Effect Of PLEC On The Biological Behaviour Of Hepatocellular Cancer Cell Line

Backgrounds: Metastasis is always the main cause of high mortality and poor clinical prognosis for most diagnosed hepatocellular carcinoma patients.In our previous study,PLEC was significantly up-regulated in high metastatic potential hepatocellular carcinoma cells compared to low metastatic potential.Furthermore,it was confirmed that over-expression of PLEC was also strongly correlated with TNM stages and tumor size using immunohistochemical analysis in 95 hepatocellular carcinoma(HCC)tissues and adjacent tissues.All of these revealed that PLEC may be associated with metastasis and prognosis of HCC.Purpose: To explore the role of PLEC in the biological behaviour of hepatocellular carcinoma cells and determine whether PLEC was identified as a specific biomarker for the metastasis of HCC.Methods: Lentivirus-mediated siRNA was applied to knockdown the expression of PLEC and it was assessed by western blot.Then we developed the down-expressing PLEC from MHCC97-H cells and SMMC-7721 cells.Scratch-wound assay,cell invasion experiments,cell cycle analysis,apoptosis assay and cell growth assays were underwent to evaluated the effects of PLEC on cell biology behaviors of hepatocellularcarcinoma cells.All the experiments were performed and repeated at least three times.The intrahepatic xenografts was established in nude mice to observe the ability of tumorigenic and distant metastasis in nude mice.Animal liver and lung were taken for serial sections and routine histology with HE staining to observe whether distant metastasis occurred.Results The knockdown of PLEC expression has no significant effect on the biological behavior of MHCC97-H cells such as cell growth,migration,invasion,cell cycle and apoptosis(P>0.05).Moreover,it was not observed distant metastasis in nude mice and there was no significant difference in tumor size in situ of liver(P>0.05).However,it is reported that the intrahepatic xenografts of MHCC97-H cells grew and metastasized to lungs(100%),which is inconsistent with our results.So the veracity of our experimental results remains to be verified.But a series of in vitro experiments of SMMC-7721 cells showed that knocking down the expression of PLEC can significantly inhibit the proliferation,migration and invasion ability of SMMC-7721 cells.Conclusion PLEC may promote hepatoma cell proliferation,metastasis and invasiveness,and it is one of the potential therapeutic targets for hepatocellular carcinoma.Our previous study also suggests that PLEC may be used as a potential indicator of hepatoma metastasis.