The Bombesin Receptor Complex and Cell Growth: Physiology and Pathology

Abstract

The amphibian tetradecapeptide bombesin and bombesin-like peptides have been detected by immunohistochemical studies in various normal mammalian tissues, like gastrointestinal tract, brain, spinal cord and lung (Walsh et al., 1979; Moody and Pert, 1979; Wharton et al., 1978) together with specific cell surface receptors (Moody et al., 1978; Jensen et al., 1978; Zachary and Rozengurt, 1985). A 27 amino acid homologue of bombesin, gastrin releasing peptide (GRP), was isolated from porcine stomach. GRP has been shown to have the same carboxy-terminal peptide as bombesin, responsible for receptor recognition. Moreover, GRP shares with bombesin also the biological effects elicited in the target cells and is considered to be the mammalian counterpart of amphibian bombesin (McDonald et al., 1979). Bombesin was initially known as a peptide stimulating hormone secretion and smooth-muscle contraction and affecting temperature control and behavior in mammals (Gibbs et al., 1979; Tache et al., 1980; Swope and Schonbrunn, 1984). Later it has been shown that bombesin and GRP can regulate the proliferation of normal and malignant cells. They have a potent mitogen activity on culture Swiss 3T3 fibroblasts (Rozengurt and Sinnet-Smith, 1983) and on normal human bronchial epithelial cells (Willey et al., 1984).