The ligand-binding properties of the gastrin-releasing peptide (GRP) receptor and the cellular processing of GRP have been studied in the small-cell lung cancer (SCLC) cell line COR-L42. Scatchard analysis of GRP receptor expression indicated a single class of high-affinity receptors (Kd 1.5 nM) and approx. 6700 receptors/cell. GRP bound to its receptor with a Ki of 2.4 nM. The bombesin-related...

Exposure of the gastrin-releasing peptide (GRP) receptor to agonists causes a rapid desensitization of the receptor-stimulated mobilization of intracellular calcium. Homologous desensitization occurs by uncoupling the G-proteins from the receptor and by ligand induced internalization. The molecular determinants of desensitization of the GRP receptor are not well known. The importance of tyrosin...

Gastrin-releasing peptide (GRP) is a mitogen and morphogen important in the development of human colon cancers. Although epithelial cells lining the colon do not normally express GRP or its receptor (GRP-R), most human tumors express GRP-R mRNA. Yet functional protein has only been detected in 24 to 40% of colon cancers. To elucidate the reason for the difference between the expression of GRP/G...

Epithelial cells lining the adult human colon do not normally express gastrin-releasing peptide (GRP) or its receptor (GRPR). In contrast, approximately one-third of human colon cancers and cancer cell lines have been shown to express GRP-binding sites. Because GRPR activation causes the proliferation of many cancer cell lines, GRP has been presumed to act as a clinically significant growth fac...

The mammalian bombesin peptides [gastrin-releasing peptide (GRP) and neuromedin B (NMB)] are important in numerous biological and pathological processes. These effects are mediated by the heptahelical GRP receptor (GRPR) and NMB receptor (NMBR). GRP has high affinity for GRPR and lower affinity for NMBR. Almost nothing is known about the molecular basis for the selectivity of GRP. To address th...

Tumoral gastrin-releasing peptide (GRP) receptors are potential targets for diagnosis and therapy using radiolabeled or cytotoxic GRP analogs. GRP-receptor overexpression has been detected in endocrine-related cancer cells and, more recently, also in the vascular bed of selected tumors. More information on vascular GRP-receptors in cancer is required to asses their potential for vascular target...

cDNA clones to human prepro-gastrin-releasing peptide (prepro-GRP) mRNA detect synthesis of prepro-GRP-related transcripts in 4 of 7 small cell lung cancer (SCLC) cell lines and 1 of 2 metastatic SCLC tumors examined. A correlation is noted between prepro-GRP gene expression and the occurrence of bombesin-related immunoreactivity in SCLC cell lines. Examination of the structure of prepro-GRP tr...

Recent studies have shown that aberrantly expressed gastrin-releasing peptide (GRP) and its receptor (GRP-R) critically regulate tumor cell differentiation in colon cancers developing in humans and mice. This finding suggested that the ability of GRP/GRP-R to promote a well-differentiated phenotype in colon cancer might reflect a re-capitulation of a normal role in regulating intestinal organog...

Gastrin-releasing peptide (GRP) has been suggested as a novel regulatory peptide in the female reproductive tract but the presence of GRP and GRP mRNA in the non-neurogenic tissue of the cervix has not yet been clarified. In the present study, immunohistochemistry and in situ hybridization were used to reveal the distribution of GRP immunoreactivity and expression of GRP mRNA in the bovine cerv...