Sampetrean, Oltea

写真a

Affiliation

Research Centers and Institutes, Human Biology-Microbiome-Quantum Research Center (Mita)

Position

Project Professor (Non-tenured)

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Research Areas 【 Display / hide 】

  • Life Science / Cell biology

  • Life Science / Neurosurgery

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Research Keywords 【 Display / hide 】

  • Malignant glioma

  • cancer

  • brain tumors

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Research Themes 【 Display / hide 】

  • 悪性脳腫瘍幹細胞の特性の解明, 

    2009.04
    -
    Present

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Papers 【 Display / hide 】

  • Berberine as a potential enhancer for 5-ALA-mediated fluorescence in glioblastoma: increasing detectability of infiltrating glioma stem cells to optimize 5-ALA-guided surgery.

    Ohtsuka Y, Suehiro S, Inoue A, Ohnishi T, Nishikawa M, Yamashita D, Yano H, Choudhury ME, Ozaki S, Sampetrean O, Saya H, Watanabe H, Tanaka J, Kunieda T

    Journal of neurosurgery    1 - 11 2024.03

    ISSN  0022-3085

  • 5-Aminolevulinic acid increases boronophenylalanine uptake into glioma stem cells and may sensitize malignant glioma to boron neutron capture therapy

    Fukumura M., Nonoguchi N., Kawabata S., Hiramatsu R., Futamura G., Takeuchi K., Kanemitsu T., Takata T., Tanaka H., Suzuki M., Sampetrean O., Ikeda N., Kuroiwa T., Saya H., Nakano I., Wanibuchi M.

    Scientific Reports (Scientific Reports)  13 ( 1 ) 10173 2023.12

    　View Summary

    Boron neutron capture therapy (BNCT) is a high-LET particle radiotherapy clinically tested for treating malignant gliomas. Boronophenylalanine (BPA), a boron-containing phenylalanine derivative, is selectively transported into tumor cells by amino acid transporters, making it an ideal agent for BNCT. In this study, we investigated whether the amino acid 5-aminolevulinic acid (ALA) could sensitize glioma stem cells (GSCs) to BNCT by enhancing the uptake of BPA. Using human and mouse GSC lines, pre-incubation with ALA increased the intracellular accumulation of BPA dose-dependent. We also conducted in vivo experiments by intracerebrally implanting HGG13 cells in mice and administering ALA orally 24 h before BPA administration (ALA + BPA-BNCT). The ALA preloading group increased the tumor boron concentration and improved the tumor/blood boron concentration ratio, resulting in improved survival compared to the BPA-BNCT group. Furthermore, we found that the expression of amino acid transporters was upregulated following ALA treatment both in vitro and in vivo, particularly for ATB0,+. This suggests that ALA may sensitize GSCs to BNCT by upregulating the expression of amino acid transporters, thereby enhancing the uptake of BPA and improving the effectiveness of BNCT. These findings have important implications for strategies to improve the sensitivity of malignant gliomas to BPA-BNCT.

  • Dual-radionuclide in vivo imaging of micro-metastasis and lymph tract with submillimetre resolution

    Yagishita A., Takeda S., Ohnuki K., Katsuragawa M., Sampetrean O., Fujii H., Takahashi T.

    Scientific Reports (Scientific Reports)  13 ( 1 ) 19464 2023.12

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    Multi-radionuclide in vivo imaging with submillimetre resolution can be a potent tool for biomedical research. While high-resolution radionuclide imaging faces challenges in sensitivity, multi-radionuclide imaging encounters difficulty due to radiation contamination, stemming from crosstalk between radionuclides and Compton scattering. Addressing these challenges simultaneously is imperative for multi-radionuclide high-resolution imaging. To tackle this, we developed a high-spatial-resolution and high-energy-resolution small animal single-photon emission computed tomography (SPECT) scanner, named CdTe-DSD SPECT-I. We first assessed the feasibility of multi-tracer SPECT imaging of submillimetre targets. Using the CdTe-DSD SPECT-I, we performed SPECT imaging of submillimetre zeolite spheres absorbed with 125I- and subsequently imaged 125I-accumulated spheroids of 200–400 µm in size within an hour, achieving clear and quantitative images. Furthermore, dual-radionuclide phantom imaging revealed a distinct image of the submillimetre sphere absorbed with 125I- immersed in a 99mTc-pertechnetate solution, and provided a fair quantification of each radionuclide. Lastly, in vivo imaging was conducted on a cancer-bearing mouse with lymph node micro-metastasis using dual-tracers. The results displayed dual-tracer images of lymph tract by 99mTc-phytic acid and the submillimetre metastatic lesion by 125I-, shown to align with the immunofluorescence image.

  • Gene therapy using genome-edited iPS cells for targeting malignant glioma

    Tamura R., Miyoshi H., Imaizumi K., Yo M., Kase Y., Sato T., Sato M., Morimoto Y., Sampetrean O., Kohyama J., Shinozaki M., Miyawaki A., Yoshida K., Saya H., Okano H., Toda M.

    Bioengineering and Translational Medicine (Bioengineering and Translational Medicine)  8 ( 5 ) e10406 2023.09

    ISSN  2380-6761

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    Glioblastoma is characterized by diffuse infiltration into the normal brain. Invasive glioma stem cells (GSCs) are an underlying cause of treatment failure. Despite the use of multimodal therapies, the prognosis remains dismal. New therapeutic approach targeting invasive GSCs is required. Here, we show that neural stem cells (NSCs) derived from CRISRP/Cas9-edited human-induced pluripotent stem cell (hiPSC) expressing a suicide gene had higher tumor-trophic migratory capacity compared with mesenchymal stem cells (MSCs), leading to marked in vivo antitumor effects. High migratory capacity in iPSC-NSCs was related to self-repulsive action and pathotropism involved in EphB-ephrinB and CXCL12-CXCR4 signaling. The gene insertion to ACTB provided higher and stable transgene expression than other common insertion sites, such as GAPDH or AAVS1. Ferroptosis was associated with enhanced antitumor immune responses. The thymidylate synthase and dihydroprimidine dehydrogenase expressions predicted the treatment efficacy of therapeutic hiPSC-NSCs. Our results indicate the potential benefit of genome-edited iPS cells based gene therapy for invasive GSCs. Furthermore, the present research concept may become a platform to promote clinical studies using hiPSC.

  • Regulatory roles of fibronectin and integrin α5 in reorganization of the actin cytoskeleton and completion of adipogenesis

    Uetaki M., Onishi N., Oki Y., Shimizu T., Sugihara E., Sampetrean O., Watanabe T., Yanagi H., Suda K., Fujii H., Kano K., Saya H., Nobusue H.

    Molecular Biology of the Cell (Molecular Biology of the Cell)  33 ( 9 ) ar78 2022.08

    ISSN  10591524

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    Cellular differentiation is characterized by changes in cell morphology that are largely determined by actin dynamics. We previously showed that depolymerization of the actin cytoskeleton triggers the differentiation of preadipocytes into mature adipocytes as a result of inhibition of the transcriptional coactivator activity of megakaryoblastic leukemia 1 (MKL1). The extracellular matrix (ECM) influences cell morphology via interaction with integrins, and reorganization of the ECM is associated with cell differentiation. Here we show that interaction between actin dynamics and ECM rearrangement plays a key role in adipocyte differentiation. We found that depolymerization of the actin cytoskeleton precedes disruption and degradation of fibrillar fibronectin (FN) structures at the cell surface after the induction of adipogenesis in cultured preadipocytes. A FN matrix suppressed both reorganization of the actin cytoskeleton into the pattern characteristic of adipocytes and terminal adipocyte differentiation, and these inhibitory effects were overcome by knockdown of integrin α5 (ITGα5). Peroxisome proliferator–activated receptor γ was required for down-regulation of FN during adipocyte differentiation, and MKL1 was necessary for the expression of ITGα5. Our findings suggest that cell-autonomous down-regulation of FN-ITGα5 interaction contributes to reorganization of the actin cytoskeleton and completion of adipocyte differentiation.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Reviews, Commentaries, etc. 【 Display / hide 】

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • Plastic regulation of chromosome dynamics in cancer

    2022.04
    -
    2027.03

    Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (S), No Setting

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    染色体不安定性は、進行がんで典型的にみられる性質で、染色体の数や構造が多様に変化した異数体細胞を作り出す。がん細胞の異数体化は、がんの生物学的悪性度と相関することが知られるが、一方で、実験的な異数体化の誘導は、細胞増殖を強く抑制するために、異数体化ががんの病態にどのように関与するのか不明である。本研究では、染色体不安定性のレベルが可逆的に変化するがん幹細胞を用いて、細胞の増殖性と関連する染色体構造を探索する。特に、染色体不安定性のレベルを操作することによりその可塑性の意義を追求して、異数体化がみられるがんはなぜ悪いのかというがん生物学に残された命題に挑戦する。
    本年度は、まず、核型のパターンによってクローン化したがん幹細胞について、染色体不安定性のレベルと増殖性を調べた。得られたクローンの核型を解析したところ、10.5%がもともとのがん幹細胞（Tumor Stem、TS細胞）と同様な核型分布を保ち(Parent-likes)、10.5%が多倍体となり(Hyperploids)、残りの79%が二倍体であった (Diploids)。これら３グループに分けられた各クローンについて、Ｍ期の染色体動態と、セントロメアにおけるAurora B機能を解析したところ、TS細胞と同程度に、Parent-likesとHyperploids は染色体分配エラーの頻度が高く、Aurora B 基質のリン酸化レベルが低下していた。このことから、TS細胞のAurora B活性が高くなりうること、二倍体の染色体不安定性が低い細胞が、異数体化する染色体不安定性が高い細胞よりも増殖に有利であることが示唆された。これらの観察は、がん幹細胞の染色体不安定性のレベルが可塑的であることを再確認する結果である。またこれらのクローンについて、低リード数でのDNAシーケンスデータを~5Mb枠で区切るKaryo-seq解析を行い、ゲノムワイドにその量的変化を検討した。そして各クローンで発現している遺伝子をトランスクリプトーム解析によって調べたところ、染色体不安定性レベルの高低を説明しうる変化が見出された。
    当初の構想どおり、がん幹細胞の染色体不安定性のレベルが可塑的であることと、その可塑性はAurora B活性の変化によってよく反映されることを再確認する結果が得られた。これをもとに、経時間的な変化を調べるための実験を当初の計画に沿って進めている。
    がん幹細胞（TS細胞）とそのクローン９系統（Diploids、Parent-likes、Hyperploidsの各３クローン）について、細胞の増殖性と染色体不安定性のレベル、遺伝子発現プロファイルを、 長期間培養して追跡する試験管内での変化と、マウスの脳実質に同所移植して、生体環境での変化を解析する。

  • 脳腫瘍幹細胞の表現型可塑性及びフェノタイプ・スイッチの実態解明と克服方法の確立

    2022.04
    -
    2025.03

    Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), No Setting

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    細胞の表現型の可塑性は細胞がゲノムの変化なく表現型のみを変化させる能力として理解されている。可塑性は個体発生において重要な役割を果たすことが知られているが、近年、癌細胞、特に癌幹細胞が環境の変化に適応する過程においても注目されている。しかし、腫瘍組織における表現型可塑性の実態が充分に解明されておらず、有効な阻害方法も確立されていない。
    本研究では脳腫瘍幹細胞の表現型可塑性を誘導する微小環境因子を広く探索し、明らかにする。さらに、その制御因子を同定し、フェノタイプ・スイッチを予防あるいは阻害することで脳腫瘍幹細胞の治療抵抗性の克服を目指す。
    細胞の表現型の可塑性は細胞がゲノムの変化なく表現型のみを変化させる能力として理解されている。可塑性は個体発生において重要な役割を果たすことが知られているが、近年、癌細胞、特に癌幹細胞が環境の変化に適応する過程においても注目されている。しかし、腫瘍組織における表現型可塑性の実態が充分に解明されておらず、有効な阻害方法も確立されていない。申請者はこれまでの研究で、脳腫瘍幹細胞が代謝可塑性を発揮することで酸素や糖の不足に可逆的な適応反応を示し、そして、その際の表現型の変化が薬剤抵抗性を引き起こすことを見出した。
    本研究では脳腫瘍幹細胞の表現型可塑性を誘導する微小環境因子を広く探索し、明らかにすることを目指し、2022年度はまず3つの評価系を確立した。
    １．培養脳切片を用いたex vivo評価系の確立：正常脳並びに腫瘍を移植した脳より脳切片を作製、培養した。Iba1, CX3CR1等に対する抗体を用いたイメージングにより腫瘍細胞と脳内常在型免疫細胞の相互作用を可視化した。また、培養条件を変えることによって微小環境を変化させた上で切片より線条体、脳表などの部位ごとに組織を摘出し、フラクス・アナライザーで代謝を測定するアッセイ系を確立した。
    ２．免疫細胞の評価系の確立：脳切片ではマイクログリア、星状細胞など、脳内に存在する免疫応答関連細胞の解析が可能であるが、血流が途絶えているため、T細胞やB細胞などの全身免疫応答関連細胞の解析は困難である。末梢免疫系の影響を検証するため、正常脳並びに腫瘍を移植した脳の免疫細胞のみを単離し、10-15種類の細胞をフローサイトメトリーによって同時に解析することで微小環境の詳細な評価を行うことに成功した。
    3．免疫応答が異なる腫瘍より3種類の脳腫瘍幹細胞を新しく樹立し、その遺伝子発現プロフィルの解析を始めた。
    脳内常在型免疫細胞のライブイメージングによる可視化、そして、脳内常在型免疫細胞並びに末梢系免疫応答関連細胞の経時的な評価に成功したため。
    前年度確立した評価系を用いて、微小環境の代謝、免疫応答に注目し、脳腫瘍幹細胞のフェノタイプ・スイッチが誘導される条件を同定する。さらに、マルチオミクス解析を用いて遺伝子発現、メタボローム、エピゲノムプロファイルを明らかにし、制御因子候補を同定する。

  • Evaluation and targeting of the autonomous niche of glioma stem cells

    2019.04
    -
    2022.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Sampetrean Oltea, Grant-in-Aid for Scientific Research (C), Principal investigator

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    Glioblastomas are fatal because they recur within months after treatment, with limited options for additional therapy. Glioma stem cells (GSCs), the cells causing recurrence form their own niche by secreting components favorable for survival and proliferation. However, the characteristics of the GSC autonomous niche have not been fully elucidated. In this study, we recorded the formation process of the autonomous niche and showed that, consistent with the recurrence patterns of glioblastomas, the niche is formed not only around the tumor mass but also in distant areas within the normal brain. Furthermore, through screening of small molecule inhibitors, we identified several drugs that disrupt the autonomic niche.Importantly, systemic factors were found to significantly influence the response of the tumor to these inhibitors. Further investigations of the interaction of the autonomous niche with systemic factors will thus be necessary to establish anti-niche therapies.

  • Novel and Interdisciplinary Application of Hard X-ray and Gamma-ray Detectors

    2018.06
    -
    2023.03

    Grants-in-Aid for Scientific Research, Takahashi Tadayuki, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), No Setting

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    We developed a gamma-ray imager based on the requirements of our research projects and nuclear medicine. We applied the technology based on a high-resolution CdTe imager to in vivo imaging of cancer-bearing mice. We succeeded in simultaneously visualizing the accumulation of three different RI compounds in the microstructure of the mouse pharynx with high spatial resolution. For image analysis, the analytical technique of X-ray observation of supernova remnants was applied. A wide-field imager was developed to study in vivo pharmacokinetics and successfully visualize At-211 accumulation in tumors, which could not be determined with the conventional SPECT system. We also applied our technology to non-destructive element analysis and polarization measurement in atomic physics and nuclear physics.

  • Characterization and targeting strategies for the glioma stem cell niche

    2016.04
    -
    2019.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, SAMPETREAN OLTEA, Grant-in-Aid for Scientific Research (C), Principal investigator

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    Eradication of glioma stem cells (GSC) is a critical task in the treatment of glioblastoma. Inhibition of the GSC niche results in loss of self-renewal of the stem cell pool and is therefore considered a promising new treatment. For GCSs, the existence of perivascular and hypoxic niches has been reported. However, their characteristics and the conditions of their formation is still not sufficiently understood. In this study, we performed live imaging of the GSC niche and succeeded in visualizing both niches and their interaction with the GSCs. We found that the two niches can co-exist within the same tumor, but their evolution throughout the tumor formation process is variable. Interestingly, we also found a subpopulation of GSCs that does not associate with either blood vessels or hypoxic regions. These GSCs secrete factors which can alter the microenvironment and create their own niche. Further investigations of such niches will be necessary to establish anti-niche therapies.

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Courses Taught 【 Display / hide 】

  • MICROBIOLOGY

    2024

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