2019 Fiscal Year Final Research Report

Study of clinically radio-resistance factors using clinical radiation-resistant oral cancer cells

Research Project

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Project/Area Number	17K11880
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Surgical dentistry
Research Institution	Oita University
Principal Investigator	YAMAMOTO NORIAKI 大分大学, 医学部, 講師 (50397923)
Co-Investigator(Kenkyū-buntansha)	菓子野元郎奈良県立医科大学, 医学部, 准教授 (00437287) 小橋川新子 (菓子野新子) 京都大学, 複合原子力科学研究所, 研究員 (70637628)
Project Period (FY)	2017-04-01 – 2020-03-31
Keywords	口腔扁平上皮癌 / 放射線耐性
Outline of Final Research Achievements	To establish the clinically radio-resistant OSCC to analyze the molecular mechanisms of the radio-resistant OSCC associated with radiotherapy for oral cancers. We create radio-resistant cell lines that continued to grow stably after irradiation of 2Gy daily. Cell morphology, cell growth ability, DNA repair capacity were compared between the parent and radio-resistant cell lines. In addition, status of expression in EMT-related proteins was evaluated. The cell morphologies presented a fusiform shape. Growth abilities of radio-resistant cell lines were decreased, but were able to maintain undiminished cell growth under γ ray irradiation. DNA repair capacity were elevated. In addition, some EMT-related proteins were over-or under-expressed in respective.The radio-resistant oral squamous cell carcinoma cell lines were established through the resistance against DNA damage derived from the active oxygen species created by irradiation and alterative expression of some EMT-related proteins.
Free Research Field	口腔外科学
Academic Significance and Societal Importance of the Research Achievements	口腔扁平上皮癌における放射線抵抗因子の解析を、より実際の治療に即したものとするための、臨床的口腔扁平上皮癌細胞株を作成して口腔扁平上皮癌における放射線耐性の解析を行った。臨床的放射線耐性細胞株とは実際の放射線治療後に残存する細胞をモデルとした、連日2Gy の放射線照射を行っても増殖し続ける細胞である。本研究では放射線耐性を獲得した細胞に上皮間葉転換を示唆する変化を認めており、活性酸素によるDNA損傷に対する耐性を獲得している事を解明した。今後この細胞を用いてより実臨床に近いかたちで口腔癌における放射線耐性克服の研究を進める事が可能であると考える。