Apoptotic effects of signal transduction inhibitors on human tumor cells with different PTEN expression

1. Introduction: An important mechanism of antitumoral targeted therapies is the induction of apoptosis in tumor cells. Tamoxifen and trastuzumab (Herceptin), respectively, are able to trigger apoptosis in human breast cancer cells. But, frequently altered apoptotic signal cascades, for instance through PTEN mutations, help tumor cells to escape antitumoral therapy. We intended to study to which extent the apoptotic effect of signal-transduction inhibitors is dependent on PTEN expression. 2. Methods: PTEN expression was analysed by western-blot analysis in tumor cell lines of the breast (BT-474, MCF7, MDA-MB 231…