H2-calponin Inhibits Proliferation And Metastasis Of Colon Cancer

BackgroundH2-calponin, a member of actin filament- associated proteins in Calponin family, was found to regulate the actin cytoskeleton and cell motility in smooth muscle and certain non-muscle cells. Previous studies of H2-calponin mainly focused on its regulation in cell cytoskeleton, but there are no reports in tumor until now. Here we investigated the expression of H2-calponin in colon cancer patients and further explored its potential role in the proliferation and metastasis of colon cancer.MethodsExpression of H2-calponin was investigated in colon cancer, adjacent, normal colonic tissues and 5 colon cancer cell lines by Western Blot. Ectopic overexpression and knockdown of H2- calponin were achieved by transfection with H2-calponin-sense vector and human H2-calponin-specific small interference RNA (H2-calponin-siRNA) vector in colon cancer cells SW620 and SW480, respectively. Using these cell line, cell proliferation was detected by MTT assay and cell cycle was analyzed by flow cytometry. Meanwhile, migration and invasive ability were determined by wound healing and transwell assay. Furthermore, tumorigenicity assay and tail vein metastasis assay were performed to verify those effects in vivo.ResultsExpression of H2-calponin was found significantly lower in colon cancer tissues compared to that in adjacent and normal tissues. Upregulation of H2-calponin could significantly decrease colon cancer cell proliferation while downregulation of H2- calponin significantly increased cell growth in MTT assay. Cell cycle analysis further revealed that H2- calponin induced cell cycle arrest at G1/S phase. Meanwhile, wound healing and transwell assay showed that upregulation of H2-calponin could significantly suppress the migratory and invasive abilities of SW620 cells while downregulation of H2-calponin in SW480 cells led to the opposite effect. Finally, tumorigenesis assay and tail vein metastasis assay confirmed those effects in vivo.ConclusionTaken together, our study demonstrated that H2- calponin is significantly downregulated in colon cancer tissues compared to adjacent and normal tissues. It may inhibit the proliferation and metastasis abilities of colon cancer, thus suggested that H2- calponin may be a useful biomarker and the potential target for the diagnosis and treatment of colon cancer.