Figure 2.

Expression of RARβ and drug sensitivity in human CCA cell lines. (A) Relative mRNA expression levels of RARβ in the normal bile duct cells and 4 CCA cell lines, as detected by reverse transcription-quantitative polymerase chain reaction. ^*P<0.05, ^**P<0.001 vs. HBd Epi cells. Protein expression detected by western blotting analysis. (B) Drug sensitivities of four CCA cell lines in response to 5-FU, CDDP, VCR and MMC chemotherapeutic agents as determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. ^*P<0.05, ^**P<0.001 vs. QBC939 cells. RARβ, retinoic acid receptor-β; CCA, cholangiocarcinoma; 5-FU, 5-fluorouracil; CDDP, cisplatin; VCR, vincristine; MMC, mitomycin C.