Establishment of evaluation method for double strand repair capacity with peripheral blood

• Project/Area Number: 23590659
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Laboratory medicine
• Research Institution: University of Tsukuba
• Principal Investigator: SUZUKAWA Kazumi 筑波大学, 医学医療系, 准教授 (50334066)
• Co-Investigator(Renkei-kenkyūsha): CHIBA Shigeru 筑波大学, 医学医療系, 教授 (60212049) ; OKOSHI Yasushi 筑波大学, 医学医療系, 准教授 (10400673) ; YOKOYAMA Yasuhisa 筑波大学, 医学医療系, 講師 (70512820)
• Project Period (FY): 2011 – 2013
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000); Fiscal Year 2013: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2011: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: DNA二重鎖切断 / 放射線 / H2AX / 脱リン酸化 / 修復 / gammaH2AX / 損傷DNA修復 / DNA二重らせん切断 / 末梢血白血球 / フローサイトメトリー / DNA損傷修復

Research Abstract

To approach the difference in the DSB repair function in healthy individuals and patients with hematological malignancies, we focused on the reversion ofgammaH2AX, an established marker of DSB, to H2AX. Irradiation induced gammaH2AX in dose dependent manner. Maximal amount of gammaH2AX was observed at one hour after irradiation. Then the amount of gammaH2AX gradually decreased, suggesting the progress of DSB repair. DSB repair evaluated by the dephosphorylation of gammaH2AX was significantly decreased in older (over 39) volunteers than younger ones. Age-matched analysis between volunteers and post-chemotherapeutic lymphoma patients revealed increase of DSB repair in patients, indicating that the impairment of DNA repair function is affected more by aging than chemotherapy. Our results suggest that aging is a significant factor for decreased DSB repair after irradiation, which might be associated with increased prevalence of cancer in aged individuals.

Research Products

• [Presentation] Decreased repair activity of double-strand DNA break by irradiation in the peripheral lymphocyte with aging (2013)
  • Author(s): Kazumi Suzukawa, Yasushi Kawakami, Shigeru Chiba
  • Organizer: 第75回日本血液学会学術集会
  • Place of Presentation: ロイトン札幌、札幌
  • Year and Date: 2013-10-12
• [Presentation] Decreased repair activity of double strand DNA break by irradiation in the peripheral lymphocyte with aging (2013)
  • Author(s): Kazumi Suzukawa, Yasushi Kawakami, Shigeru Chiba
  • Organizer: 第７５回日本血液学会学術集会
  • Place of Presentation: ロイトン札幌（札幌市）