Relevant genomics of neurotensin receptor in cancer.

The expressed sequence tag (EST) databases are an attractive starting point for gene discovery for diseases like cancer. Validation of gene targets from these sequences (both known and novel) in cancers requires a comprehensive expression profiling. We identified from the Cancer Gene Anatomy Project database (CGAP), a hit called neurotensin receptor (NT-r) that was expressed in the pancreatic cancer cDNA libraries. Neurotensin (NT), a neuroendocrine peptide, exerts trophic effects in vivo and stimulates the growth of cancer-derived cell lines in vitro. High affinity neurotensin receptors (NT-r) are expressed in cancer-derived cell lines and in some primary tumors. To date, a comprehensive expression profile of the NT-r in diverse cancers and normal tissues has not been reported. A cancer-selective expression of NT-r, if demonstrable, may provide a basis for a diagnostic and potential therapeutic utility. We demonstrate that the NT-r is expressed in a variety of cancer-derived cell lines as well as primary tumors, but only in a select few normal tissues. The expression of NT, on the other hand, was detected in many normal tissues, but not in the cancer-derived cell lines. The NT expression however, was detected in the primary tumors. We further demonstrate that NT expression is stimulated by androgen deprivation in the prostate cancer models. These results demonstrate the usefulness of a panel of cDNA repository for rapid validation of potential cancer targets.