細胞機能解析学分野

Hiroki Doi

  (土井 洋輝)

Profile Information

Affiliation
Fujita Health University
Degree
博士(医療科学)(2023年3月藤田医科大学)

ORCID ID
 https://orcid.org/0000-0002-3595-6235
J-GLOBAL ID
202201017243025185
researchmap Member ID
R000041120

Papers

 34
  • Hiroki Doi, Hidehiko Akiyama, Taei Matsui, Kazuya Shiogama, Hideaki Matsuura, Sumie Fujii, Yasuo Miura
    Anticancer research, 46(9) 4909-4921, Sep, 2026  Peer-reviewedLead authorCorresponding author
    BACKGROUND/AIM: Andrographolide (Andro), a diterpene lactone from Andrographis paniculata, induces reactive oxygen species (ROS)-dependent apoptosis in hematologic malignancy cells. This study investigated whether Andro also induces ferroptosis-associated cytotoxicity in plasma cell neoplasm cell lines. MATERIALS AND METHODS: H929 and ARH77 cells were treated with Andro in the presence or absence of Ferrostatin-1 (Fer-1). Cell viability, ROS generation, Annexin V positivity, intracellular iron, lipid peroxidation, FACL4/GPX4 expression, nuclear factor kappa B (NF-κB)/cyclooxygenase-2 (COX-2) signaling, and lipidomic changes were examined. RESULTS: Andro induced dose-dependent cytotoxicity and increased ROS generation and Annexin V positivity, while Fer-1 partially restored Andro-induced loss of cell viability. Both cell lines showed elevated basal intracellular iron levels. Andro also induced Fer-1-sensitive lipid peroxidation, increased FACL4, decreased GPX4, and promoted lipid remodeling characterized primarily by reduced monounsaturated fatty acid (MUFA) abundance, resulting in an increased polyunsaturated fatty acid (PUFA)/MUFA ratio. In addition, Andro significantly decreased nuclear NF-κB p65 levels and COX-2 expression in both cell lines. CONCLUSION: Andro induces a ferroptosis-prone lipid state characterized by Fer-1-sensitive lipid peroxidation, FACL4 up-regulation, GPX4 down-regulation, and alterations in the PUFA/MUFA phospholipid balance. Suppression of the nuclear NF-κB/COX-2 axis may be associated with this lipid remodeling, although its causal role requires further investigation.
  • Anna Yoshimine, Hideaki Matsuura, Yuya Ishihara, Yurina Yoshida, Yuri Kato, Yohei Sakai, Rie Nakagawa, Hiroki Doi, Yasuo Miura
    Vox sanguinis, Jun 22, 2026  Peer-reviewed
    BACKGROUND AND OBJECTIVES: Thawed plasma (TP) can be stored for several days to facilitate rapid emergency transfusion. However, in Japan, the 24-h post-thaw shelf life limit raises concerns about plasma wastage. We evaluated fibrinogen recovery in cryoprecipitate prepared from TP that was stored for 5 days after thawing. MATERIALS AND METHODS: Cryoprecipitate was prepared using the one-step method (OSM, n = 12), two-step method (TSM, n = 15) and the TP stored for 5 days post-thaw (n = 15). Cryoprecipitate was prepared using three protocols: OSM, in which fresh frozen plasma (FFP) was thawed once at 2-6°C for 24-30 h; TSM, in which FFP was thawed at 2-6°C, refrozen at -30°C and then thawed again at 2-6°C for 24-30 h; and TP, in which FFP was stored at 2-6°C for 5 days after initial thawing, then refrozen and thawed as in the TSM. All samples were centrifuged after the final thawing to collect the cryoprecipitate. Fibrinogen recovery was calculated from fibrinogen concentrations, and bacteriological testing was performed on the cryoprecipitate prepared from TP. RESULTS: Fibrinogen recovery differed significantly among the groups (p < 0.001), with the highest recovery in the TSM group, followed by the TP and OSM groups. Recovery in the TP group was significantly higher than that in the OSM group. No bacterial growth was detected in any of the samples. CONCLUSION: Using stored TP to prepare cryoprecipitate could offer a more efficient way to manage resources while supporting emergency transfusion readiness.
  • Hiroki Doi, Hidehiko Akiyama, Taei Matsui, Yuko Abe, Sumie Fujii, Hideaki Matsuura, Yasuo Miura
    Anticancer research, 46(6) 3067-3077, Jun, 2026  Peer-reviewedLead author
    BACKGROUND/AIM: Andrographolide (Andro), a diterpene lactone from Andrographis paniculata, induces apoptosis via reactive oxygen species (ROS)-dependent mitochondrial dysfunction but achieves low plasma concentrations because of its lipophilicity. We investigated whether low-dose Andro potentiates the cytotoxicity of the mechanistically distinct agents cytarabine (Ara-C) and vincristine (VCR) in plasma cell neoplasm cell lines. MATERIALS AND METHODS: Human plasma cell neoplasm cell lines H929 and ARH77 were treated with Andro alone or in combination with Ara-C or VCR. Cell viability was assessed in dose- and time-response experiments, and pharmacologic interactions were quantified using the combination index (CI) method. Apoptosis was evaluated by Annexin V staining, and cell-cycle distribution was analyzed to examine mechanistic complementarity. RESULTS: Andro decreased viability in a dose- and time-dependent manner (IC50 at 48 h: 3.4 μM in H929; 7.5 μM in ARH77). Combining Andro with Ara-C or VCR further reduced viability; in H929 cells, all combination conditions yielded CI values <1.0, indicating synergy. Combination treatments markedly increased Annexin V-positive fractions, implicating apoptosis as a major contributor to enhanced cytotoxicity. While Andro alone did not appreciably alter cell-cycle profiles, it modestly influenced Ara-C- and VCR-associated changes in cell-cycle distribution, consistent with complementary mechanisms. CONCLUSION: Low-dose Andro strengthens Ara-C- and VCR-driven cytotoxic programs and provides a quantitative rationale for Andro-based combination strategies in plasma cell neoplasms and related hematologic malignancies.
  • Yohei Sakai, Hideaki Matsuura, Ryusei Ito, Kakeru Ishii, Anna Yoshimine, Rie Nakagawa, Yuya Ishihara, Shota Fujiki, Shoko Arakawa, Hiroki Doi, Sumie Fujii, Yasuo Miura
    British journal of haematology, May 24, 2026  Peer-reviewed
  • Hiroki Doi, Sumie Fujii, Masaya Hirayama, Kazuya Shiogama, Ryota Miyachi, Hideaki Matsuura, Yasuo Miura
    HemaSphere, 10(Suppl.) 2606-2607, May 12, 2026  

Misc.

 15

Major Presentations

 57

Works

 1

Research Projects

 7

Other

 2
  • スーパーオキシドの発生などについてミトコンドリア呼吸鎖複合能を標的とした解析系の技術*本研究ニーズに関する産学共同研究の問い合わせは藤田医科大学産学連携推進センター(fuji-san@fujita-hu.ac.jp)まで
  • 特になし