miR-503 inhibits proliferation making human hepatocellular carcinoma cells susceptible to 5‑fluorouracil by targeting EIF4E.

Hepatocellular carcinoma (HCC), a disease that is a major health care issue across the globe, includes the deviant expression of miRNAs in its development, progression, and resistance to treatment. We focused our study on miR-503 expression and its role in HCC. miR-503 was found in HCC tissues and cell lines using quantitative real-time PCR (RT-qPCR). Western blot analyses and the luciferase reporter assay were used to determine the miR-503 potential target in the HCC cells. We used MTT to analyze cell proliferation activity and noted that there was a considerable decrease of miR-503 in HCC tissues and cell lines when measured against the controls. miR-503 upregulation decreased expression of eukaryotic translation initiation factor 4E (EIF4E), and reduced HCC cell proliferation and sensitized HCC cells to anticancer drugs. miR-503 overexpression hindered luciferase activity of EIF4E 3' untranslated region-based reporter construct among HepG2, BEL-7402, and SMMC-7721 cells, revealing that miR-503 may increase sensitivity to therapies at least partially through targeting EIF4E suppression of HCC proliferation.