BackgroundOur previous studies reported that SHC SH2-domain binding protein 1 (SHCBP1) functions as an oncogene via promoting cell proliferations in synovial sarcoma (SS) cells. However, whether SHCBP1 has any effect on tumor metastasis remains unexplored.MethodsThe expression of SHCBP1 was analyzed in 76 SS tissues and two SS cell lines by immunohistochemistry and real-time RT-PCR. The relationship between SHCBP1 expression and the clinicopathological features of SS was investigated. The role of SHCBP1 in SS cell adhesion, migration, invasion and angiogenesis was explored by adhesion, Wound healing, Transwell, and Matrigel tube formation assays. Western blotting was conducted to detect the protein expressions of TGF-β1/Smad signaling pathway and EMT-related markers. The key molecules associated with migration, invasion and EMT were evaluated by immunohistochemistry in tumor specimens.ResultsIn current study, we demonstrated that SHCBP1 overexpression significantly enhanced adhesion, migration, invasion and angiogenesis of SS cells. In contrast, SHCBP1 knockdown elicited the opposite effects on these phenotypes in vitro. SHCBP1 promoted tumor metastasis through inducing epithelial-mesenchymal transition (EMT) in SS cells. SHCBP1 knockdown could block the incidence of metastasis and EMT in SS cells. Furthermore, transforming growth factor-β1 (TGF-β1) induced SHCBP1 expression in a time-dependent pattern and SHCBP1 knockdown inhibited TGF-β1-induced EMT. The activation of the TGF-β1/Smad signaling pathway was involved in the oncogenic functions of SHCBP1 in SS. In addition, high expression of SHCBP1 in SS patients was associated with tumor progression and decreased survival as well as poor prognosis.ConclusionsTaken together, our results indicate that SHCBP1 may promote the metastasis of SS by inducing EMT through targeting TGF-β1/Smad signaling pathway and can be a potential molecular target for SS therapy.

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The SS18-SSX1 fusion gene has been shown to play important roles in the development of synovial sarcoma (SS), but the underlying molecular mechanisms and its downstream target genes are still not clear. Here SHC SH2-domain binding protein 1 (SHCBP1) was identified and validated to be a novel downstream target gene of SS18-SSX1 by using microarray assay, quantitative real-time (qPCR) and western blot. Expression of SHCBP1 was firstly confirmed in SS cell line and SS tissues. The effects of SHCBP1 overexpression or knockdown on SS cell proliferation and tumorigenicity were then studied by cell proliferation, DNA replication, colony formation, flow cytometric assays, and its in vivo tumorigenesis was determined in the nude mice. Meanwhile, the related signaling pathways of SHCBP1 were also examined in SS cells. The results indicated that SHCBP1 was significantly increased in SS cells and SS tissues compared with adjacent noncancerous tissues. The expression of SHCBP1 was demonstrated to be positively correlated with the SS18-SSX1 level. Overexpression and ablation of SHCBP1 promoted and inhibited, respectively, the proliferation and tumorigenicity of SS cells in vitro. SHCBP1 knockdown also significantly inhibited SS cell growth in nude mice, and lowered the MAPK/ERK and PI3K/AKT/mTOR signaling pathways and cyclin D1 expression. Our findings disclose that SHCBP1 is a novel downstream target gene of SS18-SSX1, and demonstrate that the oncogene SS18-SSX1 promotes tumorigenesis by increasing the expression of SHCBP1, which normally acts as a tumor promoting factor.

Our data suggested that MALAT1 exerted neuroprotective effect in a rat model of SCIRI by regulating miR-204.

Neuronal cells are highly sensitive to hypoxia and may be subjected to apoptosis when exposed to hypoxia. Several apoptosisrelated genes and miRNAs involve in hypoxia-induced apoptosis. This study aimed to examine the role of HIF1a-miR-204-BCL-2 pathway in hypoxia-induced apoptosis in neuronal cells. Annexin V/propidium iodide assay was performed to analyze cell apoptosis in AGE1.HN and PC12 cells under hypoxic or normoxic conditions. The expression of BCL-2 and miR-204 were determined by Western blot and qRT-PCR. The effects of miR-204 overexpression or knockdown on the expression of BCL-2 were evaluated by luciferase assay and Western blot under hypoxic or normoxic conditions. HIF-1a inhibitor YC-1 and siHIF-1a were employed to determine the effect of HIF-1a on the up-regulation of miR-204 and down-regulation of BCL-2 induced by hypoxia. Apoptosis assay showed the presence of apoptosis induced by hypoxia in neuronal cells. Moreover, we found that hypoxia significantly down-regulated the expression of BCL-2, and increased the mRNA level of miR-204 in neuronal cells than that in control. Bioinformatic analysis and luciferase reporter assay demonstrated that miR-204 directly targeted and regulated the expression of BCL-2. Specifically, the expression of BCL-2 was inhibited by miR-204 mimic and enhanced by miR-204 inhibitor. Furthermore, we detected that hypoxia induced cell apoptosis via HIF-1a/miR-204/BCL-2 in neuronal cells. This study demonstrated that HIF-1a-miR-204-BCL-2 pathway contributed to apoptosis of neuronal cells induced by hypoxia, which could potentially be exploited to prevent spinal cord ischemia-reperfusion injury.