Study of mechanism of medroxyprogesterone 17-acetate on the cancer stem cell-like properties of human endometrial cancer / 中华妇产科杂志

ABSTRACT

Objective To explore the mechanism resistance of medroxyprogesterone 17-acetate (MPA) on the endometrial cancer side-population (SP) cells.Methods (1) Ishikawa-SP cells from endometrial cancer cell lines Ishikawa were be separated by Hoechst 33342 dyeing method and flow cytometry analysis.The clone formation efficiency between Ishikawa-SP cells and Ishikawa-non-SP cells were performed by clone formation assay.Breast cancer resistance protein (BCRP) was examined by immunocytochemistry method.(2)Ishikawa,Ishikawa-SP,Ishikawa-non-SP cells were treated with various concentrations of MPA at 5,10,15,20 μmoL/L.After cultured for 24,48,and 72 hours,cells growth were measured by methanethiosulfomate(MTS) assay.(3) The groups of Ishikawa,Ishikawa-SP,Ishikawa-non-SP cells incubated with MPA at the half maximal inhibitory concentration(IC50) were selected for cell apoptosis assay by using flow cytometry.After MPA treatment,the expression of caspase-3 was examined by immunocytochemistry method.Results (1)There were few proportion of Ishikawa-SP cells in Ishikawa endometrial carcinoma,which were 2.7％.There were stronger clone formation efficiency for Ishikawa-SP cells than that for Ishikawa-non-SP cells in Ishikawa [(6.02 ± 1.17)％ vs.(0.53 ±0.20)％,P =0.001].And there were higher level expression of BCRP (P =0.001)and also more resistant Taxol and radiation between Ishikawa-SP cells and Ishikawa-non-SP cells.(2)The inhibitory effect of MPA was concentrationdependent and time-dependent.(3)After MPA treatment,the apoptosis rates of Ishikawa-SP,Ishikawa-nonSP,Ishikawa were (4.01 ± 0.43) ％,(9.30 ± 0.67) ％,and (4.64 ± 0.18) ％,respectively (P ＜ 0.05).The level expression of caspase-3 in Ishikawa group after MPA treated were higher than that in Ishikawa-SP group.Conclusion MPA may be inhibit the growth of endometrial cancer,Ishikawa-SP and Ishikawa-nonSP cells,while Ishikawa-SP may be more resistant to MPA than Ishikawa-non-SP,which mechanism of resistance on MPA may be related to the properties of cancer stem-like cells and cell apoptosis.