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.