Transfected siMDR1 inhibits the mRNA and protein expression of MDR1 in L2-RYC cells. (A) mRNA expression of MDR1 in group I, II, III, IV and IV was analyzed by real-time PCR. All cDNA samples were normalized with GAPDH. Real-time PCR results were confirmed in at least three batches of independent experiments. (*p < 0.05, vs other groups), (B) Protein expression of MDR1 was analyzed by Western blot. Protein were collected and lysed at 48 hr after treatment and subjected to SDS-PAGE and Western blotting using a MDR1 antibody. Equal loading of the samples was confirmed by β-actin detection. All samples gray values were normalized with β-actin. P-glycoprotein protein relative expression of each group was demonstrated as fold change in a histogram. (*P < 0.05, vs other groups).