PMID: 2499305Mar 15, 1989Paper

Characterization of difluoromethylornithine-resistant mouse and human tumour cell lines

The Biochemical Journal
A HirvonenJ Jänne

Abstract

Four mouse and two human tumour cell lines resistant to alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), were analysed for the activities of polyamine-biosynthetic and -biodegradative enzymes as well as for cellular polyamine contents. In all but one of these cell lines the resistance to DFMO was based on an overproduction of ODC. In a human myeloma cell line the resistance was based on a greatly enhanced arginase activity. Except for one L1210 variant cell line, all the resistant cell lines contained elevated S-adenosylmethionine decarboxylase activity. Similarly, all the resistant mouse, but not human, cell lines displayed enhanced spermidine and spermine synthase activities. Arginase activity was detected only in human cell lines. In both DFMO-resistant cell lines the activity of arginase was strikingly elevated. Of the biodegradative enzymes, polyamine oxidase activity was readily detectable in all mouse cells, but no measurable activity was found in the human cells. Spermidine/spermine N1-acetyltransferase activity was elevated in three out of four resistant mouse cell lines. Even though the concentration of spermidine was usually lower in the overproducer cells, this was co...Continue Reading

Citations

Aug 1, 1991·Annals of Medicine·J JänneP Leinonen
Jul 1, 1991·DNA and Cell Biology·S MyöhänenJ Jänne
Sep 21, 2001·European Journal of Gastroenterology & Hepatology·I F Pryme, S Bardocz
Mar 1, 1990·DNA and Cell Biology·J WahlforsT O Eloranta
Dec 1, 1999·APMIS : Acta Pathologica, Microbiologica, Et Immunologica Scandinavica·Gunnar Houen
Aug 10, 2007·American Journal of Physiology. Cell Physiology·Joshua L DeignanWayne W Grody

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