Treatment of cells with the polyamine analog N¹,N¹¹‐diethylnorspermine retards S phase progression within one cell cycle

Abstract

When Chinese hamster ovary cells were seeded in the presence of the spermine analog N 1 ,N 11 -diethylnorspermine (DENSPM), cell proliferation ceased; this was clearly apparent by cell counting 2 days after seeding the cells. However, 1 day after seeding there was a slight difference in cell number between control and DENSPM-treated cultures. To investigate the reason for this easily surpassed slight difference, we used a sensitive bromodeoxyuridine/flow cytometry method. Cell cycle kinetics were studied during the first cell cycle after seeding cells in the absence or presence of DENSPM. Our results show that DENSPM treatment did not affect the progression of the cells through G 1 or the first G 1 /S transition that took place after seeding the cells. The first cell cycle effect was a delay in S phase as shown by an increase in the DNA synthesis time. The following G 2 /M transition was not affected by DENSPM treatment. DENSPM treatment inhibited the transient increases in putrescine, spermidine, and spermine pools that took place within 24 h after seeding. Thus, in conclusion, the first cell cycle phase affected by the inhibition of polyamine biosynthesis caused by DENSPM was the S phase. Prolongation of the other cell cycle phases occurred at later time points, and the G 1 phase was affected before the G 2 /M phase.Keywords: bromodeoxyuridine; cell cycle; polyamines; polyamine analog; S phase.The cationic polyamines, putrescine, spermidine and spermine, are constitutive intracellular components. They are synthesized in well-regulated biochemical reactions. Studies using different polyamine biosynthesis inhibitors and analogs have shown that polyamines are necessary for normal cell growth and development [1±4]. Polyamine-deficient cells cease to proliferate. In general, the inhibition of cell proliferation is not apparent as a decrease in cell number until after one or two cell cycles. Thus, many studies trying to elucidate the role of polyamines in cell proliferation using inhibitors have been performed only after an apparent difference in cell number between control and inhibitor treated cells has been found. However, using a sensitive method to investigate cell cycle kinetics, we have found that cell cycle progression is perturbed in polyaminedeficient cells before there is an obvious decrease in cell number. The cause of this is that mammalian cells have long cell cycle times and, although the cell cycle phase distribution may be the same in percentage, the actual distribution of cells in the various cell cycle phases may be quite different.As Kramer et al.[5] reports, the requirements for polyamines in cell cycle progression have been investigated in a number of studies and variable results have been obtained: effects on the G 1 /S transition [6±11], the S and/or the G 2 phase [12±16], and all cell cycle phases [17]. A number of causes for the variability are mentioned, e.g. difference in cell type being studied, the enzyme being inhibited, and/or the specific inhibitor being used. Another important facto...

Absolute requirement of spermidine for growth and cell cycle progression of fission yeast ( Schizosaccharomyces pombe )

“…These studies are consistent with several studies in mammalian cells in which changes in the cell cycle progression were noted after treatment of the cells with inhibitors of either ornithine decarboxylase or of S-adenosylmethionine decarboxylase (17,18) or by overexpression of antizyme or antisense inhibition of ornithine decarboxylase (19).…”

Polyamines in cell growth and cell death: molecular mechanisms and therapeutic applications

“…Polyamine-depleted cells are stimulated to grow in the presence of exogenous polyamines [6][7][8]. Polyamines have specific roles in embryonic development [9], cell cycle [10,11], cancer [12,13], neurochemistry [14], as well as pulmonary [15] and immune system functions [16,17]. Cellular polyamines are regulated by a complex circuitry of synthesis, degradation, as well as cellular uptake and efflux [3][4][5]18].…”

Induction of Hypersensitive Cell Death by Hydrogen Peroxide Produced through Polyamine Degradation in Tobacco Plants

“…In animal cells, polyamines are considered to have specific roles in embryonic development (Kusunoki and Yasumasu, 1978), in control of the cell cycle (Alm et al, 2000), in carcinogenesis (Seiler et al, 1998), and in immune system functions (Seiler and Atanassov, 1994). A recent study also suggested polyamines to be linked with cell proliferation and likely with apoptosis as well (Thomas and Thomas, 2001).…”