Inhibition of HER-2 expression by RNA interference in osteosarcoma cells

[Objective]To investigate whether RNA interference(RNAi)could suppress the expression of HER-2 in osteosarcoma OS-732 cells.[Method]OS-732 cells were transsfected using chemically synthesized double stranded RNA(dsRNA)formulated with Lipofectamine 2000.The HER-2 gene expression inhibition was assessed by RT-PCR,Western Blot and immunocytochemistry.The chemosensitivity of transfected cells to cisplatin was determined by MTT measurement.[Result]Sequence specific siRNAs targeting HER-2 down-regulated the expression of HER-2 significantly.Currently,a range of effects on cell physiology,such as growth inhibition or apoptosis,was observed,Introduction of the siRNA into HER-2 positive tumor lines in vitro greatly reduced the expression of the HER-2 mRNA,effects lasted for 10 days,On the 9th day of interference,HER-2 protein expression was down-regulated in interference group.After RNAi,HER-2-siRNA increased thesensitivity of OS-732 to cisplatin by 10-fold.[Conclusion]Sequence specific siRNAs targeting HER-2 can suppress the expression of HER-2,and significantly inhibiting cellular proliferation,increasing the sensitivity of OS-732 to eisplatin.The successful application of HER-2 siRNA for inhibition of proliferation in HER-2 overexpressed cells extends the list of available therapeutic modalities in the treatment of human osteosarcoma.