Reversal Effect Of Phosphatidylinositol3’-Kinase Inhibitor LY294002in Chemotherapy On Paclitaxel Resistance Of Ovarian Cancer Cell Lines

Objective:To study the reversal effect of PI3K inhibitor LY294002to chemotherapyon paclitaxel resistance ovarian cancer cell line A2780/Taxol.Section one： Identification of paclitaxel resistant cellsMethods:1. CCK-8assay was applied to detect the proliferation ofpaclitaxel-resistant cell line A2780/Taxol cell and parental cell A2780.2. Flow cytometry was used to test the cell cycle of A2780andA2780/Taxol.3. CCK-8assay was applied to detect the drug resistance and resistanceindex of paclitaxel-resistant cell line A2780/Taxol cell and parentalcell A27804. The expression of P-gp protein was analyzed usingImmunocellulerchemistry in parental cell A2780and A2780/Taxol cellline. 5. Western blot was used to detect the protein expressions of P-gp inparental cell A2780and A2780/Taxol cell line.Results:1. To determine the effect of proliferation of cells. CCK-8and flowcytometry analyses were performed and the results showed thatcompared with the parent cells, paclitaxel resistance cells grew muchslowly.2. Both cell lines had some changes in cell cycle; In the G1phase waslonger in A2780/Taxol cell line compared with that in A2780cell line,with statistical differences between the two groups (P<0.05).3. The resistance index of A2780/Taxol is26.35.4. Based on results of western blot and immunocellulerchemistry, the datashows that P-gp expression of A2780/Taxol was increased.Section two: Reversal effect of phosphatidylinositol3’-kinaseinhibitor LY294002in chemotherapy on paclitaxel resistance of ovariancancer cell lines.Methods:1. Apoptosis of different physiological concentration PI3K specificityinhibitors LY294002intervention resistance cell were detected by flowcytometry.2. After PI3K specificity inhibitors LY294002intervention paclitaxel resistance of ovarian cancer cell lines at6,12or24hours. Cellproliferation was determined by Cell Counting Kit-8(CCK-8) solution.3. Effect of A2780/Taxol cell lines were treated with LY294002andA2780/Taxol cell lines were determined the50%inhibitionconcentration (IC50) of paclitaxel and proliferation using Cell CountingKit-8(CCK-8) solution.4. The apoptotic rates and cell cycle were detected by flow cytometry.5. The expression of Akt, p-Akt and P-gp proteins was analyzed bywestern blot.Results:1. With the increasing concentration of LY294002，the cell apoptosis rateis increasing.2. LY294002inhibited the proliferation of A2780/Taxol in a dose andtime-dependent manner.3. The IC50of paclitaxel for A2780/Taxol cell was treated with LY294002was significantly lower than that in A2780/Taxol cell line.4. The flow cytometry demonstrated that the apoptotic ratio ofexperiment group was significantly higher than control groups.5. Both groups had some changes in cell cycle, especially in S phase.6. Phosphorylated Akt and P-gp protein levels of A2780/Taxol inhibitedby LY294002decreased than the A2780/Taxol. Conclusion:PI3K inhibitor, LY294002has a reversal effect on thepaclitaxel-resistance of A2780/Taxol cell line.