Figure 4

Neurofibromin depletion confers sensitivity to tranilast. (a) HeLa cells were transfected with control (GAPD) or neurofibromin (NF1) siRNAs for 1 day, exposed to various concentrations of tranilast for 48 h, and then examined by phase-contrast microscopy. Scale bar, 100 µm. (b) HeLa cells transfected with GAPD or NF1 siRNAs as in a were incubated in the absence or presence of tranilast (250 µM) for 48 h, after which the number of viable cells and the percentage of viable cells were measured on the basis of trypan blue exclusion. Data are means ± s.d. for triplicates from a representative experiment. **P < 0.01 (Student’s unpaired t test). (c) NIH3T3 cells stably transfected with plasmids for a negative control shRNA or either of two NF1 shRNAs (249 or 611) were incubated with the indicated concentrations of tranilast for 48 h and then examined by phase-contrast microscopy. Scale bar, 100 µm.