Transgenic mice expressing proteins altering polyamine levels in a tissue-specific manner have considerable promise for evaluation of the roles of polyamines in normal, hypertrophic and neoplastic growth. This short review summarizes the available transgenic models. Mice with large increases in ornithine decarboxylase (ODC), S-adenosylmethionine decarboxylase or antizyme, a protein regulating p...

Polyamines are downstream mediators of genetic risk factors in human intestinal cancers. The adenomatous polyposis coli (APC) tumour-suppressor gene, which is mutated in essentially all human colon cancers, regulates the expression of several e-box transcription factors. These factors, in turn, regulate the transcription of ornithine decarboxylase (ODC), the first enzyme in polyamine synthesis....

OBJECTIVES Spermidine/spermine-N1-acetytransferase (SSAT) is the key enzyme in the catabolism of polyamines that are involved in regulating NMDA functioning. Over expression of SSAT leads to abnormal metabolic cycling and may disrupt NMDA receptor signaling. In fact, the HIV protein Tat induces neurotoxicity involving polyamine/NMDA receptor interactions. Thus, we investigated abnormal polyamin...

DFMO is an irreversible inhibitor of ornithine decarboxylase (ODC), the key enzyme in mammalian polyamine biosynthesis. The goal of this study was to determine the effects of DFMO 0.5 gIm2/day as a single oral dose on polyamine and ODC levels in rectal, rectosigmoidal, and cecal colonic mucosae of individuals at risk for colon cancer because of a personal history of adenomatous polyps of the co...

The innate immune system functions as a defensive front line against pathogenic invasion, but the proinflammatory products of activated monocytes and macrophages (e.g., TNF and NO) can also injure normal cells. Anti-inflammatory mediators restrain the innate immune response and prevent excessive collateral tissue damage. Spermine, a ubiquitous biogenic polyamine, specifically and reversibly sup...

mine (spm), present in mammalian tissues, are regulated under a variety of physiological conditions. Their tissue concentrations are controlled by a number of factors: (1) polyamine biosynthetic enzymes, such as ornithine decarboxylase (ODC), S-adenosyl-L-methionine decarboxylase (AdoMetDC), spermidine synthase (spd-syn) and spermine synthase (spm-syn); (2) polyamine catabolic enzymes, such as ...

In uitro poly(U)-directed polyphenylalanine synthesis, catalyzed by a cell-free extract of an extreme thermophile, Thermus thermophilus, at 65”C, required the presence of a polyamine such as spermine (1). To study the implications of polyamines in protein synthesis in uiuo, the polyamine composition in the cells of the thermophile was investigated. Two polyamines were extracted as major polyami...

Previous reports have shown elevated arginase activity in prostate cancer patients. This study was designed to compare expression levels of arginase II (AII) in various human prostate cancer cell lines and tissues. Expression levels of AII and other enzymes involved in arginine metabolism were examined in androgen-dependent (LNCaP, LAPC-4) and androgen-independent (PC3, DU145, CL-1, CL-2) prost...

The polyamines putrescine, spermidine, and spermine and ornithine decarboxylase (ODC), the rate-limiting enzyme in their biosynthetic pathway, play an important role in cell proliferation, differentiation, and transformation. In the present study, we have analyzed polyamine concentrations and ODC activity in samples from benign breast diseases (n = 36), benign breast tissue adjacent to the prim...

The 5-methylthioadenosine (MTA) or Yang cycle is a set of reactions that recycle MTA to Met. In plants, MTA is a byproduct of polyamine, ethylene, and nicotianamine biosynthesis. Vascular transcriptome analyses revealed phloem-specific expression of the Yang cycle gene 5-METHYLTHIORIBOSE KINASE1 (MTK1) in Plantago major and Arabidopsis thaliana. As Arabidopsis has only a single MTK gene, we hyp...