【Objective】 To explore the effects of siRNA-induced interleukin-1 receptor-associated kinase-4 (IRAK-4) gene silence on apoptosis of MG63 cells and the expression levels of related genes Bcl-2 and Bax. 【Methods】 The gene transfection (control group = MG63 cells; SC group = MG63 cells transfected with scrambled IRAK-4 siRNA; KD group = MG63 cells transfected with IRAK-4-specific siRNA) was performed using Lipofectamine 2000. The apoptosis of MG63 cells were tested by FCM and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) methods. The protein level of Bcl-2 and Bax were detected by Western blotting. 【Result】 The expression of IRAK-4 mRNA and protein in the KD group were significantly decreased compared with other two groups. Compared with the control groups

48 hours after the transfection

IRAK-4 gene silencing in MG63 cells caused morphological changes

inhibited growth

increased apoptosis (P < 0.05) and decreased protein expression of Bcl-2 and the ratio of Bcl-2/Bax (P <0.05). There was a significant correlation between the percentages of apoptotic MG63 cells and Bcl-2/Bax protein expression (P =0.011). 【Conclusion】 The results indicated that IRAK-4 gene silencing in MG63 cells increase apoptosis

which may be related to the decreased Bcl-2/Bax ratio.