Abstract: Objections To study the effective of nitric oxide(NO) on growth of nasopharyngeal carcinoma(NPC) cell lines,and on modulation of VEGF expression.Methods NPC cell lines CNE2 and TWO3 were treated with NO donor S-nitroso-N-acetylpenicillamine(SNAP).NO concentrations in cell culture medium were detected by nitrate reductase method.The survival rates of NPC cell lines were detected by MTT method.The expression of VEGF was detected by reverse transcription(RT-PCR) and western blot.Results NO inhibited growth of NPC cell lines in higher concentrations,while the low concentration of NO had no significant effect on NPC cell lines survival rate.NO modulated the expression of VEGF in NPC cell lines.Conclusions NO as a signal molecule plays a role in modulating the expression of VEGF,therefore it contributes to the development of NPC.Meanwhile,the high concentrations of NO can inhibit the development of NPC.

Key words: Nasopharyngeal carcinoma(NPC), Nitric oxide(NO), Vascular endothelial growth factor(VEGF), Cell line