p-STAT3 Protein Research Articles

Effects of dietary active soybean trypsin inhibitors on pancreatic weights, histology and expression of STAT3 and receptors for androgen and estrogen in different tissues of rats.

Our previous study showed that soy milks could contain high levels of active soybean trypsin inhibitors (SBTI) if they were not properly processed. This study investigated the effects of consuming active SBTI on pancreatic weights, histology, trypsinogen production and expression of STAT3, receptors for androgen (AR) and estrogen (ER) in pancreas, liver and uterus of rats. Weanling Sprague-Dawley rats were randomly divided into 3 groups (8 females and 8 males/group) and fed diets containing either 20% casein protein (Casein) or 20% soy protein (SP) in the presence of high (1.42 BAEE unit/µg, SP + SBTI) or low (0.2 BAEE unit/µg, SP-SBTI) levels of active SBTI for 8weeks. Ingestion of SP + SBTI diet markedly increased pancreatic weights and trypsinogen content (p < 0.01), and caused acinar cell hypertrophy, and reduced pancreatic STAT3, p-STAT3, AR and ERβ content, and increased uterine ERα and ERβ compared to the Casein or SP-SBTI diets (p < 0.05). The two SP-containing diets lowered hepatic STAT3, p-STAT3, and pancreatic ERα, and increased hepatic ERα and ERβ content in the female rats compared to the Casein diet (p < 0.05). This study demonstrated for the first time that consumption of high level of active SBTI not only increased pancreatic weights and acinar cell secretions, but also attenuated the expression of pancreatic STAT3, p-STAT3, AR, and ERβ proteins in both sexes and increased uterine ERα and ERβ content, and that dietary soy protein affected hepatic STAT3, p-STAT3, ERα and ERβ in a gender-dependent manner.

Meprin β Activity Modulates IL‐6/JAK/STAT Signaling Pathway in Ischemia/Reperfusion Induced Acute Kidney Injury

Meprin metalloproteases have been implicated in inflammation-induce kidney injury. Meprins proteolytically processes the pro-inflammatory cytokine, IL-6, causing IL-6 inactivation. However, it's not known how IL-6 inactivation by meprin β impact the inflammatory response in kidneys. The goal of this study was to determine whether meprin β expression modulates IL-6 signaling in ischemia/reperfusion (IR)-induced kidney injury. IL-6 trans-signaling is initiated when IL-6 binds to its soluble receptor (sIL-6r) and gp130 receptor, resulting in activation of Janus Kinase-Signal Transducer and Activator of Transcription (JAK/STAT) signaling pathway and activation of its mediators (e.g. suppressor of cytokine signaling 3, SOCS3) and downstream target genes (e.g. pro-apoptosis, anti-apoptosis and proliferation). We therefore sought to determine if meprin β expression impacts IL-6 levels and downstream mediators of the IL-6 trans-signaling mediated JAK-STAT pathway. We used the unilateral IR as a model of renal inflammation in wild-type (WT) and meprin β knockout (βKO) male mice, with the contralateral kidneys serving as controls. The mice were sacrificed at 24h post-IR, and kidney tissue processed for evaluation by RT-PCR, western blot, and immunohistochemistry (IHC). IHC staining for kidney injury molecule 1 (KIM-1) was used to assess kidney injury. Statistical analysis utilized two-way ANOVA. Our PCR data showed that meprin β deficiency associated with a significant upregulation of IL-6 mRNA (40%) in βKO mice at 24 h post-IR compared to WT. Similarly, Western blot data showed increased IL-6 protein levels. We then evaluated downstream mediators of the IL-6 signaling pathway and showed that WT kidneys which express meprin β had a 50% and 90% upregulation in the expression of the JAK/STAT negative regulator gene (SOCS3) and proliferating cell nuclear antigen (PCNA) gene, respectively when compared to βKO. However, meprin β expression did not affect the expression of the pro-apoptotic gene (BCL-2) or the anti-apoptotic gene (caspase3) at 24 h post-IR. Western Blot data showed increased levels of P-JAK2, P-STAT3, Caspase3, BCL2, SOCS3 and PCNA in βKO at 24 h post-IR compared to controls, but not in WT counterparts. Immunohistochemical analysis showed significant increases (P<0.001) in percentage of cells expressing IL-6, P-JAK2, P-STAT3, Caspase3 and BCL2 in some tubules in both genotypes subjected to IR when compared to their controls (OD levels >1.0). However, βKO kidneys had significantly higher expression level of IL-6, P-JAK2, P-STAT3, Caspase3 and BCL2 total proteins compared to WT 24h post-IR (P<0.001). Data from immunofluorescence counterstaining of kidney tissues showed that the levels of IL-6, P-STAT3, P-JAK-2, Caspase3 and BCL-2 were higher in meprin β-expressing proximal tubules (PT), at 24 h post-IR when compared to the distal kidney tubules (DT), which lack meprins. High level of IL-6, P-STAT3, P-JAK-2, Caspase3 and BCL-2 was also detected 24 post IR in the lumen of PT and DT from WT and βKO kidneys, suggesting increased release into filtrate and subsequently into urine. Taken together, our data demonstrates that meprin β expression modulates the IL-6/JAK/STAT signaling pathway in renal IR-induced inflammation.

Long non-coding RNA EGFR-AS1 in colorectal cancer: potential role in tumorigenesis and survival via miRNA-133b sponge and EGFR/STAT3 axis regulation

ABSTRACT Background Colorectal cancer is one of the most common cancers worldwide and a major cause of cancer-related death. Thus molecular biomarkers for colorectal cancer have been proposed. The role of long non-coding RNA EGFR-AS1 in colorectal cancer is still unclear. We aimed to evaluate its expression in different stages of colorectal cancer and determine any possible role in regulating the miR‑133b/EGFR/STAT3 signalling pathway. Materials and Methods The relative expression of EGFR-AS1 and miR‑133b were evaluated by quantitative real-time RT-transcription PCR in 130 colorectal cancer samples and 30 normal tissues. EGFR expression was assessed using immunohistochemistry. Furthermore, levels of p-EGFR, p-STAT3, and apoptotic proteins were determined by ELISA. Results Both EGFR-AS1 and EGFR overexpression were positively linked with colorectal cancer status (both p < 0.01), grade (both p < 0.01), and metastasis (P < 0.01 and p = 0.019 respectively). EGFR-AS1 and miR-133b were significantly inversely correlated (P < 0.01). Low expression of miR-133b was inversely associated with overexpressed EGFR and increased p-STAT3 levels. EGFR-AS1 was an independent prognostic factor for survival of colorectal cancer patients (P < 0.01, HR 2.06; 95% CI 1.32–3.19) where low EGFR-AS1 expression was associated with higher survival rate (p = 0.003). Conclusion EGFR-AS1 may have a role in colorectal cancer by regulation of miR‑133b/EGFR/STAT3 signalling. It may be a potential biomarker for early diagnosis and predicting the survival rate of colorectal cancer.

MiRNA-195: The New Target of Inhibiting the Proliferation, Migration and Invasion of Gastric Cancer Cells via Propofol

Objective: To explore the effect of propofol (Prof) on the proliferation, migration and invasion of human gastric cancer cell MGC-803 and its molecular mechanism. Methods: The MTT method was used to study the effects of Prof with different doses and durations on the viability of MGC-803 cells. Hoechst 33258 staining and electron microscopy were used to detect the effects of Prof on MGC-803 cell apoptosis. Transwell experiments were used to detect the effects of Prof on the migration and invasion of MGC-803 cells. RT-PCR detects the effect of Prof on the expression of miR-195 in MGC-803 cells, and Western Blot detects the effect of Prof on the protein expression of JAK/STAT signaling pathway. Results: Compared with 0mg/ml Prof, 5mg/ml, 10mg/ml and 20mg/ml Prof treatment with 24h, 48h and 72h can significantly reduce cell viability (P &lt;0.05). Compared with the Control group, the percentage of Hoechst 33258 staining positive cells in the Prof group and the apoptosis rate under the electron microscope were significantly increased (P &lt;0.05). Compared with the Control group, the cell migration rate and invasion rate of the Prof group were significantly reduced (P &lt;0.05). Compared with the Control group, the expression of miRNA-195 in the Prof group cells was increased significantly (P &lt;0.05). Compared with the Control group, the activity of p-Jak1 and p-STAT3 proteins in the Prof group were significantly reduced (P &lt;0.05). Conclusion: Prof can reduce the cell viability, migration and invasion of gastric cancer cell MGC-803, and promote its apoptosis. Its mechanism may be related to the promotion of miR-195 expression and inhibition of JAK/STAT signal pathway activity.

Pathological predictive factors for late recurrence of hepatocellular carcinoma in chronic liver disease.

Late recurrence of hepatocellular carcinoma (HCC) is regarded as de novo HCC from chronic hepatitis. This study investigated clinicopathological and molecular factors to develop a nomogram for predicting late HCC recurrence (>2years after curative resection). The training and validation cohorts included HCC patients with a major aetiology of hepatitis B who underwent curative resection. Clinicopathological features including lobular and porto-periportal inflammatory activity, fibrosis and liver cell change were evaluated. Proteins encoded by genes related to late recurrence were identified using a reverse phase protein array of 95 non-tumourous liver tissues. Immunoexpression of phosphorylated signal transducer and activator of transcription 3 (pSTAT3), plasminogen activator inhibitor-1, phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) and spleen tyrosine kinase (SYK) was measured. Late recurrence occurred in 74/402 (18%) and 47/243 (19%) in the training and validation cohorts respectively. Cirrhosis, moderate/severe lobular inflammatory activity, and expression of pSTAT3, pERK1/2, and SYK proteins correlated to the gene signature of hepatocyte injury and regeneration were independently associated with late recurrence, with odds ratios (95% confidence intervals) of 2.0 (1.2-3.3), 21.1 (4.3-102.7) and 6.0 (2.1-17.7) respectively (P<.05 for all). A nomogram based on these variables (histological parameters and immunohistochemical marker combinations) showed high reliability in both the training and validation cohorts (Harrell's C index: 0.701 and 0.716; 95% confidence intervals: 0.64-0.76 and 0.64-0.79 respectively). The combination of pSTAT3, pERK1/2 and SYK immunoexpression with high lobular inflammatory activity and cirrhosis (fibrosis) predicts late HCC recurrence.

Black pepper prevents anemia of inflammation by inhibiting hepcidin over-expression through BMP6-SMAD1/ IL6-STAT3 signaling pathway

Hepcidin, a circulatory hepatic peptide hormone, is associated with systemic iron homeostasis. Inflammation leads to an increase in hepcidin expression, which dysregulates body iron level. The related disorder, anemia of inflammation, is the second most prevalent anemia-related disorder worldwide. In the present study, we conducted in vitro and in vivo studies to evaluate the effect of black pepper (BP) and its major bioactive alkaloid, piperine, on anemia of inflammation. The initial in vitro study using human hepatocyte cell line, HepG2, confirmed that among different black pepper extracts: methanol (BPME), ethanol (BPEE) and aqueous (BPAE), BPME to be most effective in downregulating transcription of hepcidin gene. Further, BPME and piperine significantly downregulated hepcidin protein expression at 200 μg/ml and 100 μM concentrations, respectively. In the next phase, BPME and piperine were found to significantly attenuate BMP-6 and IL-6 induced hepcidin overexpression by downregulating the increased level of pSMAD1 and pSTAT3 proteins, respectively. For in vivo study, we first subcutaneously injected male BALB/c mice with oil of turpentine, thrice within a period of two weeks, in order to enhance the expression of hepcidin. After that, the intraperitoneal administration of BPME and piperine at 70 and 25 mg/kg body weight, respectively, on alternate days for a period of another two weeks resulted in downregulation of hepcidin overexpression in diseased mice, as confirmed by RT-PCR and immunoblot analysis. The histopathology of liver tissue confirmed increased iron bioavailability in BPME and piperine treated animals. The molecular docking-based interaction studies demonstrated the binding potential of piperine with SMAD1 and STAT3 proteins. The binding patterns supported the proposed inhibition of hepcidin activating proteins. All together, these findings suggest black pepper as a therapeutic candidate for the treatment of anemia of inflammation.

Effects of moxibustion on the P2X7R/STAT3/VEGF pathway in rats with colitis-associated colon cancer

To observe the effects of herb-partitioned moxibustion and ginger-partitioned moxibustion on the growth of colon tumors in rats with colitis-associated colon cancer (CACC), and explore the mechanism of moxibustion intervening CACC through the purinergic receptor P2X ligand-gated ion channel 7 (P2X7R)/signal transducer and activator of transcription 3 (STAT3)/vascular endothelial growth factor (VEGF) pathway. A total of 26 male Sprague-Dawley rats were selected. According to the random number table method, 6 rats were selected as the normal group. The remaining 20 rats were injected intraperitoneally with azoxymethane (AOM) combined with oral dextran sodium sulfate (DSS) to prepare the CACC model. After the model was successfully established, 2 rats were randomly selected for model identification. The remaining 18 rats which were successfully modeled were randomly divided into a model group, a herb-partitioned moxibustion group and a ginger-partitioned moxibustion group, with 6 rats in each group. Moxibustion intervention was performed in the herb-partitioned moxibustion group and the ginger-partitioned moxibustion group at Qihai (CV 6) and bilateral Tianshu (ST 25). Moxibustion was performed twice at each point each time, once a day, at a 1-day interval after 6 consecutive interventions, for a total of 30 interventions. After intervention, the colon tumor load, pathological change and histopathological score were observed. Immunohistochemistry was used to detect the expressions of VEGF, P2X7R, phospho-STAT3 (p-STAT3), and nuclear factor-kappa B p65 (NF-κB p65) proteins in rat colon tissue. Western blot was used to detect the levels of p-STAT3 and NF-κB p65 proteins in rat colon tissue. Compared with the normal group, the colon tumor load and histopathological score in the model group were significantly increased (both P<0.001), and different grades of dysplasia were observed in colon tissue from the model group, reaching the degree of adenocarcinoma; the expression level of P2X7R protein in colon tissue was significantly decreased (P<0.001), and the expression levels of p-STAT3, NF-κB p65 and VEGF proteins were significantly increased (all P<0.001) in the model group. Compared with the model group, the colon tumor load, colon histopathological score and the levels of p-STAT3, NF-κB p65 and VEGF proteins in colon tissue were significantly decreased (all P<0.05) in the herb-partitioned moxibustion group and the ginger-partitioned moxibustion group while the expression levels of P2X7R protein in colon tissue were significantly increased (both P<0.05). Both herb-partitioned moxibustion and ginger-partitioned moxibustion can reduce the colon tumor load in CACC rats and delay the progression of colon adenomas. The mechanism may be mediated by the P2X7R/STAT3 pathway to inhibit STAT3 phosphorylation, thereby reducing VEGF protein expression.

Regulator of Ribosome Synthesis 1 Influences the Proliferation, Migration, and Invasion of Ovarian Cancer Cells

We investigated the effects of silencing the regulator of ribosome synthesis 1 (RRS1) gene on the proliferation, migration, and invasion of ovarian carcinoma cells, and its possible role in modulating signal transduction in these cells. Normal ovarian epithelial cell line IOSE80 was used as a control. We examined the mRNA and protein level of RRS1 using qRT-PCR and western blot in control and ovarian carcinoma cells (SKOV-3, SW626, and CAOV3). RNA interference technology was used to knockdown RRS1 expression in CAOV3 cells. MTT was used to examine the proliferation of these cells, while a Transwell assay was used to assay the cells’ migration and invasion abilities. Western blot was used to measure the levels of CyclinD1, P21, MMP-2, MMP-9, p-JAK2 and p-STAT3 proteins. In comparison with normal ovarian epithelial cells (IOSE80), RRS1 mRNA and protein levels were increased in ovarian carcinoma cells (SKOV-3, SW626 and CAOV3) (P &lt; 0.05). Because RRS1 levels were highest in CAOV3 cells, these cells were used for subsequent experiments. RRS1 gene expression was knocked down in CAOV3 cells, and in comparison with the negative control group, siRNA-RRS1 cells exhibited decreased proliferation in the MTT assay after 48 h and 72 h (P &lt; 0.05). These cells also exhibited reduced migration and invasion (P &lt; 0.05). Further, siRNA-RRS1 cells exhibited reduced expression of CyclinD1, MMP-2, MMP-9, P-JAK2 and P-STAT3 proteins (P &lt; 0.05), while P21 protein levels were increased (P &lt; 0.05). Silencing RRS1 expression inhibits the proliferation, migration, and invasion of ovarian carcinoma cells. This effect may be mediated by the inhibition of the STAT3 signaling pathway in these cells.

Janus kinase/signal transducer and activator of transcription signaling pathway-related genes STAT3, SOCS3 and their role in thiram induced tibial dyschondroplasia chickens

Pathogenicity of tibial dyschondroplasia (TD) in broiler chickens is not detected yet. Janus Kinase/Signal Transducer and Activator of Transcription (JAK-STAT) signaling pathway-related genes were investigated in thiram induced TD chickens.Real-time qPCR and immunohistochemical (IHC) technique were used to observe the expression changes of STAT3 and SOSC3 gene on days 1, 2, 4, 6 after feeding 100 mg·kg−1 thiram.Morphological, pathological, and histological results of this study suggested that chondrocyte cells were observed more damaged on day 6 than day 1, 2, and 4. Therefore, Lameness and damaged chondrocytes gradually increased from day 1 to 6.The mRNA expression level of STAT3 was observed insignificant (P > 0.05) in thiram induced TD chickens’ group of day 1. However, on days 2, 4, and 6, the expression was significant (P < 0.05). SOCS3 increased in thiram group on days 1, 2 and 6, decreased on day 4 (P < 0.05). The p-STAT3 and SOCS3 protein's protein localization was evaluated in the control and thiram-induced TD broiler chickens through IHC, suggesting that SOSC3 protein was observed significantly higher on days 1, 2, and 6 and down-regulated on day 4. p-STAT3 protein on thiram induced group was observed significantly upregulated on days 4 and 6.In conclusion, the differential expression of STAT3 and SOCS3 showed that the JAK-STAT signaling pathway might play an important role in regulating an abnormal proliferation, differentiation, or apoptosis of chondrocytes in TD at an early stage.

MicroRNA-146a-Mediated IL-6/Signal Transducer and Activator of Transcription 3 Signaling Pathway in Chondrocyte Proliferation and Apoptosis in Mice with Osteoarthritis

Background: To investigate the MicroRNA-146a targeting regulation of IL-6/STAT3 signaling pathway activity and influence the proliferation and apoptosis behavior-related mechanisms of OA chondrocytes. Material and Methods: 10 C57 mice were isolated and cultured with membrane protease and type II collagenase. The experiment was divided into blank group, MicroRNA-146a overexpression group and low expression group. The chondrocytes were transfected with plasmid vector. After 48 hours of culture, the proliferation rate of chondrocytes was detected by MTT method. The levels of type ii collagen, MMP-9, IL-1, IL-6, and TNF-α in culture medium were detected by ELISA. Luciferase reported experimental analysis of MircoRNA-146a targeting regulation of IL-6 genes. Results: Compared with the blank group, the proliferation rate of chondrocytes in the overexpression group was significantly decreased, the apoptosis rate was increased, the levels of IL-6 and p-STAT3 protein, type II collagen, MMP-9, IL-1, IL-6 and TNF-α were increased, while the low expression group was correlated (P &lt; 0.05). Luciferase reporter experiments confirmed that MicroRNA-146a had a better binding effect with the IL-6 gene. Conclusion: MicroRNA-146a overexpression may mediate activation of IL-6/STAT3 signaling pathway and participate in decreased proliferation activity and increased apoptosis activity in OA chondrocytes. IL-6 gene may have targeted regulatory sites for MicroRNA-146a.

Curcumin Regulated the Homeostasis of Memory T Cell and Ameliorated Dextran Sulfate Sodium-Induced Experimental Colitis.

Immune memory is protective against reinvasion by pathogens in the homeostatic state, while immune memory disorders can cause autoimmune disease, including inflammatory bowel disease. Curcumin is a natural compound shown to be effective against human inflammatory bowel disease and experimental colitis, but the underlying mechanism is unclear. Here, experimental colitis was induced by dextran sulfate sodium (DSS) in this study. Significant changes in the percentages of naïve, central memory T (TCM), and effector memory (TEM) cells and their CD4+ and CD8+ subsets were found in the peripheral blood of mice with colitis using flow cytometry. After 7 days of continuous curcumin (100 mg/kg/day) administration, the DSS-induced experimental colitis was effectively relieved, with significant decreases in the ratio of day weight to initial body weight, colonic weight, pathological injury score, levels of proinflammatory cytokines IL-7, IL-15, and IL-21, colonic mucosal ulceration, and amount of inflammatory infiltrate. Importantly, curcumin significantly restored the percentages of naïve, TCM, and TEM cells and their CD4+ and CD8+ subpopulations. In addition, curcumin significantly inhibited the activation of the JAK1/STAT5 signaling pathway, downregulation of JAK1, STAT5, and p-STAT5 proteins in colon tissue, and upregulation of PIAS1 proteins. These results suggested that curcumin effectively regulated the differentiation of naïve, TCM, and TEM cells in the peripheral blood to alleviate DSS-induced experimental colitis, which might be related to the inhibition of JAK1/STAT5 signaling activity.

Modified Simiaowan prevents articular cartilage injury in experimental gouty arthritis by negative regulation of STAT3 pathway

Ethnopharmacological relevanceModified Simiaowan (MSW) is a traditional Chinese medicine formula that is composed of six herbs. It has been widely used in the treatment of gouty arthritis. Aim of the studyThis study was designed to investigate the effect of MSW on gouty arthritis and explore the possible mechanisms. Material and methodsThe rat gouty arthritis model was established by intra-articular injection of Monosodium Urate (MSU) crystal, and then treated with MSW for 5 days. The perimeter of the knee joints was measured in a time-dependent manner and serum samples were collected for the detection of TNF-α, IL-1β, and IL-6 protein levels by ELISA. The protein expressions of MMP-3, TIMP-3, STAT3, and p-STAT3 in cartilage tissues and C28/I2 cells were detected by Western blot, and the levels of proteoglycan in primary chondrocytes and cartilage tissues were determined by toluidine blue staining. In addition, AG490 and IL-6 were used in vitro to explore the function of IL-6/STAT3 pathway in the protective effect of MSU. ResultsMSW reduced the joint swelling rate in gouty arthritis model and inhibited MSU induced up-regulation of IL-1β, TNF-α, and IL-6 protein levels in serum and synovial fluid. IL-1β induced an increase in p-STAT3 and MMP-3 protein expression in C28/I2 cells, as well as a decrease in TIMP-3. MSW serum inhibited the protein expression changes induced by IL-1β in vitro. Furthermore, inhibition of STAT3 signaling negated the effect of MSW serum on p-STAT3, MMP-3, and TIMP-3 protein levels in C28/I2 cells. MSW also increased the content of proteoglycan significantly both in vivo and in vitro. ConclusionOur data indicated that MSW protected rats from MSU-induced experimental gouty arthritis and IL-1β/IL-6/STAT3 pathway played an essential role in the protective effect of MSU against GA.

Cynaropicrin Shows Antitumor Progression Potential in Colorectal Cancer Through Mediation of the LIFR/STATs Axis.

BackgroundColorectal cancer (CRC) is the second deadliest malignant disease in the world and the leukemia inhibitory factor receptor/signal transducers and activators of transcriptions (LIFR/STATs) signaling axis plays an important role in the molecular biology of CRC.MethodsCell function tests were performed to observe the inhibitory effect of cynaropicrin on human CRC cells (RKO, HCT116, and DLD-1). Expression levels of LIFR, P-STAT3, P-STAT4, and apoptotic proteins were detected by Western blotting. Immunoprecipitation confirmed the presence of LIFR/STAT3/STAT4 complex. Cell immunofluorescence assay was used to observe the subcellular localization of STAT3 and STAT4. In vivo efficacy of cynaropicrin was evaluated by a xenotransplantation model in nude mice.ResultsCynaropicrin significantly reduced the survival ability of human CRC cells and promoted apoptosis in a dose-dependent manner. Western blotting results suggested that the antitumor effects of cynaropicrin might be mediated by inhibition of the LIFR/STATs axis. Cynaropicrin reduced the formation of STAT3/STAT4 heterodimers and blocked their entry into the nucleus. Cynaropicrin also suppressed tumor growth in the xenograft model.ConclusionThe results showed that cynaropicrin exerted a strong inhibitory effect on CRC in vitro and in vivo. Our study concluded that cynaropicrin has potential application prospects in the field of anti-CRC therapy.

Vincristine upregulates PD-L1 and increases the efficacy of PD-L1 blockade therapy in diffuse large B-cell lymphoma.

Some chemotherapy drugs have immunomodulatory effects on specific tumors. The potential of vincristine (VCR) in the R-CHOP regimen to act as both a chemotherapeutic and an immunomodulatory agent via PD-L1 in tumor cells remains unclear. In vitro screening VCR showed that the IC50 value of VCR in the DLBCL cell lines was approximately 2nM. Western blotting and q-PCR were used to detect the expression of PD-L1. The effect of VCR combined with PD-L1 mAb was tested in a co-culture system of LY-OCI-3 cells and peripheral blood mononuclear cells and in DLBCL xenograft mouse model. Flow cytometry was used to determine the proportion of T lymphocyte subsets. The effect of the STAT3 inhibitor nifuroxazide on VCR-induced PD-L1 expression was tested in LY-OCI-3 and SU-DHL-4 cells. VCR upregulated PD-L1 protein and mRNA expression in various DLBCL cell lines. PD-L1 Ab combined with VCR significantly increased the proportion of CD8 + Granzyme B + , INF-γ + or TNF-α + CD3 + T cells. VCR + PD-L1 Ab inhibited tumor growth more effectively than VCR monotherapy, whereas PD-L1 Ab alone had no significant effect. Survival time did not differ significantly between the PD-L1 Ab group and the control group, whereas it was significantly longer in the VCR monotherapy and combination groups which showed more longer survival compared with the former. Nifuroxazide downregulated p-STAT3 and PD-L1 protein levels. VCR upregulated PD-L1 expression in DLBCL cells partially by promoting the p-STAT3; VCR combined with PD-L1 Ab activated effector T cells and increased the antitumor immune response in vitro and in vivo.

T3 Promotes Glioma Cell Senescence and Apoptosis via THRA and THRB.

Glioma is one of the most common types of primary intracranial tumors. The relationship between triiodothyronine (T3) and glioma is not clear. This study aimed to investigate the effect of T3 on the proliferation of glioma cells and its mechanism. Cell viability was analyzed by cell counting kit 8 assay. Flow cytometry analysis was used to detect cell apoptosis and cell cycle. Thyroid hormone receptor α (THRA) and thyroid hormone receptor β (THRB) were silenced by transfecting si-THRA and si-THRB plasmids into HS683 and A172 glioma cells. Western blot was performed to assess the protein expressions. The results indicated that triiodothyronine (T3) affected the viability, apoptosis and cell cycle of HS683 and A172 glioma cells. Cell apoptosis was significantly inhibited in si-THRA and si-THRB experimental groups. Moreover, knockdown of THRA and THRB reversed the G1 and G2 phase arrest led by T3 and induced an up-regulation of cyclin D1 expression. The phosphorylated extracellular signal-regulated kinase (p-ERK), p-AKT, and phosphorylated signal transducer and activator of transcription (p-STAT3) proteins were markedly increased by inhibiting THRA and THRB in HS683 and A172 glioma cells. T3 affected apoptosis and cell cycle of glioma cells through regulating THRA and THRB expressions. THRA and THRB may affect glioma development through regulating, at least partially, the mitogen-activated protein kinase (MAPK)/ERK and phosphoinositide 3-kinase (PI3K)/Akt signaling pathways.

Investigation of cellular effects of thymoquinone on glioma cell.

Glioblastoma, as an invasive tumor, is one of the most common primary malignant brain tumors. Despite maximum aggressive treatment, patients with glioblastoma have a dismal prognosis. Thymoquinone (TQ) has been found to show anti-cancer effects on different types of cancer. There are a few in vitro studies on the effect of TQ on glial tumors. However, the molecular mechanism of TQ's anti-cancer effect has not been fully elucidated. In the present study, we aimed to investigate the genotoxic, apoptotic, and cytotoxic effects of TQ on C6 rat glioma cells.C6 glioma cells were analyzed after 24 h of exposure to different concentrations of TQ by the ATP cell viability assay for cytotoxicity, comet assay for genotoxicity, 2′,7′dichlorodihydrofluorescein diacetate (H2DCF-DA) for intracellular reactive oxygen species (iROS) generation, 3.3′dihexyloxacarbocyanine iodide (DiOC6(3)) for mitochondrial membrane potential, GSH/GSSG-Glo Assay for glutathione level and Fura-2AM for intracellular calcium levels. Apoptosis induction was studied by acridine orange/ethidium bromide double staining, flow cytometry, and western blotting analyses. Caspase-3, Caspase-9, Bax, Bcl-2, and pSTAT3 protein levels were determined by the western blotting method.Cytotoxicity was enhanced by TQ in C6 glioma cells in a concentration-dependent manner. TQ also induced DNA damage, apoptosis, and increased iROS. Also, MMP and GSH levels were decreased by TQ. It inhibited pSTAT3, resulting in apoptosis induction through the regulation of anti-apoptotic and pro-apoptotic proteins.Our results suggest that TQ would be an effective treatment in glioma. Further studies should support these findings.

Effects of different aberrations in the CRLF2 gene on the biologicalcharacteristics and drug sensitivities of Nalm6 cells.

To investigate the effects and mechanism of action of upregulated CRLF2 expression resulting from different aberrations in the CRLF2 gene (CRLF2, CRLF2+IK6, P2RY8-CRLF2 and CRLF2 F232C) in the B cell ALL cell line Nalm6. Cell proliferation was measured using cell counting kit-8. Transcriptome sequencing technology (RNA-seq) was used to compare changes in gene expression resulting from different aberrations in CRLF2. High-throughput drug sensitivity testing was used to determine the drug sensitivity of cells. All four aberrations in CRLF2 upregulated CRLF2 expression and promoted the proliferation of Nalm6 cells. The RNA-seq results showed the upregulation of genes in the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway and the downregulation of genes in the cell cycle pathway in the CRLF2 F232C-overexpressing cells. Western blotting showed that the expression of p-STAT5 protein was significantly higher in the CRLF2 F232C-overexpressing cells. Cells with aberrations in CRLF2 were more resistant to cyclophosphamide and drugs commonly used during treatment than cells in the vector group. The half-maximal inhibitory concentration (IC50 or GI50 ) of dexamethasone was significantly higher in the CRLF2 F232C-overexpressing cell line. The overexpression of CRLF2, CRLF2+IK6, P2RY8-CRLF2 and CRLF2 F232C promotes the proliferation of Nalm6 cells, activates the JAK/STAT signalling pathway and leads to a reduction in sensitivity towards various chemotherapeutic drugs.

IL-21 enhances STAT3/Blimp-1 signaling pathway in B cells and contributes to plasma cell differentiation in newly diagnosed patients with myasthenia gravis.

The transcription factor Blimp-1 is necessary for the B cell differentiation toward immunoglobulin-secreting plasma cells. However, the immunopathological mechanisms of Blimp-1 that regulates B cell differentiation remain unclear in MG. The purpose of this study was to perform a quantitative and functional analysis of Blimp-1 in MG. A total of 34 patients with MG (18 ocular MG (OMG) and 16 generalized MG (GMG) and 20 healthy controls (HC) were recruited in this study. CD19+ B cells were isolated by positive selection using CD19 beads. The expression of Blimp-1 and p-STAT3 protein in isolated B cells was assessed by Western blot. Plasma cells were analyzed by flow cytometry. Serum IL-21 levels were detected by ELISA. Our data demonstrated that Blimp-1 in peripheral blood B cell of MG patients was significantly increased compared with HC. The increased expression of Blimp-1 was positively associated with clinical severity score (QMGs), plasma cell frequency, and serum IL-21 levels. Furthermore, glucocorticoid (GC) treatment reduced the expression of Blimp-1 and p-STAT3 in B cells, and this change was accompanied with relieved clinical severity, reduced plasma cell frequency, and decreased serum IL-21 levels. In vitro assay demonstrated that IL-21 stimulation upregulated STAT3 phosphorylation, increased Blimp-1 expression in B cells, and promoted plasma cell differentiation, and these processes could be inhibited by dexamethasone or STAT3 inhibitor stattic. This work indicates for the first time that aberrant expression of Blimp-1 exists on B cells and contributes to the plasma cell differentiation in MG patients. Modulation of IL-21/STAT3/Blimp-1 signaling pathway in B cells may be one of the mechanisms of glucocorticoid in the treatment of MG.

Effect of the isoflavone corylin from cullen corylifolium on colorectal cancer growth, by targeting the STAT3 signaling pathway

BackgroundColorectal cancer (CRC) is one of the most common cancers worldwide. Corylin is an isoflavone extracted from Cullen corylifolium (L.) Medik., which is widely used anti-inflammatory and anticancer in Asian countries. Signal transducer and activator of transcription 3 (STAT3) plays an important role in the occurrence and development of CRC. PurposeTo analyze the antitumor activity of corylin in CRC and to elucidate its molecular mechanisms of action. MethodsThe human CRC cell lines HCT116, RKO, and SW480 and immunodeficient mice were used as models to study the antitumor effect of corylin. The potent anti-proliferative, anti-migration and proapoptotic effects of corylin were observed by cell viability, colony formation assays, wound-healing migration assay, and cell apoptosis assay. Immunostaining analysis and western blot analysis revealed inhibition of the STAT3 signaling axis. ResultsWe found that corylin could significantly reduce the viability and stimulate apoptosis in human CRC cells in a dose-dependent manner. Corylin decreased the expression levels of P-STAT3 and STAT3 target proteins, such as myeloid cell leukemia-1(MCL-1), Survivin, VEGF and B-cell lymphoma 2 (BCL-2). It also upregulated the expression levels of the proapoptotic proteins BCL-2-associated X protein (BAX) and Cl-caspase 3. Moreover, corylin reduced the nuclear localization of STAT3. Furthermore, corylin inhibited the growth of the tumor in CRC mouse models. ConclusionsOur findings provide convincing results that could support the role of corylin in the treatment of CRC through inhibiting the STAT3 pathway. It is conceivable that corylin should be further explored as a unique STAT3 inhibitor in antitumor therapy.

Concurrent Targeting of Potential Cancer Stem Cells Regulating Pathways Sensitizes Lung Adenocarcinoma to Standard Chemotherapy.

Cancer stem cells (CSC) are highly resistant to conventional chemotherapeutic drugs. YAP1 and STAT3 are the two transcription factors that facilitate the therapeutic resistance and expansion of CSCs. The objective of this study was to understand the cross-talk between YAP1 and STAT3 activities and to determine the therapeutic efficacy of targeting dual CSC-regulating pathways (YAP1 and STAT3) combined with chemotherapy in lung adenocarcinoma. Here, we showed that YAP1 contributes to CSC regulation and enhances tumor formation while suppressing apoptosis. Mechanistically, YAP1 promotes phosphorylation of STAT3 by upregulating IL6. In lung adenocarcinoma clinical specimens, YAP1 expression correlated with that of IL6 (P < 0.01). More importantly, YAP1 and phosphorylated STAT3 (pSTAT3) protein expressions were significantly correlated (P < 0.0001) in primary lung adenocarcinoma as determined by IHC. Immunoblotting of 13 lung adenocarcinoma patient-derived xenografts (PDX) showed that all YAP1-expressing PDXs also exhibited pSTAT3. Additional investigations revealed that chemotherapy resistance and malignant stemness were influenced by upregulating NANOG, OCT4, and SOX2, and the expression of these targets significantly attenuated by genetically and pharmacologically hindering the activities of YAP1 and STAT3 in vivo and in vitro Therapeutically, the dual inhibition of YAP1 and STAT3 elicits a long-lasting therapeutic response by limiting CSC expansion following chemotherapy in cell line xenograft and PDX models of lung adenocarcinoma. Collectively, these findings provide a conceptual framework to target the YAP1 and STAT3 pathways concurrently with systemic chemotherapy to improve the clinical management of lung adenocarcinoma, based on evidence that these two pathways expand CSC populations that mediate resistance to chemotherapy.