Background and objective: Recently, many studies have focused on stem cells in hepatocellular carcinoma (HCC) and found some stem cell markers in HCC, which are associated with the prognosis. OCT4, as a member of the POU transcription factor family, is a key factor to maintain self-renewal and pluripotency of embryonic stem cells (ESCs). This study was to explore the expression of the ESCs marker OCT4A in HCC, and its correlations with clinicopathologic features and prognosis of HCC.
Methods: OCT4A mRNA expression was detected in five liver cancer cell lines (SMMC-7721, BEL-7402, Hep-G2, MHCC97-L, and MHCC97-H), one immortalized liver cell line L-O2, tumor tissues with matched non-neoplastic liver tissues in 107 HCC patients, and normal liver tissues of 20 cases using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The correlations between OCT4A mRNA and clinicopathologic features and prognosis of HCC were analyzed.
Results: OCT4A mRNA was detected in SMMC-7721, BEL-7402, Hep-G2, MHCC-97L, and MHCC-97H cells, but not in L-O2 cells. The positive rate of OCT4A mRNA expression was significantly higher in the HCC tissues than in the non-neoplastic liver tissues (72.0% vs. 30.8%, P<0.001). No OCT4A mRNA expression was found in the normal liver tissues. OCT4A mRNA expression was correlated with the tumor size, vascular invasion, and TNM stage (P<0.05). Kaplan-Meier survival curves showed that patients with positive expression of OCT4A mRNA had lower overall survival and disease-free survival rates.
Conclusions: OCT4A mRNA, which is highly expressed in a subset of liver cancer cell lines and HCC tissues, may be involved in the carcinogenesis of HCC. OCT4A mRNA may be a valuable biomarker for assessing the prognosis of HCC.