Fig. S2.

Dose-dependent Knockdown of CDK9 by siRNA Transfection. The expression of both the 55 kDa and 42 kDa CDK9 was measured by Western blotting in the osteosarcoma cell lines (A) U2OS, and (B) KHOS after 72 h of siRNA transfection. (C) and (D) Western blotting densitometry quantification of the 42 kDa isoform of CDK9 from Fig. S2A and B, respectively. Densitometry is presented as relative to tubulin expression. The data represent the mean ± SE of the experiment carried out in triplicate (* indicates P < .05, ** indicates P < .01).