B dye in vitro and S0456 (NIR dye) in vivo. S0456 was conjugated to PNPs to form CD44-T-PNPs/S0456 that simultaneously delivered CFM-4.16 and S0456 parenterally with selective tumor targeting, prolonged circulation, minimized off-target distribution.

Enhanced immune responses, PI3K/AKT and JAK/STAT signaling pathways following hepatitis C virus eradication by direct-acting antiviral therapy among Egyptian patients: a case control study.

The use of direct-acting antivirals (DAAs) therapy for the treatment of hepatitis C virus (HCV) results in a high-sustained virological response (SVR) and subsequently alters liver immunologic environment. However, hepatocellular carcinoma (HCC) may occur after DAAs treatment. We aimed to clarify changes of immune responses, PI3K/AKT and JAK/STAT signaling pathways in HCV-induced liver diseases and HCC following DAAs treatment. Four cohorts were classified as chronic HCV patients, HCV-related cirrhosis without HCC, HCV-related cirrhosis and HCC, and healthy control group. The patient groups were further divided into treated or untreated with DAAs with SVR12. Increased percentages of CD3, CD8 and CD4, decreased CD4/FoxP3/CD25, CD8/PD-1 and CD19/PDL-1 were found in DAAs-treated patients in the three HCV groups. Following DAAs therapy, the levels of ROS, IL-1β, IL-6, IL-8 and TNF-α were significantly decreased in the three HCV groups. Treated HCV patients showed up regulation of p-AKT and p-STAT5 and down regulation of p-STAT3, HIF-1α and COX-2. In conclusion, DAAs enhance the immune response in chronic HCV and liver cirrhosis, hence our study is the first to show change in PI3K/AKT and JAK/STAT signaling pathways in different HCV-induced liver diseases after DAAs. In chronic HCV, DAAs have better impact on the immune response while in liver cirrhosis not all immune changes were prominent.

Apigenin inhibits proliferation of hepatocellular carcinoma cell by upregulation of cleaved caspases-3/8 and downregulation of pSTAT-3/pJAK-1/pJAK-2

Apigenin is a flavonoid nutrient and possesses antineoplastic actions. Cell proliferation inhibition, induction of apoptosis, cell cycle arrest and inhibition of cancer cell spread were assessed. HepG2 cells were divided into 3 groups: HepG2/control group, HepG2/DMSO group and HepG2/Apigenin group. HepG2 cells were cultured for 24, 48 and 72 h. Apigenin was supplemented on HepG2 (100 μM). Cell viability was assessed. qRT-PCR was applied for PARP, Bcl-2 and Bax genes expression. Western blot was estimated for cleaved caspases-3/8, HIF-α, and pSTAT-3/pJAK-1/pJAK-2 proteins. VEGF level was assessed by ELISA in cell culture supernatants. Finally, ultrastructure examination of cell culture pellet by transmission electron microscope (TEM) was determined. The results revealed that cleaved caspases-3/8 and Bax were significantly upregulated and the level of PARP, BcL-2, HIF-α, pSTAT-3, pJAK-1, pJAK-2 and VEGF were significantly downregulated in apigenin group compared to control groups.

Phosphorylated STAT3 suppresses microRNA-19b/1281 to aggravate lung injury in mice with type 2 diabetes mellitus-associated pulmonary tuberculosis.

Type 2 diabetes mellitus (T2DM) is a risk factor for pulmonary tuberculosis (PTB) and increased mortality. This work focused on the functions of phosphorylated STAT3 in lung injury in mouse with T2DM‐associated PTB and the molecules involved. A mouse model with T2DM‐PTB was induced by administrations of streptozotocin, nicotinamide and mycobacterium tuberculosis (Mtb). A pSTAT3‐specific inhibitor AG‐490 was given into mice and then the lung injury in mice was observed. The molecules involved in AG‐490‐mediated events were screened out. Altered expression of miR‐19b, miR‐1281 and NFAT5 was introduced to identify their involvements and roles in lung injury and PTB severity in the mouse model. Consequently, pSTAT3 expression in mice with T2DM‐associated PTB was increased. Down‐regulation of pSTAT3 by AG‐490 prolonged the lifetime of mice and improved the histopathologic conditions, and inhibited the fibrosis, inflammation, Mtb content and number of apoptotic epithelial cells in mouse lung tissues. pSTAT3 transcriptionally suppressed miR‐19b/1281 expression to up‐regulate NFAT5. Inhibition of miR‐19b/1281 or up‐regulation of NFAT5 blocked the protective roles of AG‐490 in mouse lung tissues. To conclude, this study evidenced that pSTAT3 promotes NFAT5 expression by suppressing miR‐19b/1281 transcription, leading to lung injury aggravation and severity in mice with T2DM‐associated PTB.

Mifamurtide and TAM-like macrophages: effect on proliferation, migration and differentiation of osteosarcoma cells.

Tumor-associated macrophages and their alternative activation states together with cytokines and growth factors trapped in tumor microenvironment contribute to the progression of OS. In contrast to other tumor types, M2 polarized macrophages, reduce metastasis and improve survival in osteosarcoma patients. Mifamurtide is an immunomodulatory drug given together with standard adjuvant chemotherapy in high-grade osteosarcoma to improve outcome. Macrophages obtained from peripheral blood mononucleated cells of healthy donors and MG63 cells were cultured alone and together, and treated with Mifamurtide. We analyzed the effects of Mifamurtide on macrophage polarization and on MG63 proliferation, migration and differentiation, evaluating the expression of M1/M2 and osteoblast markers and molecules involved in metastasis and proliferation pathways.Our data suggest that Mifamurtide, switching macrophage polarization towards a TAM-like intermediate M1/M2 phenotype, may modulate the delicate balance between pro-inflammatory and immunomodulatory macrophage functions. Moreover, Mifamurtide may inhibit the cellular proliferation and induce the tumor cell differentiation, probably through the down regulation of pSTAT3, pAKT and IL-17R.

Luteolin Alters Macrophage Polarization to Inhibit Inflammation.

Luteolin is a natural flavonoid compound derived from vegetables, fruits, and herbs with potent anti-inflammatory activity. Macrophage polarization is important in the development and progression of inflammation. However, whether luteolin can inhibit inflammation by regulating the polarized phenotypes of macrophages remains unknown. The aim of this study was to investigate the effects of luteolin on the inflammatory polarization of macrophages and the underlying mechanisms. RAW264.7 macrophages were induced to M1 polarization by stimulation with lipopolysaccharide plus interferon-γ or to M2 polarization with interleukin 4 (IL-4), simultaneously, accompanied with different concentrations of luteolin. Laser confocal microscopy was used to observe cell morphology; flow cytometry was employed to detect the expression of membrane surface molecule CD86 and CD206; qPCR was performed to examine the mRNA expression of M1 markers (iNOS, IL-1β, IL-6) and M2 markers (Arg1, CD206, CD163, IL-10, and IL-13), respectively; ELISA was used to examine the levels of IL-6, TNF-α, and IL-10; and Western blotting was used to evaluate the p-STAT3 and p-STAT6 protein pathway. The morphology of activated M1 macrophages changed significantly, developing dendritic characteristics. After luteolin treatment, the expression of M1-type proinflammatory mediators and the surface marker CD86 were decreased evidently, but those of M2-related anti-inflammatory factors and CD206 were increased markedly. Moreover, p-STAT3 was downregulated and p-STAT6 was upregulated in a dose-dependent manner. Conclusion, luteolin can alter the M1/M2 polarization of macrophages, thereby playing an anti-inflammatory role via downregulation of p-STAT3 and upregulation of p-STAT6. Therefore, luteolin may be potentially valuable to inhibit inflammation.

Polo-like kinase 3 inhibits glucose metabolism in colorectal cancer by targeting HSP90/STAT3/HK2 signaling

BackgroundPolo-like kinase 3 (PLK3) has been documented as a tumor suppressor in several types of malignancies. However, the role of PLK3 in colorectal cancer (CRC) progression and glucose metabolism remains to be known.MethodsThe expression of PLK3 in CRC tissues was determined by immunohistochemistry. Cells proliferation was examined by EdU, CCK-8 and in vivo analyses. Glucose metabolism was assessed by detecting lactate production, glucose uptake, mitochondrial respiration, extracellular acidification rate, oxygen consumption rate and ATP production. Chromatin immunoprecipitation, luciferase reporter assays and co-immunoprecipitation were performed to explore the signaling pathway. Specific targeting by miRNAs was determined by luciferase reporter assays and correlation with target protein expression.ResultsPLK3 was significantly downregulated in CRC tissues and its low expression was correlated with worse prognosis of patients. In vitro and in vivo experiments revealed that PLK3 contributed to growth inhibition of CRC cells. Furthermore, we demonstrated that PLK3 impeded glucose metabolism via targeting Hexokinase 2 (HK2) expression. Mechanically, PLK3 bound to Heat shock protein 90 (HSP90) and facilitated its degradation, which led to a significant decrease of phosphorylated STAT3. The downregulation of p-STAT3 further suppressed the transcriptional activation of HK2. Moreover, our investigations showed that PLK3 was directly targeted by miR-106b at post-transcriptional level in CRC cells.ConclusionThis study suggests that PLK3 inhibits glucose metabolism by targeting HSP90/STAT3/HK2 signaling and PLK3 may serve as a potential therapeutic target in colorectal cancer.

Dovitinib Triggers Apoptosis and Autophagic Cell Death by Targeting SHP-1/p-STAT3 Signaling in Human Breast Cancers.

Breast cancer is the most common cancer and the leading cause of cancer deaths in women worldwide. The rising incidence rate and female mortality make it a significant public health concern in recent years. Dovitinib is a novel multitarget receptor tyrosine kinase inhibitor, which has been enrolled in several clinical trials in different cancers. However, its antitumor efficacy has not been well determined in breast cancers. Our results demonstrated that dovitinib showed significant antitumor activity in human breast cancer cell lines with dose- and time-dependent manners. Downregulation of phosphor-(p)-STAT3 and its subsequent effectors Mcl-1 and cyclin D1 was responsible for this drug effect. Ectopic expression of STAT3 rescued the breast cancer cells from cell apoptosis induced by dovitinib. Moreover, SHP-1 inhibitor reversed the downregulation of p-STAT3 induced by dovitinib, indicating that SHP-1 mediated the STAT3 inhibition effect of dovitinib. In addition to apoptosis, we found for the first time that dovitinib also activated autophagy to promote cell death in breast cancer cells. In conclusion, dovitinib induced both apoptosis and autophagy to block the growth of breast cancer cells by regulating the SHP-1-dependent STAT3 inhibition.

Inhibition of STAT3 in gastric cancer: role of pantoprazole as SHP-1 inducer

BackgroundWe investigated the inhibitory effect of pantoprazole on signal transducer and activator of transcription 3 (STAT3) activity and invasiveness of gastric adenocarcinoma cells, and the role of SH2-containing protein tyrosine phosphatase 1 (SHP-1) in mediating role.MethodsWe used AGS and MKN-28 cells because of reduced SHP-1 and preserved p-STAT3 expression. Western blot, wound closure assay, Matrigel invasion assay and 3-D culture invasion assay were performed. Pharmacologic inhibitor of SHP-1 and siRNA were used for validation of the role of SHP-1.ResultsWe observed that pantoprazole at 40, 80, and 160 μg/ml upregulated SHP-1 and downregulated p-STAT3 expression in a dose-dependent manner in AGS and MKN-28 cells. Furthermore, pantoprazole significantly downregulated mesenchymal markers (Snail1 and vimentin), upregulated epithelial marker (E-cadherin), and inhibited migration and invasion of AGS and MKN-28 cells. To validate the role of SHP-1 in inhibition of STAT3 activity by pantoprazole in gastric cancer cells, we performed pharmacologic inhibition (pervanadate) or knockdown of SHP-1 before pantoprazole treatment, which significantly attenuated the suppression of p-STAT3 and anti-migration and invasion effect by pantoprazole in AGS cells. In xenograft tumor model, tumor volume was significantly reduced by intraperitoneal injection of pantoprazole, with upregulation of SHP-1 and downregulation of p-STAT3, which were attenuated by concomitant injection of pervanadate.ConclusionOur data suggest that the inhibitory effect of pantoprazole on cellular migration and invasion might be through inducing SHP-1 in gastric cancer cells.

Abstract 1876: INCB052793, a JAK1 selective inhibitor, is highly efficacious in PDX and xenograft models of acute myeloid leukemia (AML) expressing elevated endogenous pSTAT3/pSTAT5

Abstract Acute myeloid leukemia (AML) is characterized by infiltration of abnormally differentiated, clonal and highly proliferative cells of the hematopoietic system that acquire successive genomic alterations. AML is the most common acute leukemia in adults. Current therapies are of limited utility and involve a combination of cytarabine and anthracycline based regimens with allogeneic stem cell transplantation for eligible candidates, but there is an urgent need to improve therapies for AML. JAK/STAT pathway dysregulation plays a role in the pathogenesis of AML and the JAK2 V617F mutation is present in only a small percentage of these patients. Studies were conducted to evaluate the in vitro and in vivo activities of INCB052793, a highly JAK1-selective inhibitor having 100-fold selectivity for JAK1 over JAK2 in cell lines, xenograft and PDX models of human AML having elevated endogenous pSTAT3 and or pSTAT5 activation. In vitro, INCB052793 effectively inhibited p-Stat3 and/or p-Stat5 phosphorylation MV411, Molm 16 and Molm 13 cell lines and caused marked reductions in p-Akt and c-Myc levels in MV411 and Molm16 cells. Given these observations, oral administration of INCB052793 was evaluated at doses of 3-30 mg/kg twice daily in MOLM-16 xenografts and FLT3-ITD AML xenograft models, MV-4-11 and Molm-13, in SCID mice. INCB052793 administration significantly inhibited tumor growth in MOLM-16 xenografts in a dose dependent manner and resulted in complete downregulation of p-Stat3 and p-Stat5 levels in MOLM-16 tumors. Similarly, INCB052793 administration was highly effective in inhibiting tumor growth in FLT3-ITD AML models, MV-4-11 and Molm-13. Administration of INCB052793 in a systemic PDX model of AML with elevated endogenous levels of p-Stat3 and p-Stat5 resulted in amelioration of disease severity and demonstrated a significant effect on median survival in leukemic SCID mice. All dosing regimens of INCB052793 in both xenograft and PDX models were well tolerated. Since azacitidine and cytarabine are standards of care for the treatment of AML, the efficacy of INCB052793 was benchmarked against optimal dosing regimens of these agents. In the AML xenograft models evaluated, INCB052793 was comparably or more efficacious in reducing tumor burden than azacitidine and cytarabine. The combination of INCB052793 with cytarabine showed superior efficacy in comparison to single agents in the MOLM-16 xenograft model, and combinatorial studies are in progress in additional AML models. These findings suggest the therapeutic potential of INCB052793 as a single agent and in combination with standard of care chemotherapeutic regimens for the management of AML. Citation Format: Ashish Juvekar, Sindy Condon, Xiaoming Wen, Bruce Ruggeri, Peggy Scherle, Reid Huber, Yunlong Li, Wenqing Yao, Song Mei, Deepak Bhasin, Maria Mancini. INCB052793, a JAK1 selective inhibitor, is highly efficacious in PDX and xenograft models of acute myeloid leukemia (AML) expressing elevated endogenous pSTAT3/pSTAT5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1876.

STAT3-siRNA induced B16.F10 melanoma cell death: more association with VEGF downregulation than p-STAT3 knockdown

STAT3 knockdown by small interfering RNA (siRNA) has been described to inhibit carcinogenic growth in various types of tumors. Earlier we have reported delivery of siRNA by oleic acid- and stearic acid-modified-polyethylenimine and enhancement of silencing of STAT3 by small interfering RNA (siRNA) in B16.F10 melanoma cell lines and consequent tumor suppression. Present investigation mainly focused on the downstream events involved in B16.F10 melanoma cell death and consequent tumor suppression following knockdown of p-STAT3 by siRNA. Lipid-substituted polyethylenimine (PEI)-p-STAT3-siRNA were prepared and characterized by measuring its N/P ratio, zeta potential, size, association and dissociation with siRNA. B16.F10 melanoma cells were treated with six different concentrations of PEI-p-STAT3-siRNA (200, 100, 50, 25, 12.5 and 6.25 nM). Downregulation of p-STAT3 and VEGF were studied using western blot and ELISA in association with the melanoma cell death. PEI-p-STAT3-siRNA hydrodynamic diameter ranged from 110 to 270 nm. PEI assisted p-STAT3-siRNA delivery exhibited increased uptake by B16.F10, when analyzed by fluorescent and confocal microscopy along with flowcytometry. It induced concentration-dependent knockdown of the p-STAT3 that also downregulated VEGF expression in similar fashion and induced B16.F10 cell death. Higher concentrations of p-STAT3-siRNA appear to significantly downregulate the VEGF expression via p-STAT3 knockdown. Decreasing survival of B16.F10 cells with the increasing concentration of p-STAT3-siRNA significantly correlated with VEGF downregulation, not with p-STAT3 expression. Data suggest that VEGF downregulation following knockdown of p-STAT3 may be a key event in survival reduction in B16.F10 melanoma cells and.

Abstract 2074: Targeting SHP-1 mediated VEGF signaling to block the migration of human triple negative breast cancer

Abstract Patients with triple-negative breast cancer (TNBC) had an increased likelihood of distant recurrence and death, as compared with those with non-TNBC subtype. Regorafenib is a multi-receptor tyrosine kinase (RTK) inhibitor targeting oncogenesis and has been approved for metastatic colorectal cancer and advanced gastrointestinal stromal tumor. Recently, scientists have suggested that regorafenib also acts as a SHP-1 phosphatase agonist. In this study, we aimed to investigate the role of regorafenib in suppressing metastasis of TNBC cells through targeting the SHP-1/p-STAT3/VEGF-A axis. We first observed a significant correlation between migration ability and SHP-1/p-STAT3/VEGF-A expression in several human TNBC cell lines. Importantly, we also demonstrated that VEGF-A expression is correlated with worse disease-free and distant metastasis-free survival in clinical TNBC patients. Furthermore, we showed that regorafenib could inhibit the migration of human TNBC cells, which was related to downregulation of p-STAT3 and VEGF-A. To exclude the role of RTK inhibition in regorafenib-induced anti-metastasis, we synthesized a regorafenib derivative, SC-78, that had minimal effect on VEGFR2 and PDGFR kinase inhibition, while having more potent effects on SHP-1 activation. SC-78 demonstrated superior in vitro and in vivo anti-migration to regorafenib. This study indicated that the SHP-1/p-STAT3/VEGF-A axis is a potential therapeutic target for metastatic TNBC, and SC-78 may be a promising lead compound for suppressing metastasis of TNBC. (Grant supported by MOST 104-2628-B-075-001-MY3, MOST 105-2325-B-010-007, 105F026 ) Citation Format: Jung-Chen Su, Ai-Chung Mar, Chun-Yu Liu, Kuen-Feng Chen, Chung-Wai Shiau. Targeting SHP-1 mediated VEGF signaling to block the migration of human triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2074. doi:10.1158/1538-7445.AM2017-2074

Metformin inhibits proliferation and growth hormone secretion of GH3 pituitary adenoma cells.

Metformin is an anti-hyperglycemic agent used to treat diabetes, and recent evidence suggests it has antitumor efficacy. Because growth hormone-secreting pituitary adenoma (GH-PA) patients have a high incidence of diabetes frequently treated with metformin, we assessed the antitumor effect of metformin on GH-PA. We found that metformin effectively inhibited proliferation and induced apoptosis in the GH-PA cell line GH3. We detected a decrease in mitochondrial membrane potential (MMP), an increase in expression of pro-apoptotic proteins, and a decrease in expression of an anti-apoptotic protein in metformin-treated GH3 cells, which suggests involvement of the mitochondrial-mediated apoptosis pathway. Inhibition of AMPK, which is activated by metformin, failed to reverse the antiproliferative effect. ATF3 was upregulated by metformin, and its knockdown significantly reduced metformin-induced apoptosis. In addition, GH secretion was inhibited by metformin through suppression of STAT3 activity independently of AMPK. Metformin also significantly suppressed cellular proliferation and GH secretion in primary human GH-PA cells. Metformin also significantly inhibited GH3 cell proliferation and GH secretion in vivo. ATF3 upregulation and p-STAT3 downregulation were confirmed in xenografts. These findings suggest metformin is a potentially promising therapeutic agent for the treatment of GH-PA, particularly in patients with diabetes.