Transfection of osteosarcoma MG63 cells

The negative control siRNA (NC siRNA) and CBX3 small interfering RNA (siRNA) were provided by Shanghai GeneChem Biotechnology Co., Ltd. (Shanghai, China). The sequences of the siRNAs used in the present study were: Si-CBX3, 5′-GCGTTTCTTAACTCTCAGAAA-3′ and negative control (NC), 5′-TTCTCCGAACGTGTCACGT-3′. The cells were cultured to 60% confluence, and were then plated in a 6-well plate at the density of 5×10⁵/well. The cells were then transfected with 50 nM NC siRNA or CBX3 siRNA. Transfection was performed using Lipofectamine 2000 (Invitrogen; Thermo Fisher Scientific, Inc.) according to the manufacturer's protocol. qPCR and western blotting were used to validate the transfection efficiency of CBX3 siRNA 48 h after transfection.