Figure 4.

miR-633 regulates chemotherapy resistance through FADD in gastric tumor cells.

(a), the mRNA and protein expression levels of FADD were analyzed by qRT-PCR and western blot in SGC-7901 cells after miR-633 inhibition. (b), overexpression of miR-633 prevented the FADD protein expression increase in SGC-7901 treated with 2 μM DOX for 24 h. (c), inhibition of miR-633 promoted the FADD protein expression in SGC-7901 treated with 0.2 μM DOX 24 h. (d), inhibition of miR-633 enhanced cell death in SGC-7901 in response to 0.2 μM DOX treatment for 36 h, which was reversed by FADD siRNA. (e), luciferase activity detected in HEK-293 transfected with synthesized miR-633 mimics or mimic control, along with human FADD 3ʹUTR luciferase reporter constructs as indicated. (f), detection of FADD 3ʹUTR by qRT-PCR in SGC-7901 cells transfected with Bio-633, Bio-633mut, or Bio-nc by RNA pull-down assay and results were normalized to human GAPDH (n = 3). Error bars represent S.D. Data are expressed as the mean ± SD of 3 independent experiments.*P < 0.05. Mut, mutated; Wt, wild type.