In Vitro Study on Apoptosis Induced by Strontium-89 in Human Breast Carcinoma Cell Line

摘要

Many radiopharmaceuticals used for medical diagnosis and therapyare beta emitters; however, the mechanism of the cell death causedby beta-irradiation is not well understood. The objective of thisstudy was to investigate the apoptosis of human breast carcinomaMCF-7 cell lines induced by Strontium-89 (89Sr) and itsregulation and control mechanism. High-metastatic Breast CarcinomaMCF-7 cells were cultured in vitro using 89Sr withdifferent radioactive concentration. The inhibition rate of cellproliferation was measured by MTT color matching method. The cellcycle retardation, apoptosis conditions, mitochondriontransmembrane potential difference and Fas expression were testedand analyzed. The genes P53 and bcl-2 expressions was alsoanalyzed using immunity histochemical analysis. After beinginduced by 89Sr with various of radioactiveconcentration, it was found that the inhibition of cellproliferation of MCF-7 cells was obviously, the retardation ofcell cycle occurred mainly in G2-M. It was also found that theobvious apoptosis occurred after being induced by 89Sr,the highest apoptosis rate reached 46.28%. The expressions ofFas acceptor and P53 gene increased, while bcl-2 gene expressiondecreasesd. These findings demonstrate that in the ranges of acertain radioactive concentration, the inhibition rate of MCF-7cell proliferation and retardation of cell cycle had positivecorrelation with the concentration of 89Sr. And themitochondrion transmembrane potential decrease would induce theapoptosis of MCF-7 cell notably, which were controlled by P53 andbcl-2 genes, involved with the Fas acceptor.