Regulation of ornithine decarboxylase during oncogenic transformation: mechanisms and therapeutic potential.
The activity of ornithine decarboxylase (ODC(1)), the first enzyme in polyamine biosynthesis, is induced during carcinogenesis by a variety of oncogenic stimuli. Intracellular levels of ODC and the polyamines are tightly controlled during normal cell growth, and regulation occurs at the levels of transcription, translation and protein degradation. Several known proto-oncogenic pathways appear to control ODC transcription and translation, and dysregulation of pathways downstream of ras and myc result in the constitutive elevation of ODC activity that occurs with oncogenesis. Inhibition of ODC activity reverts the transformation of cells in vitro and reduces tumor growth in several animal models, suggesting high levels of ODC are necessary for the maintenance of the transformed phenotype. The ODC irreversible inactivator DFMO has proven to be not only a valuable tool in the study of ODC in cancer, but also shows promise as a chemopreventive and chemotherapeutic agent in certain types of malignancies.
Shantz
L M
LM
Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA. lms17@psu.edu
Levin
V A
VA
D012437:Adenosylmethionine Decarboxylase / Q000037:antagonists & inhibitors; D000818:Animals; D030801:Animals, Genetically Modified; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000378:metabolism*; D004359:Drug Therapy, Combination; D000518:Eflornithine / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000502:physiology; D009955:Ornithine Decarboxylase / Q000096:biosynthesis / Q000378:metabolism*; D065108:Ornithine Decarboxylase Inhibitors; D011506:Proteins / Q000494:pharmacology; D012878:Skin Neoplasms / Q000209:etiology
D065108:Ornithine Decarboxylase Inhibitors; D011506:Proteins; C031017:ornithine decarboxylase antizyme; D020930:MAP Kinase Kinase Kinases; D009955:Ornithine Decarboxylase; D012437:Adenosylmethionine Decarboxylase; D000518:Eflornithine