Figure 5.

NOS1 activity inhibition or shRNA-mediated NOS1 knockdown increases the sensitivity of OVCAR3 cells to DDP treatment. (A) Cytotoxic curve, as determined by MTT assay, indicated the IC₅₀ of cisplatin for OVCAR3 cells was 5 µM. (B) MTT assay indicated that the cytotoxicity of OVCAR3 cells to DDP treatment was increased by treatment with NOS inhibitors. (C) MTT assay demonstrated that NOS1 knockdown also decreased the viability of OVCAR3 cells in response to DDP treatment. Data is presented as the mean ± standard deviation of three independent tests. *P<0.05 and **P<0.01. DDP, cisplatin; shRNA, short hairpin RNA; L-NAME, NG-nitro-L-arginine methyl ester; NOS, nitric oxide synthase.