scholarly journals Investigations of the mechanism by which mammalian cell growth is inhibited by N1N12-bis(ethyl)spermine

1993 ◽  
Vol 291 (1) ◽  
pp. 131-137 ◽  
Author(s):  
L Albanese ◽  
R J Bergeron ◽  
A E Pegg

N1N12-Bis(ethyl)spermine (BESM) and related compounds are powerful inhibitors of cell growth that may have potential as anti-neoplastic agents [Bergeron, Neims, McManis, Hawthorne, Vinson, Bortell and Ingeno (1988) J. Med. Chem. 31, 1183-1190]. The mechanism by which these compounds bring about their effects was investigated by using variant cell lines in which processes thought to be altered by these agents are perturbed. Comparisons between the response of these cells and of their parental equivalents to BESM, N1N11-bis(ethyl)norspermine, N1N14-bis(ethyl)homospermine and N1N8-bis(ethyl)spermidine were then made. It was found that D-R cells, an L1210-derived line that over-expresses ornithine decarboxylase, were not resistant to these compounds. This indicates that the decrease in ornithine decarboxylase is not critical for the action of the compounds on cell growth. Furthermore, although polyamine levels were decreased in the D-R cells, the content was not totally depleted, indicating that such depletion is also not essential for the anti-proliferative effect. Two cell lines lacking mitochondrial DNA (human 143B206 cells and chicken DU3 cells) did not differ in sensitivity to BESM from their parental 143BTK- and DU24 cells. Furthermore, the inhibition of respiration in L1210 cells in response to BESM developed more slowly than the inhibition of growth. Thus it appears that the inhibitions of mitochondrial DNA synthesis and of mitochondrial respiration are also not primary factors in the anti-proliferative effects of these polyamine analogues. The inhibition of growth did, however, correlate with the intracellular accumulation of the analogues. It appears that the bis(ethyl)polyamine derivatives act by binding to intracellular target molecules and preventing macromolecular synthesis. The decline in normal polyamines may facilitate such binding, but is not essential for growth arrest.

2002 ◽  
Vol 366 (2) ◽  
pp. 663-671 ◽  
Author(s):  
John L.A. MITCHELL ◽  
Aviva LEYSER ◽  
Michelle S. HOLTORFF ◽  
Jill S. BATES ◽  
Benjamin FRYDMAN ◽  
...  

The polyamines spermidine and spermine and their diamine precursor putrescine are essential for mammalian cell growth and viability, and strategies are sought for reducing polyamine levels in order to inhibit cancer growth. Several structural analogues of the polyamines have been found to decrease natural polyamine levels and inhibit cell growth, probably by stimulating normal feedback mechanisms. In the present study, a large selection of spermine analogues has been tested for their effectiveness in inducing the production of antizyme, a key protein in feedback inhibition of putrescine synthesis and cellular polyamine uptake. Bisethylnorspermine, bisethylhomospermine, 1,19-bis-(ethylamino)-5,10,15-triazanonadecane, longer oligoamine constructs and many conformationally constrained analogues of these compounds were found to stimulate antizyme synthesis to different levels in rat liver HTC cells, with some producing far more antizyme than the natural polyamine spermine. Uptake of the tested compounds was found to be dependent on, and limited by, the polyamine transport system, for which all these have approximately equal affinity. These analogues differed in their ability to inhibit HTC cell growth during 3days of exposure, and this ability correlated with their antizyme-inducing potential. This is the first direct evidence that antizyme is induced by several polyamine analogues. Selection of analogues with this potential may be an effective strategy for maximizing polyamine deprivation and growth inhibition.


2003 ◽  
Vol 31 (2) ◽  
pp. 375-380 ◽  
Author(s):  
R.G. Schipper ◽  
J.C. Romijn ◽  
V.M.J.I. Cuijpers ◽  
A.A.J. Verhofstad

The importance of polyamines in prostatic growth and differentiation has prompted studies to evaluate the clinical relevance of the ornithine decarboxylase/polyamine system in prostatic cancer. These studies show that differences in biological behaviour of prostatic (cancer) cells are associated with changes in polyamine levels and/or the activity of their metabolic enzymes. Faulty antizyme regulation of polyamine homoeostasis may play an important role in the growth and progression of prostatic carcinoma. Treatment of human prostate carcinoma cells with inhibitors of polyamine metabolic enzymes or polyamine analogues induces cell growth arrest or (apoptotic) cell death. Our recent in vitro studies using conformationally restricted polyamine analogues show that these compounds inhibit cell growth, probably by inducing antizyme-mediated degradation of ornithine decarboxylase. Sensitivity of human prostate cancer cells for these compounds was increased in the absence of androgens. These results suggest that these analogues might have chemotherapeutic potential in case prostatic cancer has become androgen-independent. Pilot data in an in vivo model show that these analogues have effects on tumour cell proliferation, vascularity, blood perfusion and tissue hypoxia. Overall, these studies show that polyamines may serve as important biomarkers of prostatic malignancy and provide a promising target for chemotherapy of prostatic cancer.


1981 ◽  
Vol 194 (1) ◽  
pp. 79-89 ◽  
Author(s):  
Anthony E. Pegg ◽  
Ronald T. Borchardt ◽  
James K. Coward

1. A number of compounds known to inhibit polyamine biosynthesis at various steps in the biosynthetic pathway were tested for their ability to inhibit growth and decrease polyamine concentrations in virally transformed mouse fibroblasts (SV-3T3 cells). 2. Virtually complete inhibition of growth was produced by the inhibitors of ornithine decarboxylase α-methylornithine and α-difluoromethylornithine and by the inhibitors of S-adenosylmethionine decarboxylase 1,1′-[(methylethanediylidene)dinitrilo]diguanidine and 1,1′-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine). The former inhibitors decreased putrescine and spermidine contents in the cells to very low values, whereas the latter substantially increased putrescine but decreased spermidine concentrations. The inhibitory effects of all of these inhibitors on cell growth could be prevented by the addition of spermidine, suggesting that spermidine depletion is the underlying cause of their inhibition of growth. 3. α-Difluoromethylornithine, which is an irreversible inhibitor of ornithine decarboxylase, was a more potent inhibitor of growth and polyamine production (depleting spermidine almost completely and spermine significantly) than α-methylornithine, which is a competitive inhibitor. This was not the case with the inhibitors of S-adenosylmethionine decarboxylase where 1,1′-[(methylethanediylidene)dinitrilo]diguanidine, a reversible inhibitor, was more active than 1,1′-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine), an irreversible inhibitor. It is suggested that this effect may be due to the lesser uptake and/or greater chemical reactivity of the latter compound. 4. Various nucleoside derivatives of S-adenosylhomocysteine that inhibited spermidine synthase in vitro did not have significant inhibitory action against polyamine accumulation in the cell. These compounds, which included S-adenosylhomocysteine sulphone, decarboxylated S-adenosylhomocysteine sulphone, decarboxylated S-adenosylhomocysteine sulphoxide and S-adenosyl-4-thio-butyric acid sulphone did not inhibit cell growth or polyamine content until cytotoxic concentrations were added. 5. 5′-Methylthioadenosine, 5′-isobutylthioadenosine and 5′-methylthiotubercidin, which inhibit aminopropyltransferase activity in vitro, all inhibited cell growth and decreased spermidine content. Although these compounds were most active against spermine synthase in vitro, they acted in the cell primarily to decrease spermidine content. Cell growth could not be restored to normal values by addition of spermidine, suggesting that these nucleosides have another inhibitory action towards cellular proliferation. 6. 5′-Methylthioadenosine and 5′-isobutylthioadenosine are degraded by a phosphorylase present in SV3T3 cells, yielding 5-methylthioribose-1-phosphate and 5-isobutylthioribose-1-phosphate respectively, and adenine. This degradation appears to decrease the inhibitory action towards cell growth, suggesting that the nucleosides themselves are exerting the inhibitory action. 5′-Methylthiotubercidin, which is not a substrate for the phosphorylase and is a competitive inhibitor of it, was the most active of these nucleosides in inhibiting cell growth and spermidine content. 5′-Methylthiotubercidin and α-difluoromethylornithine had additive effects on retarding cell growth, but not on cellular spermine accumulation, also suggesting that the primary growth-inhibiting action of the nucleoside was not on polyamine production. 7. These results support the concept that 5′-methylthioadenosine phosphorylase plays an important role in permitting cell growth to continue by preventing the build-up of inhibitory intracellular concentrations of 5′-methylthioadenosine.


1996 ◽  
Vol 320 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Margaret E TOME ◽  
Eugene W GERNER

Selection of HTC cells in drugs that inhibit ornithine decarboxylase (ODC) has produced two cell lines, HMOA and DH23A/b, that contain increased amounts of more stable ODC. In addition to alterations in ODC, these cells appear to produce modified eukaryotic initiation factor 5A (eIF-5A) at different rates, a reaction that both requires spermidine and is essential for proliferation. Alterations to the modification of eIF-5A by spermidine cannot be accounted for by changes in eIF-5A protein or modified eIF-5A turnover. Deoxyhypusine synthetase activity is similar in the parental and variant cell lines and is unaltered by growth into plateau phase or by spermidine depletion. The increased rate of eIF-5A modification in DH23A/b cells is due to an increased accumulation of the unmodified eIF-5A precursor. Increased precursor accumulation is not due to increased eIF-5A transcription, but rather it can be attributed to a metabolic accumulation caused by growth under conditions of chronically limiting spermidine. Selection using drugs that inhibit ODC apparently does not cause alterations in the eIF-5A modification pathway. These data support the hypothesis that one of the main effects of spermidine depletion is depletion of the modified eIF-5A pool, and that this is a critical factor in the cytostasis often observed after depletion of cellular polyamines.


NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050098
Author(s):  
Mustansir Bhori ◽  
Kanchanlata Tungare ◽  
Yasar Arfat Kasu ◽  
Mukeshchand Thakur

Highly-dispersed graphene nanodots (GNDs) up to 10[Formula: see text]nm are synthesized using D-galactose as a carbon precursor. The GNDs are self-passivized, emit dual-color excitation-dependent emission and highly biocompatible in cell lines. Their applicability is demonstarted for cellular bioimaging and Raman mapping of cells. Furthermore, their implications on mammalian cell growth and plant seed germination are expounded.


1987 ◽  
Vol 242 (2) ◽  
pp. 433-440 ◽  
Author(s):  
C W Porter ◽  
F G Berger ◽  
A E Pegg ◽  
B Ganis ◽  
R J Bergeron

Polyamine biosynthesis in intact cells can be exquisitely controlled with exogenous polyamines through the regulation of rate-limiting biosynthetic enzymes, particularly ornithine decarboxylase (ODC). In an attempt to exploit this phenomenon as an antiproliferative strategy, certain polyamine analogues have been identified [Porter, Cavanaugh, Stolowich, Ganis, Kelly & Bergeron (1985) Cancer Res. 45, 2050-2057] which lower ODC activity in intact cells, have no direct inhibitory effects on ODC, are incapable of substituting for spermidine (SPD) in supporting cell growth, and are growth-inhibitory at micromolar concentrations. In the present study, the most effective of these analogues, N1N8-bis(ethyl)SPD (BES), is compared with SPD in its ability to regulate ODC activity in intact L1210 cells and in the mechanism(s) by which this is accomplished. With respect to time and dose-dependence of ODC suppression, both polyamines closely paralleled one another in their response curves, although BES was slightly less effective than SPD. Conditions of minimal treatment leading to near-maximal ODC suppression (70-80%) were determined and found to be 3 microM for 2 h with either SPD or BES. After such treatment, ODC activity was fully recovered within 2-4 h when cells were re-seeded in drug-free media. By assessing BES or [3H]SPD concentrations in treated and recovered cells, it was possible to deduce that an intracellular accumulation of BES or SPD equivalent to less than 6.5% of the combined cellular polyamine pool was sufficient to invoke ODC regulatory mechanisms. Decreases in ODC activity after BES or SPD treatment were closely paralleled by concomitant decreases in ODC protein. Since cellular ODC mRNA was not similarly decreased by either BES or SPD, it was concluded that translational and/or post-translational mechanisms, such as increased degradation of ODC protein or decreased translation of ODC mRNA, were probably responsible for regulation of enzyme activity. Experimental evidence indicated that neither of these mechanisms seemed to be mediated by cyclic AMP or ODC-antizyme induction. On the basis of the consistent similarities between BES and SPD in all parameters studied, it is concluded that the analogue most probably acts by the same mechanisms as SPD in regulating polyamine biosynthesis.


2019 ◽  
Vol 8 ◽  
Author(s):  
Masoumeh Abedi Nejad ◽  
Mohsen Nikbakht ◽  
Masoomeh Afsa ◽  
Kianoosh Malekzadeh

Background: Acute lymphoblastic leukemia (ALL) is a highly prevalent pediatric cancer accounting for approximately 78% of leukemia cases in patients younger than 15 years old. Different studies have demonstrated that B-cell translocation gene 3 (BTG3) plays a suppressive role in the progress of different cancers. Genistein is considered a natural and biocompatible compound and a new anti-cancer agent. In this study, we evaluate the effect of genistein on BTG3 expression and proliferation of ALL cancer cells. Materials and Methods: ALL cell lines (MOLT4, MOLT17, and JURKAT) were cultured in standard conditions. Cytotoxicity of genistein was detected using MTT assay. The cells were treated with different concentrations of genistein (10, 25, 40, and 55μM) for 24, 48, and 72 hours, and then cell viability and growth rate were measured. The quantitative real-time polymerase chain reaction was applied to investigate the effect of genistein on BTG3 expression. Results: The percentage of vital cells treated with genistein significantly decreased compared to the non-treated cells, showed an inverse relationship with an increasing genistein concentration. The present study suggests a dose of 40μM for genistein as a potent anticancer effect. Genistein could elevate BTG3 for 1.7 folds in MOLT4 and JURKAT and 2.7 folds in MOLT17 cell lines at transcription level conveged with 60 to 90% reduction in the proliferation rate of cancer cells. Conclusion: Up-regulation of BTG3 as a tumor suppressor gene can be induced by genistein. It seems that BTG3 reactivation can be introduced as another mechanism of anti-proliferative effect of genistein and could be considered as a retardant agent candidate against hematopoietic malignancy.[GMJ. 2019;inpress:e1229]


1993 ◽  
Vol 21 (2) ◽  
pp. 206-209
Author(s):  
Anders H. G. Andrén ◽  
Anders P. Wieslander

Cytotoxicity, measured as inhibition of cell growth of cultured cell lines, is a widely used method for testing the safety of biomaterials and chemicals. One major technical disadvantage with this method is the continuous routine maintenance of the cell lines. We decided to investigate the possibility of storing stock cultures of fibroblasts (L-929) in an ordinary refrigerator as a means of reducing the routine workload. Stock cultures of the mouse fibroblast cell line L-929 were prepared in plastic vials with Eagle's minimum essential medium. The vials were stored in a refrigerator at 4–10°C for periods of 7–31 days. The condition of the cells after storage was determined as cell viability, cell growth and the toxic response to acrylamide, measured as cell growth inhibition. We found that the L-929 cell line can be stored for 2–3, weeks with a viabilty > 90% and a cell growth of about 95%, compared to L-929 cells grown and subcultured in the normal manner. The results also show that the toxic response to acrylamide, using refrigerator stored L-929 cells, corresponds to that of control L-929 cells. We concluded that it is possible to store L-929 cells in a refrigerator for periods of up to 3 weeks and still use the cells for in vitro cytotoxic assays.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Wang ◽  
Zhiwei He ◽  
Jian Xu ◽  
Peng Chen ◽  
Jianxin Jiang

AbstractAn accumulation of evidence indicates that long noncoding RNAs are involved in the tumorigenesis and progression of pancreatic cancer (PC). In this study, we investigated the functions and molecular mechanism of action of LINC00941 in PC. Quantitative PCR was used to examine the expression of LINC00941 and miR-335-5p in PC tissues and cell lines, and to investigate the correlation between LINC00941 expression and clinicopathological features. Plasmid vectors or lentiviruses were used to manipulate the expression of LINC00941, miR-335-5p, and ROCK1 in PC cell lines. Gain or loss-of-function assays and mechanistic assays were employed to verify the roles of LINC00941, miR-335-5p, and ROCK1 in PC cell growth and metastasis, both in vivo and in vitro. LINC00941 and ROCK1 were found to be highly expressed in PC, while miR-335-5p exhibited low expression. High LINC00941 expression was strongly associated with larger tumor size, lymph node metastasis, and poor prognosis. Functional experiments revealed that LINC00941 silencing significantly suppressed PC cell growth, metastasis and epithelial–mesenchymal transition. LINC00941 functioned as a molecular sponge for miR-335-5p, and a competitive endogenous RNA (ceRNA) for ROCK1, promoting ROCK1 upregulation, and LIMK1/Cofilin-1 pathway activation. Our observations lead us to conclude that LINC00941 functions as an oncogene in PC progression, behaving as a ceRNA for miR-335-5p binding. LINC00941 may therefore have potential utility as a diagnostic and treatment target in this disease.


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