The Exploration Of The Role And Mechanism Of CMTM4 In The Occurrence And Development Of Hepatocellular Carcinoma

Objective: By detecting the expression of CMTM4 in hepatocellular carcinoma(HCC)patients and adjacent tissues,the relationship between the clinicopathological features and prognosis of HCC patients and the expression of CMTM4 was investigated;The effects of CMTM4 changes on the biological characteristics of hepatocellular carcinoma cells were determined by cell function experiments in vitro;By analyzing the correlation between the expression of CMTM4 and epithelial mesenchymal transformation(EMT)related factors in liver cancer tissues and cells,the regulatory mechanism of the involvement of CMTM4 in HCC invasion and metastasis was clarified.Methods : The expression of CMTM4 protein in 75 patients with hepatocellular carcinoma and their corresponding para-carcinoma tissues was detected by immunohistochemistry(IHC).The correlation between the clinicopathological features and prognosis of HCC patients and the expression of CMTM4 was analyzed by chi-square test;The expression of CMTM4 in liver cancer cell lines was detected by real-time fluorescence quantitative PCR(q RT-PCR).Cell proliferation was detected by cck-8 and plate cloning,apoptosis and cell cycle were detected by flow cytometry,and changes in cell migration and invasion ability were detected by scratch test and transwell test.The expression of EMT-related factors in HCC cell lines was detected by q RT-PCR after the change of CMTM4 expression.Immunohistochemistry was used to detect the expression of EMT-related factors in 166 HCC cancers and adjacent tissues,chi-square test was used to analyze the expression of EMT-related factors in liver cancer tissues,and Spearman correlation was used to analyze the correlation between the expression of CMTM4 and EMT-related factors in liver cancer tissues.Results:(1)The positive expression of CMTM4 in HCC tissues was significantly down-regulated compared with that in para-carcinoma tissues(P<0.05),and its expression was closely related to tumor size,clinical stage,TNM stage and distant metastasis of HCC patients,and was an independent prognostic factor for HCC patients(OR=2.433,95%CI=1.057-5.786,P<0.05).(2)CMTM4 was poorly expressed in hepatocellular carcinoma cells.Compared with the control group,after CMTM4 overexpression,cell proliferation decreased,monoclonal formation decreased,migration and invasion decreased,cell cycle stagnated in G2/M phase,and cell apoptosis in creased.However,after CMTM4 interference,cell proliferation,monoclonal formation,migration and invasion were all enhanced,G1 phase cell number increased,G2/M phase cell number decreased,and cell apoptosis decreased.(3)Compared with the control group,after CMTM4 interference,the expression of epithelial factors(E-cadherin,?-catenin)in liver cancer cells increased,and the expression of interstromal factors(N-cadherin,Vimentin,ZEB1)decreased,However,after overexpression of CMTM4,the expression of these epithelial factors decreased and the expression of interstitial factors increased,suggesting that CMTM4 gene could inhibit epithelium-interstitial transformation(EMT)in HCC cells.In addition,the epithelium factor(E-cadherin,beta-catenin)expressed in liver cancer tissues was significantly lower than tissue adjacent to carcinoma(P < 0.05),the EMT in terstitial factor(N-cadherin,Vimentin,ZEB1)expression in liver cancer tissue is significantly higher than in adjacent tissues(P < 0.05),and there was a correlation between CMTM4 and EMT partially related factors in liver cancer tissues(correlation coefficient r = 0.563,r = 0.609,r = 0.338,r = 0.055,r =-0.128).Conclusions:(1)Low expression of CMTM4 in hepatocellular carcinoma is associated with distant tumor metastasis and poor prognosis in patients with hepatocellular carcinoma.(2)In Huh-7 and Hep3 B hepatocellular carcinoma cell lines,the differential expression of CMTM4 significantly changed the proliferation,invasion and migration of hepatocellular carcinoma cells,and affected the cell cycle and apoptosis as well.(3)Changes in CMTM4 expression in HCC cell lines can cause changes in EMT-related factors.(4)the expression of CMTM4 in liver cancer tissues is correlated with the expression of EMT-related factors.It was suggested that the low expression of CMTM4 in HCC promoted HCC metastasis by inducing EMT process.