{"created":"2023-05-15T14:51:08.589731+00:00","id":69913,"links":{},"metadata":{"_buckets":{"deposit":"51a4bf7b-ee8f-4324-8c5f-449b86adf1e1"},"_deposit":{"created_by":1,"id":"69913","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"69913"},"status":"published"},"_oai":{"id":"oai:repo.qst.go.jp:00069913","sets":["10:28"]},"author_link":["686477","686480","686485","686482","686483","686486","686488","686479","686478","686487","686484","686481"],"item_10005_date_7":{"attribute_name":"発表年月日","attribute_value_mlt":[{"subitem_date_issued_datetime":"2009-10-24","subitem_date_issued_type":"Issued"}]},"item_10005_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"　DNA二本鎖切断(DSBs)は，DNA損傷の中でも最も重篤な細胞障害性を有し，その修復の不全は，細胞死，突然変異，発がんの原因となる．MDC1(Mediator of DNA-damage Checkpoint 1)は，DNA損傷に続く細胞周期チェックポイント機構に関与する因子の一つとして同定され，DNA-DSBs部位に集積してフォーカスを形成する．我々は，MDC1がDNA損傷応答にどのような役割を果たしているのか明らかにするために，ヒト大腸がん由来HCT116細胞においてMDC1遺伝子を破壊し，その諸性質について解析を進めている．MDC1欠損（MDC1-/-）細胞では放射線感受性が親株よりも高くなり，また，放射線誘発の染色体異常頻度も亢進することから， MDC1は放射線誘発のDNA-DSBsの修復に関与するであろうと考えられた．一方，放射線誘発突然変異に対するMDC1の関与については未だに不明であることから，今回，MDC1-/-細胞におけるHPRT遺伝子の突然変異について，6-thioguanine耐性コロニー形成を指標に検討した．\n　親株のHCT116細胞については，〜2 GyまでのX線照射ではHPRT遺伝子の突然変異誘発率が非照射群（0 Gy）よりも高くなることはなかった．一方，MDC1-/-細胞については，（非照射および）〜0.2 Gyまでの低線量のX線照射ではHPRT遺伝子の突然変異を示すコロニーは検出されなかった．しかし，0.5〜2 GyのX線照射後には，線量に依存してHPRT遺伝子の突然変異率が上昇した．特に，2 Gy照射後では，親株の非照射群（HPRT遺伝子の突然変異率：4.4 x 10-6）よりも100倍以上も突然変異率が高くなっていた． MDC1-/-細胞における放射線被ばく後の染色体異常頻度の亢進や放射線感受性上昇といったDNA-DSBs修復不全を示す結果とあわせて考えると，MDC1は放射線によって誘発されたDNA-DSBsの再結合過程に重要な役割を果たしていると思われる．","subitem_description_type":"Abstract"}]},"item_10005_description_6":{"attribute_name":"会議概要（会議名, 開催地, 会期, 主催者等）","attribute_value_mlt":[{"subitem_description":"第82回 日本生化学会大会","subitem_description_type":"Other"}]},"item_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"metadata only access","subitem_access_right_uri":"http://purl.org/coar/access_right/c_14cb"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"小野田, 眞"}],"nameIdentifiers":[{"nameIdentifier":"686477","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"森, 雅彦"}],"nameIdentifiers":[{"nameIdentifier":"686478","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"勝部, 孝則"}],"nameIdentifiers":[{"nameIdentifier":"686479","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"辻, 秀雄"}],"nameIdentifiers":[{"nameIdentifier":"686480","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"塩見, 尚子"}],"nameIdentifiers":[{"nameIdentifier":"686481","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"塩見, 忠博"}],"nameIdentifiers":[{"nameIdentifier":"686482","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"小野田 眞","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"686483","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"森 雅彦","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"686484","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"勝部 孝則","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"686485","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"辻 秀雄","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"686486","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"塩見 尚子","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"686487","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"塩見 忠博","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"686488","nameIdentifierScheme":"WEKO"}]}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"conference object","resourceuri":"http://purl.org/coar/resource_type/c_c94f"}]},"item_title":"MDC1欠損ヒト細胞における放射線誘発突然変異","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"MDC1欠損ヒト細胞における放射線誘発突然変異"}]},"item_type_id":"10005","owner":"1","path":["28"],"pubdate":{"attribute_name":"公開日","attribute_value":"2009-10-26"},"publish_date":"2009-10-26","publish_status":"0","recid":"69913","relation_version_is_last":true,"title":["MDC1欠損ヒト細胞における放射線誘発突然変異"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-05-15T20:08:59.578821+00:00"}