The Effect And Mechanism Of Dihydroartemisinin On The Human Ovarian Cancer Cell SKOV3/CDDP

Objective: To investigate the effects of dihydroartemisinin on human ovarian cancer cisplatin resistance SKOV3/CDDP cells,and the expression of Livin,P-gp,Topo-Ⅱβ,also to explore its possible mechanisms of anticancer effects.Methods: 1 Human ovarian cancer SKOV3 cells and cisplatin resistance SKOV3/CDDP cells were incubated with different concentration of dihydroartemisinin and (or) cisplatin in vitro. The cytotoxic effect on the proliferation and reversion of cisplatin resistance were measured by MTT colorimetric method.2 Cell cycle and apoptosis were assessed by flow cytometry.3 Morphological changes of Giemsa staining were observed by light microscope. 4 The expression of Livin,P-gp and Topo-Ⅱβwere analyzed by immunocytochemistry(ICC).Results: 1 The IC₅₀ for cisplatin of SKOV3 and SKOV3/CDDP was 7.52 and 34.12 mg/L.The resistance multiple was 4.54. 2 Dihydroartemisinin inhibited the proliferation and induced apoptosis of ovarian cancer cells on dose depending manner,and the differences among different concentration were significant(P<0.05).The same concentration on two cell lines were not significant (P>0.05).The IC₅₀ for dihydroartemisinin of SKOV3 and SKOV3/CDDP were 27.45 and 29.22μmol/L.3 In the combined group,on SKOV3, the IC₅₀ of cisplatin was 7.52 to 2.16 mg/L,on SKOV3/CDDP ,the IC₅₀ of cisplatin was 15.25mg/L in the low dose group and 4.83 mg/L in the high dose dihydroartemisinin group.The reversion multiple was 2.24 and 7.06. 4 After treated with dihydroartemisinin and cisplatin for 48h, there was an apoptosis peak in SKOV3/CDDP cells after incubating and the ratio of S phase decline, cell mainly arrested in G0/G1 phase by flow cytometry(P<0.05),and the apoptotic percentage raised up, which were in dose-dependent manner. These were not manifest in cells with cisplatin 2.5mg/L detected.5 The morphology observation by light microscopy:When treated with dihydroartemisinin and cisplatin for 24h,SKOV3 and SKOV3/CDDP cells changed significantly in morphology observed by light microscopy.The culture solution was clear, control group cells growth were concentrated,glossiness was good. That every adds medicine group cell density is lower than control group,glossiness comes down.After 48h the control group cells already has overlapping growth,but the dihydroartemisinin group and united group adherence module decrease.There were the typical apoptotic morphological changes,for example,cell population decrease,rarefaction,dimi- nution,rupture of membrane,nucelus engorgement, caryocinesia, karyopycnosis. The changes were more obvious in the high dose group.6 In SKOV3/CDDP,Livin and P-gp were hypso- expression,Topo-Ⅱβwas low- expression,and the differences in SKOV3 were significant (P<0.01).7 When SKOV3/CDDP treated for 48h, Livin and P-gp expressions were downregulated and Topo-Ⅱβwere upregulated significantly(P<0.05).Conclusion: 1 Dihydroartemisinin can inhibit the proliferation of human ovarian cancer cell in a dose dependent manner and reverse cisplatin resistance in vitro. 2 Dihydroartemisinin arrested SKOV3/CDDP cell cycle in G0/G1 phase, effected DNA composition, and induced the apoptosis. 3 The cisplatin resistant mechanism in SKOV3/CDDP was related to the expression of Livin, P-gp and Topo-Ⅱβ. 4 Dihydroartemisinin could inhabit the growth and induce the apoptosis to reverse cisplatin resistance, and maybe its mechanisms were arresting cell cycle; inducing apoptosis through downregulating Livin and p-gp expression and upregulating Topo-IIβexpression. The experiment is only preliminary go into ,which definite mechanism but only , pend for studying in a deepgoing way further.