The mechanism of somatostatin receptor subtype 2 reversed hepatocellular carcinoma cells epithelial mesenchymal transition and inhibited invasion and metastasis

Abstract

Objective To investigate the effect of the somatostatin receptor subtype 2 (SSTR2) on the migration and invasion of human Hepatocellular carcinoma cells MHCC-97H and the change of epithelial-mesenchymal transition (EMT).Methods Constructed 3FLAG-puromycin-LV and SSTR2-LV and transfected hunman Hepatocellular carcinoma cells (MHCC-97H) respectively.The expression of SSTR2 was detected by real-time quantitative polymerase chain reaction (Real-time PCR) and Western blot.The migration and invasion of Non-transfected (blank control group),3FLAG-puromycin-LV transfected (negative control group) and SSTR2-LV (experimental group) transfected MHCC-97H cells was detected by Transwell invasion assay and Transwell migration assay.The changes in morphology of cells were observed by optical microscopy.The localization and expression of the epithelial markers and the mesenchymal markers were assayed by immunofluorescence and Western blotting.Results The stable mRNA and protein expression of SSTR2 was detected in the cells transfected with SSTR2-LV.The migration and invasion was restrained in the experimental group compared with control groups (P ＜ 0.05).Transfection of SSTR2-LV induced a morphologic change of MHCC-97H cells from fibroblastic shape with cell scattering to a paving stone structure with cell-cell adhesion.In SSTR2-LV-transfected cells,the localization of E-cadherin was altered from the cytoplasm to cell-cell contacts and the level of Vimentin decreased.Moreover,the expression of the epithelial marker,E-cadherin and β-catenin,were increased; the expression of the mesenchymal marker,N-cadherin and Vimentin,were reduced.Conclusion MHCC-97H re-expression of SSTR2 induced the increasing expression of epithelial marker and the decrease expression of mesenchymal marker reversed HCC EMT then suppressed the HCC cells migration and invasion. Key words: Somatostatin receptor subtype 2 ; Epithelial mesenchymal transition ; Hepatocellular carcinoma; Invasion; Metastasis