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Gastric cancer (GC) has become the first malignant tumor with highest incidence rate and mortality of cancer in China, finding therapeutic targets for gastric cancer is of great significant for improving the survival rate of patients with GC. Recently, many of studies have shown that LncRNAs is involved in multiple biological progresses in the development of GC. This study, we screened for abnormally high expression of LncSHANK3 in GC through the TCGA database, and found that LncSHANK3 sponge adsorbs miR-4530, further competing with MNX1 and binding to miR-4530. We demonstrated the interaction between LncSHANK3 and miR-4530 through luciferase reporting analysis, with miR-4530 negatively regulating MNX1.Through CCK8, colony formation, transwell, and wound healing assays, it was found that LncSHANK3 affects the occurrence of GC through cell proliferation, migration and invasion. In conclusion, LncSHANK3/miR-4530/MNX1 axis is a potential mechanism for the treatment of GC.

Abstract Aldolase A (ALDOA), an important metabolic enzyme in the glycolytic pathway, plays an important role in regulating tumour metabolism. In this study, we investigated the expression pattern of ALDOA in hepatocellular carcinoma (HCC) and its biological role in tumour progression. Bioinformatics analysis, western blot (WB) and RT-qPCR were performed to detect the relative expression of ALDOA in HCC tissues and cell lines. A loss-of-function approach was used to investigate the biological function of ALDOA. The role of ALDOA on glycolysis was assessed by WB, glucose and lactate assay kits and a nude mouse xenograft model. Luciferase reporter experiment, chromatin immunoprecipitation and WB were performed to elucidate the underlying molecular. The expression level of ALODA was up-regulated in HCC tissues and cell lines. High ALDOA levels were associated with poorer patient overall survival. Mechanistic studies suggest that ALDOA is a direct target of miR-34a-5p, which can inhibit glycolysis in hepatocellular carcinoma cells by targeting the 3′UTR of ALDOA. PINK1 antisense RNA (PINK1-AS) competitively sponged miR-34a-5p to increase ALDOA expression by antagonizing miR-34a-5p-mediated ALDOA inhibition. MKL-1 acted as a transcription factor to promote the expression of PINK1-AS and ALDOA, thus promoting the deterioration of HCC cells. This study shows that high expression of ALDOA contributes to the development and poor prognosis of hepatocellular carcinoma and will be a target and potential prognostic biomarker for the treatment of HCC.

Abstract Background Long non-coding RNAs (lncRNAs) are closely related to the occurrence and development of cancer. Abnormally expressed lncRNA can be used as a diagnostic marker for cancer. In this study, we aim to investigate the clinical significance of MIR99AHG expression in lung adenocarcinoma (LUAD), and its biological roles in LUAD progression. Methods The relative expression of MIR99AHG in LUAD tissues and cell lines was analyzed using public databases and RT-qPCR. The biological functions of MIR99AHG were investigated using a loss-of-function approach. The effect of MIR99AHG on lung fibrosis was assessed by scratch assay, invasion assay and lung fibrosis rat model. FISH, luciferase reporter assay and immunofluorescence were performed to elucidate the underlying molecular mechanisms. Results LncRNA MIR99AHG expression level was downregulated in LUAD tissues and cell lines. Low MIR99AHG levels were associated with poorer patient overall survival. Functional analysis showed that MIR99AHG is associated with the LUAD malignant phenotype in vitro and in vivo. Further mechanistic studies showed that, MIR99AHG functions as a competitive endogenous RNA (ceRNA) to antagonize miR-136-5p-mediated ubiquitin specific protease 4 (USP4) degradation, thereby unregulated the expression of angiotensin-converting enzyme 2 (ACE2), a downstream target gene of USP4, which in turn affected alveolar type II epithelial cell fibrosis and epithelial–mesenchymal transition (EMT). In summary, the MIR99AHG/miR-136-5p/USP4/ACE2 signalling axis regulates lung fibrosis and EMT, thus inhibiting LUAD progression. Conclusion This study showed that downregulated MIR99AHG leads to the development of pulmonary fibrosis. Therefore, overexpression of MIR99AHG may provide a new approach to preventing LUAD progression.

Purpose: miR-5100 participates in the proliferation of lung cancer and pancreatic cancer cells, and participates in the differentiation of osteoblasts. However, the regulation of gastric cancer cells in gastric cancer cells remains unclear. Experimental design: The blood of patients was collected to detect the expression level of miR-5100, and the apoptosis and autophagy levels of cells were detected using western blot, flow cytometry, and confocal. At the same time, in vitro tumor formation experiments in nude mice were used to verify the results of in vitro experiments. Results: The expression of miR-5100 is related to the prognosis of gastric cancer, miR-5100 can enhance the apoptosis level of gastric cancer cells and inhibit the occurrence of autophagy by targeting CAAP1. MKL1 can inhibit the apoptosis of gastric cancer cells and promote the occurrence of autophagy by targeting CAAP1. At the same time, MKL1 can also increase the expression of miR-5100. Conclusions: Our research reveals the mechanism by which the MKL1/miR-5100/CAAP1 loop regulates apoptosis and autophagy levels in gastric cancer cells, and miR-5100 is expected to become a new potential target for gastric cancer treatment. Keywords: MKL1, miR-5100, CAAP1, Autophagy, Apoptosis, Gastric cancer

Abstract Background Breast cancer is the leading cause of cancer death in women worldwide which is closely related to metastasis. But the exact molecular mechanism of ERα-36 and STAT3 on metastasis is still not fully understood. Methods MCF-7 and MDA-MB-231 human breast cancer cell lines and MCF-10A were overexpressioned or knockdown ERα-36 and STAT3 and tested for migration, invasion and proliferation assays. Direct interaction of STAT3 and ERα-36 were analyzed by coimmunoprecipitation assays. The effect of STAT3 and ERα-36 on MMP2/9 expression was analyzed by qPCR and western blotting. STAT3 phospholyation and acetylation by ERα-36 and p300 were observed and quantified by coimmunoprecipitation assays and western blotting. Results Cross-talk between ERα-36 and STAT3 was demonstrated to mediate through a direct physical association between the two proteins. Furthermore, the interaction between ERα-36 and STAT3 was demonstrated to give rise to functional changes in their signaling events. Both MMP2 and MMP9 expression require the binding of the newly identified protein complex, ERα-36-STAT3, to its promoter, the second phase, which is more robust, depends on ERα-mediated recruitment of p300 onto the complex and the subsequent acetylation of STAT3. In addition, STAT3 is tyrosine-phosphorylated in a biphasic manner, and the late phase requires ERα-36-mediated p300-dependent acetylation. Furthermore, interference with acetylation of STAT3 by overexpression of acetylation null STAT3 mutant led to the loss of MMP2 and MMP9 expression. ChIP analysis and reporter gene assays revealed that ERα-36-STAT3 complex binding to the MMP2 and MMP9 promoter led to an enhanceosome formation and facilitated MMP2 and MMP9 expression. Conclusions Our studies demonstrate for the first time that the function of MMP2 and MMP9 in breast cancer cell migration, which is mediated by interactions between ERα-36 and STAT3.

OBJECTIVE To observe the effect of all-trans retinoic acid (ATRA) on inducing human glioma MO59K cells differentiation and further explore the underlying molecular mechanisms.METHODS The expression of glial fibrillary acidic protein (GFAP) was detected by immunocytochemistry staining. The mRNA levels of GFAP, retinoid X receptor α (RXRα), p21 were examined by semi-quantitative RT-PCR analysis. Luciferase activity assay was performed in the COS-7, MO59K cells to measure p21 promoter transcription activity.RESULTS ATRA could significantly enhance the expression and mRNA level of GFAP by immunostaining and RT-PCR (P < 0.05). Simultaneously, the mRNA levels of RXRα and p21 were remarkably increased in dose-dependent manner by RT-PCR (P < 0.05). Furthermore, luciferase assay confirmed that ATRA and RXRα could transactivate p21 promoter in COS-7 and glioma cells (P < 0.05).CONCLUSION ATRA can induce differentiation of human Glioma cells. The RXRα and p21 were activated during ATRA-induced differentiation process. This effect may be caused by directly RXRα-induced p21 gene transactivation. Our findings provide novel evidence for the future studies to explore the molecular mechanism of transcriptional regulation for glioma cell differentiation and cellular therapeutic approaches for glioblastoma.

The JAK-STAT3 signaling pathway is one of the critical pathways regulating cell proliferation, differentiation, and apoptosis. Myocardin is regarded as a key mediator for the change of smooth muscle phenotypes. However, the relationship between STAT3 and myocardin in the vascular smooth muscle cell (VSMC) phenotypic switch has not been investigated. The goal of this study was to investigate the molecular mechanism by which STAT3 affects the myocardin-regulated VSMC phenotypic switch. Data presented in this study demonstrated that STAT3 was rapidly up-regulated after stimulation with VEGF. Inhibition of the STAT3 activation process impaired VSMC proliferation and enhanced the expression of VSMC contractile genes by increasing serum-response factor binding to the CArG-containing regions of VSMC-specific contractile genes. In contrast, the interaction between serum-response factor and its co-activator myocardin was reduced by overexpression of STAT3. In addition, treated VEGF inhibited the transcription activity of myocardin, and overexpression of STAT3 inhibited myocardin-induced up-regulation of VSMC contractile phenotype- specific genes. Although myocardin and STAT3 are negatively correlated, interestingly, both of them can enhance the expression of VEGF, suggesting a feedback loop to regulate the VSMCphenotypic switch. Taken together, these results indicate that the JAK-STAT3 signaling pathway plays a key role in controlling the phenotypic switch of VSMCs through the interactions between STAT3 and myocardin by various coordinated gene regulation pathways and feedback loops. [ABSTRACT FROM AUTHOR]

Myocardin is a remarkably potent transcriptional coactivator expressed specifically in cardiac muscle lineages and smooth muscle cells during postnatal development. Myocardin shares homology with myocardin-related transcription factor-A (MRTF-A), which are expressed in a broad range of embryonic and adult tissues. Our previous results show that myocardin induces cardiac hypertrophy. However, the effects of MRTF-A in cardiac hypertrophy remain poorly understood. Our present work further demonstrates that myocardin plays an important role in inducing hypertrophy. At the same time, we find that overexpression of MRTF-A in neonatal rat cardiomyocytes might induce cardiomyocyte hypertrophy. Furthermore, MRTF-A expression is induced in phenylephrine, angiotensin-II, and transforming growth factor-β-stimulated cardiac hypertrophy, whereas a dominant-negative form of MRTF-A or MRTF-A siRNA strongly inhibited upregulation of hypertrophy genes in response to hypertrophic agonists in neonatal rat cardiomyocytes. Our studies indicate that besides myocardin, MRTF-A might play an important role in cardiac hypertrophy. Our findings provide novel evidence for the future studies to explore the roles of MRTFs in cardiac hypertrophy. © 2011 IUBMB IUBMB Life, 63(1):54-61, 2011. [ABSTRACT FROM AUTHOR]

Abstract Background Foxp3+CD4+ regulatory T cells (Treg) constitutes a key event in autoimmune diseases. STAT5b is the critical link between the IL-2/15 and FOXP3, the master regulator of Treg cells. Methods The CD3+T cell and Foxp3+CD4+ regulatory T cells were overexpressioned or knockdown MKL-1 and STAT5a and tested for Treg cell development and function. Direct interaction of MKL-1 and STAT5a were analyzed by coimmunoprecipitation assays, Luciferase assay, Immunofluoresence Staining and Yeast two-hybrid screening. The effect of MKL-1 and STAT5a on the Treg genes expression was analyzed by qPCR and western blotting and Flow cytometry. Results However, the molecular mechanisms mediating STAT5b-dependent Treg genes expression and Treg cell phenotype and function in autoimmune diseases are not well defined. Here, we report that the MKL-1 is a coactivator for the major Treg genes transcription factor STAT5b, which is required for human Treg cell phenotype and function. The N terminus of STAT5b, which contains a basic coiled-coil protein–protein interaction domain, binds the C-terminal activation domain of MKL-1 and enhances MKL-1 mediated transcriptional activation of Treg-specific, CArG containing promoters, including the Treg-specific genes Foxp3. Suppression of endogenous STAT5b expression by specific small interfering RNA attenuates MKL-1 transcriptional activation in cultured human cells. The STAT5b–MKL-1 interaction identifies a role of Treg-specific gene regulation and regulated mouse Treg cell development and function and suggests a possible mechanism for the protective effects of autoimmune disease Idiopathic Thrombocytopenic Purpura (ITP). Conclusions Our studies demonstrate for the first time that MKL-1 is a coactivator for STAT5b, the regulator of Treg cell development and function. Video abstract

Abstract Vascular endothelial growth factor A (VEGF-A) is a pivotal player in angiogenesis. It is capable of influencing such cellular processes as tubulogenesis and vascular smooth muscle cell (VSMC) proliferation, yet very little is known about the actual signaling events that mediate VEGF-A induced VSMC phenotypic switch. In this report, we describe the identification of an intricate VEGF-A-induced signaling cascade that involves VEGFR2, STAT3, and Myocardin. We demonstrate that VEGF-A promotes VSMC proliferation via VEGFR2/STAT3-mediated upregulating the proliferation of markers like Cyclin D1 and PCNA. Specifically, VEGF-A leads to nitrosylation of Myocardin, weakens its effect on promoting the expression of contractile markers and is unable to inhibit the activation of STAT3. These observations reinforce the importance of nitric oxide and S-nitrosylation in angiogenesis and provide a mechanistic pathway for VEGF-A-induced VSMC phenotypic switch. In addition, Myocardin, GSNOR and GSNO can create a negative feedback loop to regulate the VSMC phenotypic switch. Thus, the discovery of this interactive network of signaling pathways provides novel and unexpected therapeutic targets for angiogenesis-dependent diseases.