CSC vapor decreased the expression of AK3 and increased cisplatin resistance.

<p>(a) Western blot analysis was performed using anti-<i>AK3</i> and anti-<i>AK2</i> antiserum. Protein extracts in each lane are as indicated. Even loading was confirmed by re-probing the membrane with β-Actin antibody. HUC1-6M or SCaBER-6M indicates the cells chronically exposed to CSC vapor. HUC1-0.1%6M are SV-HUC-1 cells exposed to 0.1% CSC for 6 months. SV-HUC-1 and HUC1-6M (b), SCaBER and SCaBER-6M (c) were treated with 0 to 5 µg/ml cisplatin for 48 h, or with 3 µg/ml cisplatin for 24, 48 and 72 h, in the presence and absence of AK3 as indicated. (d) Colony formation assays were performed with SCaBER and SCaBER-6M in the presence and absence of AK3 as indicated. Data were expressed as mean ±SD. * indicates <i>P</i><0.05 (e) SV-HUC-1 and SCaBER cells were transfected with AK3 RNAi for 48 h and Western blot analysis was performed using anti-AK3 antiserum. (f) SCaBER cells were transfected with AK3 RNAi and 48 h after transfection the cells were treated with 0 to 5 µg/ml cisplatin for 48 h and cellular survival was assessed. Error bars represent standard deviation of three experiments.