Bombesin-like peptides: neuropeptides with mitogenic activity.

In recent years, a remarkable advance has been made in identifying the extracellular factors that control cell proliferation in a variety of cells. Bombesin-like peptides (BN-LP) are neuropeptides involved in the regulation of many important functions, including sensory transmission, regulation of central autonomic pathways, thermoregulation, pituitary, gastric, and pancreatic secretion, food intake, and satiety. They also may stimulate cellular proliferation in a developmental and tissue-specific manner. Their role in pathogenesis appears to be related to their properties as growth factors, especially in the lung, where BN-LP are proposed to induce growth of normal and neoplastic epithelial cells. The formulated hypothesis of control of SCLC growth by BN-LP will be tested using specific synthetic BN antagonists. Neuronal modulation of the release of BN-LP from neuroepithelial bodies and paracrine effects of BN-LP as sensory neurotransmitters indicate possible pathways of nervous system involvement in tissue development, proliferation, and differentiation, as well as repair processes and wound healing.