Knockdown of HDAC3 and HDAC7 up-regulates ATX expression in cancer cells. A, SW480 cells were co-transfected with the indicated Class I and Class II HDAC siRNAs. ATX mRNA expression was detected by RT-PCR 48 hrs post transfection. B, SW480 cells were co-transfected with HDAC3 and HDAC7 siRNAs. ATX expression at the RNA (in cells) and protein levels (in culture medium) were detected 48 hrs post transfection by real-time RT-PCR and Western blotting, respectively. C, HDAC3 and HDAC7 siRNAs were co-transfected into Hela, MDA-MB-231, A2780, and Du145 cells, respectively, with non-specific siRNA (siNC) as a control. Real-time RT-PCR was used for detecting ATX mRNA expression. The p value derived from Student's t test is (**) p < 0.001.