Different patterns of inducible nitric oxide synthase gene expression in ovarian carcinoma cell lines

Background: Stimulation of inducible nitric oxide synthase (iNOS) and relea se of nitric oxide by tumor cells may play a critical role in cancer develo pment, either by exhibiting tumoricidal effects ol by promoting tumor progr ession, Materials and Methods: In the present study, we investigated foul o varian carcinoma cell lines with respect to their iNOS expressing character istics. Results. Following incubation with interferon-gamma, tumor necrosis factor-alpha and interleukin-1 beta a marked stimulation of iNOS gene expr ession was found in SKOV-6 and OVCAR-3 cells, while only minor iNOS synthes is was detectable in HOC-7. Time-dependent accumulation of nitrite/nitrate in the culture sypernatant indicated that the three cell lines were stimula ted to produce and release nitric oxide. In contrast no NO generation was o bserved in the fourth cell line under investigation 2774. Conclusion: Due t o the growth regulatory functions attributed to NO, variations in NO produc tion may be of importance e.g, following interferon-gamma therapy in patien ts with ovarian cancer.