Autophagy induced by topotecan in ovarian cancer cells

OBJECTIVE: To evaluate the growth inhibition of topotecan(TPT) on OVCAR3 cells and investigate autophagy induced by TPT.METHODS: The growth inhibition of TPT on OVCAR3 cells was detected by MTT assay.Formation of acidic vesicle organelles(AVO) was examined in fluorescence microscopy by staining with acridine orange(AO).MDC staining was used to examine autophagosome.Western blot analysis was used to detect the expression of LC3-Ⅱ and Beclin1 induced by TPT in OVCAR3 cells.RESULTS: MTT assay showed that TPT could evidently inhibit the proliferation of OVCAR3 cells in a dose-dependent manner.The half maximal inhibitory concentration(IC50) value was 0.057 μg/mL.After TPT treatment for 24 h,AO staining was performed,and AVOs were increased compared to the control group.Then we performed MDC staining after TPT treatment.As the result showed,after TPT treatment for 24 h,autophagosomes were increased compared to the negative group.After TPT treatment for the indicated time,LC3-Ⅱ and Beclin1 were detected by Western blot assay.The results showed that the expression of LC3-Ⅱ and Beclin1 were gradually upregulated.CONCLUSIONS: TPT can strongly inhibit proliferation of OVCAR3.It can also induce an autophagic cell death in OVCAR3 cells.The autophagic cell death induced by TPT in OVCAR3 cells may be related to Beclin1 upregulation.