1988 Fiscal Year Final Research Report Summary
Deoxyribonucleoside Triphosphate Imbalance: The Mechanism of Cell Death and DNA-Double Strand Breaks.
| Project/Area Number |
62570989
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biological pharmacy
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| Research Institution | Okayama University, Faculty of Pharmaceutical Sciences |
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Principal Investigator |
WATAYA Yusuke Okayama University, Faculty of Pharmaceutical Sciences, 薬学部, 助教授 (90127598)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Cell Death / dNTP Imbalance / Nucleotide Metabolism / DNA Strand Breaks / Double Strand Breaks / パルスフィールドゲル電気泳動 / dNTP不均衡死 |
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| Research Abstract |
The mechanism of intracellular deoxyribonucleoside-triphosphate (dNTP)-pool imbalance induced cell death and dNA double strand breaks in mouse FM3A cells was investigated. imbalance of the dNTP pools occurred within 3 h of treatment with 20 m 2-chlorodeoxyadenosine; the dATP and dGTP pools were depleted and the dTTP pool increased. 2-Chlorodeoxyadenosine added to the culture medium broke mature DNA strands, giving fragments of 100-200 kilobase pairs as found by orthogonal-field-alternation gel electrophoresis. DNA strand breaks, measured by this technique, were observed in the treated cells about 12 h after the addition. The cells also lost viability at about 12 h. Breaks in the single and double strands of DNA, as measured by alkaline and neutral filter elution, became evident 18 h after treatment with 20 m 2-chlorodeoxyadenosine; there were as many od single-strand breaks as would be caused by 130 rads of -ray irradiation. Double-strand breaks were equivalent to those caused by 2180 rads of -ray irradiation. Comparison of the ratio of singl- and double-strand breaks caused by 2-chlorodeoxyadenosine to that following radiation suggested that 2-chlorodeoxyadenosine broke only double strands. Cycloheximide inhibited the breakage of DNA double strands and the cell death caused by this compound. Flow cytometric studies of cytostatit brought about by 2-chlorodeoxyadenosine in FM3A cells that cells accumulated in the earlier part of the s phase. 2-Chlorodeoxyadenosine decreased DNA synthesis more than RNA or protein synthesis. The breaks in double strands DNA were probably important in the cell death caused by 2-chlorodeoxyadenosine. The intracellular dNTP imbalance may trigger these events.
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