細胞増殖の抑制とその破綻機構の解析

• Project/Area Number: 12215119
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Kumamoto University
• Principal Investigator: 佐谷 秀行 熊本大学, 大学院・医学薬学研究部, 教授 (80264282)
• Co-Investigator(Kenkyū-buntansha): 豊島 秀夫 (豊島 秀男) 筑波大学, 医学専門学群・臨床医学系, 講師 (20197966)
• Project Period (FY): 2000 – 2004
• Project Status: Completed (Fiscal Year 2004)
• Budget Amount: ¥124,500,000 (Direct Cost: ¥124,500,000); Fiscal Year 2004: ¥26,500,000 (Direct Cost: ¥26,500,000); Fiscal Year 2003: ¥25,000,000 (Direct Cost: ¥25,000,000); Fiscal Year 2002: ¥25,000,000 (Direct Cost: ¥25,000,000); Fiscal Year 2001: ¥25,000,000 (Direct Cost: ¥25,000,000); Fiscal Year 2000: ¥23,000,000 (Direct Cost: ¥23,000,000)
• Keywords: 分裂期キナーゼ / 細胞分裂 / チェックポイント / 細胞死 / Aurora-A / WGEF / p21 / LIM kinase / WARTS / CENP-A / Ajuba / p57 / Omi / LIM kinase-a / PP2A / DT40細胞 / Cdh1 / anaphase promoting complex(APC) / 細胞質分離 / 細胞周期 / warts / cdc2 / zyxin / TGFβ / Smad

Research Abstract

細胞周期が回転することにより細胞は増殖を行なうが、正確な複製と分裂を遂行するためにその過程は精密な分子機構により監視されている。従って、この機構の破綻は、遺伝子不安定化、染色体異常、細胞分化異常などを引き起こし、癌の発生ならびに悪性化の原因となりうる。本研究は細胞周期の分裂期並びにG1/S移行期に働く分子の機能を解析し、その機能破綻が腫瘍化に働くメカニズムについて検討することを目的として行った。
以下に本年度の成果を要約する。
1)細胞周期の分裂期並びにG1/S移行期に働く分子の機能を解析し、その機能破綻が腫瘍化に働くメカニズムについて検討を行った。
2)分裂期キナーゼAurora-Aの過剰発現を乳腺特異的に誘導すると、分裂異常が生じて多くの二核細胞が生じたが、その後p53依存性に細胞死を起こすために癌化しないことが分かった。そこでp53不活化マウスと交配したところ、細胞死は抑制され、乳腺に腫瘍性変化が観察された。
3)抗癌剤で処理した癌細胞が、分裂期に進入した後、崩壊死する現象を捉え、この細胞死にスピンドルチェックポイントの活性化が必要であることを見出した。つまりスピンドルチェックポイント機能に障害のある癌細胞は抗癌剤に耐性であることが分かった。
4)腸管、肝臓、心臓、腎臓に特異的に発現が見られる新規のGEF(guanine nucleotide exchangefactor)、WGEFを同定した。
5)脂質合成において重要な転写因子であるSREBP-1aの発現がマウスにおいて肝腫大を引き起こすことを見出し、その際CDK阻害因子であるp21の転写制御を介して細胞周期を調節に関わることを明らかにした。

Research Products

• [Journal Article] Aurora A - A guardian of poles (2005)
  • Author(s): Marumoto, T. et al.
  • Journal Title: Nature Review Cancer 5 Pages: 42-50
• [Journal Article] Spindle checkpoint function is required for mitotic catastrophe induced by DNA-damaging agents. (2004)
  • Author(s): Nitta, M. et al.
  • Journal Title: Oncogene 23 Pages: 6548-6558
• [Journal Article] The tumor suppressor WARTS ensures genomic integrity by regulating both mitotic progression and G_1 tetraploidy checkpoint function. (2004)
  • Author(s): Iida, S. et al.
  • Journal Title: Oncogene 23 Pages: 5266-5274
• [Journal Article] Cell-matrix interaction via CD44 is independently regulated by different metalloproteinases activated in response to extracellular Ca2+ influx and PKC activation. (2004)
  • Author(s): Nagano, O. et al.
  • Journal Title: Journal of Cell Biology 165 Pages: 893-902
• [Journal Article] Activation of m-calpain is required for chromosome alignment on the metaphase plate during mitosis. (2004)
  • Author(s): Honda, S. et al.
  • Journal Title: Journal of Biological Chemistry 279 Pages: 10615-10623
• [Journal Article] Cre-loxP-controlled periodic Aurora-A overexpression induces mitotic abnormalities and hyperplasia in mammary elands of mouse models. (2004)
  • Author(s): Zhang, D. et al.
  • Journal Title: Oncogene 23 Pages: 8720-8730
• [Publications] Hirota, T.et al.: "Aurora-A and an interacting activator, the LIM protein Ajuba, are required for mitotic commitment in human cells."Cell. 114. 585-598 (2003)
• [Publications] Marumoto, T.et al.: "Aurora-A kinase maintains the fidelity of early and late mitotic events in HeLa cells"J Biol Chem. 278. 51786-51795 (2003)
• [Publications] Kunitoku, N., et al.: "Aurora-A-dependent phosphorylation of CENP-A in prophase is essential for concentration of Aurora-B at inner centromeres and for kinetochore function."Dev Cell. 5. 853-864 (2003)
• [Publications] Murakami, D., et al.: "Presenilin-dependent g-secretase activity mediates the intramembranous cleavage of CD44."Oncogene. 22. 1511-1516 (2003)
• [Publications] Iida, S., et al.: "The tumor suppressor WARTS ensures genomic integrity by regulating both mitotic progression and G_1 tetraloidy checkpoint function."Oncogene. (印刷中). (2004)
• [Publications] Honda, S.et al.: "Activation of m-calpain is required for chromosome alignment on the metaphase plate during mitosis."J Biol Chem. (印刷中). (2004)
• [Publications] Nitta, M. et al.: "Hyperploidy induced by drugs that inhibit formation of microtubule promotes chromosome instability"Genes Cells. 7. 151-162 (2002)
• [Publications] Morisaki, T. et al.: "WARTS tumor suppressor is phosphorylated by Cdc2/cyclin B at spindle poles during mitosis"FEBS Lett. 529. 319-324 (2002)
• [Publications] Okamoto, I., et al.: "Proteolytic Cleavage of CD44 Adhesion Molecule in Multiple Human Tumors"Am J Pathol. 160. 441-447 (2002)
• [Publications] Honda, Y., et al.: "Cooperation of HECT-domain ubiquitin ligase hHYD and DNA topoisomerase II-binding protein for DNA damage response"J Biol Chem. 277. 3599-3605 (2002)
• [Publications] Tojo, M., et al.: "The Aryl hydrocarbon receptor nuclear transporter is modulated by the SUMO-1 conjugating system."J Biol Chem. 277. 46576-46585 (2002)
• [Publications] Murakami, D., et la.: "Presenilin-dependent g-secretase activity mediates the intramembranous cleavage of CD44"Oncogene. (印刷中). (2003)
• [Publications] Sudo, T. et al.: "Activation of Cdh1-dependent APC is required for Gi cell cycle arrest and DNA damage-induced G2 checkpoint in vertebrate cells"EMBO J. 20・22. 6499-6508 (2001)
• [Publications] Tsuiki, H. et al.: "Mechanism of hyperploid cell formation induced by microtubule inhibiting drug in glioma cell lines"Oncogen. 20・4. 420-429 (2001)
• [Publications] Nitta, M. et al.: "Hyperploidy induced by drugs that inhibit formation of microtubule promotes chromosome instability"Genes Cells. 7・2. 151-162 (2002)
• [Publications] Okamoto, I. et al.: "Proteolytic release of CD44 intracellular domain and its role in the CD44 signaling pathway"J Cell Biol. 155・5. 755-762 (2001)
• [Publications] Honda, Y. et al.: "Cooperation of HECT-domain ubiquitin ligase hHYD and DNA topoisomerase II-binding protein for DNA damage response"J Biol Chem. 277・5. 3599-3605 (2002)
• [Publications] Nishimori, S. et al.: "Smad-mediated transcription is required for TGF-β1-induced p57Kip2 proteolysis in osteoblastic cells"J Biol Chem. 276・14. 10700-10705 (2001)
• [Publications] 生塩之敬, 山浦晶, 佐谷秀行編集: "脳神経外科医に必要な分子細胞生物学"三輪書店. 153 (2001)
• [Publications] Hirota,T.et al: "Zyxin,a regulator of actin filament assembly,targets the mitotic apparatus by interacting with h-warts/LATS1 tumor suppressor."J Cell Biol. 149. 1073-1086 (2000)
• [Publications] Kawano,Y.et al: "Ras oncoprotein induces CD44 cleavage through phosphoinositide 3-OH kinase and the Rho family of small G proteins."J Biol Chem. 275. 29628-29635 (2000)
• [Publications] Hanada,N.et al: "NE-dlg,a mammalian homolog of Drosophila dlg tumor suppressor,induces growth suppression and impairment of cell adhesion:Possible involvement of down-regulation of b-catenin by NE-dlg expression."Int J Cancer. 86. 480-488 (2000)
• [Publications] Fujita,N.et al: "The mechanism of transcriptional regulation by methyl-CpG binding protein MBD1."Mol Cell Biol. 20. 5107-5118 (2000)
• [Publications] Eto,H.et al: "Mapping and regulation of the tumor-associated epitope recognized by mAb RS-11."J Biol Chem. 275. 27075-27083 (2000)
• [Publications] Tsuiki,H.et al: "Mechanism of hyperploid cell formation induced by microtubule inhibiting drug in glioma cell lines."Oncogene. (印刷中). (2001)