Figure 2.

Analysis of mRNA and protein expression of NOS isoforms, and NO production in ovarian cancer cell lines. (A) mRNA expression of NOS isoforms were analyzed by reverse transcription-quantitate polymerase chain reaction, and expression varied in OVCAR3, SKOV3 and ES-2 cells. The levels of NOS mRNA expression were normalized to GAPDH expression. (B) The proteins of the three NOS isoforms were all detected by western blotting in SKOV3 and OVCAR3 cells. (C) The levels of NO expression in the culture medium of OVCAR3 cells was determined by Griess assay and was less than half of the concentration released by cells treated with 50 µM DETA-NONOate (50 nM NO). Error bars represent the mean ± standard deviation of triplicate experiments. *P<0.05 and ***P<0.001. All compared with control. CON, control; DETA, DETA-NONOate; L-NAME, NG-nitro-L-arginine methyl ester; NOS, nitric oxide synthase; NO, nitric oxide.