Abstract:

Abstract:Objective To study the anti-tumor effects of ^125I radioactive particles implantation on transplantated tumor model of human breast cancer cells in nude mice and clarify their anti-tumor mechanisms.Methods 120 nude mice transplantated with human breast cancer cells MCF-7 were randomly devided into 3 groups（n=40）:¹²⁵I radioactive particles implanted group,non-radioactive particles implanted group and non-particles implanted group.The articles were implanted into mice according to Pairs system principle. The expressions of Fas mRNA and protein and the activaties of caspase-3 and caspase-8 enzyme weredetected by RT-PCR and Western blotting.The changes of cell cycle were detected by flow cytometry.Results Compared with non-radioactive particles implanted group and non-particles implanted group,the size of cancer tisses in   ^125I radioactive particles implanted group was reduced significantly(P<0.05).The expressions of Fas mRNA,Fas protein,caspase-3 and caspase-8 were  incresed remarkably(P<0.05).The expressions of  caspase-3 and caspase-8 were more than 0.6. The flow cytometry results showed that the number of cells in G0/G1 phase was significatly increased(P<0.05) while the number of cells in S phase was decreased remarkably(P<0.05). Conclusion The implantation of^125I radioactive particles into transplantated tumor model of human breast cancer cells can kill tumor cells,inhibit the  growth cycle of tumor cells and induce the apoptosis of  tumor cells in nude mice.

Key words: ^125I particles;MCF-7 cell;Fas;caspase-3;caspase-8;cell cycle