Figure 3.

TFII-I and DBC1 play a role in the repair of DSBs induced by irradiation. (A) TFII-I and DBC1 siRNA inhibit colony formation efficiency after irradiation. U2OS cells were transfected with the indicated siRNAs and irradiated. The cells were allowed to grow for 14 days and stained with Giemsa. The knockdown of TFII-I or DBC1 resulted in a significant inhibition of colony formation efficiency. The solid line represents control siRNA and the broken lines represent three independent siRNA. The siRNA-mediated knockdown of SIRT1 serves as a positive control because SIRT1 has been shown to maintain genomic stability and is required for efficient DSB (Jeong et al, 2007; Wang et al, 2008). (B) Efficiency of siRNA-mediated knockdown of SIRT1 is demonstrated by western blot.