Signal Transducer And Activator Of Transcription 3 Axis Research Articles

Long non-coding RNA TMEM147 antisense RNA 1/microRNA-124/signal transducer and activator of transcription 3 axis in estrogen receptor-positive breast cancer.

This research aimed to probe the expression of long noncoding RNA TMEM147 antisense RNA 1 (TMEM147-AS1)/micro-RNA (miR)-124/signal transducer and activator of transcription 3 (STAT3) axis in estrogen receptor (ER)-positive breast cancer (BC). Sixty ER-positive BC patients undergoing surgical treatment were gathered. TMEM147-AS1, miR-124, and STAT3 expression levels in BC cells and tissues were measured. The binding sites of TMEM147-AS1 and miR-124, miR-124, and STAT3 were analyzed and validated. The miR-124, STAT3 overexpression (oe) sequences, TMEM147-AS1 oe, and interference sequences and their control sequences were planned and cells were transfected to assess their functions in BC cells biological functions. TMEM147-AS1, as well as STAT3 was extremely expressed and miR-124 was lowly expressed in BC cells and tissues. Interference with TMEM147-AS1 restrained ER-positive BC cell malignant activities. Mechanistically, TMEM147-AS1 could competitively bind miR-124 in refraining miR-124 expression, and STAT3 was a target gene of miR-124. Oe of miR-124 effectively reversed the enhancement of BC cell proliferation and invasion induced by TMEM147-AS1 upregulation. Oe of STAT3 could reverse the inhibitory effect of miR-124 on BC cell malignant behaviors. TMEM147-AS1 has oncogenic activity in ER-positive BC, which may be a result of the altered miR-124/STAT3 axis. Therefore, targeting the TMEM147-AS1/miR-124/STAT3 axis may be a target for ER-positive BC therapy.

KLHDC8A Regulates M1/M2 Macrophage Polarization Through the PD-1/STAT3 Pathway to Promote Papillary Thyroid Cancer Development.

Papillary thyroid cancer (PTC) is one of the most frequent endocrine malignancies. Kelch domain containing 8A (KLHDC8A) is reported as an epigenetically driven oncogene, but the role of KLHDC8A in PTC is still unclear. This study aimed to explore the function of KLHDC8A in PTC progression. KLHDC8A expression was analyzed by the Gene Expression Profiling Interactive Analysis (GEPIA) website, quantitative real-time PCR (qRT-PCR), and western blot. The viability of PTC cells (TPC-1 and BCPAP) was assessed by cell counting kit-8 (CCK-8) kit. A transwell assay was carried out to evaluate the invasion and migration of PTC cells. Macrophage polarization-associated markers were determined by qRT-PCR and western blot. Mice tumor xenograft models were established to analyze the role of KLHDC8A in vivo. Pathway-related proteins (programmed cell death protein 1 (PD-1) and signal transducer and activator of transcription 3 (STAT3)) were determined by western blot. GEPIA demonstrated that KLHDC8A was highly expressed in PTC (p < 0.05). Knockdown of KLHDC8A hindered cell viability, invasion, and migration of PTC cells (p < 0.0001). Additionally, KLHDC8A knockdown inhibited M2 polarization while promoting M1 polarization (p < 0.0001). Meanwhile, KLHDC8A silencing inhibited tumor growth in mice xenografted models (p < 0.0001). Moreover, the PD-1/STAT3 pathway was suppressed by KLHDC8A silencing (p < 0.01), and the STAT3 activator (colivelin) attenuated the inhibitory effects of KLHDC8A silencing on PTC progression (p < 0.01). Through in vivo and in vitro experiments, KLHDC8A silencing could restrain PTC cell viability, migration, and invasion, inhibit tumor growth, and promote M1 polarization via the PD-1/STAT3 axis, providing a new therapeutic idea for PTC clinical treatment.

Tumor-associated NK cells drive MDSC-mediated tumor immune tolerance through the IL-6/STAT3 axis.

Apart from their killer identity, natural killer (NK) cells have integral roles in shaping the tumor microenvironment. Through immune gene deconvolution, the present study revealed an interplay between NK cells and myeloid-derived suppressor cells (MDSCs) in nonresponders of immune checkpoint therapy. Given that the mechanisms governing the outcome of NK cell-to-myeloid cell interactions remain largely unknown, we sought to investigate the cross-talk between NK cells and suppressive myeloid cells. Upon contact with tumor-experienced NK cells, monocytes and neutrophils displayed increased expression of MDSC-related suppressive factors along with increased capacities to suppress T cells. These changes were accompanied by impaired antigen presentation by monocytes and increased ER stress response by neutrophils. In a cohort of patients with sarcoma and breast cancer, the production of interleukin-6 (IL-6) by tumor-infiltrating NK cells correlated with S100A8/9 and arginase-1 expression by MDSCs. At the same time, NK cell-derived IL-6 was associated with tumors with higher major histocompatibility complex class I expression, which we further validated with b2m-knockout (KO) tumor mice models. Similarly in syngeneic wild-type and IL-6 KO mouse models, we then demonstrated that the accumulation of MDSCs was influenced by the presence of such regulatory NK cells. Inhibition of the IL-6/signal transducer and activator of transcription 3 (STAT3) axis alleviated suppression of T cell responses, resulting in reduced tumor growth and metastatic dissemination. Together, these results characterize a critical NK cell-mediated mechanism that drives the development of MDSCs during tumor immune escape.

Sodium tanshinone IIA sulfonate suppresses microglia polarization and neuroinflammation possibly via regulating miR-125b-5p/STAT3 axis to ameliorate neuropathic pain

The spinal cord microglia play a pivotal role in neuroinflammation and neuropathic pain (NP). Sodium tanshinone IIA sulfonate (STS), a derivative of tanshinone IIA, has anti-inflammatory and anti-hyperalgesic effects. However, its underlying mechanism in NP remains unclear. This study aimed to investigate the effect of STS and elucidate possible mechanisms in a rat model of spared nerve injury. In vivo experiments, STS and AG490 were administered intraperitoneally once daily for 14 consecutive days after surgery. The results showed that the expression of miR-125b-5p in the spinal dorsal horn was substantially reduced, whereas signal transducer and activator of transcription 3 (STAT3) signaling was increased. After treatment with STS, the mechanical thresholds, expression of miR-125b-5p, and microglial M2 marker such as Arg-1 in the spinal cord horn increased significantly, whereas multiple pro-inflammatory cytokines and apoptosis were significantly reduced. Moreover, STAT3 pathway-related proteins and expression of the microglial M1 marker, CD68, were appreciably inhibited. In vitro, lipopolysaccharide (LPS) was used to induce an inflammatory response in BV-2 microglial cells. STS pretreatment inhibited LPS-stimulated pro-inflammatory cytokine secretion, reduced STAT3 pathway related-proteins and apoptosis, increased miR-125b-5p and proopiomelanocortin expression, and enhanced microglia transformation from M1 to M2 phenotype in BV-2 cells. These effects were reversed after the inhibition of miR-125b-5p expression in BV-2 cells. A dual-luciferase reporter assay confirmed that STAT3 binds to miR-125b-5p. In summary, these results suggest that STS exerts anti-hyperalgesic and anti-neuroinflammatory effects in rats with NP possibly via the miR-125b-5p/STAT3 axis.

MicroRNA-124 negatively regulates STAT3 to alleviate hypoxic-ischemic brain damage by inhibiting oxidative stress.

MicroRNA-124 (miR-124) is implicated in various neurological diseases; however, its significance in hypoxic-ischaemic brain damage (HIBD) remains unclear. This study aimed to elucidate the underlying pathophysiological mechanisms of miR-124 in HIBD. In our study performed on oxygen-glucose deprivation followed by reperfusion (OGD)/R-induced primary cortical neurons, a substantial reduction in miR-124 was observed. Furthermore, the upregulation of miR-124 significantly mitigated oxidative stress, apoptosis, and mitochondrial impairment. We demonstrated that miR-124 interacts with the signal transducer and activator of transcription 3 (STAT3) to exert its biological function using the dual-luciferase reporter gene assay. As the duration of OGD increased, miR-124 exhibited a negative correlation with STAT3. STAT3 overexpression notably attenuated the protective effects of miR-124 mimics, while knockdown of STAT3 reversed the adverse effects of the miR-124 inhibitor. Subsequently, we conducted an HIBD model in rats. In vivo experiments, miR-124 overexpression attenuated cerebral infarction volume, cerebral edema, apoptosis, oxidative stress, and improved neurological function recovery in HIBD rats. In summary, the neuroprotective effects of the miR-124/STAT3 axis were confirmed in the HIBD model. MiR-124 may serve as a potential biomarker with significant therapeutic implications for HIBD.

Long noncoding RNA MEG8 induces an imbalance of Th17/Treg cells through the miR-107/STAT3 axis in Henoch-Schonlein purpura rats.

T-helper (Th) 17/ T-regulatory (Treg) cell dysregulation underlies the pathogenesis of Henoch-Schonlein purpura (HSP). This research focused on the implication/s of the long noncoding RNA (lncRNAs) maternally expressed gene 8 (MEG8) in Th17 and Treg cell differentiation in HSP rats. MEG8, miR-107, signal transducer and activator of transcription-3 (STAT3), receptor-related orphan receptor γt (RORγt), and the transcription factor forkhead box P3 (Foxp3) expression levels were detected using real-time quantitative polymerase chain reaction and Western blot analyses. Flow cytometry was employed for measuring Th17 and Treg cells within the CD4+ T cell population. The interaction between miR-107 and MEG8 or STAT3 was examined. A low proportion of MEG8 and Treg cells together with Th17 cells were denoted within HSP rats. Moreover, MEG8 overexpression altered the Th17/Treg imbalance in peripheral blood CD4+ T-cell population, and the miR-107 mimic and STAT3 silencing reversed this effect. Thus, MEG8 served as a sponge for miR-107, lowering binding activity to STAT3 and thus overexpressing the molecule. Taken together, MEG8 induces an imbalance of Th17/Treg cells through the miR-107/STAT3 axis in HSP rats.

Exploring CircRNA N6-methyladenosine in human rheumatoid arthritis: Hyper-methylated hsa_circ_0007259 as a potential biomarker and its involvement in the hsa_circ_0007259/hsa_miR-21-5p/STAT3 axis

BackgroundN6-methyladenosine (m6A) is a highly enriched modification found in circular RNAs (CircRNAs); however, the ability and mechanism of CircRNAs to encode for m6A function in rheumatoid arthritis (RA) remain poorly understood. MethodsWe utilized an epitranscriptomic microarray to measure levels and quantities of m6A methylated CircRNAs in synovial tissues of patients with RA and osteoarthritis (OA). We then utilized methylated RNA immunoprecipitation- and MazF-quantitative PCR to identify and validate differentially m6A-methylated RNAs between the groups, conducted a functional enrichment analysis, and selected protein–protein interaction hub genes. Lastly, we predicted and validated the CircRNA/miRNA/mRNA interaction networks. ResultsWe detected 4,845 CircRNAs containing m6A in our samples, with 53 CircRNAs upregulated, and 139 CircRNAs downregulated compared to human OA synovial tissue (|fold change| ≥ 1.2 and p ≤ 0.05). The differentially m6A-modified CircRNAs were associated with the interleukin-6-mediated signaling pathway, with an increase in relative m6A-methylated levels of hsa_circ_0007259 in human RA, a significant decrease in hsa_miR-21-5p, and an increase in signal transducer and activator of transcription 3（STAT3）. The Luciferase Reporter Gene assay verified the binding of hsa_circ_0007259 to hsa_miR-21-5p and the subsequent binding of hsa_miR-21-5p to STAT3. ConclusionWe showed a notable increase in the relative m6A-methylated levels of hsa_circ_0007259 in human RA, indicating a potential role of hypermethylated hsa_circ_0007259 in RA pathogenesis. This may provide valuable insight into the mechanism of RA and the possibility of utilizing hsa_circ_0007259 as a valuable biomarker.

Role of IL-6/STAT3 Axis in Resistance to Cisplatin in Gastric Cancers.

Gastric cancer, the second most common cause of death worldwide, is characterized by poor prognosis and low responsiveness to chemotherapy. Indeed, multidrug resistance, based mainly on cellular and molecular factors, remains one of the most limiting factors of the current approach to gastric cancer (GC) therapy. We employed a comprehensive gene expression analysis through data mining of publicly available databases to assess the role of the signal transducer and activator of transcription 3 (STAT3) in gastric cancer drug efficiency. It has been proposed that gastric cancer cells are less sensitive to these drugs because they develop resistance to these agents through activating alternative signalling pathways responsible for overcoming pharmacological inhibition. Our study evaluated the hypothesis that activating STAT3 signalling in response to cisplatin reduces the reaction to the drug. Consistent with this hypothesis, inhibition of interleukin 6 (IL-6)/STAT3 in combination therapy with cisplatin prevented both STAT3 activation and more lethality than induction by a single agent. The data suggest that the IL-6/STAT3 axis block associated with cisplatin treatment may represent a strategy to overcome resistance.

KCNQ1OT1 sponges miR-34a to promote malignant progression of malignant melanoma via upregulation of the STAT3/PD-L1 axis.

Malignant melanoma is a leading cause of skin cancer-related death. In over 30% of cases, the melanoma is invasive and has a metastatic phenotype. KCNQ1 overlapping transcript 1 (KCNQ1OT1) was previously identified as an oncogenic long noncoding RNA (lncRNA). Our study intends to uncover the mechanism of KCNQ1OT1 functioning in melanoma. qRT-PCR, immunohistochemical analysis, and Western blotting were used to investigate mechanisms of the lncRNA KCNQ1OT1, on its downstream genes in melanoma tissues, cells as well as the impact on CD8+ T cells. Proliferation, apoptosis, and migration/invasion were assessed in melanoma cells to evaluate the effects of KCNQ1OT1, miR-34a, and signal transducer and activator of transcription 3 (STAT3). The RNA interactions were determined by dual-luciferase reporter, and melanoma cells were co-cultured with CD8+ T cells to study immune evasion. A lactate dehydrogenase (LDH) cytotoxicity assay was used to investigate the cytotoxicity of CD8+ T cells toward melanoma cells. The in vivo tumorigenic potential of KCNQ1OT1 was defined using xenograft models. KCNQ1OT1 was upregulated in melanoma tissues leading to a poor prognosis, and knocking down it inhibited melanoma cell proliferation, migration, and invasion. KCNQ1OT1 regulated the progression of the melanoma via its action as a miR-34a sponge. STAT3 was found to be a downstream target of miR-34a, resulting in transcriptional regulation of Programmed cell death 1 ligand 1 (PD-L1). KCNQ1OT1 regulated STAT3 by targeting miR-34a. Knockdown of KCNQ1OT1 reduced PD-L1 level, enhanced CD8+ T cell cytotoxicity, and proliferation and inhibited apoptosis of CD8+ T cells. Melanoma cells overexpressed KCNQ1OT1, which influenced the miR-34a/STAT3 axis, to promote proliferation, migration, and invasion of melanoma cells. In addition, KCNQ1OT1 inhibited CD8+ T cell function, also via the miR-34a/STAT3/PD-L1 axis, thus promoting immune evasion of melanoma cells. The current findings expose a potential therapeutic target of melanoma.

IL-6/STAT3 axis dictates the PNPLA3-mediated susceptibility to non-alcoholic fatty liver disease

A number of genetic polymorphisms have been associated with susceptibility to or protection against non-alcoholic fatty liver disease (NAFLD), but the underlying mechanisms remain unknown. Here, we focused on the rs738409C>G single nucleotide polymorphism (SNP), which produces the I148M variant of patatin-like phospholipase domain-containing protein 3 (PNPLA3) and is strongly associated with NAFLD. To enable mechanistic dissection, we developed a human pluripotent stem cell (hPSC)-derived multicellular liver culture by incorporating hPSC-derived hepatocytes, hepatic stellate cells, and macrophages. We first applied this liver culture to model NAFLD by utilising a lipotoxic milieu reflecting the circulating levels of disease risk factors in affected individuals. We then created an isogenic pair of liver cultures differing only at rs738049 and compared NAFLD phenotype development. Our hPSC-derived liver culture recapitulated many key characteristics of NAFLD development and progression including lipid accumulation and oxidative stress, inflammatory response, and stellate cell activation. Under the lipotoxic conditions, the I148M variant caused the enhanced development of NAFLD phenotypes. These differences were associated with elevated IL-6/signal transducer and activator of transcription 3 (STAT3) activity in liver cultures, consistent with transcriptomic data of liver biopsies from individuals carrying the rs738409 SNP. Dampening IL-6/STAT3 activity alleviated the I148M-mediated susceptibility to NAFLD, whereas boosting it in wild-type liver cultures enhanced NAFLD development. Finally, we attributed this elevated IL-6/STAT3 activity in liver cultures carrying the rs738409 SNP to increased NF-κB activity. Our study thus reveals a potential causal link between elevated IL-6/STAT3 activity and 148M-mediated susceptibility to NAFLD. An increasing number of genetic variants manifest in non-alcoholic fatty liver disease (NAFLD) development and progression; however, the underlying mechanisms remain elusive. To study these variants in human-relevant systems, we developed an induced pluripotent stem cell-derived multicellular liver culture and focused on a common genetic variant (i.e. rs738409 in PNPLA3). Our findings not only provide mechanistic insight, but also a potential therapeutic strategy for NAFLD driven by this genetic variant in PNPLA3. Our liver culture is therefore a useful platform for exploring genetic variants in NAFLD development.

Curcumol Inhibits the Development of Prostate Cancer by miR-125a/STAT3 Axis

Aim This study aimed to learn the antineoplastic activity of curcumol (Cur) on prostate cancer (PCa) and elucidate its potential molecular mechanism. Methods The proliferation, invasion, and migration of PCa cells (PC3 and 22RV1) were detected by the cell counting kit 8 (CCK8), transwell, and wound healing assay, respectively. The expression of genes and proteins was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting (WB), respectively. The protein expression in tissues and cells was tested through immunohistochemistry (IHC) and immunocytochemistry (ICC). Enzyme-linked immunosorbent assay (ELISA) was utilized to quantify the level of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF). The interaction between microRNA125a (miR-125a) and the signal transducer and activator of transcription 3 (STAT3) was confirmed via dual-luciferase reporter assay. Results Cur effectively restrained the proliferation, invasion, and migration of PC3 and 22RV1 cells. After Cur intervention, miR-125a, miR-375, miR-149, miR-183, and miR-106b were all upregulated in PC3 cells, among which miR-125a was the most significantly upregulated. Dual-luciferase reporter assay combined with qRT-PCR and WB experiments confirmed that miR-125a targeted STAT3. Both in vitro and in vivo, Cur enhanced miR-125a expression and suppressed the activation of the STAT3 pathway in PCa. Also, Cur effectively inhibited the growth of PCa. Conclusion Cur inhibited the development of PCa by miR-125a/STAT3 axis. This may provide a potential agent for treating PCa.

KT2 alleviates ulcerative colitis by reducing Th17 cell differentiation through the miR-302c-5p/STAT3 axis

BackgroundThe abnormal differentiation of Th17 cells aggravates ulcerative colitis (UC). Antimicrobial peptides (AMPs) exert pivotal protection functions against UC. KT2 is a cationic AMP that mediates colon cancer development. However, KT2′s function in UC remains unclear. MethodsThe UC mouse model was induced by administering 2.5% dextran sulfate sodium, and the mice were given an enema of KT2. KT2′s function in UC and Th17 cell differentiation in vivo was evaluated through various molecular experiments. The KT2′s function in Th17 cell differentiation in vitro was evaluated by the proportion of CD4+ IL-17+ T cells, IL-17 levels, and RORγt expression levels. Meanwhile, the mechanism was assessed through quantitative real-time PCR, various loss-of-function assays, and dual-luciferase reporter gene assay. ResultsKT2 restrained Th17 cell differentiation in both in vivo and in vitro UC models and slowed the UC process. KT2 elevated miR-302c-5p expression, as well as restrained Th17 cell differentiation by increasing miR-302c-5p. Meanwhile, miR-302c-5p interacted with the signal transducer and activator of transcription 3 (STAT3) and negatively regulated its expression. Furthermore, our data revealed that KT2 restrained the activation of STAT3 by elevating miR-302c-5p, thereby inhibiting Th17 cell differentiation. ConclusionKT2 alleviates UC by repressing Th17 cell differentiation through the miR-302c-5p/STAT3 axis.

Long noncoding RNA regulatory factor X3- antisense RNA 1 promotes non-small cell lung cancer via the microRNA-577/signal transducer and activator of transcription 3 axis

ABSTRACT Lung cancer is the most frequent malignancy, and non-small cell lung cancer (NSCLC) is its most common pathological type. Molecular targeted therapy has been testified to be effective in intervening in the occurrence and development of malignancies. This study investigates the effect of lncRNA Regulatory Factor X3- antisense RNA 1 (RFX3-AS1) in NSCLC progression. The RFX3-AS1 profile in NSCLC tissues and cells was measured by quantitative reverse transcription PCR (qRT-PCR). The RFX3-AS1 overexpression model was constructed. The cell counting kit-8 (CCK-8) experiment and cell colony formation assay were adopted to test cell viability. The cell apoptosis was determined by flow cytometry (FCM). Cell migration and invasion were monitored by the Transwell assay, and Western blot was implemented to verify the protein profiles of signal transducer and activator of transcription 3 (STAT3), E-cadherin, Vimentin and N-cadherin. In vivo, we validated the impact of RFX3-AS1 overexpression on the NSCLC xenograft mouse model. The targeting relationships between RFX3-AS1 and miR-577, miR-577 and STAT3 were confirmed by the dual-luciferase reporter assay. The results manifested that overexpressing RFX3-AS1 markedly facilitated NSCLC cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), and suppressed cell apoptosis. In contrast, miR-577, which was a downstream target of RFX3-AS1, dramatically impeded the malignant biological behaviors of NSCLC cells. STAT3 was a direct target of miR-577, and it was negatively regulated by the latter. STAT3 activation reversed miR-577-mediated anti-tumor roles. In brief, RFX3-AS1 aggravated NSCLC progression by regulating the miR-577/STAT3 axis.

Histone H1.2 promotes hepatocarcinogenesis by regulating signal transducer and activator of transcription 3 signaling.

Linker histone H1.2 (H1.2), encoded by HIST1H1C (H1C), is a major H1 variant in somatic cells. Among five histone H1 somatic variants, upregulated H1.2 was found in human hepatocellular carcinoma (HCC) samples and in a diethylnitrosamine (DEN)‐induced HCC mouse model. In vitro, H1.2 overexpression accelerated proliferation of HCC cell lines, whereas H1.2 knockdown (KD) had the opposite effect. In vivo, H1.2 insufficiency or deficiency (H1c KD or H1c KO) alleviated inflammatory response and HCC development in DEN‐treated mice. Mechanistically, H1.2 regulated the activation of signal transducer and activator of transcription 3 (STAT3), which in turn positively regulated H1.2 expression by binding to its promoter. Moreover, upregulation of the H1.2/STAT3 axis was observed in human HCC samples, and was confirmed in mouse models of methionine‐choline‐deficient diet induced nonalcoholic steatohepatitis or lipopolysaccharide induced acute inflammatory liver injury. Disrupting this feed‐forward loop by KD of STAT3 or treatment with STAT3 inhibitors rescued H1.2 overexpression‐induced proliferation. Moreover, STAT3 inhibitor treatment‐ameliorated H1.2 overexpression promoted xenograft tumor growth. Therefore, H1.2 plays a novel role in inflammatory response by regulating STAT3 activation in HCC, thus, blockade of the H1.2/STAT3 loop is a potential strategy against HCC.

Circ_0001947 promotes cell proliferation, invasion, migration and inflammation and inhibits apoptosis in human rheumatoid arthritis fibroblast-like synoviocytes through miR-671-5p/STAT3 axis

BackgroundCircular RNAs (circRNAs) have emerged as vital regulators in the development of rheumatoid arthritis (RA). In this study, we aimed to explore the functions and mechanisms of circ_0001947 in RA.MethodsThe expression of circ_0001947, microRNA-671-5p (miR-671-5p) and signal transducer and activator of transcription 3 (STAT3) was determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Cell Counting Kit-8 (CCK-8) assay, 5′-ethynyl-2′-deoxyuridine (EdU) assay, flow cytometry analysis, transwell assay and wound-healing assay were performed to assess cell proliferation, apoptosis, invasion and migration. The concentrations of inflammatory factors were examined with enzyme-linked immunosorbent assay (ELISA) kits. Dual-luciferase reporter assay was used to analyze the relationships of circ_0001947, miR-671-5p and STAT3.ResultsCirc_0001947 was upregulated in RA patients and RA-FLSs. Knockdown of circ_0001947 repressed cell proliferation, invasion, migration and inflammatory response and facilitated apoptosis in RA-FLSs. Circ_0001947 served as the sponge for miR-671-5p and the inhibitory effect of circ_0001947 in RA-FLS progression was reversed by miR-671-5p inhibition. STAT3 was the target gene of miR-671-5p. MiR-671-5p overexpression restrained RA-FLS growth, invasion, migration and inflammation and promoted apoptosis, but STAT3 upregulation reversed the impacts.ConclusionCirc_0001947 contributed to the progression of RA-FLSs by elevating STAT3 through adsorbing miR-671-5p.

Aloperine inhibits colorectal cancer cell proliferation and metastasis progress via regulating miR-296-5p/STAT3 axis

Anti-tumorous effect of Aloperine (ALO) has been previously found. This study examined the role and the underlying mechanism of ALO in colorectal cancer (CRC). CRC cells were processed by different concentrations of ALO, and subsequently the cell proliferation was detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and miR-296-5p expression was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Moreover, the target gene of miR-296-5p was predicted by TargetScan and confirmed by dual-luciferase reporter assay. The expressions of signal transducer and activator of transcription 3 (STAT3), apoptosis-related proteins and epithelial-mesenchymal transition (EMT)-related markers were measured by Western blot. Clone formation assay, flow cytometry, wound-healing and Transwell assays were respectively employed to detect cell proliferation, apoptosis, migration and invasion. ALO inhibited CRC cell proliferation in a dose-dependent manner. MiR-296-5p was low-expressed in CRC tissues and cells, and ALO promoted miR-296-5p expression. STAT3 was targeted by miR-296-5p. Up-regulation of miR-296-5p and ALO treatment both suppressed STAT3 expression, inhibited CRC cell proliferation, migration, invasion as well as the expressions of Bcl-2 and N-cadherin, but promoted apoptosis and expressions of Bax and E-cadherin, which were all reversed by overexpressed STAT3. ALO inhibited CRC cell proliferation, metastasis and EMT but promoted apoptosis via regulating miR-296-5p/STAT3 axis.

The inhibition of circular RNA circNOLC1 by propofol/STAT3 attenuates breast cancer stem cells function via miR-365a-3p/STAT3 signaling

BackgroundBreast cancer remains one of the most dreadful female malignancies globally, in which cancer stem cells (CSCs) play crucial functions. Circular RNAs have drawn great attention in cancer research area and propofol is a widely applied intravenous anesthetic agent. Methods: In the current study, we explored the function of circular RNA nucleolar and coiled-body phosphoprotein 1 (circNOLC1) in CSCs of breast cancer and the inhibitory impact of propofol on circNOLC1.ResultsThe expression of circNOLC1 was induced in breast cancer tissues compared with the non-tumor tissues. The silencing of circNOLC1 was able to repress the viability of breast cancer cells. Meanwhile, the numbers of colony formation were suppressed by circNOLC1 knockdown in breast cancer cells. The inhibition of circNOLC1 reduced the invasion and migration ability of breast cancer cells. The mRNA and protein levels of E-cadherin were enhanced but Vimentin levels were reduced by the silencing of circNOLC1. The repression of circNOLC1 decreased the side population (SP) ratio in breast cancer cells. Meanwhile, the sphere formation ability of breast cancer cells was attenuated by the silencing of circNOLC1. The levels of ATP-binding cassette (ABC) superfamily G member 2 (ABCG2), c-Myc, B cell-specific Moloney murine leukemia virus integration site 1 (Bmi1), and SRY-box transcription factor 2 (Sox2) were repressed by the depletion of circNOLC1 in the cells. Regarding to the mechanism, circNOLC1 functioned as a competing endogenous RNAs (ceRNAs) for microRNA-365a-3p (miR-365a-3p) and the inhibition of miR-365a-3p rescued circNOLC1 depletion-repressed proliferation and cancer stem cell activity of breast cancer. MiR-365a-3p targeted signal transducer and activator of transcription 3 (STAT3) in breast cancer cells and circNOLC1 enhanced STAT3 expression by sponging miR-365a-3p. The overexpression of STAT3 could reverse miR-365a-3p or circNOLC1 depletion-inhibited proliferation and cancer stem cell properties of breast cancer. Interestingly, the expression of circNOLC1 and STAT3 was repressed by the treatment of propofol. The enrichment of STAT3 on circNOLC1 promoter was inhibited by propofol. The expression of circNOLC1 was suppressed by the silencing of STAT3 in the cells. The inhibition of circNOLC1 expression by propofol was rescued under the co-treatment of STAT3 overexpression. The overexpression of circNOLC1 rescued propofol-attenuated proliferation and cancer stem cell functions in vitro and in vivo.ConclusionsThus, we concluded that circNOLC1 contributes to CSCs properties and progression of breast cancer by targeting miR-365a-3p /STAT3 axis and propofol inhibited circNOLC1 by repressing STAT3 in a feedback mechanism.

Depleting SOX2 improves ischemic stroke via lncRNA PVT1/microRNA-24-3p/STAT3 axis

ObjectivesStudies have widely explored in the filed of ischemic stroke (IS) with their focus on transcription factors. However, few studies have pivoted on sex determining region Y-box 2 (SOX2) in IS. Thus, this study is launched to figure out the mechanisms of SOX2 in IS.MethodsRat middle cerebral artery occlusion (MCAO) was established as a stroke model. MCAO rats were injected with depleted SOX2 or long non-coding RNA plasmacytoma variant translocation 1 (PVT1) to explore their roles in neurological deficits, cerebral water content, neuron survival, apoptosis and oxidative stress. The relationship among SOX2, PVT1, microRNA (miR)-24-3p and signal transducer and activator of transcription 3 (STAT3) was verified by a series of experiments.ResultsSOX2, PVT1 and STAT3 were highly expressed while miR-24-3p was poorly expressed in cerebral cortex tissues of MCAO rats. Depleted SOX2 or PVT1 alleviated brain injury in MCAO rats as reflected by neuronal apoptosis and oxidative stress restriction, brain water content reduction, and neurological deficit and neuron survival improvements. Overexpression of PVT1 functioned oppositely. Restored miR-24-3p abolished PVT1 overexpression-induced brain injury in MCAO rats. SOX2 directly promoted PVT1 expression and further increased STAT3 by sponging miR-24-3p.ConclusionThis study presents that depleting SOX2 improves IS via PVT1/miR-24-3p/STAT3 axis which may broaden our knowledge about the mechanisms of SOX2/PVT1/miR-24-3p/STAT3 axis and provide a reference of therapy for IS.

CucurbitacinB enhances apoptosis in gefitinib resistant non‑small cell lung cancer by modulating the miR‑17‑5p/STAT3 axis.

Tyrosine kinase inhibitors, such as gefitinib, are currently widely used as targeted therapeutics for non-small cell lung cancer (NSCLC). Although drug resistance has become a major obstacle to successful treatment, mechanisms underlying resistance to gefitinib remain unclear. Therefore, the present study aimed to investigate the impact of adjunctive cucurbitacin B (CuB) on gefitinib resistance (GR) in the PC9 cell line, including identifying underlying mechanisms. Reverse transcription-quantitative PCR demonstrated significant downregulation of microRNA (miR)-17-5p expression in GR PC9 cells (PC9/GR), and this could be reversed by CuB. During combination treatment with CuB and gefitinib at IC25, PC9/GR cell proliferation was downregulated, and apoptosis was upregulated. The presence of a miR-17-5p inhibitor negated the effects of CuB and gefitinib, whereas the presence of a miR-17-5p mimic enhanced them. Luciferase assays demonstrated that the hypothetical target gene, signal transducer and activator of transcription 3 (STAT3), was directly targeted by miR-17-5p. Moreover, significant elevation of the STAT3 protein and phosphorylation levels in PC9/GR cells was reversed by the addition of CuB, despite a lack of change in STAT3 transcription level. During combined treatment with CuB and gefitinib at IC25, the STAT3 protein expression was negatively associated with the expression of miR-17-5p. Overexpression of STAT3 increased proliferation and decreased apoptosis and the protein levels of apoptosis-related factors cleaved caspase-3 and cleaved caspase-9 of PC9/GR cells. Findings indicated that STAT3 protein and phosphorylation levels became elevated in response to gefitinib, and that CuB-induced miR-17-5p expression led to STAT3 degradation, thereby ameliorating GR. In summary, CuB reduced the proliferation of GR PC9 cells by modulating the miR-17-5p/STAT3 axis, and may represent a promising potential novel strategy for the reversal of GR.

A meta-analyses on the role of IL-6 associated JAK/STAT3 signaling pathway modulation in the inflammatory bowel disease complicated colonic cancer development

The signalling pathway of Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) is suggested to be involved in various pathophysiological processes, including immune function, cell growth, differentiation, hematopoiesis and more importantly oncogenesis of distinct tumoral conditions. Interleukin (IL) 6 is a proinflammatory cytokine produced by antigen-presenting cells and non-hematopoietic cells in response to external stimuli and considered to be a key player in the development of the microenvironment of malignancy by promoting tumor growth and metastasis by acting as a bridge between chronic inflammation and cancerous tissue. Recent studies suggest that aberrant interleukin IL6/JAK/STAT3 signaling pathway exists in both IBD and inflammation-related gastrointestinal cancers. In the present meta-analysis we aimed to analyze the relationship between IL-6/JAK/STAT3 and IBD associated colorectal carcinogenesis and the effect of the inhibition of this system on disease follow-up and management.In light of the small number of studies able to be included in the meta-analysis evidence strongly proposed that JAK/STAT3 signaling, especially via the IL-6/STAT3 axis is involved in the transition of inflammatory lesions to tumoral diseases and leading to ulcerative colitis associated colorectal cancer. For this reason, based on the evidence presented in this meta-analysis it is reasonable to suggest that targeting components of the IL-6/JAK/STAT3 signalling pathway can inhibit tumour cell growth and relieve immunosuppression in the UC associated colonic tumoral microenvironment.