Sakihama Shugo

写真a

Title

Assistant Professor

Researcher Number(JSPS Kakenhi)

30835129

Current Affiliation Organization 【 display / non-display

  • Duty   University of the Ryukyus   Graduate School of Health Sciences   Division of Health Sciences   Assistant Professor  

University 【 display / non-display

  •  
    -
    2013.03

    University of the Ryukyus   Faculty of Medicine   Graduated

Graduate School 【 display / non-display

  • 2013.04
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    2015.03

    University of the Ryukyus  Graduate School, Division of Health Care  Doctor's Course (first term)  Completed

  • 2015.04
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    2018.03

    University of the Ryukyus  Graduate School, Division of Health Care  Doctor's Course (second term)  Completed

External Career 【 display / non-display

  • 2018.04
    -
    2022.05

    Department of Pathology and Cell Biology, Graduate School of Medicine and Faculty of Medicine, University of the Ryukyus  

  • 2022.06
     
     

     

Research Interests 【 display / non-display

  • Adult T-cell leukemia/lymphoma

Research Areas 【 display / non-display

  • Life Science / Hematology and medical oncology

Published Papers 【 display / non-display

  • Coactivation of innate immune suppressive cells induces acquired resistance against combined TLR agonism and PD-1 blockade

    Nishinakamura, H; Shinya, S; Irie, T; Sakihama, S; Naito, T; Watanabe, K; Sugiyama, D; Tamiya, M; Yoshida, T; Hase, T; Yoshida, T; Karube, K; Koyama, S; Nishikawa, H

    SCIENCE TRANSLATIONAL MEDICINE ( Science Translational Medicine )  17 ( 785 ) eadk3160   2025.02 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Immune checkpoint blockade therapy has been successfully applied in clinical settings as a standard therapy for many cancer types, but its clinical efficacy is restricted to patients with immunologically hot tumors. Various strategies to modify the tumor microenvironment (TME), such as Toll-like receptor (TLR) agonists that can stimulate innate immunity, have been explored but have not been successful. Here, we show a mechanism of acquired resistance to combination treatment consisting of an agonist for multiple TLRs, OK-432 (Picibanil), and programmed cell death protein 1 (PD-1) blockade. Adding the TLR agonist failed to convert the TME from immunogenically cold to hot and did not augment antitumor immunity, particularly CD8+ T cell responses, in multiple animal models. The failure was attributed to the coactivation of innate suppressive cells, such as polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) expressing CXCR2, through high CXCL1 production by macrophages in the TME upon OK-432 treatment. A triple combination treatment with OK-432, PD-1 blockade, and a CXCR2 neutralizing antibody overcame the resistance induced by PMN-MDSCs, resulting in a stronger antitumor effect than that of any dual combinations or single treatments. The accumulation of PMN-MDSCs was similarly observed in the pleural effusions of patients with lung cancer after OK-432 administration. We propose that successful combination cancer immunotherapy intended to stimulate innate antitumor immunity requires modulation of unwanted activation of innate immune suppressive cells, including PMN-MDSCs.

  • Recent progress in pathological understanding of adult T-cell leukemia/ lymphoma in the new classification era

    Karube, K; Sakihama, S; Takatori, M; Morichika, K; Tamaki, T; Wada, N; Fukushima, T

    LEUKEMIA RESEARCH ( Leukemia Research )  148   107634 - 107634   2025.01 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell lymphoma caused by Human T-cell leukemia virus type 1 (HTLV-1) infection. Although the 5th Edition of the WHO classification (WHO-5) did not make drastic changes regarding the disease concept of ATLL from the revised 4th Edition of the WHO classification (WHO-4R), WHO-5 newly introduced the essential and desirable diagnostic criteria, namely, "neoplastic lymphoid cell proliferation with mature T-cell phenotype; proven HTLV-1 carriership" and "identification of monoclonal integration of HTLV-1", respectively. To satisfy the desirable criteria, a new diagnostic method using a combination of HBZ-ISH and tax-PCR was introduced for the identification of the HTLV-1 in addition to the conventionally used Southern blot hybridization, especially in the case when only FFPE specimens are available. Morphologically, pleomorphic- and anaplastic large cell-type, account for most cases, while minor variants, ATLL with dermatopathic reaction, angioimmunoblastic T-cell lymphoma-like variant, and classic Hodgkin lymphoma-like variant, should also be noted as diagnostic pitfalls. Phenotypically, about 80 % of ATLL cases show a typical phenotype of CD3 + CD4 +CD25 +CCR4 + , while about 10 % show atypical phenotypes such as T follicular helper cell-like one. Many genetic abnormalities, mainly associated with the TCR signaling pathway, are observed, and most are more frequent in the aggressive type than in the indolent type, except for STAT3, indicating the heterogeneous pathogenic process of ATLL. In this review, we present the latest findings on molecular pathogenesis and histopathological findings of ATLL in the era of the new classification of lymphomas, serving as a basis for future research and classification.

  • A Comprehensive Study of the Immunophenotype and its Clinicopathologic Significance in Adult T-Cell Leukemia/Lymphoma.

    Tamaki T, Karube K, Sakihama S, Tsuruta Y, Awazawa R, Hayashi M, Nakada N, Matsumoto H, Yagi N, Ohshiro K, Nakazato I, Kitamura S, Nishi Y, Miyagi T, Yamaguchi S, Nakachi S, Morishima S, Masuzaki H, Takahashi K, Fukushima T, Wada N

    Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc   36 ( 8 ) 100169 - 100169   2023.03 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell tumor caused by human T-lymphotropic virus type 1 (HTLV-1). The typical ATLL immunophenotypes are described in the 2017 World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues (positive: CD2, CD3, CD5, CD4, and CD25; negative: CD7, CD8, and cytotoxic markers; and partially positive: CD30, CCR4, and FOXP3). However, limited studies are available on the expression of these markers, and their mutual relationship remains unknown. Furthermore, the expression status of novel markers associated with T-cell lymphomas, including Th1 markers (T-bet and CXCR3), Th2 markers (GATA3 and CCR4), T follicular helper markers (BCL6, PD1, and ICOS), and T-cell receptor (TCR) markers, and their clinicopathologic significance is unclear. In this study, we performed >20 immunohistochemical stains in 117 ATLL cases to determine the comprehensive immunophenotypic profile of ATLL, which were compared on the basis of clinicopathologic factors, including morphologic variants (pleomorphic vs anaplastic), biopsy locations, treatments, Shimoyama classification-based clinical subtype, and overall survival. CD3+/CD4+/CD25+/CCR4+ was considered a typical immunophenotype of ATLL, but approximately 20% of cases did not conform to this pattern. Simultaneously, the following new findings were obtained: (1) most cases were negative for TCR-β and TCR-δ (104 cases, 88.9%), indicating the usefulness of negative conversion of TCR expression to provide differentiation from other T-cell tumors; (2) the positivity of CD30 and CD15 and the negativity of FOXP3 and CD3 were significantly associated with anaplastic morphology; and (3) atypical cases, such as T follicular helper marker-positive (12 cases, 10.3%) and cytotoxic molecule-positive cases (3 cases, 2.6%), were identified. No single markers could predict the overall survival among patients with acute/lymphoma subtypes of ATLL. The results of this study illustrate the diversity of ATLL phenotypes. In T-cell tumors occurring in HTLV-1 carriers, the possibility of ATLL should not be eliminated even when the tumor exhibits an atypical phenotype, and the confirmation of HTLV-1 in the tissue is recommended.

  • Spindle cell tumor with histiocytic and myogenic marker expression in the lymph node of a human T-cell leukemia virus type 1 carrier.

    Kubo T, Hirayama Y, Sakihama S, Kikuchi T, Hirohashi Y, Tsujiwaki M, Karube K, Hasegawa T, Torigoe T

    Pathology, research and practice ( Pathology Research and Practice )  234   153935   2022.06 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Genetic Alterations in Adult T-Cell Leukemia/Lymphoma: Novel Discoveries with Clinical and Biological Significance.

    Sakihama S, Karube K

    Cancers ( Cancers )  14 ( 10 )   2022.05 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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