MDR1 and MDR3 Genes and Drug Resistance to Cisplatin of Ovarian Cancer Cells

To investigate the relationship between MDR1 and MDR3 gene and drug resistance to cisplatin of ovarian cancer cells. Two siRNAs （MDRI, MDR3） which specifically targeted MDRI and MDR3 genes were transfered into A2780/DDP cells. Then double staining with Annexin- V-FITC/PI was used to detect cell apoptosis by the flow cytometry （FCM）. A2780/DDP cell viability was determined by MTT. MDR1 and MDR3 mRNA were assessed by RT-PCR. Caspase-3 protein was detected by Western blotting. Transfection of MDRI and MDR3 siRNA into A2780/DDP cells failed to reverse the drug-resistance of A2780/DDP cells to cisplatin （P〉0.05）. No significant difference in the apoptosis efficiency was observed between the MDR1 and MDR3 siRNA, pSuppressor- Neo vector transfection cells and untreated cells （P〉0.05）. In the presence of cisplatin of different concentrations, the viability of A2780/DDP cells was not significantly decreased after the transfection No changes in MDR1 and MDR3 mRNA were found in MDRI and MDR3 siRNA-transfected A2780/DDP cells. As compared with pSuppressorNeo and untreated groups, no significant difference existed in the expression of MDR1 and MDR3 mRNA （P〉0.05）. The expression of caspase-3 protein in MDR1 and MDR3 siRNA transfected A2780/DDP cells was not significantly increased. It is concluded that multidrug resistance induced by cisplatin in ovarian carcinoma cell lines is not due to overexpression of MDR1 and MDR3 gene. The drug resistance of ovarian carcinoma cells to cisplatin is not mediated by P-glycoprotein.

Smilax China L.Rhizome Extract Inhibits Nuclear Factor-κB and Induces Apoptosis in Ovarian Cancer Cells

Objective： To study the antitumor effects and associated mechanisms of extract of the Smilax china L. rhizome （SCR） on ovarian cancer cells. Methods： Ovarian cancer cells A2780 were treated with different concentrations of SCR extract （SCRE）, and compared with controls. Effects on cell growth were evaluated by cell counting kit-8 （CCK-8） assay; proliferation effects by EdU incorporation assay; cell cycle by propidium iodide staining; apoptosis by annexin V-fluorescein isothiocyanate/propidium iodide; cellular distribution of nuclear factor- κ B （NF-κ B） by immunofluorescence; protein levels of NF- κB, caspase-3, poly-adenosine diphosphate （ADP）-ribose polymerase （PARP）, Bcl-2-associated X protein （Bax）, cellular inhibitor of apoptosis （clAP）-1, anti-X-linked inhibitor of apoptosis protein （XlAP）, B-cell lymphoma-extra large （BcI-XL）, B-cell lymphoma-2 （Bcl-2） and AKT by Western blotting; and effects of SCRE combined with cisplatin or adriamycin on A2780 cells by CCK-8 assay. Results： SCRE suppressed A2780 cell proliferation in a dose-dependent manner （P〈0.05, /=〈0.01）, arrested cells in GJM phase and induced apoptosis by activating caspase-3, PARP and Bax. SCRE treatment also correlated with inhibition of NF-κ B and downregulation of Bcl-2, Bcl-XL, clAP-l, XlAP and AKT. SCRE can promote chemosensitivity to cisplatin and adriamycin in A2780 cells （P〈0.01）. Conclusion： SCR effectively inhibits NF- κ B, induces apoptosis and reduces chemoresistance to cisplatin and adriamycin in ovarian cancer cells, which might be its molecular basis for treating ovarian cancer.