Expression And Function Of LncRNA XIST In Hepatocellular Carcinoma

Objective To determine the expression level of long noncoding RNA X-inactive specific transcript(lnc RNA XIST)in paired hepatocellular carcinoma and normal tissues.To analyze the relationship between the expression of lnc RNA XIST and patients,clinicalpathologic parameters.To compare the expression of lnc RNA XIST in hepatocellular carcinoma cell lines and that in normal hepatic cells.To evaluate the effects of lnc RNA XIST in hepatocellular carcinoma cells on cell proliferation,migration and invasion.To explore the related molecule(s)involved in lnc RNA XIST,function in hepatocellular carcinoma.To provide new mechanism(s)of tumorigenesis and progression of hepatocellular carcinoma.Method The expression level of lnc RNA XIST in hepatocellular carcinoma and normal hepatic tissues,four hepatocellular carcinoma cell lines(Hep G2?Hep3B?SNU449?SNU398),and normal hepatic cells(L-02)were quantified by using real-time fluorescence quantitative PCR(q RT-PCR).The correlation analysis of the expression level of lnc RNA XIST and patients,clinicalpathologic parameters was analyzed by using independent-Samples Test respectively.RNA interference(RNAi)was used to knockdown the expression of lnc RNA XIST in SNU449 cells followed by cell proliferation,metastasis and invasion assay in this cell line.Biological information database(Target Scan?Starbase)were employed to explore the related molecule(s)of lnc RNA XIST in hepatocellular carcinoma followed by q RT-PCR confirmation of the predicted molecule(s).Results The expression level of lnc RNA XIST in hepatocellular carcinoma tissues was significantly higher than that in paired normal adjacent tissues(P<0.001).Sixteen out of 29 patients exhibit more than 1.5 times insease of lnc RNA XIST in cancer tissues than that in normal tissues(16/29,55.17%).The expression level of lnc RNA XIST was related to tumor cell differentiation(P=0.008),but not with sex,age,Hepatitis B virus(HBV),alpha fetoprotein(AFP),tumor size,infiltration of capsule,or Protal vein tumor thrombosis(PVTT).Compared with the human liver cell line L-02,the four hepatocellular carcinoma cell lines have significantly higher expression level of lnc RNA XIST.Knockdown of the expression of lnc RNA XIST by RNAi significantly inhibited cell proliferation,invasion and migaration(P<0.05).Analyzing by using Target Scan database(http://www.targetscan.org),Starbase(http://starbase.sysu.edu.cn/),we found that mi R-200b-3p is one of the targets regulated by lnc RNA XIST.q RT-PCR analysis demonstrated that the expression level of mi R-200b-3p in hepatocellular carcinoma cell lines was significantly lower than that in the normal liver cell line L-02(P<0.001).Knockdown the expression of the lnc RNA XIST in SNU449 significantly increased the expression level of mi R-200b-3p(P<0.05).Conclusion The expression level of lnc RNA XIST was significantly up-regulated in hepatocellular carcinoma tissues and cell lines,and its up regulation was related to poor differentiation of hepatocellular carcinoma.Knockdown the expression level of lnc RNA XIST in hepatocellular carcinoma cells significantly inhibited the proliferation,migration and invasion.mi R-200b-3p is the target of lnc RNA XIST in hepacellular carcinoma.