Figure 3.

N78 targets N-Myc inhibiting neuroblastoma cells growth and induces apoptosis. (A) Knockdown efficacy of N-Myc in NB cell lines was detected by western blot analysis. SK-N-BE(2) and IMR-32 cells were transfected with either a control shRNA or two independent small hairpin RNAs (shRNA) targeting N-Myc, and the expression levels of N-Myc were analyzed by western blot. (B-C) N-Myc knockdown inhibited NB cells growth. The different groups of stably transduced with vector control or MYCN shRNAs cell viabilities were detected by SRB (n=3). (D) Neuroblastoma cells stably transduced with vector control or MYCN shRNAs, the colony formation of different groups were detected. (E-F) N78 was less effective against the N-Myc knockdown NB cells. The different groups of stably transduced with vector control or MYCN shRNAs were treated with indicated concentrations of N78 for 72 h and cell viabilities were detected by MTS (n=3). (G) N78 was more sensitive to N-Myc overexpressed SH-SY5Y cell lines (n=3). (H) N78 induced apoptosis of NB cells with concentration gradient detected by flow cytometry. The effects of N78 on apoptosis in NB cells (SK-N-BE(2), IMR-32, and NB1) after 48 h treatment were evaluated by flow cytometry. (I) N78 induced apoptosis of NB cells with concentration gradient detected by western blot. The effects of N78 on apoptosis in NB cells after 12 h treatment were evaluated by western blot. Data shown as mean ± sd. n.s., not significant, ** P < 0.01, *** P < 0.001, **** P < 0.0001 by one-way ANOVA followed by multiple-comparison tests.