TAMOXIFEN AND SOMATOSTATIN AFFECT TUMORS BY INDUCING APOPTOSIS

Tamoxifen is a commonly used chemotherapeutic agent in human breast ca ncer, although some tumours develop resistance. Somatostatin is also b eing introduced as an anti-tumour agent. Here we show that the action of these drugs is, at least partly, due to their induction of apoptosi s. Both 50 nM somatostatin, and 60 nM tamoxifen significantly enhanced the percentage of cells undergoing apoptosis, when compared to untrea ted or oestrogen treated control cells, This effect was observed in SK -N-BE(2) human neuroblastoma cells and in MCF-7G human breast cancer c ells but not in their drug-resistant counterpart MCF-7A which showed a very low rate of spontaneous programmed cell death. Finally, we propo se a simple test of the sensitivity and resistance of individual tumou rs to these agents by assessing their ability to induce apoptosis in v itro as measured by flow cytometry.