Abstract: Objective The objective of this study was to investigate the expression and clinical significance of serum miRNA-24 (miR-24) and miRNA-509 (miR-509) in patients with hepatocellular carcinoma (HCC). Methods Ninety-four HCC patients (HCC group) who visited Suining Central Hospital in Sichuan province from January 2019 to October 2020 were selected,and 90 healthy subjects (control group) who underwent the physical examination center at the same time were selected.The expression of miR-24 and miR-509 in human liver cancer cell lines and the serum of participants in the two groups was detected by real-time quantitative polymerase chain reaction (qRT-PCR).The correlation between miR-24 and miR-509 levels and the clinicopathological characteristics and prognosis of HCC was analyzed. Results The expression of miR-24 in the serum of HCC patients was significantly higher than that of the control group (3.19±0.29vs. 0.66 ± 0.20),(t=-68.601,P＜0.01),and the expression of miR-509 was significantly lower than that of the control group(0.74±0.27vs. 1.24 ± 0.28),(t=12.331,P＜0.01).The expression of miR-24 in serum was positively correlated with alpha fetoprotein (AFP) level,metastasis,and TNM stage (r=0.821,0.510,0.762,P＜0.01),and negatively correlated with the degree of differentiation (r=-0.771,P＜0.01).The expression of miR-509 in serum was negatively correlated with AFP level,metastasis and TNM stage (r=-0.820,-0.506,-0.766,P＜0.01),and negatively correlated with the degree of differentiation (r=0.775,P＜0.01). Conclusion The expression of serum mir-24 is up-regulated in HCC patients,while the expression of serum mir-509 is down-regulated.Both of them are closely related to HCC metastasis and malignancy.Clinical testing of serum miR-24 and miR-509 levels in patients can help diagnose and evaluate the condition of HCC.

Key words: miR-24, miR-509, Hepatocellular carcinoma, Liver cancer metastasis