Decreased expression of N-myc protein inhibits cell proliferation and migration of neuroblastoma cell line SK-N-BE (2)

Abstract

Objective To investigate the roles of N-myc in migration and proliferation of neuroblastoma (NB).Methods The N-myc siRNA was transfected to NB cell line SK-N-BE(2).The efficiency of gene silence was confirmed by real time RT-PCR and western-blot.After N-myc silencing,cell migration and proliferation were detected by transwell system and colorimetric BrdU assay.The expressions of RACK 1,N-myc,phospho-Src (Tyr416),phospho-Src (Tyr527),phospho-Akt,phosphoERK1/2 and phospho-p38 were analyzed by western blotting.Results When the expression of N-Myc protein was significantly reduced (0.61 ± 0.15 vs 1.97 ± 0.26,P＜0.05),the migration (0.85 ± 0.06)and proliferation (0.68 ± 0.05) of SK-N-BE(2) were significantly decreased (P＜0.05).The expressions of RACK1 (Control group 1.46 ± 0.18 vs RNAi group 1.13 ± 0.10) and phospho-Src(Tye416)(Control group 1.34 ± 0.11 vs RNAi group 0.72 ± 0.23) were also significantly decreased (P＜0.05),while the expression of phospho-Akt (Control group 0.551 9 ± 0.121 9 vs RNAi group 0.8360 ± 0.1535)was significantly increased (P＜0.05).The expressions of phospho-Src(Tye527),phospho-ERK1/2 and phospho-p38 were not changed significantly by N-Myc gene silencing in SK-N-BE(2) (P＞0.05).Conclusions These results suggest that the high expression of N-myc in SK-N-BE(2) is crucial for cell migration and proliferation.The expressions of RACK1,phosphorylation of Src (Tye416)and Akt might be involved in the N-myc-induced migration and proliferation of NB. Key words: Proto-oncogene proteins c-myc; Neuroblastoma; Cell proliferation; Apoptosis