MicroRNA-221 accelerates the proliferation of laryngeal cancer cell line Hep-2 by suppressing Apaf-1.

Laryngeal cancer is one of the most commonly occurring malignant cancers of the head and neck region. In the present study, we investigated the roles of miR-221 in laryngeal squamous cell carcinoma cell line, Hep-2. We examined the function and mechanism of miR-221 in Hep-2 cells using techniques of cell biology and molecular pathology, such as western blotting, quantitative PCR, immunohistochemical staining and flow cytometry. Using a luciferase assay, the apoptotic protease activating factor-1 (Apaf-1) mRNA 3'-UTR was shown to have complementary binding sites using bioinformatics prediction software including TargetScan, PicTar and miRanda. In conclusion, our results showed that miR-221 inhibition caused elevated expression levels of the Apaf-1 apoptotic pathway proteins caspase-3, -8 and -9. miR-221 may therefore be used as a novel therapeutic target for laryngeal cancer.