Expression of poly adenosine di-phosphate-ribose polymerase-1 in hepatocellular carcinoma tissues and its relationship with epithelial-mesenchymal transition

Abstract

Objective To investigate the expression of poly adenosine di-phosphate (ADP)-ribose polymerase-1 (PARP-1) in hepatocellular carcinoma (HCC) tissues and its relationship with epithelial-mesenchymal transition (EMT). Methods Eigthy-two cases of HCC undergoing elective surgical resection were selected. The expression levels of PARP-1, E-cadherin, Vimentin and Snail proteins in HCC and paracancerous tissues were detected by immunohistochemical staining. The expression levels of PARP-1, E-cadherin, Vimentin and Snail genes in HCC and paracancerous tissues were detected using real-time fluorescent quantitative polymerase chain reaction (FQ-PCR). The correlations between variables were analyzed by Pearson correlation analysis. The effect of PARP-1 protein in HCC tissues on the survival time was analyzed by Kaplan-Meier survival analysis. Results The positive expression rate of PARP-1, Vimentin and Snail proteins in HCC tissues was higher than that in the paracancerous tissues, and that of E-cadherin protein was lower in HCC tissues than that in the paracancerous tissues with the differences being statistically significant (P=0.000). The expression levels of PARP-1 proteins in HCC tissues were related with pathological grade, TNM stage, microscopic tumor thrombus and portal vein thrombosis (P=0.000). The relative expression levels of PARP-1, Vimentin and Snail mRNA in HCC tissues were higher than those in the paracancerous tissues, and the relative expression level of E-cadherin mRNA was lower than that in the paracancerous tissues with the differences being statistically significant (P=0.000). Pearson correlation analysis showed that the relative expression levels of PARP-1 mRNA in HCC tissues were negatively correlated with E-cadherin mRNA (r=-0.617, P=0.000), but positively correlated with Vimentin mRNA and Snail mRNA (r=0.483 and 0.517, P=0.000). Kaplan-Meier survival analysis showed that the median disease-free survival time for PARP-1-positive patients was 9.0 months, and that for PARP-1 negative patients was 15.2 months with the difference being statistically significant (χ2=6.973, P=0.008). The median overall survival time for PARP-1 positive patients was 28.6 months, and that for PARP-1 negative patients was 44.0 months with the difference being statistically significant (χ2=6.248, P=0.012). Conclusion The up-regulation of PARP-1 in HCC tissues was closely related with EMT. Key words: Hepatocellular carcinoma; Poly adenosine di-phosphate-ribose polymerase-1; Epithelial-mesenchymal transition; Prognosis