Figure 2.

Effects of RA on apoptosis, cellular melanin content and Cis sensitivity of melanoma cells. (a-c), A375 cells were exposed to 0, 50, 100 and 200 μg/ml RA for 48 h, then cell apoptosis was observed by TUNEL staining (a); the expression of proteins involved in apoptosis including Bcl-2, Bax and cleaved-caspase3 was detected by western blot (b); the cellular melanin content was measured (c). ***P < 0.001 vs 0 group. D, A375 cells were pre-treated with 0, 50, 100 and 200 μg/ml RA for 24 h, followed by 8 μM Cis co-treatment for another 24 h, then cell viability was detected. **P < 0.01 vs 0 μg/ml RA group; ^##P < 0.01 and ^###P < 0.001 vs Cis + 0 μg/ml RA group