The Study Of Expression, Function And Mechanism Of LKB1 In Hepatocellular Carcinoma

Objective: To study the expression of LKB1 in human hepatocellular carcinoma and adjacent noncancerous tissue(ANT),and analyze the relationship of expression of LKB1 and prognosis of HCC patients.To clarify the clinical significance of LKB1 expression in HCC.Methods: A total of 79 patients with HCC who underwent hepatectomy in Tumor Hospital of Guangxi Medical University from January 2014 to December2014 were recruited in this study.HCC cell lines,including MHCC-97 H ?QGY-7703 ? SSMC-7721 ? Hep-G2 ? Huh7 and human normal liver cell line(HL7702)were used in this study.The expression of LKB1 m RNA in hepatocellular carcinoma cell lines was analyzed by q RT-PCR.The expression of LKB1 protein in hepatocarcinoma cell lines was detected by Western Blotting.The expression of LKB1 protein in 79 cases of hepatocellular carcinoma and adjacent tissues was detected by immunohistochemistry.The expression of LKB1 protein was divided into LKB1 low expression group(0-5)and LKB1 high expression group(6-12).To analyze the relationship between LKB1 expression and clinicopathological features and long-term prognosis of HCC.The effect of LKB1 gene silencing on the proliferation,invasion andmigration of hepatocarcinoma cells was studied and the possible regulatory mechanism was discussed.Results: ??The expression levels of LKB1 in MHCC-97 H,QGY-7703,SSMC-7721 and Hep-G2 cell lines were lower than those in HL7702.The expression of LKB1 m RNA in hepatocellular carcinoma tissues was significantly lower than that in adjacent tissues.?? The expression of LKB1 was correlated with the maximum diameter of tumor(P = 0.005)and histological stage(P = 0.024),but not with age,sex,hepatitis B,BCLC staging,liver function staging,tumor number,tumor thrombus and serum AFP concentration.Survival analysis showed that the overall survival time of LKB1 low expression group was shorter.(P = 0.032),histological stage(P = 0.032),low expression of LKB1(P = 0.018)were closely related to the prognosis of HCC.The single factor analysis showed that the maximum diameter of tumor(P = 0.038),tumor number(P = 0.012)COX multivariate model analysis showed that the number of tumors(P = 0.015)and low expression of LKB1(P = 0.021)were independent factors in the prognosis of patients with liver cancer.? ? The expression of LKB1 m RNA and protein in hepatocellular carcinoma cell line Huh7 was significantly down-regulated after LKB1 expression.The proliferation,invasion and migration of Huh7 cells after LKB1 gene silencing were significantly enhanced.It was also found that when LKB1 expression was decreased,the expression of phosphorylated p38 was significantly increased,the expression of E-cadherin decreased and the expression of vimentin was up-regulated.Conclusion: In hepatocellular carcinoma,LKB1 showed low expression level,which was related to the maximum diameter and histological stage oftumor,and the prognosis of patients with low expression was poor.The expression of LKB1 in Huh7 cells was significantly higher than that in hepatocarcinoma cell lines.The proliferation,invasion and migration of hepatocarcinoma cells were significantly enhanced by RNAi silencing the gene expression.LKB1 as a tumor suppressor gene,it is possible to inhibit the phosphorylation of p38 to inhibit the cell's EMT process,p38 phosphorylation to strengthen and regulate the expression of downstream molecules in the LKB1 expression decreased,then leading to tumor cell malignancy increased.Therefore,further study the regulation mechanism for the treatment of liver cancer is expected to find new drug targets and prognostic indicator.