Anti-IgM-induced growth inhibition and apoptosis are independent of ornithine decarboxylase in Ramos cells

Experimental Cell Research
C K LinP M Lad

Abstract

Ornithine decarboxylase (ODC) is a key enzyme involved in polyamine production and is thought to regulate growth and apoptosis in multiple cell systems. A potential link between ODC and growth may involve the action of an oncogene c-myc which is thought to transcriptionally regulate ODC. We have examined the involvement of ODC in anti-IgM-induced growth inhibition and apoptosis in Burkitt's lymphoma cells. Inhibitors of ODC such as difluoromethylornithine (DFMO) completely blocked ODC activity, resulting in growth inhibition but not apoptosis. Addition of putrescine, the product of ODC enzymatic action, to Ramos cells had only a minor effect on growth, did not cause apoptosis, did not augment or block anti-IgM-mediated growth inhibition and apoptosis, but did reverse DFMO-mediated growth inhibition. Anti-IgM treatment of Ramos cells, which markedly decreased c-myc mRNA and protein, caused a paradoxical increase in ODC mRNA level as well as ODC enzymatic activity and increased cellular levels of putrescine. DFMO and putrescine did not alter c-myc mRNA levels directly, nor did they have any affects on anti-IgM-mediated down-regulation of c-myc mRNA. TNF-alpha, which inhibited anti-IgM-mediated apoptosis, did not inhibit either an...Continue Reading

Citations

Jul 9, 2003·Genes and Immunity·J Ollila, M Vihinen
Sep 2, 2006·Proteomics·Johanna M SalonenMauno Vihinen
Jul 5, 2005·The Journal of Biological Chemistry·Ramesh M RayLeonard R Johnson
Jul 11, 2000·Seminars in Cancer Biology·R G SchipperA A Verhofstad
May 2, 2000·Critical Reviews in Oncology/hematology·K KrishnanD E Brenner

❮ Previous
Next ❯

Related Concepts

Related Feeds

Apoptosis

Apoptosis is a specific process that leads to programmed cell death through the activation of an evolutionary conserved intracellular pathway leading to pathognomic cellular changes distinct from cellular necrosis