Objective:To investigate the relationship of the expression of bcl-2 and bad in breast cancer cells with chemosensitivity.Methods:Surgical samples of breast cancer

diagnosed by pathology

were obtained from The First Affiliated Hospital of Chongqing Medical University.The cancer sample cells were cultured separately in the incubator at 37℃

5% CO2 in vitro.The rate of inhibition of cancer cells by 4 kindsof anticancer drugs

which were EADM(Epirubicin adriamycin)

5-Fu(Fluorouracil)

NVB(Navelbine) and DDP(Diaminedichloroplatinum)

were assayed by MTT(3-(4

5-Dimethylthiazol-2-yl)-2

5-diphenyltetrazolium bromide)method.Immuno histochemistry was used to detect the expression of IL-2 and IL-4 in the breast cancer tissues.Results:Sensitivity rates of 20 breast cancer cells in 0.1×PPC(plasma peak concentration) within 48h in vitro were 30%(EADM)

20%(5-Fu)

45%(NVB)and 25%(DDP).Respectively the rate of inhibition of EADM

5-Fu

NVB and DDP were significantly higher in the bcl-2 negative cancer cells than in the bcl-2 positive cancer cells.A negative correlation was found between expression of bcl-2 and chemosensitivity for all the 4 anticancer drugs.The rates of inhibition of EADM and NVB were significantly lower in the bad negative cancer cells than in the bad positive cancer cells.A positive correlation was found between expression of bad and chemosensitivity for EADM.Conclusion:The combined detection of bcl-2 and bad may be taken as an index of the selection of anticancer drugs.Regulated the expression level of bcl-2 and bad may be a new way to the therapy of breast cancer.