慶應義塾研究者情報データベース

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• 疾患の発症機序解明や治療薬の開発につながる基礎研究を行っています。特に、がんの悪性化と関わりが深い生命現象である血管擬態や糖鎖修飾に注目し、化学的なアプローチを用いてその機構を解析しています。

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• 2020年04月

  -

  2022年03月

  日本学術振興会 特別研究員DC2

• 2024年04月

  -

  継続中

  慶應義塾大学, 理工学部　応用化学科, 助教 (有期)

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学歴 【 表示 ／ 非表示 】

• 2013年04月

  -

  2017年03月

  慶應義塾大学, 理工学部, 応用化学科

  大学, 卒業

• 2017年04月

  -

  2019年03月

  慶應義塾大学, 理工学研究科

  大学院, 修了, 修士

• 2019年04月

  -

  2022年03月

  慶應義塾大学, 理工学研究科

  大学院, 修了, 博士

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学位 【 表示 ／ 非表示 】

• 博士(理学), 慶應義塾大学, 課程, 2022年03月

研究分野 【 表示 ／ 非表示 】

研究分野 【 表示 ／ 非表示 】

• ライフサイエンス / 分子生物学

• ライフサイエンス / 細胞生物学

研究キーワード 【 表示 ／ 非表示 】

研究キーワード 【 表示 ／ 非表示 】

• がん生物学

• ケミカルバイオロジー

• 糖鎖生物学

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• DPY19L3 promotes vasculogenic mimicry by its C-mannosyltransferase activity

  Hassan Baydoun, Yuji Kato, Hiroki Kamo, Anna Hüsch, Hayato Mizuta, Ryota Kawahara, Siro Simizu

  Oncology Research （Oncology Research）  32 （ 4 ） 607 - 614 2024年

  共著, 査読有り,  ISSN  09650407

  　概要を見る

  C-mannosylation is a post-translational modification that occurs intracellularly in the endoplasmic reticulum. In humans, biosynthesis of C-mannosylation in proteins containing thrombospondin type 1 repeat is catalyzed by the DPY19 family; nonetheless, biological functions of protein C-mannosylation are not yet fully understood, especially in tumor progression. Vasculogenic mimicry (VM) is the formation of fluid-conducting channels by highly invasive and genetically deregulated tumor cells, enabling the tumors to form matrix-embedded vasculogenic structures, containing plasma and blood cells to meet the metabolic demands of rapidly growing tumors. In this study, we focused on DPY19L3, a C-mannosyltransferase, and aimed to unravel its role in VM. Knockout of DPY19L3 inhibited the formation of VM in HT1080 human fibrosarcoma cells. Re-expression of wild-type DPY19L3 recovered VM formation; however, DPY19L3 isoform2, an enzymatic activity-defect mutant, did not restore it, suggesting that the C-mannosyltransferase activity of DPY19L3 is crucial to its function. Furthermore, the knockdown of DPY19L3 in MDA-MB-231 breast cancer cells hindered its network formation ability. Altogether, our findings suggest that DPY19L3 is required for VM formation and stipulate the relevance of C-mannosylation in oncogenesis.

  • Access to Document (DOI)

• Biogenesis of fibrils requires C-mannosylation of PMEL

  Ryota Kawahara, Tomoko Usami, Satoko Arakawa, Hiroki Kamo, Takehiro Suzuki, Ryosuke Komatsu, Hiroyuki Hara, Yuki Niwa, Erina Shimizu, Naoshi Dohmae, Shigeomi Shimizu, Siro Simizu

  FEBS Journal （FEBS Journal）  290 （ 22 ） 5373 - 5394 2023年11月

  共著, 筆頭著者, 査読有り,  ISSN  1742464X

  　概要を見る

  Premelanosome protein (PMEL), a melanocyte-specific glycoprotein, has an essential role in melanosome maturation, assembling amyloid fibrils for melanin deposition. PMEL undergoes several post-translational modifications, including N- and O-glycosylations, which are associated with proper melanosome development. C-mannosylation is a rare type of protein glycosylation at a tryptophan residue that might regulate the secretion and localization of proteins. PMEL has one putative C-mannosylation site in its core amyloid fragment (CAF); however, there is no report focusing on C-mannosylation of PMEL. To investigate this, we expressed recombinant PMEL in SK-MEL-28 human melanoma cells and purified the protein. Mass spectrometry analyses demonstrated that human PMEL is C-mannosylated at multiple tryptophan residues in its CAF and N-terminal fragment (NTF). In addition to the W153 or W156 residue (CAF), which lies in the consensus sequence for C-mannosylation, the W104 residue (NTF) was C-mannosylated without the consensus sequence. To determine the effects of the modifications, we deleted the PMEL gene by using CRISPR/Cas9 technology and re-expressed wild-type or C-mannosylation-defective mutants of PMEL, in which the C-mannosylated tryptophan was replaced with a phenylalanine residue (WF mutation), in SK-MEL-28 cells. Importantly, fibril-containing melanosomes were significantly decreased in W104F mutant PMEL-re-expressing cells compared with wild-type PMEL, observed using transmission electron microscopy. Furthermore, western blot and immunofluorescence analysis suggested that the W104F mutation may cause mild endoplasmic reticulumretention, possibly associated with early misfolding, and lysosomal misaggregation, thus reducing functional fibril formation. Our results demonstrate that C-mannosylation of PMEL is required for proper melanosome development by regulating PMEL-derived fibril formation.

  • Access to Document (DOI)

• Cofilin promotes vasculogenic mimicry by regulating the actin cytoskeleton in human breast cancer cells

  Minami Nakajima, Ryota Kawahara, Siro Simizu

  FEBS Letters （FEBS Letters）  597 （ 8 ） 1114 - 1124 2023年04月

  共著, 査読有り,  ISSN  00145793

  　概要を見る

  Vasculogenic mimicry (VM) is the formation of microvascular channels by cancer cells. VM requires cellular processes that are regulated by changes in cellular migration and morphology. Cofilin (CFL), a key regulator of actin depolymerization, has been reported to affect malignant phenotypes of cancer. We show that treatment with inhibitors of actin dynamics suppresses VM in MDA-MB-231 human breast cancer cells. We established CFL-knockout (KO) MDA-MB-231 cells and found that VM was attenuated in CFL-KO cells. Although the re-expression of wild-type CFL restored VM in CFL-KO cells, inactive phosphomimetic CFL failed to do so. Collectively, our results demonstrate that CFL is a critical regulator of VM and implicate CFL as a novel therapeutic target for breast cancer.

  • Access to Document (DOI)

• Tyrosinase suppresses vasculogenic mimicry in human melanoma cells

  Hiroki Kamo, Ryota Kawahara, Siro Simizu

  Oncology Letters （Oncology Letters）  23 （ 5 ）  2022年05月

  共著, 査読有り,  ISSN  17921074

  　概要を見る

  Melanoma is a type of skin cancer that derives from melanocytes; this tumor is highly metastatic and causes poor clinical outcomes in patients. Vasculogenic mimicry (VM), a vascular-like network that is formed by tumor cells instead of endothelial cells, promotes the growth and metastasis of tumors by providing tumors with oxygen- and nutrient-containing blood. VM correlates with a poor prognosis in patients with melanoma, but the melanoma-specific mechanisms of VM are unknown. The present study revealed that treatment with the melanogenesis stimulators 3-isobutyl 1-methylxanthine (IBMX) and α-melanocyte-stimulating hormone (α-MSH) significantly inhibited VM in MNT-1 human pigmented melanoma cells. Tyrosinase (TYR), an essential enzyme in melanin production, was upregulated on treatment with α-MSH and IBMX, prompting an examination of the association between TYR and VM. A TYR inhibitor, arbutin, promoted VM in melanoma cells. Furthermore, CRISPR/Cas9-mediated knockout (KO) of TYR increased VM by melanoma cells. Notably, even in non-pigmented melanoma cells, TYR attenuated VM. Although re-expression of wild-type TYR suppressed VM in TYR-KO cells, T373K TYR, a frequently detected mutation in individuals with albinism, failed to inhibit VM. Overall, these results demonstrated that TYR negatively regulates VM, providing novel insights into the antioncogenic function of TYR in melanomas.

  • Access to Document (DOI)

• ErbB4-mediated regulation of vasculogenic mimicry capability in breast cancer cells

  Ryota Kawahara, Siro Simizu

  Cancer Science （Cancer Science）  113 （ 3 ） 950 - 959 2022年03月

  共著, 筆頭著者, 査読有り,  ISSN  13479032

  　概要を見る

  ErbB4 is a member of the ErbB receptor tyrosine kinase family. It has both pro- and anti-oncogenic activities in tumors. Vasculogenic mimicry (VM), a phenomenon in which cancer cells form capillary-like structures without endothelial cells, has been recognized to be a cause of malignant phenotypes in some solid tumors. Here, we used an in vitro VM formation assay, and demonstrated that ErbB4 negatively regulated VM formation in human breast cancer cells. By using CRISPR/Cas9-mediated gene knockout, we verified that the depletion of endogenous ErbB4 improved the VM formation capability. Although treatment with neuregulin 1 (NRG1), a ligand of ErbB4, induced the phosphorylation of ErbB4 and promoted VM formation in a dose-dependent manner, it did not induce such activities in kinase-dead K751M ErbB4-overexpressing cells. Moreover, we examined the effect of the missense mutation E872K of ErbB4, which has been reported in multiple tumors, on VM formation, and found that the mutation enhanced the basal phosphorylation level and ErbB4-mediated VM formation in the absence of NRG1 stimulation. Whereas NRG1 stimulated VM formation, excessive activation of ErbB4 induced a negative effect. In E872K ErbB4-overexpressing cells, but not in wild-type ErbB4-overexpressing cells, the number of VM tubes was significantly decreased by low-dose treatment with the ErbB inhibitor afatinib. Taken together, our findings demonstrated the significance of ErbB4-mediated VM formation, and suggested the possibility of ErbB4 mutations as effective targets in breast cancer.

  • Access to Document (DOI)

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• ヒトがん細胞の血管擬態における細胞表面受容体の役割解析 (本文)

  川原, 遼太

  （慶應義塾大学大学院理工学研究科）  2021年

• ヒトがん細胞の血管擬態における細胞表面受容体の役割解析 (要旨)

  川原, 遼太

  （慶應義塾大学大学院理工学研究科）  2021年

• ヒトがん細胞の血管擬態における細胞表面受容体の役割解析 (審査報告)

  川原, 遼太

  （慶應義塾大学大学院理工学研究科）  2021年

受賞 【 表示 ／ 非表示 】

受賞 【 表示 ／ 非表示 】

• 第80回日本癌学会学術総会　JCA若手研究者ポスター賞

  2021年10月, 日本癌学会, ErbB4 はヒト乳がん細胞の血管擬態を負に調節する

  受賞区分： 国内学会・会議・シンポジウム等の賞

担当授業科目 【 表示 ／ 非表示 】

担当授業科目 【 表示 ／ 非表示 】

• 自然科学実験

  2024年度

• 応用化学実験Ｄ

  2024年度

所属学協会 【 表示 ／ 非表示 】

所属学協会 【 表示 ／ 非表示 】

• 日本糖質学会, 

  2024年

  -

  継続中

• 日本がん分子標的治療学会, 

  2020年

  -

  継続中

• 日本癌学会, 

  2017年

  -

  継続中

• 日本がん転移学会, 

  2017年

  -

  継続中