Objective To investigate the possible effects of phosphorylated signal transduction and activator of transcription3 (STAT3) in the formation of choroidal neovascuarization (CNV) induced by photocoagulation in rats. Methods The CNV model in rats induced by photocoagulation was established, and the expression of phosphorylated STAT3 at the early stage in CNV were observed by immunofluorescence. To set up the hypoxia model, the specific inhibitor of Janus kinase 2 (JAK2), AG490 was mixed into cell culture fluid and then cultured for 0,1 hour,3,6,12,and 24 hours.Retinal pigment epithelial (RPE) cells proliferation activity were detected by flow cytometry (FCM).the expression of hypoxiainducible factor (HIF)1α and vascular endothelial grow factor (VEGF) mRNA were detected by reverse transcriptase polymerase chain reaction (RT-PCR); the expression of HIF1α protein was detected by Western blot; the content of VEGF in the supernatant of cell culture fluid was measured by enzyme linked immunosorbent assay (ELISA). Results Phosphorylated STAT3 highly expressed in CNV areas in rats 3 days after the photocoagulation. The proliferation activity of human RPE cells under hypoxia condition significantly decreased after inhibition of JAK2/STAT3 signal transduction pathway (t=1.472, 3.566,2.391,6.420; P=0.054,0.038,0.042,0.016). The expression of HIF-1α and VEGF mRNA increased gradually with increasing time of hypoxia;while the expression of HIF1α and VEGF mRNA and the activation of HIF1α protein in cultured human RPE cells with the JAK/STAT3 signal transduction pathway blocked by AG490 were suppressed obviously under hypoxia condition (t=0.07,0.02,0.01, P<0.05); the content of VEGF in RPE cells supernatant decreased significantly (t=1.330,1.106,2.828,7.742,5.610,6.894; P=0.082,0.063,0.014,0.002,0.016,0.011). Conclusion STAT3 may be involved in CNV formation, which may partly dependent on JAK2/STAT3 signal transduction pathway regulating the expression of HIF-1α and VEGF in RPE cells.
ObjectiveTo systematically review the correlation of pSTAT3 overexpression and prognosis in lung cancer patients.MethodsWe searched from PubMed, EMbase, Web of Science, CNKI, VIP and WanFang Data databases to collect relevant studies about the correlation of pSTAT3 overexpression and prognosis in lung cancer patients from inception to November 2016. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed by using RevMan 5.2 software.Results A total of thirteen studies were enrolled. The results of the meta-analysis showed that the overall survival (HR=1.23, 95%CI 1.04 to 1.46, P=0.02) of pSTAT3 overexpression group was shorter than that of low expression group. In terms of clinical prognostic characteristics, pSTAT3 overexpression rate in stage Ⅲ to Ⅳ group was significantly higher than stage Ⅰ to Ⅱ (OR=1.92, 95%CI 1.13 to 3.27, P=0.02). pSTAT3 overexpression rate of lung cancer patients with lymphatic node metastasis was also significantly higher than lung cancer patients without lymphatic node metastasis (OR=1.81, 95%CI 1.20 to 2.72, P=0.004). However, there was no statistical difference of pSTAT3 overexpression between well-moderately differentiation and poorly differentiation group (OR=0.82, 95%CI 0.44 to 1.53, P=0.54).ConclusionpSTAT3 overexpression is associated with poorer overall survival of lung cancer patients, as well as with more and advanced TNM grade and lymph node metastasis. It may be an indicator poor biomarker in lung cancer patients. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify above conclusion.
ObjectiveTo study the effects of sea cucumber polysaccharide (SCPS) on the proliferation and apoptosis of hepatocellular carcinoma (HCC) cells, and to explore its effect on JAK2/STAT3/survivin pathway. MethodsThe human HCC cell lines HepG2 were placed into 24-well plates after culturing to the logarithmic phase, then dealed with different concentrations (0, 50, 100, 200 μg/mL) of SCPS. The MTT assay was used to detect the effects of different concentrations of SCPS on cell proliferation at 12 h, 24 h, and 36 h. The effect of SCPS on cell apoptosis was analyzed by flow cytometry. The mRNA and protein expression levels of JAK2, STAT3, and survivin were detected by real-time quantitative PCR (qRT-PCR) and Western blot at 36 h after treatment with SCPS, respectively. Then, the human HepG2 cells treated with different concentrations (0, 50, 100, 200 μg/mL) of SCPS were subcutaneously xenografted into nude mice to observe the effect of SCPS on the growth of tumor tissues in nude mice. At the same time, the expressions of phosphorylated JAK2, STAT3, and survivin proteins in tumor tissues were detected by immunohistochemical method. ResultsAfter treatment with different concentrations of SCPS, the proliferation inhibition rate of HepG2 cells increased over time and increased SCPS concentrations (P<0.05). After 36 h cultivation time, the apoptosis rate of cells treated with different concentrations of SCPS was statistically significant (F=117.110, P<0.001) and increased with the increase of SCPS concentrations (P<0.05). The protein expression levels of JAK2, STAT3, survival and their phosphorylated proteins decreased gradually with the increase of SCPS concentrations (P<0.05), but there was no significant difference in the mRNA expression level (P>0.05). With the increase of SCPS concentration, the tumor volume of nude mice gradually reduced (P<0.05). At the same time, the results of immunohistochemical detection showed that the positive expression rates of phosphorylated JAK2, STAT3, and survivin proteins in tumor tissues decreased with the increase of SCPS concentrations (P<0.05). ConclusionFrom preliminary results of this study, SCPS could inhibit the proliferation of HCC cells and promote their apoptosis, which might be achieved by regulating the phosphorylated expressions of JAK2, STAT3, and survivin in the JAK2/STAT3/survivin pathway.
Objective To explore the molecular mechanism of LINC00626 regulating malignant progression of lung adenocarcinoma metastasis through JAK1/STAT3/KHSRP axis. Methods Quantitative real-time polymerase chain polymerase chain reaction was used to detect the expression of LINC00626 and KHSRP mRNA in human non-small-cell lung carcinoma cell lines (A549, H1299, H1975, H1437), human normal bronchial epithelial cell line (16HBE) and 144 lung adenocarcinoma tissues. The knockdown LINC00626 lentivirus and the control lentivirus were transferred into H1299 and H1437 cells, and named as sh-LINC00626 group (silencing of LINC00626 by transfecting short hairpin RNA lentiviral vector and sh-NC Group negative control by transfecting short hairpin RNA lentiviral). The overexpressed LINC00626 lentivirus and the control lentivirus were transferred into A549 and H1975 cells and named as LINC00626 group and Vector group. KHSRP vector on the basis of silencing LINC00626 and blank vector on the basis of silencing LINC00626 were added in H1437 cells. Cell counting kit-8 assay and Transwell migration/invasion assay were used to detect cell proliferation, migration and invasion. The expression levels of JAK/STAT and KHSRP in stably transfected cells were detected by Western blot. The effect of LINC00626 in vivo was studied in nude mice. Nuclear-cytoplasmic separation and RNA fluorescence in situ hybridization assay are used to predict the subcellular localization of LINC00626 and KHSRP. RNA pull down and mass spectrometry analysis were used to identify LINC00626 binding proteins. Results The expression levels of LINC00626 and KHSRP in non-small-cell lung carcinoma cell lines were significantly higher than those in normal human bronchial epithelial cells. LINC00626 and KHSRP were highly expressed in lung adenocarcinoma. Compared with the control group, the cell proliferation rate, colony formation, cell migration and invasion of H1437 cells were significantly decreased in knockdown group, while the reverse was true for over-expression. LINC00626 and KHSRP were located in the nucleus. LINC00626 directly binded to the KHSRP protein. Compared with the control group, H1437 cells transfected with knockdown LINC00626 and KHSRP significantly increased cell proliferation rate, cell migration, number of invasions. Compared with the control group, knockdown group showed a significant decrease in tumor volume and weight, cell proliferation rate and proliferation index, and the number of lung metastases. While the overexpression group showed an opposite effect, there were significant differences among the groups (P<0.01). The expression of JAK1 and STAT3 mRNA and protein in sh-LINC00626 group was lower than that in sh-NC Group (P<0.05), and the expression of JAK1 and STAT3 mRNA and protein in sh-LINC00626 group was higher than that in Vector group (P<0.05). Conclusion LINC00626 promotes malignant progression of lung adenocarcinoma metastasis through JAK1/STAT3/KHSRP signaling axis.
Objective To explore the therapeutic effect of basic fibroblast growth factor (bFGF) on spinal cord injury (SCI) in rats and the influence of Notch/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Methods A total of 40 10-week-old male Sprague Dawley (SD) rats were selected to establish T10-segment SCI model by a free falling object. Among them, 32 successful models were randomly divided into model group and bFGF group, with 16 in each group. Another 16 SD rats were selected as sham-operation group, with only T10 processes, dura mater, and spinal cord exposed. After modeling, the rats in bFGF group were intraperitoneally injected with 100 μg/kg bFGF (once a day for 28 days), and the rats in model group and sham-operation group were injected with normal saline in the same way. The survival of rats in each group were observed after modeling. Basso-Beattie-Bresnahan (BBB) scores were performed before modeling and at immediate, 14 days, and 28 days after modeling to evaluate the functional recovery of hind limbs. Then, the spinal cord tissue at the site of injury was taken at 28 days and stained with HE, Nissl, and propidium iodide (PI) to observe the pathological changes, neuronal survival (number of Nissl bodies) and apoptosis (number of PI red stained cells) of the spinal cord tissue; immunohistochemical staining and ELISA were used to detect the levels of astrocyte activation markers [glial fibrillary acidic protein (GFAP)] and inflammatory factors [interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), interferon γ (IFN-γ)] in tissues, respectively. Western blot was used to detect the expressions of Notch/STAT3 signaling pathway related proteins [Notch, STAT3, phosphoryl-STAT3 (p-STAT3), bone morphogenetic protein 2 (BMP-2)] in tissues. Results All rats survived until the experiment was completed. At immediate after modeling, the BBB scores in model group and bFGF group significantly decreased when compared to sham-operation group (P<0.05). At 14 and 28 days after modeling, the BBB scores in model group significantly decreased when compared to sham-operation group (P<0.05); the bFGF group showed an increase compared to model group (P<0.05). Compared with before modeling, the BBB scores of model group and bFGF group decreased at immediate after modeling, and gradually increased at 14 and 28 days, the differences between different time points were significant (P<0.05). The structure of spinal cord tissue in sham-operation group was normal; in model group, there were more necrotic lesions in the spinal cord tissue and fewer Nissl bodies with normal structures; the number of necrotic lesions in the spinal cord tissue of the bFGF group significantly reduced compared to the model group, and some normally structured Nissl bodies were visible. Compared with sham-operation group, the number of Nissl bodies in spinal cord tissue significantly decreased, the number of PI red stained cells, GFAP, IL-1β, TNF-α, IFN-γ, Notch, p-STAT3 /STAT3, BMP-2 protein expression levels significantly increased in model group (P<0.05). The above indexes in bFGF group significantly improved when compared with model group (P<0.05). Conclusion bFGF can improve motor function and pathological injury repair of spinal cord tissue in SCI rats, improve neuronal survival, and inhibit neuronal apoptosis, excessive activation of astrocytes in spinal cord tissue and inflammatory response, the mechanism of which may be related to the decreased activity of Notch/STAT3 signaling pathway.