RESUMO
Background:Dysregulation of microRNA expression is involved in the carcinogenesis of many tumors,expression of miR-504 has been observed in many tumors,but its expression in primary hepatocellular carcinoma(HCC)has not been reported. Aims:To explore the expression and clinical significance of miR-504 in HCC tissues and cells. Methods:Tumor and para-cancerous tissue in 85 HCC patients were collected. Five liver cancer cell lines and immortalized liver cell line were conventionally cultured. Effect of miR-504 expression on HepG2 cells proliferation was determined by CCK8 assay. The expression of miR-504 was determined by real time fluorescent quantitative PCR. Relationships between expression of miR-504 and clinicopathological features and prognosis of HCC patients were analyzed. Results:Compared with normal liver cells,expression of miR-504 was significantly downregulated in five liver cancer cells(P < 0. 05). Up-regulation of miR-504 inhibited proliferation of HepG2 cells,and down-regulation of miR-504 promoted proliferation of HepG2 cells. miR-504 expression in tumor tissue was significantly decreased than that in corresponding para-cancerous tissue. Expression of miR-504 was correlated with tumor differentiation(P = 0. 002),TNM stage(P = 0. 021),alpha fetoprotein(P = 0. 012)and portal vein tumor thrombus(P = 0. 003),but not with gender,age,tumor size and tumor number. Survival in HCC patients with lower miR-504 expression was significantly shorter than that in patients with high expression(P < 0. 05). Conclusions:Expression of miR-504 is downregulated in HCC,and is correlated with the prognosis of patients,suggesting that miR-504 can be used as an independent predictor for prognosis of HCC patients.