In Vitro Study Of Human Breast Carcinoma Cell Apoptosis Induced By Strontium-89

Many radiopharmaceuticals used for medical diagnosis and therapy are beta emitters;however,the mechanism of the cell death caused by beta-irradiation is not well understood.The objective of this study is to investigate the apoptosis of human breast carcinoma MCF-7 cell lines induced by Strontium-89(89Sr)and its underlying mechanism.High-metastatic breast cancer cells MCF-7 were treated with l9Sr at different radioactive concentrations.The inhibition rate of cell proliferation was measured by MTT assay.The cell cycle retardation,cell apoptosis,mitochondrion transmembrane potential change,and Fas receptor expression were detected by FACS.The protein expressions of pro-apoptotic P53 and anti-apoptotic Bcl-2 were analyzed by immunohistochemistry.When the MCF-7 cells were treated with various concentrations of 89Sr,the cell proliferation was significantly inhibited and the cell cycle was mainly retarded in G2-M phase in a dose-dependent manner.In addition,the mitochondrial transmembrane potential was decreased and the apoptosis of MCF-7 cells was observed after the MCF-7 cells were treated with 89Sr.The apoptotic rate was up to 46.28%.The expressions of Fas receptor and pro-apoptotic P53 were increased,while the expression of anti-apoptotic Bcl-2 was decreased.These findings indicated that 89Sr may induce the apoptosis of MCF-7 by regulation the expression of Fas receptor,P53 and Bcl-2.Our study providetherapeutic evidence for tumor radiotherapy.