Terry W. Moody - US grants

Oat cell carcinoma, or small cell lung cancer (SCLC), is a tumor enriched in its neuroendocrine properties. High levels of enzymes, such as neuron specific enolase and dopamine decarboxylase, and polypeptide hormones are associated with SCLC. In particular, high levels of bombesin(BN)-like peptides are found in SCLC cells, tumors and xenographs in nude mice. BN-like peptides are secreted from SCLC cells when the cells are depolarized and SCLC cells have receptors for BN-like peptides. BN stimulates the growth of SCLC cells. Thus BN-like peptides may function as important growth factors in oat cell carcinoma. The underlying hypothesis of this study is the BN-like peptides function as autocrine growth factors in SCLS. The long term objective is to define the role of BN-like peptides in oat cell carcinoma. The specific aims are: 1) To determine what factors regulate the secretion of BN-like peptides. 2) To isolate and characterize the cellular receptors for BN-like peptides. 3) To determine the mechanism of action of BN-like peptides in SCLC cells. 4) To determine if antibodies, other factors or BN receptor antagonists can act as inhibitors of the growth of oat cells. A variety of biochemical, pharmacological and immunological techniques will be employed. The levels of BN-like peptides will be determined by radioimmunoassay. Specifically, factors which inhibit the secretion of BN-like peptides will be defined. Receptors for BN-like peptides will be solubilized and purified. Anti-receptor antibodies will be generated and tested for their ability to inhibit SCLC growth. Biochemical techniques will be used to investigate the ability of BN-like peptides to alter Ca++-flux, cGMP production and phosphatidyl inositol turnover with the goal of defining BN-receptor antagonists. The results of these studies will provide a more comprehensive understanding of the properties of SCLC cells and may yield new therapeutic approaches in the form of agents which inhibit the growth of oat cell carcinoma.

Small cell lung cancer (SCLC) is a tumor enriched in its neuroendocrine properties. High levels of neurotransmitters, neural enzymes and polypeptide hormones are associated with SCLC. These polypeptide hormones include ACTH, calcitonin, vasopressin, physalaemin and bombesin-like peptides. Peptides may play an important regulatory role in SCLC and in particular, bombesin-like peptides function as autocrine growth factors in SCLC. Thus addition of an anti-bombesin monoclonal antibody inhibits the growth of SCLC in vitro and in vivo. Recently, neurotensin was found in high concentrations in SCLC cell lines and biopsy tissue. The specific aims of this study are: 1) to determine factors which regulate the secretion of neurotensin from SCLC, 2) to characterize receptors for neurotensin on SCLC cells, 3) to investigate whether neurotensin induces second messenger production in SCLC cells and 4) to determine neurotensin levels in the blood of patients. The hypothesis of this study is that neurotensin functions as a regulatory peptide in SCLC. The long term objectives are to investigate the role of peptides in the development and regulation of SCLC. A variety of biochemical and pharmacological techniques will be employed. The levels of neurotensin will be determined by radioimmunoassay. Factors which stimulate and inhibit the secretion of neurotensin will be defined. Receptors for neurotensin will be characterized biochemically and the pharmacology of these receptors defined using synthetic neurotensin analogues. Biochemical techniques will be used to investigate if neurotensin induces second messenger production (cAMP, cGMP, Ca++ flux or phosphatidyl inositol turnover). Also, the role of neurotensin as a possible growth factor for SCLC will be investigated. Studies will indicate if neurotensin is elevated in the blood of patients with SCLC relative to control patients and if blood neurotensin levels may serve as useful biochemical markers in the diagnosis of SCLC. The results of these studies will provide a more comprehensive understanding of the properties of SCLC and the potential role of neurotensin as an important regulatory peptide in this disease.

Bombesin-like peptides play a pivotal role in both normal and pathological processes in the mammalian central nervous system (CNS). This class of neuropeptides are potent hypothermic, hyperglycemic and satiety agents and they also alter pituitary hormone secretion as well as behavior. Bombesin stimulates turnover of dopamine, an important neurotransmitter in schizophrenia, Huntington"s and Parkinson"s disease. Although it is clear that bombesin-like peptides are biologically active in the CNS, its precise physiological role remains unknown. Dr. Moody hypothesizes that bombesin-like neuropeptides alter the growth and/or development of brain cells. During his previous National Science Foundation support, Dr. Moody reported the presence of high affinity receptors in discrete brain regions. He will now characterize and determine the regulatory role of bombesin-like peptides and their receptors in CNS. He will evaluate the possibility that receptors for these neuropeptides regulate cell growth by examining effects on neural transplants, development and human cultured cells. In addition, Dr. Moody plans to solubilize and purify the bombesin-like neuropeptide receptors and then generate specific monoclonal antibodies. Interestingly, high levels of receptor have been localized to some types of cancer cells and bombesin-like peptides stimulate the growth of these malignant cells. Thus, understanding the various effects and mechanisms of action of these neuropeptides could lead to important breakthroughs as well as the development of new therapeutic approaches in the cancer field.

Over 90,000 males and 40,000 females in the United States develop lung cancer annually. The four main types of lung cancer are small cell lung cancer (SCLC), a neuroendocrine tumor which responds to chemo- and/or radiation therapy, adenocarcinoma, large cell carcinoma and squamous cell carcinoma. We found that SCLC produces bombesin-like peptides, which function as autocrine growth factors. Little is known about the biochemical properties of non-small cell lung cancer (NSCLC). Recently, we observed that vasoactive intestinal polypeptide (VIP) binds with high affinity to NSCLC cell lines as well as SCLC. These data suggest that VIP receptors may represent a common cell surface antigen on all types of lung cancer. In addition, epidermal growth facto (EGF) receptors are present in high density on adenocarcinoma, large cell carcinoma and squamous cell carcinoma cells but are present only in low density on SCLC cells. This proposal concerns the biological role of VIP and EGF receptors in NSCLC. The specific aims are to: 1) determine the binding and second messenger properties of adenocarcinoma, large cell carcinoma and squamous cell carcinoma cell lines. Also, the ability of VIP and EGF to bind to biopsy specimens will be determined using in vitro autoradiographic techniques. These studies will elucidate if neuropeptide and growth factor receptors are present in tumors as well as the subsequently derived cell lines. 2) The VIP receptor from NSCLC cells will be characterized biochemically using crosslinking techniques. Also, the VIP receptor will be solubilized and purified in order learn more about the molecular structure of VIP receptors. 3) Monoclonal antibodies will be developed against the human VIP receptor. These antibodies may serve as unique probes for the VIP receptor. 4) The ability of VIP receptor agonists and antagonists as well as monoclonal antibodies against the EGF receptor to alter the growth of NSCLC will be determined. A hypothesis to be tested is that neuropeptide and growth factor receptors regulate the growth of NSCLC. The long term objective of this study is to investigate the role neuropeptides and growth factor receptors in lung cancer. These studies will further define the cell surface receptors present on lung cancer cells and aid in determining if these receptors can be utilized to develop novel therapeutic approaches for the treatment of lung cancer.

Small cell lung cancer (SCLC) represents one of the 4 major types of lung cancer. SCLC is a neuroendocrine tumor which makes and secretes high levels of bombesin/gastrin releasing peptide (BN/GRP) and insulin-like growth factor I (IGF-I). BN/GRP and IGF-I bind with high affinity to cell surface receptors and stimulate the growth of SCLC cells. The underlying hypothesis of this study is that BN/GRP and IGF-I function as autocrine growth factors in SCLC. The long term objective is to define the role of growth factors in lung cancer. This proposal concerns the biochemical characterization of BN/GRP and IGF-I as well as their receptors in human cell lines. The specific aims are to: 1) characterize enzymes which regulate the posttranslational processing of BN/GRP. In particular, a SCLC enzyme which amidates the C-terminal of the BN/GRP will be studied. 2) The ability of somatostatin (SRIF) analogues to inhibit the secretion and biosynthesis of SCLC BN/GRP and IGF-I will be investigated.These studies will employ radioimmunoassay and molecular biology techniques. 3) BN/GRP receptors will be solubilized and purified to homogeneity from human lung cell lines. Monoclonal antibodies will be elicited against the human BN/GRP receptor and these monoclonal antibodies may serve as unique probes for the BN/GRP receptor. 4) The ability of peptide antagonists and monoclonal antibodies to inhibit the growth of SCLC will be determined. Previously, we found that certain BN analogues inhibited binding to SCLC BN/GRP receptors, the increase in cytosolic Ca 2+ caused by BN and clonal growth of SCLC cells, however, more potent BN/GRP receptor antagonists have recently been discovered. Also, the ability of anti-IGF-I receptor monoclonal antibodies to inhibit the growth of SCLC will be investigated in vitro and in vivo using nude mice. The results of these studies will provide a more comprehensive understanding about the neuroendocrine properties of SCLC and may yield new therapeutic approaches in the form of agents which inhibit the growth of SCLC.