Biomaterial Database

Polyamines regulate human medullary thyroid carcinoma TT-cell proliferation and secretion of calcitonin and calcitonin gene-related peptide. 1994

A Sjöholm, and E Bucht, and E Theodorsson, and R Larsson, and P Nygren

Department of Molecular Medicine (L6:02), Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.

The significance of polyamines for the neoplastic proliferation and secretion of calcitonin (CT) and calcitonin-gene-related peptide (CGRP) by the human medullary thyroid carcinoma TT cell line was investigated. TT cells were cultured in vitro for 6 days with or without additions of pathway inhibitors of polyamine biosynthetic enzymes. Treatment of the cells with 1 mM of the specific L-ornithine decarboxylase (ODC) inhibitor DL-alpha-difluoromethylornithine (DFMO) resulted in a 97% decrease in ODC activity, lowered contents of putrescine (96%) and spermidine (85%) and cell proliferation rates (90%) along with a compensatory 15-fold increase in S-adenosyl-L-methionine decarboxylase (SAMDC) activity. DFMO treatment also led to a decrease in cellular content of CT (33%) and CGRP (26%), while the drug enhanced secretion of CT (31%) but depressed that of CGRP (26%), and elevated the ratio of CT to CGRP secreted into the medium by 74%. Ethylglyoxal bis(guanylhydrazone) (EGBG), a SAMDC inhibitor, at 100 microM evoked a similar reduction of cell proliferation and lowered the content of spermine by 81%. Furthermore, EGBG treatment caused a 34-fold increase in ODC activity and a subsequent 35-fold build-up of putrescine, but also seemed to stabilize SAMDC as evidenced by a highly enhanced SAMDC activity (approximately 200-fold) during enzyme assays in the absence of the inhibitor. EGBG exposure resulted in an increase in cellular CT content (110%) and secretion of the hormone (82%), while not affecting CGRP content or release.2+ EGBG effects were partially counteracted by DFMO.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008935	Mitoguazone	Antineoplastic agent effective against myelogenous leukemia in experimental animals. Also acts as an inhibitor of animal S-adenosylmethionine decarboxylase.	Methylglyoxal Bis(guanylhydrazone),MGBG,Methyl-gag,NSC-32946,Methyl gag,Methylgag,NSC 32946,NSC32946
D009955	Ornithine Decarboxylase	A pyridoxal-phosphate protein, believed to be the rate-limiting compound in the biosynthesis of polyamines. It catalyzes the decarboxylation of ornithine to form putrescine, which is then linked to a propylamine moiety of decarboxylated S-adenosylmethionine to form spermidine.	Ornithine Carboxy-lyase,Carboxy-lyase, Ornithine,Decarboxylase, Ornithine,Ornithine Carboxy lyase
D011073	Polyamines	Amine compounds that consist of carbon chains or rings containing two or more primary amino groups.	Polyamine
D011700	Putrescine	A toxic diamine formed by putrefaction from the decarboxylation of arginine and ornithine.	1,4-Butanediamine,1,4-Diaminobutane,Tetramethylenediamine,1,4 Butanediamine,1,4 Diaminobutane
D002116	Calcitonin	A peptide hormone that lowers calcium concentration in the blood. In humans, it is released by thyroid cells and acts to decrease the formation and absorptive activity of osteoclasts. Its role in regulating plasma calcium is much greater in children and in certain diseases than in normal adults.	Thyrocalcitonin,Calcitonin(1-32),Calcitrin,Ciba 47175-BA,Eel Calcitonin,Calcitonin, Eel,Ciba 47175 BA,Ciba 47175BA
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000518	Eflornithine	An inhibitor of ORNITHINE DECARBOXYLASE, the rate limiting enzyme of the polyamine biosynthetic pathway.	Difluoromethylornithine,alpha-Difluoromethylornithine,DL-alpha-Difluoromethylornithine,Eflornithine Hydrochloride,Eflornithine Monohydrochloride, Monohydrate,MDL-71,782 A,Ornidyl,RMI 71782,Vaniqa,alpha-Difluoromethyl Ornithine,DL alpha Difluoromethylornithine,MDL 71,782 A,MDL71,782 A,Ornithine, alpha-Difluoromethyl,alpha Difluoromethyl Ornithine,alpha Difluoromethylornithine
D012437	Adenosylmethionine Decarboxylase	An enzyme that catalyzes the decarboxylation of S-adenosyl-L-methionine to yield 5'-deoxy-(5'-),3-aminopropyl-(1), methylsulfonium salt. It is one of the enzymes responsible for the synthesis of spermidine from putrescine. EC 4.1.1.50.	S-Adenosylmethionine Decarboxylase,Decarboxylase, Adenosylmethionine,Decarboxylase, S-Adenosylmethionine,S Adenosylmethionine Decarboxylase
D013095	Spermidine	A polyamine formed from putrescine. It is found in almost all tissues in association with nucleic acids. It is found as a cation at all pH values, and is thought to help stabilize some membranes and nucleic acid structures. It is a precursor of spermine.