Research Of The Mechanism Of PTPRD Gene On Proliferation And Migration Of Hepatocellular Carcinomas Cells Via PI3K-Akt-mTOR Signaling Pathway

Objectives1 To determine the tumor suppressor activity of protein tyrosine phosphatase D(PTPRD)gene in hepatocellular carcinoma cells.2 To elucidate the molecular mechanism of PTPRD gene on the proliferation and migration of hepatocellular carcinoma cells via Phosphatidylinositol-3-kinase(PI3K)-protein kinase b(PKB/Akt)-mammalian target of rapamycin(mTOR)signaling pathway.3 To provide a new idea for finding new genetic markers of hepatocellular carcinoma(HCC)and new targets for the treatment of HCC.Methods1 The mRNA and protein levels of PTPRD gene in human normal liver cells(L02)and HCC cell lines(HepG2 and HuH-7)were detected by RT-PCR and Western blot.2 PTPRD gene overexpression adenovirus and shRNA-PTPRD lenti-virus were used to construct stable HCC cell lines with PTPRD gene overexpression and silencing,respectively.The effects of PTPRD gene expression on proliferation and migration of HCC cells were detected by MTT and cell scratch test respectively.3 Effect of PTPRD expression on Akt,p-Akt,mTOR and p-mTOR in the stable HCC cell lines of PTPRD gene overexpression and silencing was detected by Western blot.Results1 The mRNA and protein levels of PTPRD gene in HCC cell lines(HepG2 and HuH-7)were significantly lower than those in normal hepatocytes(L02)(P<0.05).2 PTPRD gene overexpression of the HepG2 and HuH-7 cells lines was successfully constructed,compared with the negative control group,the proliferation and migration ability of the HepG2 and HuH-7 cells line in the PTPRD gene overexpression group was significantly inhibited(P<0.05);only the shRNA-HepG2 cells line was constructed successfully,the proliferation and migration of HepG2 cells in the negative control group was increased(P<0.05)after PTPRD gene silencing.3 Compared with the negative control group,the expression of p-Akt and p-mTOR protein level in the two HCC cell lines overexpression with PTPRD was down-regulated(P<0.05),on the contrary,the expression of p-Akt and p-mTOR protein level in HepG2 cell line with PTPRD gene silencing was both increased(P<0.05).Conclusions1 PTPRD gene may act as a tumor suppressor in HCC.2 PTPRD gene may affect the proliferation and migration of HCC cells by regulating PI3K-Akt-mTOR signaling pathway.