Expression and effect of miR-27b in primary liver cancer

The occurrence and development of primary liver cancer is associated with microRNA. Specifically, the expression of microRNA-27b (miR-27b) is upregulated in four liver cancer drug-resistance cell lines. Despite that, the function of miR-27b in liver cancer is not clear yet. The aim of the present study was to investigate the effect of miR-27b expression during oncogenesis, cell proliferation, apoptosis and chemotherapy resistance development in a model of liver cancer. Expression of miR-27b was detected with reverse transcription-quantitative PCR. To establish stable overexpression of miR-27b and negative control liver cancer cell lines, a lentiviral pre-miR-27b overexpression vector and negative control vector were transfected into each cell line. Cell Counting Kit-8 assay, clone formation assay and immunohistochemical assay were used to detect cell proliferation. Apoptosis and drug sensitivity were detected by flow cytometry and MTT assay, respectively. The expression level of miR-27b in liver cancer tissues was also lower than in liver tissues adjacent to the tumor. Two stable miR-27b overexpression liver cancer cell lines (Huh-7/miR-27b and HepG2/miR-27b) and their control cell lines (Huh-7/NC and HepG2/NC) were successfully constructed. It was revealed that upregulation of miR-27b can suppress cell proliferation, promote cell apoptosis and chemotherapy resistance. In addition, the findings of the present study demonstrated that patients with cirrhosis expressed lower miR-27b compared with patients without cirrhosis. The expression level of miR-27b was significantly associated with the age, serum alpha-fetoprotein and alanine aminotransferase level of patients with liver cancer. Meanwhile, it was indicated that the disease survival time of the low miR-27b expression group was longer than that of the high miR-27b expression group. The present study suggested that miR-27b functions as a liver cancer suppressor. Moreover, miR-27b can act as a biomarker to estimate drug sensitivity to chemotherapy in patients with liver cancer.