(A) BEAS-2B cells were treated with sodium arsenic for 24 h, 48 h, 2 weeks, 4 weeks, 8 weeks, and 12 weeks at indicated doses. Taqman-qRT assay was used to determine miR-199a-5p expression level. (B) HFL cells were treated with arsenic for 2 weeks followed by miR-199a-5p determination. Data are presented as mean ± SD, *P < 0.05, compared with control cells.