2024/02/02 更新

写真a

アサツマ　トモコ
朝妻　知子
Asatsuma Tomoko
所属
先端医学研究所 細胞生物学部門 助教
職名
助教
外部リンク

研究分野

  • ライフサイエンス / 分子生物学

論文

  • Molecular Mechanisms of the Teratogenic Effects of Thalidomide. 国際誌

    Tomoko Asatsuma-Okumura, Takumi Ito, Hiroshi Handa

    Pharmaceuticals (Basel, Switzerland)   13 ( 5 )   95 - 95   2020年5月

    　詳細を見る

    記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：{MDPI} {AG}  

    Thalidomide was sold worldwide as a sedative over 60 years ago, but it was quickly withdrawn from the market due to its teratogenic effects. Thalidomide was later found to have therapeutic effects in several diseases, although the molecular mechanisms remained unclear. The discovery of cereblon (CRBN), the direct target of thalidomide, a decade ago greatly improved our understanding of its mechanism of action. Accumulating evidence has shown that CRBN functions as a substrate of Cullin RING E3 ligase (CRL4CRBN), whose specificity is controlled by ligands such as thalidomide. For example, lenalidomide and pomalidomide, well-known thalidomide derivatives, degrade the neosubstrates Ikaros and Aiolos, resulting in anti-proliferative effects in multiple myeloma. Recently, novel CRBN-binding drugs have been developed. However, for the safe handling of thalidomide and its derivatives, a greater understanding of the mechanisms of its adverse effects is required. The teratogenic effects of thalidomide occur in multiple tissues in the developing fetus and vary in phenotype, making it difficult to clarify this issue. Recently, several CRBN neosubstrates (e.g., SALL4 (Spalt Like Transcription Factor 4) and p63 (Tumor Protein P63)) have been identified as candidate mediators of thalidomide teratogenicity. In this review, we describe the current understanding of molecular mechanisms of thalidomide, particularly in the context of its teratogenicity.

    DOI： 10.3390/ph13050095

    PubMed

    researchmap

  • p63 is a cereblon substrate involved in thalidomide teratogenicity. 国際誌

    Tomoko Asatsuma-Okumura, Hideki Ando, Marco De Simone, Junichi Yamamoto, Tomomi Sato, Nobuyuki Shimizu, Kazuhide Asakawa, Yuki Yamaguchi, Takumi Ito, Luisa Guerrini, Hiroshi Handa

    Nature chemical biology   15 ( 11 )   1077 - 1084   2019年11月

    　詳細を見る

    記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media {LLC}  

    Cereblon (CRBN) is a primary target of thalidomide and mediates its multiple pharmacological activities, including teratogenic and antimyeloma activities. CRBN functions as a substrate receptor of the E3 ubiquitin ligase CRL4, whose substrate specificity is modulated by thalidomide and its analogs. Although a number of CRL4CRBN substrates have recently been identified, the substrate involved in thalidomide teratogenicity is unclear. Here we show that p63 isoforms are thalidomide-dependent CRL4CRBN neosubstrates that are responsible, at least in part, for its teratogenic effects. The p53 family member p63 is associated with multiple developmental processes. ∆Np63α is essential for limb development, while TAp63α is important for cochlea development and hearing. Using a zebrafish model, we demonstrate that thalidomide exerts its teratogenic effects on pectoral fins and otic vesicles by inducing the degradation of ∆Np63α and TAp63α, respectively. These results may contribute to the invention of new thalidomide analogs lacking teratogenic activity.

    DOI： 10.1038/s41589-019-0366-7

    Scopus

    PubMed

    researchmap

  • ZNF276 and WIZ are CRBN neosubstrates involved in the anti-angiogenic activity of thalidomide and immunomodulatory drugs

    Takumi Ito, Tomoko Asatsuma-Okumura, Akinori Endo, Junichi Yamamoto, Yoshiko Iwai, Yuki Yamaguchi, Mikihiko Naito, Hiroshi Handa, Yasushi Saeki

    2023年11月

    　詳細を見る

    出版者・発行元：Research Square Platform LLC  

    Abstract

    Thalidomide was once developed as a sedative but had been withdrawn from the market in the 1960s because of its serious teratogenicity. Currently, this drug is reevaluated and used for the treatment of multiple myeloma, and many derivatives such as lenalidomide and pomalidomide have been developed. CRBN is a primary target of thalidomide and its derivatives and forms an E3 ubiquitin ligase complex with DDB1 and CUL4. Although the basic mechanism of action of thalidomide is quite well understood, a long-standing question remains regarding its inhibitory effect on angiogenesis. Here, we employed a comprehensive proteomic approach using thalidomide-treated endothelial cells to identify ZNF276 and WIZ as CRBN neosubstrates. Thalidomide and its derivatives exert their anti-angiogenic effects through these two zinc finger proteins, resulting in the downregulation of FABP4. This study reveals the CRBN neosubstrates involved in thalidomide-induced anti-angiogenesis and provides attractive therapeutic targets of CRBN-based protein degraders.

    DOI： 10.21203/rs.3.rs-3510134/v1

    researchmap

    その他リンク： https://www.researchsquare.com/article/rs-3510134/v1.html

  • PLZF and its fusion proteins are pomalidomide-dependent CRBN neosubstrates. 国際誌

    Nobuyuki Shimizu, Tomoko Asatsuma-Okumura, Junichi Yamamoto, Yuki Yamaguchi, Hiroshi Handa, Takumi Ito

    Communications biology   4 ( 1 )   1277 - 1277   2021年11月

    　詳細を見る

    記述言語：英語   掲載種別：研究論文（学術雑誌）  

    Pomalidomide and lenalidomide are immunomodulatory agents that were derived from thalidomide. Cereblon (CRBN) is a common direct target of thalidomide and related compounds and works as a Cullin Ring 4 E3 ubiquitin ligase (CRL4) with DDB1, CUL4, and ROC1. The substrate specificity of CRL4CRBN is modulated by thalidomide-related compounds. While lenalidomide is approved for the treatment of several diseases including multiple myeloma, 5q- syndrome, mantle cell lymphoma, and follicular lymphoma, pomalidomide is approved only for the treatment of lenalidomide-resistant multiple myeloma. Here we show that PLZF/ZBTB16 and its fusion proteins are pomalidomide-dependent neosubstrates of CRL4CRBN. PLZF joins to RARα or potentially other partner genes, and the translocation causes leukemias, such as acute promyelocytic leukemia and T-cell acute lymphoblastic leukemia. We demonstrate that pomalidomide treatment induces PLZF-RARα degradation, resulting in antiproliferation of leukemic cells expressing PLZF-RARα. This study highlights a potential therapeutic role of pomalidomide as a degrader of leukemogenic fusion proteins.

    DOI： 10.1038/s42003-021-02801-y

    PubMed

    researchmap

  • ARID2 is a pomalidomide-dependent CRL4CRBN substrate in multiple myeloma cells. 国際誌

    Junichi Yamamoto, Tetsufumi Suwa, Yuki Murase, Shumpei Tateno, Hirotaka Mizutome, Tomoko Asatsuma-Okumura, Nobuyuki Shimizu, Tsutomu Kishi, Shuji Momose, Masahiro Kizaki, Takumi Ito, Yuki Yamaguchi, Hiroshi Handa

    Nature chemical biology   16 ( 11 )   1208 - 1217   2020年11月

    　詳細を見る

    記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media {LLC}  

    The immunomodulatory drug (IMiD) thalidomide and its derivatives lenalidomide and pomalidomide are therapeutic agents used in the treatment of multiple myeloma. Although pomalidomide offers considerable clinical benefits to patients with lenalidomide-resistant multiple myeloma, the molecular mechanisms underlying its superior efficacy remain unclear. Here we show that ARID2, a component of the polybromo-associated BAF (PBAF) chromatin-remodeling complex, is a pomalidomide-induced neosubstrate of CRL4CRBN. BRD7, another subunit of PBAF, is critical for pomalidomide-induced ARID2 degradation. ARID2 is involved in transcriptional regulation of pomalidomide target genes including MYC. Pomalidomide is more effective than lenalidomide in degrading ARID2 and is capable of inhibiting MYC expression and proliferation in lenalidomide-resistant cell lines. Notably, ARID2 expression is associated with a poor prognosis and is higher in chemoresistant minimal residual disease (MRD) populations, and in patients with relapsed/refractory multiple myeloma. These findings suggest that ARID2 is a promising target for overcoming lenalidomide resistance in patients with multiple myeloma.

    DOI： 10.1038/s41589-020-0645-3

    PubMed

    researchmap

  • Molecular mechanisms of cereblon-based drugs. 国際誌

    Tomoko Asatsuma-Okumura, Takumi Ito, Hiroshi Handa

    Pharmacology & therapeutics   202   132 - 139   2019年10月

    　詳細を見る

    記述言語：英語   掲載種別：研究論文（学術雑誌）  

    Thalidomide, well known for its potent teratogenicity, has been re-evaluated as a clinically effective drug for the treatment of multiple myeloma. Although the direct target of thalidomide had been unclear until recently, we identified cereblon (CRBN) as a primary direct target of this drug by affinity purification using ferrite glycidyl methacrylate (FG) beads in 2010. CRBN functions as a unique substrate receptor of cullin-RING ligase 4 (CRL4). Various ligands including thalidomide bind to CRBN and alter substrate specificity depending on compound shape, resulting in multiple beneficial effects and/or teratogenicity. Lenalidomide, a thalidomide derivative approved by the US Food and Drug Administration (FDA), induces the degradation of onco-proteins such as Ikaros and casein kinase 1 alpha (CK1α), resulting in anti-cancer effects. Recently, novel CRBN-binding compounds have been developed and their mechanisms of action have been analyzed, including identification of CRBN-related ubiquitin conjugating enzymes (E2s). Moreover, the 3D structure of several CRBN-ligand-substrate complexes has been determined. Ligands were shown to work as a molecular glue between CRBN and its neosubstrate. In addition, investigators have been recently developing CRBN-based proteolysis-targeting chimeras to achieve degradation of proteins of interest. In this review, the molecular mechanisms of classical and new CRBN-based drugs are described, and recent advances in this field are discussed.

    DOI： 10.1016/j.pharmthera.2019.06.004

    Scopus

    PubMed

    researchmap

  • Cereblon Control of Zebrafish Brain Size by Regulation of Neural Stem Cell Proliferation. 国際誌

    Hideki Ando, Tomomi Sato, Takumi Ito, Junichi Yamamoto, Satoshi Sakamoto, Nobuhiro Nitta, Tomoko Asatsuma-Okumura, Nobuyuki Shimizu, Ryota Mizushima, Ichio Aoki, Takeshi Imai, Yuki Yamaguchi, Arnold J Berk, Hiroshi Handa

    iScience   15   95 - 108   2019年5月

    　詳細を見る

    記述言語：英語   掲載種別：研究論文（学術雑誌）  

    Thalidomide is a teratogen that causes multiple malformations in the developing baby through its interaction with cereblon (CRBN), a substrate receptor subunit of the CRL4 E3 ubiquitin ligase complex. CRBN was originally reported as a gene associated with autosomal recessive non-syndromic mild mental retardation. However, the function of CRBN during brain development remains largely unknown. Here we demonstrate that CRBN promotes brain development by facilitating the proliferation of neural stem cells (NSCs). Knockdown of CRBN in zebrafish embryos impaired brain development and led to small brains, as did treatment with thalidomide. By contrast, overexpression of CRBN resulted in enlarged brains, leading to the expansion of NSC regions and increased cell proliferation in the early brain field and an expanded expression of brain region-specific genes and neural and glial marker genes. These results demonstrate that CRBN functions in the determination of brain size by regulating the proliferation of NSCs during development.

    DOI： 10.1016/j.isci.2019.04.007

    Scopus

    PubMed

    researchmap

  • Identification of Posttranslational Modifications in Peroxisome Proliferator-Activated ReceptorγUsing Mass Spectrometry

    Shogo Katsura, Tomoko Okumura, Ryo Ito, Akira Sugawara, Atsushi Yokoyama

    PPAR Research   2014   1 - 8   2014年

    　詳細を見る

    掲載種別：研究論文（学術雑誌）   出版者・発行元：Hindawi Limited  

    DOI： 10.1155/2014/468925

    researchmap

  • TET3-OGT interaction increases the stability and the presence of OGT in chromatin 国際誌

    Ryo Ito, Shogo Katsura, Hiroki Shimada, Hikaru Tsuchiya, Masashi Hada, Tomoko Okumura, Akira Sugawara, Atsushi Yokoyama

    Genes to Cells   19 ( 1 )   52 - 65   2013年

    　詳細を見る

    記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

    Gene expression is controlled by alterations in the epigenome, including DNA methylation and histone modification. Recently, it was reported that 5-methylcytosine (5mC) is converted to 5-hydroxymethylcytosine (5hmC) by proteins in the ten-eleven translocation (TET) family. This conversion is believed to be part of the mechanism by which methylated DNA is demethylated. Moreover, histones undergo modifications such as phosphorylation and acetylation. In addition, modification with O-linked-N-acetylglucosamine (O-GlcNAc) by O-GlcNAc transferase (OGT) was recently identified as a novel histone modification. Herein, we focused on TET3, the regulation of which is still unclear. We attempted to elucidate the mechanism of its regulation by biochemical approaches. First, we conducted mass spectrometric analysis in combination with affinity purification of FLAG-TET3, which identified OGT as an important partner of TET3. Co-immunoprecipitation assays using a series of deletion mutants showed that the C-terminal H domain of TET3 was required for its interaction with OGT. Furthermore, we showed that TET3 is GlcNAcylated by OGT, although the GlcNAcylation did not affect the global hydroxylation of methylcytosine by TET3. Moreover, we showed that TET3 enhanced its localization to chromatin through the stabilization of OGT protein. Taken together, we showed a novel function of TET3 that likely supports the function of OGT.

    DOI： 10.1111/gtc.12107

    PubMed

    researchmap

▼全件表示

MISC

産業財産権

  • p63スプライシングバリアントの分解剤およびその用途

    半田 宏, 伊藤 拓水, 朝妻 知子, ルイ-ザ ゲリーニ, 山口 雄輝

    　詳細を見る

    出願人：学校法人東京医科大学

    出願番号：特願2019-139820  出願日：2019年7月

    公開番号：特開2021-020879  公開日：2021年2月

    J-GLOBAL

    researchmap

共同研究・競争的資金等の研究課題

  • HDAC阻害剤およびIMiDsのコンビネーション抗骨髄腫効果の解明

    研究課題/領域番号：20K16314  2020年4月 - 2022年3月

    日本学術振興会  科学研究費助成事業 若手研究  若手研究

    朝妻 知子

    　 詳細を見る

    配分額：3640000円 （ 直接経費：2800000円 、 間接経費：840000円 ）

    本研究では、HDAC阻害剤とIMiDsのコンビネーション抗骨髄腫効果の分子機構解明を目指しており、本年度ではpomalidomide (pom) 依存的なCRL4CRBN分解基質KEYに着目し、KEYとHDAC阻害剤の分子基盤および機能的相互作用の詳細を明らかにする解析を主に行なった。
    これまでの実験結果においてKEYのタンパク質量減少が見られたHDAC阻害剤、panobinostatやromidepsinは、pan-HDAC阻害剤であり複数のHDACを阻害することが知られている。そこで、KEYのタンパク質減少を担うHDACを絞り込むため、多発性骨髄腫由来細胞株であるOPM2において各HDACのノックダウン実験を行い、immunoblottingによりKEYのタンパク質量変動を分析した。並行して、各HDACの細胞増殖への重要性もcell growthアッセイにより調べた。この結果、KEYのタンパク質減少・抗骨髄腫活性に関与するHDACs、HDAC X及びHDAC Yを見出した。加えてHDAC X/YのノックダウンやHDAC阻害剤処理を行ったOPM2細胞のサンプルを用いて定量的リアルタイムPCRを行い、KEYがmRNAレベルで減少していることを見出した。さらに、これらの処理を行ったOPM2細胞のサンプルを用いてトランスクリプトーム解析を行った。この結果、KEYが減少することにより変動する下流遺伝子群が明らかとなった。その中でも特に、c-mycやその標的遺伝子群の減少が見られることが判明した。以上から、HDAC阻害剤の抗骨髄腫活性はすくなくともc-mycの減少が重要な位置付けを閉めている可能性が示唆された。

    researchmap

  • ビタミンD受容体のユビキチンリガーゼ活性の分子機構解明

    研究課題/領域番号：11J03265  2011年 - 2012年

    日本学術振興会  科学研究費助成事業 特別研究員奨励費  特別研究員奨励費

    朝妻 知子

    　 詳細を見る

    配分額：1300000円 （ 直接経費：1300000円 ）

    昨年度までに、ビタミンD受容体(VDR)複合体についてVDRの自己ユビキチン化活性を指標に分画し、自己ユビキチン化活性の有する複合体を2つの方法で精製した。これら複合体の構成因子候補として、BEND3及びMYSM1の二因子を同定していた。今年度はこれら因子の機能解析を中心に研究を行い、この結果両者共VDRのビタミンD依存的な転写活性化に寄与することを見出した。まず、BEND3がVDRの転写活性化能に与える影響について解析を行った。具体的な方法としては、過剰発現系及び内在性遺伝子ノックダウン下におけるレポーターアッセイ及び、VDR標的遺伝子の定量的RT-PCRを用いた。
    まず、内在性VDRによるビタミンD応答が見られないHEK293細胞において、VDR、BEND3を過剰発現してレポーターアッセイを行った結果、BEND3はVDRの転写活性化能を抑制する結果を得た。一方、内在性VDRが機能しているとされるHT-29細胞でBEND3のみ過剰発現して同様の検討を行った結果、この細胞ではBEND3の発現量依存的にVDRの転写活性化能が促進された。BEND3に関する先行研究では、過剰発現させたBEND3がヘテロクロマチンに局在すると言われており(Kizhakke M. et al., J. of Cell Sci., 2011)、HEK293細胞ではこの結果が反映されたと考えられる。一方で、ノックダウンや標的遺伝子発現等、内在性の機能に迫った方法では転写活性化を促進する機能が見られ、内在性BEND3は異なる挙動を示す、乃至は細胞(組織)特異的な作用機構を有すると推測した。
    MYSM1についても、先に述べたBEND3と同様の方法で解析を行い、MYSM1がVDRの転写活性化能を促進する事を見出した。本結果は、MYSM1についての先行論文(アンドロゲン受容体(AR)の転写を活性化する、Zhu P. et al., Mol. Cell, 2007)を支持する結果であった。さらに、MYSM1についてはMS-MS解析により、このユビキチン化候補サイトを2ヶ所同定した。その内の1つは、MYSM1の脱ユビキチン化活性の酵素中心付近であったことから、MYSM1の酵素活性がユビキチン化により制御される可能性がある。
    これらの結果により、VDRの転写因子としての作用機序について、他の核内受容体とは異なる面(BEND3)、共通な面(MYSM1)の両面性が示唆された。核内受容体の中ではVDR独自の活性である自己ユビキチン化活性を指標に、リガンド依存的に機能する因子を取得できた事は意義深いと考える。

    researchmap