Genome-wide identification of double-strand break sites induced by activated estrogen receptors and Topoisomerase IIBeta

• Project/Area Number: 19K22561
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 50:Oncology and related fields
• Research Institution: Kyoto University
• Principal Investigator: Takeda Shunichi 京都大学, 医学研究科, 教授 (60188191)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2020: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2019: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
• Keywords: BRCA1 / HBOC症候群 / 乳がん / 卵巣がん / DNA Topoisomerase IIB / エストロゲン / エンハンサー / DNA Topoisomerase IIΒ / Topoisomerase IIβ

Outline of Research at the Start

我々は、C-MYCエンハンサーがエストロゲン刺激依存的Top2β触媒部位であることを既に解明した。BRCA1欠損MCF-7細胞では、エストロゲン刺激後にC-MYCエンハンサー領域に病的DNA切断-Top2β複合体が蓄積した。C-MYCエンハンサー領域に切断があると、エストロゲン刺激後のC-MYC発現が上がる。同様に、エストロゲン刺激依存的Top2β触媒部位毎にBRCA1欠損の影響を解明する。

Outline of Final Research Achievements

BRCA2 is a key player in homologous DNA recombination (HR), repairing double-strand breaks (DSBs) only at S/G2 in all cycling cells. It is unclear why loss of BRCA2 leads to an increase in carcinogenesis only in the mammary gland and ovary in HBOC syndrome. Our working hypothesis is that (i) TOP2 generates DSBs at E2-dependent enhancers during treatment with E2, (ii) BRCA2 play a crucial role in repairing TOP2-dependent DSBs independent of its function in HR, (iii) unrepaired breakage dysregulates transcriptional response to E2 in many genes, (iv) resulting overexpression of c-Myc oncogene in response to E2 explains oncogenesis in estrogen-regulated tissues, which explains the tissue specificity of HBOC. We have shown that (ii), (iii), and (iv) hypotheses are correct by analyzing the repair of TOP2-dependent DSBs in BRCA2-depleted G1 cells, transcriptome during response to E2, and c-Myc expression in BRCA2-deficient mice in cooperation with the Netherland Cancer Center, respectively.

Academic Significance and Societal Importance of the Research Achievements

乳がんは、日本も含め東アジア全体で患者数が増加している。乳癌の問題点は、若い患者が多いことにある。BRCA1やBRCA2の変異のキャリアは乳癌の発症率が増加する（HBOC症候群）。BRCA1やBRCA2は、腫瘍抑制遺伝子であるにもかかわらず、なぜキャリアで発癌率が増加するのか不明である。この増加の原因は、キャリアの乳腺上皮がごくまれにloss of heterozygosityが起こるや否や、BRCA1やBRCA2の欠損によって一気に癌化が進む為と推定されている。この「一気に癌化が進む」分子機構が解明できれば、HBOC症候群の予防法開発と治療法開発に貢献できる。

Research Products

• [Int'l Joint Research] National Institutes of Health(米国)
• [Int'l Joint Research] National Institutes of Health/Memorial Sloan Kettering Cancer Center(米国)
• [Journal Article] RAD52 Adjusts Repair of Single-Strand Breaks via Reducing DNA-Damage-Promoted XRCC1/LIG3α Co-localization. (2021)
  • Author(s): Wang J, Oh YT, Li Z, Dou J, Tang S, Wang X, Wang H, Takeda S, Wang Y.
  • Journal Title: Cell Rep. Volume: 34 Issue: 2 Pages: 108625-108625
  • DOI: 10.1016/j.celrep.2020.108625
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Epigenetic suppression of SLFN11 in germinal center B-cells during B-cell development (2021)
  • Author(s): Moribe F, Nishikori M, Takashima T, Taniyama D, Onishi N, Arima H, Sasanuma H, Akagawa R, Elloumi F, Takeda S, Pommier Y, Morii E, Takaori-Kondo A, Murai J.
  • Journal Title: PLoS One. Volume: 16 Issue: 1 Pages: 0237554-0237554
  • DOI: 10.1371/journal.pone.0237554
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Tyrosyl-DNA phosphodiesterases are involved in mutagenic events at a ribonucleotide embedded into DNA in human cells (2020)
  • Author(s): Takeishi Ayuna、Kogashi Hiroyuki、Odagiri Mizuki、Sasanuma Hiroyuki、Takeda Shunichi、Yasui Manabu、Honma Masamitsu、Suzuki Tetsuya、Kamiya Hiroyuki、Sugasawa Kaoru、Ura Kiyoe、Sassa Akira
  • Journal Title: PLOS ONE Volume: 15 Issue: 12 Pages: 0244790-0244790
  • DOI: 10.1371/journal.pone.0244790
  • Peer Reviewed / Open Access
• [Journal Article] Genetic evidence for the involvement of mismatch repair proteins, PMS2 and MLH3, in a late step of homologous recombination. (2020)
  • Author(s): Rahman MM, Mohiuddin M, Shamima Keka I, Yamada K, Tsuda M, Sasanuma H, Andreani J, Guerois R, Borde V, Charbonnier JB, Takeda S.
  • Journal Title: J Biol Chem. Volume: 295 Issue: 51 Pages: 17460-17475
  • DOI: 10.1074/jbc.ra120.013521
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Participation of TDP1 in the repair of formaldehyde-induced DNA-protein cross-links in chicken DT40 cells (2020)
  • Author(s): Toshiaki Nakano, Mahmoud I. Shoulkamy, Masataka Tsuda, Hiroyuki Sasanuma, Kouji Hirota, Minoru Takata, Shin-ichiro Masunaga, Shunichi Takeda, Hiroshi Ide, Tadayoshi Bessho, Keizo Tano
  • Journal Title: PLOS ONE Volume: 15 Issue: 6 Pages: 0234859-0234859
  • DOI: 10.1371/journal.pone.0234859
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Topoisomerase I-driven repair of UV-induced damage in NER-deficient cells (2020)
  • Author(s): Saha Liton Kumar、Wakasugi Mitsuo、Akter Salma、Prasad Rajendra、Wilson Samuel H.、Shimizu Naoto、Sasanuma Hiroyuki、Huang Shar-yin Naomi、Agama Keli、Pommier Yves、Matsunaga Tsukasa、Hirota Kouji、Iwai Shigenori、Nakazawa Yuka、Ogi Tomoo、Takeda Shunichi
  • Journal Title: Proceedings of the National Academy of Sciences Volume: 117 Issue: 25 Pages: 14412-14420
  • DOI: 10.1073/pnas.1920165117
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] BRCA1 and BRCA2 protect transcriptional response to estrogens from abortive catalysis by Topoisomerase II (2019)
  • Author(s): Rahman MM, Sasanuma H, Tsuda M, Morimoto S, Yamada S, Nussenzweig A, Tanaka H, Takeda S
  • Organizer: FASEB Science Research Conference “The Genetic Recombination and Genome Rearrangements Conference”
  • Int'l Joint Research
• [Presentation] BRCA1 and BRCA2 protect transcriptional response to estrogens from abortive catalysis by Topoisomerase II (2019)
  • Author(s): Takeda S
  • Organizer: 2019 International Conference: Korean Society for Molecular and Cellular Biology
  • Int'l Joint Research / Invited
• [Presentation] BRCA1 and BRCA2 protect transcriptional response to estrogens from abortive catalysis by Topoisomerase II (2019)
  • Author(s): Takeda S
  • Organizer: The 10th International Symposium on DNA Damage Response & Human Disease, isDDRHD-2019
  • Int'l Joint Research / Invited