Cmar_a_228429 419..430

E.N.T. Department, Taizhou Municipal Hospital, Taizhou City, Zhejiang Province 318000, People’s Republic of China Background/Aims: miR-802 plays a key role in cancer progression and development. The purpose of this work is to investigate the functional role of miR-802 in laryngeal cancer and to elucidate the function of miR-802 and cAMP-regulated phosphoprotein 19 (ARPP19) on laryngeal cancer. Methods: RT-qPCR was applied to study the expression level of ARPP19 and miR-802 in the laryngeal carcinoma cell lines and tissues. CCK-8, colony formation, flow cytometry (FACS) assay were used to study the effect of ARPP19 and miR-802 on apoptosis, proliferation, and cell cycle of laryngeal carcinoma cells. Target gene prediction and luciferase reporter gene assay were applied to identify target gene of miR-802. The transcriptional mRNA and protein expression levels of ARPP19 were measured by RT-qPCR or Western blotting. Results: miR-802 was down-regulated in laryngeal carcinoma cell lines and tissues. Laryngeal cancer cells transfected by miR-802 mimic were significantly inhibited in the terms of cell colony formation and proliferation. Furthermore, miR-802 can inhibit the expression level of ARPP19 by directly targeting the 3ʹ untranslated region (3ʹ-UTR) of ARPP19. Overexpression of the ARPP19 gene can reverse the suppressive effect of miR-802 on laryngeal cancer cells. Conclusion: miR-802 can exert tumor suppressor effects in laryngeal carcinoma by targeting ARPP19, indicating that miR-802 protein may play a role of potential therapeutic target for clinical laryngeal cancer.