GASC1 gene knockdown optimization with siRNA sequence A in HCC1954 cells at different time points (A), or different siRNA concentration 24 h post transfection (B). Lipofectamine 2000 (LF) was used as transfection agent, and RT-PCR was performed with specific GASC1 primers; normalization was carried out against the housekeeping gene PUM1. NC = scrambled siRNA; error bars reflect SD, n = 3; ns, nonsignificant; *P < 0.05, ***P < 0.001, and ****p < 0.0001.