Abstract: Objective To investigate the effect of miR-216a-5p on gastric cancer cell proliferation, migration and the underlying mechanism. Methods The protein expressions of high-mobility group box 1 (HMGB1) in gastric cancer tissue and non-tumor tissue were measured by Western blot, the expression of miR-216a-5p was measured by RT-qPCR. The miR-216a-5p mimic and inhibitor were synthetic and transfected into gastric cancer cell line MGC-803. Cell proliferation was detected by MTT method. Cell migration was detected by scratching assay. The target reaction between miR-216a-5p and HMGB1 was measured by Western blot and luciferase reporter assay. Results The expression of HMGB1 was elevated and miR-216a-5p was decreased in gastric cancer tissues compared to non-tumor tissues (P<0.05). miR-216a-5p mimic increased miR-216a-5p expression, inhibited cell proliferation and migration in gastric cancer cell line MGC-803. miR-216a-5p inhibitor decreased miR-216a-5p expression, promoted cell proliferation and migration in gastric cancer cells (P<0.05). MiR-216a-5p inhibited HMGB1 expression by directly binding to the 3’UTR of HMGB1. Conclusions miR-216a-5p may inhibit gastric cancer cell proliferation and migration by targeting HMGB1.

Key words: gastric cancer, miR-216a-5p, HMGB1, MGC-803