Figure 10

Impact of depleting endogenous NONO or RALY proteins in YB-1 overexpressing SW480 and HT29 oxaliplatin resistant cells. A) Survival assays of SW480 cells transfected with either siRNA against YB-1 (siYB-1-b or siYB-1-c) or a nonspecific control siRNA. Three days after the transfections, cells were treated with one or two μM of oxaliplatin for 24 h. Live cells were then counted with a hemacytometer by the trypan blue exclusion technique. Experiments were performed in duplicate. Bars represent SEM. B) Example of Western blots showing YB-1 expression in transfected cells (96 hours after transfection). Bands were revealed using an ECL plus kit after less than five second of exposition. The histogram below the Western blots represents the YB-1 signal over β-actin signal. C) SW480 cells were transfected with the indicated siRNA sequences specific to NONO (siRNA sequence a), RALY (siRNA sequence c), or scrambled control siRNA. Forty-eight hours later, cells were transfected with YB-1 expression vector or empty expression control vector. Transfected cells were plated in 100 mm-petri dishes and were then treated with one μM of oxaliplatin for 16 hours in culture before counting live cells. Results represent the mean ± SEM of quadruplicate experiments. D) HT29 cells were transfected with the indicated siRNA sequences specific to NONO, RALY, or scrambled control siRNA. Forty-eight hours later, cells were transfected with YB-1 expression vector or empty expression control vector. Transfected cells were plated in 100 mm-petri dishes and were then treated with two μM of oxaliplatin for 16 hours in culture before counting live cells. Results represent the mean ± SEM of triplicate experiments.