10 results on '"Holst CM"'
Search Results
2. Bowhead NEIL1: molecular cloning, characterization, and enzymatic properties.
- Author
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Holm S, Larsen RM, Holst CM, Heide-Jørgensen MP, Steffensen JF, Stevnsner T, and Larsen K
- Subjects
- Animals, Humans, Escherichia coli genetics, Escherichia coli metabolism, DNA Repair, Cloning, Molecular, DNA, RNA, Messenger, Deoxyribonuclease (Pyrimidine Dimer) genetics, Deoxyribonuclease (Pyrimidine Dimer) metabolism, Bowhead Whale genetics, Bowhead Whale metabolism, DNA Glycosylases genetics, DNA Glycosylases chemistry, DNA Glycosylases metabolism, Lyases metabolism, Escherichia coli Proteins genetics
- Abstract
Nei Like DNA Glycosylase 1 (NEIL1) is a DNA glycosylase, which specifically processes oxidative DNA damage by initiating base excision repair. NEIL1 recognizes and removes bases, primarily oxidized pyrimidines, which have been damaged by endogenous oxidation or exogenous mutagenic agents. NEIL1 functions through a combined glycosylase/AP (apurinic/apyrimidinic)-lyase activity, whereby it cleaves the N-glycosylic bond between the DNA backbone and the damaged base via its glycosylase activity and hydrolysis of the DNA backbone through beta-delta elimination due to its AP-lyase activity. In our study we investigated our hypothesis proposing that the cancer resistance of the bowhead whale can be associated with a better DNA repair with NEIL1 being upregulated or more active. Here, we report the molecular cloning and characterization of three transcript variants of bowhead whale NEIL1 of which two were homologous to human transcripts. In addition, a novel NEIL1 transcript variant was found. A differential expression of NEIL mRNA was detected in bowhead eye, liver, kidney, and muscle. The A-to-I editing of NEIL1 mRNA was shown to be conserved in the bowhead and two adenosines in the 242Lys codon were subjected to editing. A mass spectroscopy analysis of liver and eye tissue failed to demonstrate the existence of a NEIL1 isoform originating from RNA editing. Recombinant bowhead and human NEIL1 were expressed in E. coli and assayed for enzymatic activity. Both bowhead and human recombinant NEIL1 catalyzed, with similar efficiency, the removal of a 5-hydroxyuracil lesion in a DNA bubble structure. Hence, these results do not support our hypothesis but do not refute the hypothesis either., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.) more...
- Published
- 2023
- Full Text
- View/download PDF
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3. Molecular markers of DNA repair and brain metabolism correlate with cognition in centenarians.
- Author
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Sanchez-Roman I, Ferrando B, Holst CM, Mengel-From J, Rasmussen SH, Thinggaard M, Bohr VA, Christensen K, and Stevnsner T
- Subjects
- Aged, 80 and over, Brain metabolism, Cognition, DNA Repair, Humans, Male, Centenarians, Leukocytes, Mononuclear
- Abstract
Oxidative stress is an important factor in age-associated neurodegeneration. Accordingly, mitochondrial dysfunction and genomic instability have been considered as key hallmarks of aging and have important roles in age-associated cognitive decline and neurodegenerative disorders. In order to evaluate whether maintenance of cognitive abilities at very old age is associated with key hallmarks of aging, we measured mitochondrial bioenergetics, mitochondrial DNA copy number and DNA repair capacity in peripheral blood mononuclear cells from centenarians in a Danish 1915 birth cohort (n = 120). Also, the circulating levels of brain-derived neurotrophic factor, NAD
+ /NADH and carbonylated proteins were measured in plasma of the centenarians and correlated to cognitive capacity. Mitochondrial respiration was well preserved in the centenarian cohort when compared to young individuals (21-35 years of age, n = 33). When correlating cognitive performance of the centenarians with mitochondrial function such as basal respiration, ATP production, reserve capacity and maximal respiration, no overall correlations were observed, but when stratifying by sex, inverse associations were observed in the males (p < 0.05). Centenarians with the most severe cognitive impairment displayed the lowest activity of the central DNA repair enzyme, APE1 (p < 0.05). A positive correlation between cognitive capacity and levels of NAD+ /NADH was observed (p < 0.05), which may be because NAD+ /NADH consuming enzyme activities strive to reduce the oxidative DNA damage load. Also, circulating protein carbonylation was lowest in centenarians with highest cognitive capacity (p < 0.05). An opposite trend was observed for levels of brain-derived neurotrophic factor (p = 0.17). Our results suggest that maintenance of cognitive capacity at very old age may be associated with cellular mechanisms related to oxidative stress and DNA metabolism., (© 2021. The Author(s), under exclusive licence to American Aging Association.) more...- Published
- 2022
- Full Text
- View/download PDF
4. Apoptosis induced by the potential chemotherapeutic drug N1, N11-Diethylnorspermine in a neuroblastoma cell line.
- Author
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Söderstjerna E, Holst CM, Alm K, and Oredsson SM
- Subjects
- Acetyltransferases antagonists & inhibitors, Acetyltransferases metabolism, Caspase 3 metabolism, Cell Line, Tumor, Cell Proliferation drug effects, Child, Culture Media, Dose-Response Relationship, Drug, Humans, Inhibitor of Apoptosis Proteins, Microtubule-Associated Proteins metabolism, Neuroblastoma metabolism, Neuroblastoma pathology, Ornithine Decarboxylase metabolism, Ornithine Decarboxylase Inhibitors, Spermine pharmacology, Survivin, Antineoplastic Agents pharmacology, Apoptosis drug effects, Neuroblastoma therapy, Spermine analogs & derivatives
- Abstract
Neuroblastoma is a highly malignant neoplasm found in young children. Although children with high-risk neuroblastoma respond to chemotherapy, relapses are common. On account of poor treatment outcome, new treatment strategies are constantly sought for neuroblastoma. Polyamine analogues are potentially novel substances for treatment of neuroblastoma. In this study, we have treated two neuroblastoma cell lines, SH-SY5Y and LA-N-1, with the spermine analogue N1, N11-Diethylnorspermine (DENSPM). SH-SY5Y was the most sensitive cell line, in which DENSPM treatment resulted in an inhibition of cell proliferation and an induction of cell death. The cell death induced by DENSPM treatment was apoptotic, as evidenced by cleavage of procaspase 3 and induction of caspase-3 activity. In contrast, DENSPM treatment only resulted in a slight inhibition of cell proliferation in LA-N-1 cells. There were several possible causes for the lower sensitivity to DENSPM treatment in the latter cell line when compared with SH-SY5Y cells. DENSPM-induced polyamine depletion was more extensive in SH-SY5Y cells than in LA-N-1 cells. This was partly because of a higher induction of the polyamine catabolic enzyme spermidine/spermine N1-acetyltransferase in the cell line SH-SY5Y. The DENSPM-induced polyamine depletion was also caused by the inhibition of ornithine decarboxylase. LA-N-1 cells contained a higher level of the prosurvival protein survivin, which was further increased after DENSPM treatment. In contrast, DENSPM treatment resulted in a decreased survivin level in SH-SY5Y cells. more...
- Published
- 2010
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5. Molecular mechanisms underlying N1, N11-diethylnorspermine-induced apoptosis in a human breast cancer cell line.
- Author
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Holst CM, Staaf J, Jönsson G, Hegardt C, and Oredsson SM
- Subjects
- Apoptosis drug effects, Caspase 3 metabolism, Cell Line, Tumor, Cytochromes c metabolism, Humans, Membrane Potential, Mitochondrial, Mitochondria metabolism, Spermine pharmacology, Antineoplastic Agents pharmacology, Breast Neoplasms drug therapy, Spermine analogs & derivatives
- Abstract
Polyamine analogue treatment results in growth inhibition and sometimes in cell death. Therefore, polyamine analogues are considered in the treatment of cancer; however, the cellular properties that govern sensitivity are not known. The objective of this study was to elucidate molecular mechanisms behind apoptosis induced by the polyamine analogue N, N-diethylnorspermine (DENSPM). Four different breast cancer cell lines were treated with DENSPM. Cell death was evaluated with flow cytometry and a caspase 3 assay. The levels of a number of proapoptotic and antiapoptotic proteins in subcellular compartments were evaluated with western blot. In the most sensitive cell line, DENSPM treatment induced the release of cytochrome c from mitochondria, resulting in activation of caspase 3 but without decreasing the mitochondrial transmembrane potential. However, in the three other cell lines DENSPM treatment did not induce extensive cell death. This is partly explained by the high levels of antiapoptotic proteins Bcl-2 and Bad and low levels of proapoptotic proteins Bax and procaspase 3 in these three cell lines. The results are also partly explained by the degree of activation of the catabolic enzyme spermidine/spermine-N-acetyltransferase and polyamine pool reduction achieved by DENSPM treatment. Our results show that the protein profile of proapoptotic and antiapoptotic proteins may contribute to the outcome to treatment with the polyamine analogue DENSPM. The results also indicate that it should be possible to find molecular markers for sensitivity to DENSPM that could be used in the clinic to predict sensitivity to a polyamine analogue. more...
- Published
- 2008
- Full Text
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6. Novel anti-apoptotic effect of Bcl-2: prevention of polyamine depletion-induced cell death.
- Author
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Holst CM, Johansson VM, Alm K, and Oredsson SM
- Subjects
- Acetyltransferases metabolism, Apoptosis Inducing Factor metabolism, Apoptosis Regulatory Proteins metabolism, Caspase 3 metabolism, Cell Line, Tumor, Cytochromes c metabolism, Gene Expression Regulation, Neoplastic, Humans, Inhibitor of Apoptosis Proteins, Intracellular Signaling Peptides and Proteins metabolism, Microtubule-Associated Proteins metabolism, Mitochondrial Proteins metabolism, Neoplasm Proteins metabolism, Polyamines metabolism, Proto-Oncogene Proteins c-bcl-2 biosynthesis, Spermine pharmacology, Survivin, Transfection, bcl-2-Associated X Protein metabolism, Apoptosis drug effects, Breast Neoplasms metabolism, Proto-Oncogene Proteins c-bcl-2 physiology, Spermine analogs & derivatives
- Abstract
The spermine analogue N(1),N(11)-diethylnorspermine (DENSPM) efficiently depletes the polyamine pools in the breast cancer cell line L56Br-C1 and induces apoptotic cell death via the mitochondrial pathway. In this study, we have over-expressed the anti-apoptotic protein Bcl-2 in L56Br-C1 cells and investigated the effect of DENSPM treatment. DENSPM-induced cell death was significantly reduced in Bcl-2 over-expressing cells. Bcl-2 over-expression reduced DENSPM-induced release of the pro-apoptotic proteins AIF, cytochrome c, and Smac/DIABLO from the mitochondria. Bcl-2 over-expression reduced the DENSPM-induced activation of caspase-3. Bcl-2 over-expression also prevented DENSPM-induced Bax cleavage and reduction of Bcl-X(L) and survivin levels. The DENSPM-induced activation of the polyamine catabolic enzyme spermidine/spermine N(1)-acetyltransferase was reduced by Bcl-2 over-expression, partly preventing polyamine depletion. Thus, Bcl-2 over-expression prevented a number of DENSPM-induced apoptotic effects. more...
- Published
- 2008
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7. Subcellular distribution of spermidine/spermine N1-acetyltransferase.
- Author
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Holst CM, Nevsten P, Johansson F, Carlemalm E, and Oredsson SM
- Subjects
- Apoptosis drug effects, Cell Fractionation, Cell Line, Tumor, Cell Nucleus enzymology, Cytoplasm enzymology, Humans, Immunohistochemistry, Microscopy, Electron, Scanning, Microscopy, Electron, Transmission, Mitochondria enzymology, Spermine analogs & derivatives, Spermine pharmacology, Acetyltransferases metabolism
- Abstract
The subcellular distribution of the polyamine catabolic enzyme spermidine/spermine N(1)-acetyltransferase (SSAT) was studied in L56Br-C1 cells treated with 10 microM N(1),N(11)-diethylnorspermine (DENSPM) for 24 h. Cells were fractioned into three subcellular fractions. A particulate fraction containing the mitochondria was denoted as the mitochondrial fraction. After DENSPM treatment, an increase in SSAT activity was mainly found in the mitochondrial fraction. Western blot analysis showed an increased level of the SSAT protein in the mitochondrial fraction compared to the cytosolic fraction. Immunofluorescence microscopy and immunogold labeling transmission electron microscopy also showed a mitochondrial association of SSAT. Transmission electron microscopy revealed that the endoplasmic reticulum was devoid of ribosomes in DENSPM-treated cells, in contrast to control cells that contained ample ribosomes. An increased SSAT activity in connection with the mitochondria may be part of the mechanism of DENSPM-induced apoptosis. more...
- Published
- 2008
- Full Text
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8. Inhibition of cell proliferation and induction of apoptosis by N(1),N(11)-diethylnorspermine-induced polyamine pool reduction.
- Author
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Oredsson SM, Alm K, Dahlberg E, Holst CM, Johansson VM, Myhre L, and Söderstjerna E
- Subjects
- Animals, Cell Death drug effects, Cell Differentiation drug effects, Cell Line, Cell Line, Tumor, Humans, Putrescine analogs & derivatives, Putrescine pharmacology, Spermine pharmacology, Apoptosis drug effects, Cell Cycle drug effects, Cell Division drug effects, Polyamines metabolism, Spermine analogs & derivatives
- Abstract
Reduction of cellular polyamine pools results in inhibition of cell proliferation and sometimes in induction of cell death. Reduction of cellular polyamine pools can be achieved by several strategies involving all the mechanisms of polyamine homoeostasis, i.e. biosynthesis, catabolism and transport across the cell membrane. In the present paper, we concentrate on results achieved using the polyamine analogue DENSPM (N(1),N(11)-diethylnorspermine) on different cell lines. We discuss polyamine levels in DENSPM-treated cells in relation to effects on cell cycle kinetics and induction of apoptosis. To really understand the role of polyamines in cell cycle regulation and apoptosis, we believe it is now time to go through the vast polyamine literature in a meta-analysis-based manner. This short review does not claim to be such a study, but it is our hope to stimulate such studies in the polyamine field. Such work is especially important from the viewpoint of introducing drugs that affect polyamine homoeostasis in the treatment of various diseases such as cancer. more...
- Published
- 2007
- Full Text
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9. Differential polyamine analogue effects in four human breast cancer cell lines.
- Author
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Holst CM, Frydman B, Marton LJ, and Oredsson SM
- Subjects
- Cell Line, Tumor, Cell Survival drug effects, Dose-Response Relationship, Drug, Female, Flow Cytometry, Humans, Microscopy, Fluorescence, Spermine pharmacology, Antineoplastic Agents pharmacology, Apoptosis drug effects, Breast Neoplasms pathology, Polyamines pharmacology, Spermine analogs & derivatives
- Abstract
Polyamine analogues have demonstrated anti-tumour activity in a number of solid tumour models. In the present study we compared the cytotoxicities of three polyamine analogues against four breast cancer cell lines. All cell lines are derived from tumours of women with breast cancer and, although we are sampling just a small number of tumours, they represent a spectrum of the genetic plethora of breast cancers. Cytotoxicity, over a dose range from 0.1 to 100 microM, was evaluated with three different cytotoxicity assays performed in 96-well plates. Comparing the effects of the analogues on polyamine pools with data from the cytotoxicity assays indicates that there was not a direct correlation between polyamine pool depletion and cytotoxicity. Flow cytometry was used to investigate analogue-induced cell death as measured by the appearance of a sub-G(1) peak. Induction of cell death by the analogues differed in the cell lines, however, cell death when induced was apoptotic, as demonstrated by detection of apoptotic bodies with immunofluorescence microscopy of propidium iodide-stained nuclei. Comparing the flow cytometry-derived data and the data from the cytotoxicity assays reveals that the analogues exert their effects by inhibiting cell growth and/or inducing cell death. more...
- Published
- 2006
- Full Text
- View/download PDF
10. Comparison of three cytotoxicity tests in the evaluation of the cytotoxicity of a spermine analogue on human breast cancer cell lines.
- Author
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Holst CM and Oredsson SM
- Subjects
- Adenocarcinoma metabolism, Adenocarcinoma pathology, Apoptosis drug effects, Breast Neoplasms metabolism, Breast Neoplasms pathology, Cell Line, Tumor drug effects, Cell Line, Tumor pathology, Cell Survival drug effects, Dose-Response Relationship, Drug, Drug Screening Assays, Antitumor, Female, Formazans metabolism, Humans, Tetrazolium Salts metabolism, Adenocarcinoma drug therapy, Antineoplastic Agents toxicity, Breast Neoplasms drug therapy, Spermine analogs & derivatives, Spermine toxicity
- Abstract
Using three cytotoxicity assays, we have investigated the effect of the spermine analogue N1,N11-diethylnorspermine (DENSPM) on four human breast cancer cell lines with different known genetic lesions. Cells were seeded in 96 well plates and DENSPM was added 24 h later to give final concentrations from 0.1 to 100 microM. At 24, 48 and 72 h of treatment, the protein content was determined with a modified Lowry assay. Mitochondrial activity was determined with the AlamarBlue and MTT assays. These two assays differ with respect to where in the electron transport chain the reduction of the substrate takes place. Treatment with increasing concentrations of DENSPM resulted in differential responses in the four cell lines. There was a good of agreement between the protein content and the MTT assay showing increased negative effect with increased dose of DENSPM. The AlamarBlue assay on the other hand showed a stimulation of substrate reduction compared to control at DENSPM concentrations that were inhibitory according to the protein content and MTT assay. Thus, the data clearly show that the MTT and AlamarBlue assays are not equivalent. Importantly, the AlamarBlue assay presumably also reflects cytoplasmic reduction of the substrate through DENSPM-induced mechanisms. more...
- Published
- 2005
- Full Text
- View/download PDF
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