title: [Inhibitors of oncogene product functions].
abstract: Streptomyces and other microorganisms produce antibiotics, and enzyme inhibitors as secondary metabolites. Thus, they could be said as a treasury of organic compounds which have various structures and biological functions. Since oncogene theory has been extensively developed, we have screened oncogene function inhibitors from microorganisms as a new group of microbial secondary metabolites. Erbstatin is an inhibitor of epidermal growth factor (EGF) receptor and p60v-src-associated tyrosine kinase. Its inhibitory pattern vs. peptide is competitive. In cell culture it inhibited both EGF receptor autophosphorylation and internalization. Recently, we have isolated lavendustin A, an extremely potent inhibitor of tyrosine kinase, from Streptomyces. Lavendustin A is a novel compound and about 50 times stronger than erbstatin in inhibiting tyrosine kinase. Oxanosine is an inhibitor of ras oncogene product activity. It induces normal phenotypes in temperature-sensitive Kirsten sarcoma virus-infected rat kidney cells, lowering the intracellular levels of guanine nucleotides. Many oncogenes including src, ras, sis, fms and erbB are known to activate cellular phosphatidylinositol (PI) turnover. Therefore we have screened inhibitors of PI turnover and isolated psi-tectorigenine and pendolmycin from Nocardiopsis and inostamycin from Streptomyces. PI kinase is an enzyme involved in PI turnover pathways. We have isolated 2, 3-dihydroxybenzoic acid from Streptomyces as an inhibitor of PI kinase. These oncogene function inhibitors from microorganisms will be useful for the mechanistic study of oncogene product activities.
authors.affiliation: Dept. of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Umezawa
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase; D001547:Benzaldehydes / Q000494:pharmacology; D001565:Benzoates / Q000494:pharmacology; D019817:Benzoic Acid; D011905:Genes, ras; D019833:Genistein; D006873:Hydroquinones / Q000494:pharmacology*; D007529:Isoflavones / Q000494:pharmacology; D015513:Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000502:physiology; D010636:Phenols / Q000494:pharmacology*; D010770:Phosphotransferases / Q000037:antagonists & inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D012263:Ribonucleosides / Q000494:pharmacology
chemical_list: D001547:Benzaldehydes; D001565:Benzoates; D006873:Hydroquinones; D007529:Isoflavones; D015513:Oncogene Proteins; D010636:Phenols; D012263:Ribonucleosides; C062898:lavendustin A; C032886:oxanosine; D019817:Benzoic Acid; D019833:Genistein; D010770:Phosphotransferases; D019870:1-Phosphatidylinositol 4-Kinase; D011505:Protein-Tyrosine Kinases; C048212:erbstatin