Geldanamycin Sensitizes Human Breast Cancer Cells to Adriamycin both in vitro and in vivo

Objective To explore effects of Geldanamycin (GA) combined with adriamycin (ADM) on human breast cancer cells. Method Human breast cancer MCF-7 cells were treated with GA, ADM and GA plus ADM, respectively. The expression of AKT and HSP70 was tested. MTT was used to test proliferation. Flow cytometer assay was performed to determine cellular apoptosis. Furthermore, MCF-7-bearing nude mice model was established and received different treatment. Tumor volume was measured. Apoptosis within tumor tissue was detected by a TUNEL assay. Results GA inhibited the expression of p-AKT but HSP70 in MCF-7 cells. Combination of GA and ADM significantly inhibited the proliferation of MCF-7 cells (Survival rate 51.9±6.8%,P＜0.01) and induced apoptosis (Apoptosis rate 42.97±4.1%,P＜0.05). Tumor growth was also inhibited in vivo (68±9.4%,P＜0.05). TUNEL assay revealed that combined treatment of GA and ADM induced increased apoptosis (14.7±3.3%,P＜0.01). Conclusion GA sensitized human breast cancer MCF-7 cells to ADM, and GA+ADM thus was a promising combination for breast caner treatment.