Nitric oxide induces oral squamous cell carcinoma cells apoptosis with p53 accumulation.
Nitric oxide has been reported to have cytotoxic effects in several tumor cells. The objective of this study was to investigate the effects of exogenous nitric oxide on apopotosis in oral squamous cell carcinoma cells and to reveal its possible mechanism. Tca8113 cells were cultured with various concentrations of nitric oxide that were released from sodium nitroprusside (SNP). Nitrite/nitrate levels in the culture supernatant were determined using a commercial available nitric oxide kit. Cellular proliferation was determined by MTT assay. Apoptosis was detected by flow cytometry. Expression of inducible nitric oxide synthase (iNOS) was determined by immunocytochemistry. p53 expression was assessed by Western blot. SNP can release nitric oxide into the culture medium in a dose-dependent manner. Nitric oxide remarkably inhibits proliferation in a dose and time-dependent manners and lead to apoptosis of the Tca8113 cell. The p53 expression was elevated accompanying by the increased apoptotic cells. No difference of iNOS was found whether or not the cells were treated with SNP. Exogenous nitric oxide had an inhibitory effect on Tca8113 cells proliferation in a dose and time-dependent manners and possibly via p53 dependent apoptosis pathway. Exogenous nitric oxide had no significant effect on cellular iNOS protein.
Zhao
Shi-fang
SF
Department of Oral and Maxillofacial Surgery, School of Stomatology, Zhejiang University, Hangzhou, China. zju_txy@hotmail.com
Tong
Xiao-yan
XY
Zhu
Fu-dong
FD
D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D006801:Humans; D009569:Nitric Oxide / Q000494:pharmacology*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D014062:Tongue Neoplasms / Q000473:pathology*; D014407:Tumor Cells, Cultured / Q000187:drug effects; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D016159:Tumor Suppressor Protein p53; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II