1988 Fiscal Year Final Research Report Summary
Induction of numerical chromosome changes and neoplastic transformation by radiations.
| Project/Area Number |
62580164
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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 |
放射線5生物学
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| Research Institution | Kanazawa University |
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Principal Investigator |
SUZUKI Fumio Faculty of Pharmaceutical Sciences, Kanazawa University, 薬学部, 助教授 (10019672)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUNAGA Tsukasa Faculty of Pharmaceutical Sciences, Kanazawa University, 薬学部, 教務職員 (60192340)
NIKAIDO Osamu Faculty of Pharmaceutical Sciences, Kanazawa University, 薬学部, 教授 (60019669)
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| Project Period (FY) |
1987 – 1988
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| Keywords | X-rays / Ultraviolet light / Golden hamster / Neoplastic transformation / Trisomy / Oncogene / トランスフェクション |
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| Research Abstract |
Using gloden hamster embryo (GHE) cells, we examined the induction of chromosome changes and neoplastic transformation by X-rays or ultraviolet litht (UV).
Unirradiated cells were grown at a constant growth rate for 7 passages but later ceased to divide. X-ray- or UV-irradiated cells escaped from senescence ans showed morphological transformation accompanying with the expression of the ability to form colonies in soft agar medium at later passages. In contrast to these changes, the aquisition of tumorigenicity in nude mice was observed much later (11 passages after the irradiation). When methaphese chromosomes were prepared at various passages after X-irradiation, one or two additional chromosomes were detected in the cells depending on passage numbers. For example, almost all the cells showing 45 chromosomes at passage 5 contained trisomy of chromosome 7 and the cells transferred for 13 passages had futher numerical chromosome changes on chromosome 6,9 and/or 20. Similar chromosome changes were observed in anchorage-independent and tumorigenic cells induced by UV. Mouse NIH3T3 cells transfected with DNA from various transformed GHE cells expressed malignant phenotypes. From Southern blot analysis, all malignant NIH3T3 cells derived from tumors after transfection were found to contain some amount of golden hamster DNA.
These results suggest that radiation induced transformation is a multistep in GHE cells, and that the numerical change of specific chromosomes and the activation of some oncogenes may play an important role for the expression of each transformed phenotypes.
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