Fig. 3.

Knockdown of NOX1 by siRNA transfection inhibits NADPH oxidase activities in human colon cancer cells. DLD-1/COX-2-B2-βGal-BSD cells were transfected with negative control or NOX1 siRNAs (si-1, si-2 and si-1&2), and cultured for 6 days. (A) NOX1 protein levels were analyzed by western blot. β-actin was proved as a loading control. Densities of the bands were calculated and are shown under the band as % of control. (B) COX-2 transcriptional activity was evaluated by β-galactosidase activity and was normalized with viable cell numbers assessed by MTT assay.