Targeting miR-9 suppresses proliferation and induces apoptosis of HL-60 cells by PUMA upregulation in vitro

Objective: Recent studies have shown that upregulation of miR-9 occurs in several types of human cancer, suggesting a tumor promotive function of miR-9. miR-9 has been found to be overexpressed in the acute myeloid leukemia (AML). In the present study, we observed the effect of targeting miR-9 on proliferation and apoptosis in AML HL-60 cells and explored its mechanisms. Methods: HL-60 cells were transfected with MiR-9-inhibitor and its scrambled siRNA or/and PUMA siRNA for 24-72 h. After transfection with PUMA siRNA or/and miR-9 inhibitor 24-72 h, cell viability and cell apoptosis was detected by MTT assay, flow cytometry and TUNEL assay; qRT-PCR and western blot assay was used to detected PUMA and miR-9 mRNA and protein levels. Results: Targeting miR-9 inhibited proliferation and induced apoptosis of HL-60 cells, accompanying the upregulation of PUMA protein and mRNA. Knockdown of PUMA by siRNA blocked miR-9 inhibitor-induced apoptosis and growth inhibition. Conclusion: These findings suggested that targeting miR-9 inhibited cell growth and induced apoptosis of HL-60 cells via increasing PUMA expression.