Conclusions
The growth inhibitory effect of imatinib on breast cell lines may be caused by inhibiting the activity of the tyrosine kinases PDGFR beta and Akt. Imatinib is a promising novel drug for targeted therapy of breast cancer patients.
Methods
Expression of imatinib targets was analyzed with reverse transciptase PCR and immunoblotting assays in the breast cell lines MDA MB 231, MCF 7, ZR 75-1, and T 47-D. Changes on receptor expression and phosphorylation status under imatinib were evaluated using drug concentrations of 2 to 10 microM. The anti-proliferative and pro-apoptotic effects of imatinib alone and in combination with vinorelbine were investigated with an MTT and TUNEL assay.
Results
Imatinib inhibited growth and induced apoptosis of all cell lines examined. This effect was increased when combined with vinorelbine. A dose-dependent inhibitory effect on the phosphorylation of PDGFR beta and Akt was detected. Conclusions: The growth inhibitory effect of imatinib on breast cell lines may be caused by inhibiting the activity of the tyrosine kinases PDGFR beta and Akt. Imatinib is a promising novel drug for targeted therapy of breast cancer patients.