Abstract: ObjectiveTo research the apoptosis of breast cancer cells by application of small direct-current electric field(EF) and its related possible mechanism.MethodsSmall direct-current EFs were applied in human breast cancer cell line MCF7 in vitro to observe the effects on apoptosis of cancer cells by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)and to detect the mRNA expression of p53, Rb and E2F1 genes by reverse transcriptase-polymerase chain reaction (RT-PCR).ResultsA lot of cancer cells were observed slaughed from culture dish by 200mV/mm of the field strength and the number of the apoptotic cancer cells was gradually significantly increased with the application of EFs(P<0.01). mRNA expression level for p53 and Rb genes was elevated but that for E2F1 gene was decreased overtly in cancer cells exposed to EFs.ConclusionApoptosis of breast cancer cells can be induced by small direct-current EFs and the change for expression of p53, Rb and E2F1 genes may be involved in the mechanism.

Key words: breast neoplasm, direct-current electric field, apoptosis, gene