Objective To evaluate the effects of endogenous NO on the chemosensitivity of human breast cancer cell. Methods MCF-7 cells were cultured as monolayer, incubated with cytokine IL-1β. The pro-duction of NO was detected by NO assay. The expression of iNOS protein was measured by Western blotting. Establishing control group and experimental group, the chemosensitivity of MCF-7 cells incubated by L-NMMA and L-Arg to ADM and 5-Fu was studied by MTT assay. Results There was a positive correlation of dose-dependence between NO production and IL-1β concentration. MCF-7 cells expressed plenty of iNOS by induetion of IL-1β. There was no significant difference on iNOS whether L-NMMA and L-Arg existed or not. Incubating MCF-7 cells with 0. 5 μmol/L or 1 μmol/L ADM, the survival rate of experiment group was remarkablely decreased(P < 0.05) ; L-NMMA significantly increased survival rate of experiment group(P < O. 05) ; L-Arg decreased survival rate of experiment group(P < 0.05). Conclusion The induction of IL-113 in MCF-7 cells can increase the production of endogenous NO, which increases MCF-7 cells' sensitivity to chemotherapy.

Objective To observe the effects of 5-fluorouraeil(5-FU)and eisplatin(DDP)on the expression of Toll-like receptor 2 (TLR2)and Toll-like receptor4(TLR4)in hepatocellular carcinoma cell lines HepG2 and HepG2.2.15.Methods Direct immanotlaorescenee flow cytometry was used to detect mean flubrescence intensity(MFI)of TLR2 and TLR4,and TLR2 and TLR4 positive cell percentage in HepG2 and HepG2.2.15 cells before and after treated with 5-FU.and DDP at various concentrations for 24h,48h and 72h.Results MFI of TLR2 and TLR4.and TLR2 and 11LR4 positive cell percentage in HepG2.2.15 cells were significantly higher than those in HepG2(P＜0.01).After HepG2 and HepG2.2.15 cells were treated with different concentration of 5-FU and DDP,MFI of TLR2 and TLR4,TLR2 and TLR4 positive cell percentage in HepG2 and HepG2.2.15 cells almost had no change.only MFI of TLR2 in HepG2.2.15 cells decreased after cells were treated with 5-FU at the concentrations of 100,200μg/ml and DDP at the concentrations of 20μg/ml for 72h(P＜0.05 for all).Conclusions 5-FU and DDP can not activate TLR2 and TLR4 signal pathway in hepatocellular carcinoma cell lines HepG2 and HepG2.2.15.To find the activated pathway in TLR2 and TLR4 signal pathway,some other methods should be used,and this will be helpful in antieancer therapy.