This strategy was explored in the current study, where p53 downstream target miR-34 was restored in p53-mutant gastric cancer Kato III cells with a high level of Bcl-2 and low levels of miR-34, resulting in downregulation of Bcl-2 and Notch/HMGA2, tumor cell growth inhibition and accumulation in G1 phase, and chemosensitization and Caspase-3 activation/apoptosis. The gene discussed is HMGA2; the disease is neoplasm.