Neurotensin (NT) is a neuropeptide interacting with specific G protein coupled receptors. In the periphery, NT is a hormone of the gastrointestinal tract. The high affinity neurotensin receptor (NT-1 receptor) is over-expressed in a numbers of cancers. Consequently NT growth effects, largely described in normal and adenocarcinomatous tissues, may be of a major importance in tumor proliferation. In this study we demonstrated an anti-apoptotic effect of NT agonist, in the mammary adenocarcinoma cells, MCF-7. Focusing on the cellular events involved, we found an increase in Bcl-2 protein and mRNA levels, resulting in Bcl-2 transcriptional activation, and dependent on MAP kinase pathway. (C) 2002 Elsevier Science (USA). All rights reserved.