The expression and clinical significance of 5-hmC and TETs in hepatocellular carcinoma / 中华普通外科杂志

ABSTRACT

Objective To investigate the levels of 5-hydroxymethylcytosine (5-hmC) and teneleven-translocation proteins (TET1/2/3) in diagnosis and prognosis prediction of hepatocellular carcinoma (HCC).Methods The expression of 5-hmC in 130 cases of HCC tissues were detected by immunohistochemical staining.Kaplan-Meier test was used for survival analysis.TET family plays critical role in the conversion of 5-methylcytosine (5-mC) to 5-hmC.The TET levels were detected by using immunohistochemical staining and RT-PCR,the correlation between 5-hmC and TET was analyzed.Results The level of 5-hmC decreased in HCC tissues,as compared with non-tumor tissues,the expression of TET1 was downregulated in HCC.There was significant difference in the expression between low and high grades of HCC tissues (x2 =10.611,P =0.001).Kaplan-Meier survival analysis showed that there was significant difference between the 5-hmC expression level and the survival rate of HCC patients (x2 =4.412,P =0.036).Conclusions In HCC tissues the expression of 5-hmC was specifically downregulated.Low 5-hmC level is significantly correlated with poor differentiation of the tumor and worse overall survival.Decreased expression of TET1 is likely one of the mechanisms underlying 5-hmC loss in HCC.