Updated on 2025/11/10

All information, except for affiliations, is reprinted from the information registered on researchmap.

写真a

 
Tomohiro Shibata
 
Organization
Graduate School of Medicine Department of Medicine Pharmacology Assistant Professor
School of Medicine Medical Course
Title
Assistant Professor
External link

Degree

  • 博士(臨床薬学) ( 九州大学 )

Research Areas

  • Life Science / Cell biology

  • Life Science / Tumor biology

Education

  • Kyushu University

    2012.4 - 2016.3

      More details

  • Kyushu University   School of Pharmaceutical Sciences

    2006.4 - 2012.3

      More details

Research History

  • Yokohama City University   School of Medicine Medical Course Pharmacology   Assistant Professor

    2024.4

      More details

  • Cedars-Sinai Medical Center   Post-doctoral Scientist

    2023.4 - 2024.3

      More details

  • Cedars-Sinai Medical Center   Visiting Scientist

    2021.4 - 2023.3

      More details

    Country:United States

    researchmap

  • 信州大学医学部   外科学教室乳腺内分泌外科学分野   特任講師

    2020.6 - 2024.3

      More details

  • 信州大学医学部   外科学教室乳腺内分泌外科学分野   日本学術振興会 特別研究員(PD)

    2020.4 - 2023.3

      More details

  • Kyushu University   Faculty of Pharmaceutical Sciences

    2019.4 - 2020.3

      More details

  • Kyushu University   Faculty of Pharmaceutical Sciences

    2017.4 - 2019.3

      More details

  • 九州大学大学院   薬学研究院   日本学術振興会 特別研究員(PD)

    2016.4 - 2017.3

      More details

▼display all

Professional Memberships

  • 日本内分泌学会

    2024.10

      More details

  • 日本心血管内分泌代謝学会

    2024.9

      More details

  • 日本薬理学会

    2024.4

      More details

  • THE PHARMACEUTICAL SOCIETY OF JAPAN

    2016.4

      More details

  • 日本がん転移学会

    2012.6

      More details

  • THE JAPANESE ASSOCIATION FOR MOLECULAR TARGET THERAPY OF CANCER

    2012.6

      More details

  • THE JAPANESE CANCER ASSOCIATION

    2012.6

      More details

▼display all

Papers

  • 甲状腺癌の分子標的治療耐性メカニズム

    柴田智博

    BIO Clinica   40 ( 11 )   60 - 62   2025.10

     More details

    Authorship:Lead author, Corresponding author  

    researchmap

  • 乳癌の薬剤耐性化機構の解明と克服治療法の創出研究

    柴田智博

    Medical Science Digest   51 ( 10 )   34 - 36   2025.9

     More details

    Authorship:Lead author, Corresponding author  

    researchmap

  • The Nrf2 Activator CDDO-Imidazole Suppresses Inflammation-Induced Red Blood Cell Alloimmunization Reviewed

    Che-Yu Chang, Rosario Hernández-Armengol, Kausik Paul, June Young Lee, Karina Nance, Tomohiro Shibata, Peibin Yue, Christian Stehlik, David R. Gibb

    Antioxidants   14 ( 6 )   678 - 678   2025.6

     More details

    Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    Experimental Objective: During red blood cell (RBC) transfusion, inflammation promotes the production of anti-RBC alloantibodies that can cause significant hemolytic events. Avoiding RBC antigen exposure is the only strategy to prevent RBC alloimmunization in transfusion recipients. Identifying mechanisms that inhibit alloimmunization may lead to novel prophylactic interventions. One potential regulatory mechanism is the activation of the transcription factor nuclear factor erythroid-derived 2-like 2 (Nrf2), a master regulator of antioxidant pathways. Pharmacologic Nrf2 activators induce antioxidant production and improve the sequelae of inflammatory diseases. Thus, we tested the hypothesis that a Nrf2 activator, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]-imidazole (CDDO-Im), regulates inflammation-induced RBC alloimmunization. Methods: WT and Nrf2-deficient mice were treated with inflammatory stimuli and CDDO-Im prior to transfusion with RBCs expressing the KEL antigen (KEL+ RBCs). Anti-KEL IgM and IgG were measured in the serum of transfused mice. Nrf2-activated gene expression and interferon activity were measured in mice and human macrophages pre-treated with CDDO-Im and interferon stimuli. Results: Here, we report that CDDO-Im induces Nrf2-activated gene expression and inhibits type 1 interferon activity, which promotes RBC alloimmunization in transfusion models. In mice transfused with KEL+ RBCs, pre-treatment with CDDO-Im inhibited inflammation-induced anti-KEL antibody production and increased the post-transfusion recovery of KEL+ RBCs in a Nrf2-dependent manner. CDDO-Im also inhibited RBC alloimmunization in mice with pre-existing inflammation. Conclusions: These results indicate that the activation of the Nrf2 antioxidant pathway regulates RBC alloimmunization to the KEL antigen in a pre-clinical model. If these findings translate to other models and human studies, Nrf2 activators may represent a potential prophylactic intervention to inhibit alloimmunization.

    DOI: 10.3390/antiox14060678

    researchmap

  • Peroxisome proliferator-activated receptor alpha is an essential factor in enhanced macrophage immune function induced by angiotensin-converting enzyme Reviewed

    Suguru Saito, Duo-Yao Cao, Ellen A. Bernstein, Tomohiro Shibata, Anthony E. Jones, Amy Rios, Aoi O. Hoshi, Aleksandr B. Stotland, Erika E. Nishi, Jennifer E. Van Eyk, Ajit Divakaruni, Zakir Khan, Kenneth E. Bernstein

    Cellular & Molecular Immunology   2025.2

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    Abstract

    Increased expression of angiotensin-converting enzyme (ACE) by myeloid lineage cells strongly increases the immune activity of these cells, as observed in ACE10/10 mice, which exhibit a marked increase in antitumor and antibactericidal immunity. We report that peroxisome proliferator-activated receptor alpha (PPARα), a transcription factor that regulates genes critical for lipid metabolism, is a key molecule in the enhanced macrophage function induced by ACE. Here, we used a Cre–LoxP approach with LysM-Cre to create a modified ACE10/10 mouse line in which macrophages continue to generate abundant ACE but in which monocyte and macrophage PPARα expression is selectively suppressed. These mice, termed A10-PPARα-Cre, have significantly increased growth of B16-F10 tumors compared with ACE10/10 mice with Cre expression. PPARα depletion impaired cytokine production and antigen-presenting activity in ACE-expressing macrophages, resulting in reduced tumor antigen-specific CD8<sup>+</sup> T-cell generation. Additionally, the elevated bactericidal resistance typical of ACE10/10 mice was significantly reduced in A10-PPARα-Cre mice, such that these mice resembled WT mice in their resistance to methicillin-resistant Staphylococcus aureus (MRSA) infection. THP-1 cells expressing increased ACE (termed THP-1-ACE) constitute a human macrophage model with increased PPARα that shows enhanced cytotoxicity against tumor cells and better phagocytosis and killing of MRSA. RNA silencing of PPARα in THP-1-ACE cells reduced both tumor cell death and bacterial phagocytosis and clearance. In contrast, the in vivo administration of pemafibrate, a specific agonist of PPARα, to WT and A10-PPARα-Cre mice reduced B16-F10 tumor growth by 24.5% and 25.8%, respectively, but pemafibrate reduced tumors by 57.8% in ACE10/10 mice. With pemafibrate, the number of antitumor CD8<sup>+</sup> T cells was significantly lower in A10-PPARα-Cre mice than in ACE10/10 mice. We conclude that PPARα is important in the immune system of myeloid cells, including wild-type cells, and that its increased expression by ACE-expressing macrophages in ACE10/10 mice is indispensable for ACE-dependent functional upregulation of macrophages in both mice and human cells.

    DOI: 10.1038/s41423-025-01257-y

    researchmap

    Other Link: https://www.nature.com/articles/s41423-025-01257-y

  • Tumor derived cell‐free nucleic acid upregulates programmed death‐ligand 1 expression in neutrophil via intracellular Toll‐like receptor signaling Reviewed

    Suguru Saito, Duo‐Yao Cao, Tomohiro Shibata, Yan Liu, Aoi Otagiri‐Hoshi, Xiaojiang Cui, Kenneth E. Bernstein

    Cancer Communications   45 ( 1 )   4 - 8   2024.10

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Wiley  

    DOI: 10.1002/cac2.12615

    researchmap

  • Y-box binding protein 1/cyclin A1 axis specifically promotes cell cycle progression at G2/M phase in ovarian cancer Reviewed

    Yuichi Murakami, Daisuke Katsuchi, Taichi Matsumoto, Kuon Kanazawa, Tomohiro Shibata, Akihiko Kawahara, Jun Akiba, Nozomu Yanaihara, Aikou Okamoto, Hiroaki Itamochi, Toru Sugiyama, Atsumu Terada, Shin Nishio, Naotake Tsuda, Kiyoko Kato, Mayumi Ono, Michihiko Kuwano

    Scientific Reports   14 ( 1 )   2024.9

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    DOI: 10.1038/s41598-024-72174-9

    researchmap

    Other Link: https://www.nature.com/articles/s41598-024-72174-9

  • Classical and nonclassical effects of angiotensin-converting enzyme: How increased ACE enhances myeloid immune function Reviewed

    Kenneth E. Bernstein, DuoYao Cao, Tomohiro Shibata, Suguru Saito, Ellen A. Bernstein, Erika Nishi, Michifumi Yamashita, Warren G. Tourtellotte, Tuantuan V. Zhao, Zakir Khan

    Journal of Biological Chemistry   300 ( 6 )   107388 - 107388   2024.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jbc.2024.107388

    researchmap

  • Distinct RBC alloantibody responses in type 1 interferon-dependent and -independent lupus mouse models Reviewed

    Kausik Paul, Rosario Hernández-Armengol, June Young Lee, Che-Yu Chang, Tomohiro Shibata, Michifumi Yamashita, Caroline Jefferies, David R. Gibb

    Frontiers in Immunology   14   2024.1

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Frontiers Media SA  

    During transfusion of red blood cells (RBCs), recipients are exposed to both ABO and non-ABO ‘minor’ antigens. RBC donor units and recipient RBCs are not routinely matched for non-ABO antigens. Thus, recipients are exposed to many RBC alloantigens that can lead to RBC alloantibody production and subsequent clinically significant hemolysis. RBC alloantibodies also significantly limit the provision of compatible RBC units for recipients. Prior studies indicate that the frequency of RBC alloimmunization is increased during inflammatory responses and in patients with autoimmune diseases. Still, mechanisms contributing to alloimmune responses in patients with autoimmunity are not well understood. More than half of adult patients with systemic lupus erythematosus (SLE) produce type 1 interferons (IFNα/β) and express IFNα/β stimulated genes (ISGs). Previously, we reported that IFNα/β promote RBC alloimmune responses in the pristane mouse model, which develops a lupus-like phenotype that is dependent on IFNα/β signaling. However, it is unclear whether IFNα/β or the lupus-like phenotype induces alloimmunization in lupus models. Therefore, we tested the hypothesis that IFNα/β promotes RBC alloimmune responses in lupus by examining alloimmune responses in IFNα/β-independent (MRL-lpr) and IFNα/β-dependent (pristane) lupus models. Whereas pristane treatment significantly induced interferon-stimulated genes (ISGs), MRL-lpr mice produced significantly lower levels that were comparable to levels in untreated WT mice. Transfusion of murine RBCs that express the KEL antigen led to anti-KEL IgG production by pristane-treated WT mice. However, MRL-lpr mice produced minimal levels of anti-KEL IgG. Treatment of MRL-lpr mice with recombinant IFNα significantly enhanced alloimmunization. Collectively, results indicate that a lupus-like phenotype in pre-clinical models is not sufficient to induce RBC alloantibody production, and IFNα/β gene signatures may be responsible for RBC alloimmune responses in lupus mouse models. If these findings are extended to alternate pre-clinical models and clinical studies, patients with SLE who express an IFNα/β gene signature may have an increased risk of developing RBC alloantibodies and may benefit from more personalized transfusion protocols.

    DOI: 10.3389/fimmu.2023.1304086

    researchmap

  • Testicular ACE regulates sperm metabolism and fertilization through the transcription factor PPARγ

    Tomohiro Shibata, Shabir A. Bhat, DuoYao Cao, Suguru Saito, Ellen A. Bernstein, Erika Nishi, Juliet D. Medenilla, Erica T. Wang, Jessica L. Chan, Margareta D. Pisarska, Warren G. Tourtellotte, Jorge F. Giani, Kenneth E. Bernstein, Zakir Khan

    Journal of Biological Chemistry   300 ( 1 )   105486 - 105486   2024.1

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jbc.2023.105486

    researchmap

  • Diverse biological functions of the renin‐angiotensin system

    Adithi Rao, Shabir A. Bhat, Tomohiro Shibata, Jorge F. Giani, Florian Rader, Kenneth E. Bernstein, Zakir Khan

    Medicinal Research Reviews   44 ( 2 )   587 - 605   2023.11

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Wiley  

    Abstract

    The renin‐angiotensin system (RAS) has been widely known as a circulating endocrine system involved in the control of blood pressure. However, components of RAS have been found to be localized in rather unexpected sites in the body including the kidneys, brain, bone marrow, immune cells, and reproductive system. These discoveries have led to steady, growing evidence of the existence of independent tissue RAS specific to several parts of the body. It is important to understand how RAS regulates these systems for a variety of reasons: It gives a better overall picture of human physiology, helps to understand and mitigate the unintended consequences of RAS‐inhibiting or activating drugs, and sets the stage for potential new therapies for a variety of ailments. This review fulfills the need for an updated overview of knowledge about local tissue RAS in several bodily systems, including their components, functions, and medical implications.

    DOI: 10.1002/med.21996

    researchmap

  • Myeloid cell ACE shapes cellular metabolism and function in PCSK-9 induced atherosclerosis Reviewed

    DuoYao Cao, Suguru Saito, LiMin Xu, Wei Fan, Xiaomo Li, Faizan Ahmed, Predrag Jovanovic, Tomohiro Shibata, Mingtian Che, Ellen A. Bernstein, Jorge Gianni, Ajit S. Divakaruni, Derick Okwan-Duodu, Zakir Khan, Celine E. Riera, Fanfan Chen, Kenneth E. Bernstein

    Frontiers in Immunology   14   2023.10

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Frontiers Media SA  

    The pathogenesis of atherosclerosis is defined by impaired lipid handling by macrophages which increases intracellular lipid accumulation. This dysregulation of macrophages triggers the accumulation of apoptotic cells and chronic inflammation which contributes to disease progression. We previously reported that mice with increased macrophage-specific angiotensin-converting enzyme, termed ACE10/10 mice, resist atherosclerosis in an adeno-associated virus-proprotein convertase subtilisin/kexin type 9 (AAV-PCSK9)-induced model. This is due to increased lipid metabolism by macrophages which contributes to plaque resolution. However, the importance of ACE in peripheral blood monocytes, which are the primary precursors of lesional-infiltrating macrophages, is still unknown in atherosclerosis. Here, we show that the ACE-mediated metabolic phenotype is already triggered in peripheral blood circulating monocytes and that this functional modification is directly transferred to differentiated macrophages in ACE10/10 mice. We found that Ly-6Clo monocytes were increased in atherosclerotic ACE10/10 mice. The monocytes isolated from atherosclerotic ACE10/10 mice showed enhanced lipid metabolism, elevated mitochondrial activity, and increased adenosine triphosphate (ATP) levels which implies that ACE overexpression is already altered in atherosclerosis. Furthermore, we observed increased oxygen consumption (VO2), respiratory exchange ratio (RER), and spontaneous physical activity in ACE10/10 mice compared to WT mice in atherosclerotic conditions, indicating enhanced systemic energy consumption. Thus, ACE overexpression in myeloid lineage cells modifies the metabolic function of peripheral blood circulating monocytes which differentiate to macrophages and protect against atherosclerotic lesion progression due to better lipid metabolism.

    DOI: 10.3389/fimmu.2023.1278383

    researchmap

  • Macrophage angiotensin-converting enzyme reduces atherosclerosis by increasing peroxisome proliferator-activated receptor α and fundamentally changing lipid metabolism Reviewed

    DuoYao Cao, Zakir Khan, Xiaomo Li, Suguru Saito, Ellen A Bernstein, Aaron R Victor, Faizan Ahmed, Aoi O Hoshi, Luciana C Veiras, Tomohiro Shibata, Mingtian Che, Lei Cai, Ryan E Temel, Jorge F Giani, Daniel J Luthringer, Ajit S Divakaruni, Derick Okwan-Duodu, Kenneth E Bernstein

    Cardiovascular Research   2023.5

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Oxford University Press (OUP)  

    Abstract

    Aims

    The metabolic failure of macrophages to adequately process lipid is central to the aetiology of atherosclerosis. Here, we examine the role of macrophage angiotensin-converting enzyme (ACE) in a mouse model of PCSK9-induced atherosclerosis.

    Methods and results

    Atherosclerosis in mice was induced with AAV-PCSK9 and a high-fat diet. Animals with increased macrophage ACE (ACE 10/10 mice) have a marked reduction in atherosclerosis vs. WT mice. Macrophages from both the aorta and peritoneum of ACE 10/10 express increased PPARα and have a profoundly altered phenotype to process lipids characterized by higher levels of the surface scavenger receptor CD36, increased uptake of lipid, increased capacity to transport long chain fatty acids into mitochondria, higher oxidative metabolism and lipid β-oxidation as determined using 13C isotope tracing, increased cell ATP, increased capacity for efferocytosis, increased concentrations of the lipid transporters ABCA1 and ABCG1, and increased cholesterol efflux. These effects are mostly independent of angiotensin II. Human THP-1 cells, when modified to express more ACE, increase expression of PPARα, increase cell ATP and acetyl-CoA, and increase cell efferocytosis.

    Conclusion

    Increased macrophage ACE expression enhances macrophage lipid metabolism, cholesterol efflux, efferocytosis, and it reduces atherosclerosis. This has implications for the treatment of cardiovascular disease with angiotensin II receptor antagonists vs. ACE inhibitors.

    DOI: 10.1093/cvr/cvad082

    researchmap

  • miR766-3p and miR124-3p Dictate Drug Resistance and Clinical Outcome in HNSCC Reviewed

    Tomohiro Shibata, Duo-Yao Cao, Tahir B. Dar, Faizan Ahmed, Shabir A. Bhat, Luciana C. Veiras, Ellen A. Bernstein, Abdul Arif Khan, Manita Chaum, Stephen L. Shiao, Warren G. Tourtellotte, Jorge F. Giani, Kenneth E. Bernstein, Xiaojiang Cui, Eric Vail, Zakir Khan

    Cancers   14 ( 21 )   5273 - 5273   2022.10

     More details

    Authorship:Lead author   Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive disease with poor prognosis, which is mainly due to drug resistance. The biology determining the response to chemo-radiotherapy in HNSCC is poorly understood. Using clinical samples, we found that miR124-3p and miR766-3p are overexpressed in chemo-radiotherapy-resistant (non-responder) HNSCC, as compared to responder tumors. Our study shows that inhibition of miR124-3p and miR766-3p enhances the sensitivity of HNSCC cell lines, CAL27 and FaDu, to 5-fluorouracil and cisplatin (FP) chemotherapy and radiotherapy. In contrast, overexpression of miR766-3p and miR124-3p confers a resistance phenotype in HNSCC cells. The upregulation of miR124-3p and miR766-3p is associated with increased HNSCC cell invasion and migration. In a xenograft mouse model, inhibition of miR124-3p and miR766-3p enhanced the efficacy of chemo-radiotherapy with reduced growth of resistant HNSCC. For the first time, we identified that miR124-3p and miR766-3p attenuate expression of CREBRF and NR3C2, respectively, in HNSCC, which promotes aggressive tumor behavior by inducing the signaling axes CREB3/ATG5 and β-catenin/c-Myc. Since miR124-3p and miR766-3p affect complementary pathways, combined inhibition of these two miRNAs shows an additive effect on sensitizing cancer cells to chemo-radiotherapy. In conclusion, our study demonstrated a novel miR124-3p- and miR766-3p-based biological mechanism governing treatment-resistant HNSCC, which can be targeted to improve clinical outcomes in HNSCC.

    DOI: 10.3390/cancers14215273

    researchmap

  • Comparative Upper Respiratory Tract Transcriptomic Profiling Reveals a Potential Role of Early Activation of Interferon Pathway in Severe COVID-19 Reviewed

    Shabir A. Bhat, Tomohiro Shibata, Matthew Leong, Jasmine Plummer, Eric Vail, Zakir Khan

    Viruses   14 ( 10 )   2182 - 2182   2022.10

     More details

    Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    Infection with SARS-CoV-2 results in Coronavirus disease 2019 (COVID-19) is known to cause mild to acute respiratory infection and sometimes progress towards respiratory failure and death. The mechanisms driving the progression of the disease and accumulation of high viral load in the lungs without initial symptoms remain elusive. In this study, we evaluated the upper respiratory tract host transcriptional response in COVID-19 patients with mild to severe symptoms and compared it with the control COVID-19 negative group using RNA-sequencing (RNA-Seq). Our results reveal an upregulated early type I interferon response in severe COVID-19 patients as compared to mild or negative COVID-19 patients. Moreover, severely symptomatic patients have pronounced induction of interferon stimulated genes (ISGs), particularly the oligoadenylate synthetase (OAS) family of genes. Our results are in concurrence with other studies depicting the early induction of IFN-I response in severe COVID-19 patients, providing novel insights about the ISGs involved.

    DOI: 10.3390/v14102182

    researchmap

  • Epidermal growth factor receptor activation confers resistance to lenvatinib in thyroid cancer cells Reviewed

    Koichi Ohno, Tomohiro Shibata, Ken‐ichi Ito

    Cancer Science   113 ( 9 )   3193 - 3210   2022.9

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Wiley  

    DOI: 10.1111/cas.15465

    researchmap

    Other Link: https://onlinelibrary.wiley.com/doi/full-xml/10.1111/cas.15465

  • The non-cardiovascular actions of ACE Reviewed

    DuoYao Cao, Luciana Veiras, Faizan Ahmed, Tomohiro Shibata, Ellen A. Bernstein, Derick Okwan-Duodu, Jorge F. Giani, Zakir Khan, Kenneth E. Bernstein

    Peptides   152   170769 - 170769   2022.6

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.peptides.2022.170769

    researchmap

  • The mechanisms involved in the resistance of estrogen receptor-positive breast cancer cells to palbociclib are multiple and change over time Reviewed

    Mayu Ono, Takaaki Oba, Tomohiro Shibata, Ken-ichi Ito

    Journal of Cancer Research and Clinical Oncology   2021.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    <title>Abstract</title><sec>
    <title>Purpose</title>
    Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors are widely used for the treatment of advanced estrogen receptor (ER)-positive breast cancer. To develop a treatment strategy for cancers resistant to CDK4/6 inhibitors, here, we established palbociclib-resistant sublines and analyzed their resistance mechanisms.


    </sec><sec>
    <title>Methods</title>
    Palbociclib-resistant sublines were established from T47D and MCF7 cells. Sensitivity to other drugs was assessed via the WST assay. Altered expression/phosphorylation of proteins related to signal transduction and cell cycle regulation was examined using western blotting. Copy number alterations and mutations in the retinoblastoma (<italic>RB1</italic>) gene were also analyzed.


    </sec><sec>
    <title>Results</title>
    Although an increase in CDK6 and decrease in retinoblastoma protein (Rb) expression/phosphorylation were commonly observed in the resistant sublines, changes in other cell cycle-related proteins were heterogeneous. Upon extended exposure to palbociclib, the expression/phosphorylation of these proteins became altered, and the long-term removal of palbociclib did not restore the Rb expression/phosphorylation patterns. Consistently a copy number decrease, as well as <italic>RB1</italic> mutations were detected. Moreover, although the resistant sublines exhibited cross-resistance to abemaciclib, their response to dinaciclib was the same as that of wild-type cells. Of note, the cell line exhibiting increased mTOR phosphorylation also showed a higher sensitivity to everolimus. However, the sensitivity to chemotherapeutic agents was unchanged in palbociclib-resistant sublines.


    </sec><sec>
    <title>Conclusion</title>
    ER-positive breast cancer cells use multiple molecular mechanisms to survive in the presence of palbociclib, suggesting that targeting activated proteins may be an effective strategy to overcome resistance. Additionally, palbociclib monotherapy induces mutations and copy number alterations in the <italic>RB1</italic> gene.


    </sec>

    DOI: 10.1007/s00432-021-03722-3

    researchmap

    Other Link: https://link.springer.com/article/10.1007/s00432-021-03722-3/fulltext.html

  • Tamoxifen resistance alters sensitivity to 5-fluorouracil in a subset of estrogen receptor-positive breast cancer Reviewed

    Takayuki Watanabe, Takaaki Oba, Keiji Tanimoto, Tomohiro Shibata, Shinobu Kamijo, Ken-ichi Ito

    PLOS ONE   16 ( 6 )   e0252822 - e0252822   2021.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Public Library of Science (PLoS)  

    Sequential treatment with endocrine or chemotherapy is generally used in the treatment of estrogen receptor (ER)-positive recurrent breast cancer. To date, few studies have investigated the effect of long-term endocrine therapy on the response to subsequent chemotherapy in ER-positive breast cancer. We examined whether a preceding endocrine therapy affects the sensitivity to subsequent chemotherapy in ER-positive breast cancer cells. Three ER-positive breast cancer cell lines (T47D, MCF7, BT474) and tamoxifen-resistant sublines (T47D/T, MCF7/T, BT474/T) were analyzed for sensitivity to 5-fluorouracil, paclitaxel, and doxorubicin. The mRNA levels of factors related to drug sensitivity were analyzed by RT-PCR. MCF7/T cells became more sensitive to 5-fluorouracil than wild-type (wt)-MCF7 cells. In addition, the apoptosis induced by 5-fluorouracil was significantly increased in MCF7/T cells. However, no difference in sensitivity to chemotherapeutic agents was observed in T47D/T and BT474/T cells compared with their wt cells. Dihydropyrimidine dehydrogenase (<italic>DPYD</italic>) mRNA expression was significantly decreased in MCF7/T cells compared with wt-MCF7 cells. The expression of <italic>DPYD</italic> mRNA was restored with 5-azacytidine treatment in MCF7/T cells. In addition, <italic>DPYD</italic> 3′-UTR luciferase activity was significantly reduced in MCF7/T cells. These data indicated that the expression of <italic>DPYD</italic> mRNA was repressed by methylation of the <italic>DPYD</italic> promoter region and post-transcriptional regulation by miRNA in MCF7/T cells. In the mouse xenograft model, capecitabine significantly reduced the tumor volume in MCF7/T compared with MCF7. The results of this study indicate that endocrine therapy could alter the sensitivity to chemotherapeutic agents in a subset of breast cancers, and 5-fluorouracil may be effective in tamoxifen-resistant breast cancers.

    DOI: 10.1371/journal.pone.0252822

    researchmap

  • Selective Covalent Targeting of Mutated EGFR(T790M) with Chlorofluoroacetamide-Pyrimidines Reviewed International journal

    Mami Sato, Hirokazu Fuchida, Naoya Shindo, Keiko Kuwata, Keisuke Tokunaga, Guo Xiao-Lin, Ryo Inamori, Keitaro Hosokawa, Kosuke Watari, Tomohiro Shibata, Naoya Matsunaga, Satoru Koyanagi, Shigehiro Ohdo, Mayumi Ono, Akio Ojida

    ACS Medicinal Chemistry Letters   11 ( 6 )   1137 - 1144   2020.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Chemical Society (ACS)  

    Covalent modification of disease-associated proteins with small molecules is a powerful approach for achieving an increased and sustained pharmacological effect. To reduce the potential risk of nonselective covalent modification, molecular design of covalent inhibitors is critically important. We report herein the development of a targeted covalent inhibitor for mutated epidermal growth factor receptor (EGFR) (L858R/T790M) using α-chlorofluoroacetamide (CFA) as the reactive group. The chemically tuned weak reactivity of CFA was suitable for the design of third-generation EGFR inhibitors that possess the pyrimidine scaffold. The structure-activity relationship study revealed that CFA inhibitor 18 (NSP-037) possessed higher inhibition selectivity to the mutated EGFR over wild-type EGFR when compared to clinically approved osimertinib. Mass-based chemical proteomics analyses further revealed that 18 displayed high covalent modification selectivity for the mutated EGFR in living cells. These findings highlight the utility of CFA as a warhead of targeted covalent inhibitors and the potential application of the CFA-pyrimidines for treatment of non-small-cell lung cancer.

    DOI: 10.1021/acsmedchemlett.9b00574

    PubMed

    researchmap

  • NDRG1 activates VEGF-A-induced angiogenesis through PLCγ1/ERK signaling in mouse vascular endothelial cells. Reviewed International journal

    Kosuke Watari, Tomohiro Shibata, Hideaki Fujita, Ai Shinoda, Yuichi Murakami, Hideyuki Abe, Akihiko Kawahara, Hiroshi Ito, Jun Akiba, Shigeo Yoshida, Michihiko Kuwano, Mayumi Ono

    Communications biology   3 ( 1 )   107 - 107   2020.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Many diseases, including cancer, have been associated with impaired regulation of angiogenesis, of which vascular endothelial growth factor (VEGF)-A is a key regulator. Here, we test the contribution of N-myc downstream regulated gene 1 (NDRG1) to VEGF-A-induced angiogenesis in vascular endothelial cells (ECs). Ndrg1-/- mice exhibit impaired VEGF-A-induced angiogenesis in corneas. Tumor angiogenesis induced by cancer cells that express high levels of VEGF-A was also reduced in a mouse dorsal air sac assay. Furthermore, NDRG1 deficiency in ECs prevented angiogenic sprouting from the aorta and the activation of phospholipase Cγ1 (PLCγ1) and ERK1/2 by VEGF-A without affecting the expression and function of VEGFR2. Finally, we show that NDRG1 formed a complex with PLCγ1 through its phosphorylation sites, and the inhibition of PLCγ1 dramatically suppressed VEGF-A-induced angiogenesis in the mouse cornea, suggesting an essential role of NDRG1 in VEGF-A-induced angiogenesis through PLCγ1 signaling.

    DOI: 10.1038/s42003-020-0829-0

    PubMed

    researchmap

  • Targeting Phosphorylation of Y-Box-Binding Protein YBX1 by TAS0612 and Everolimus in Overcoming Antiestrogen Resistance. Reviewed International journal

    Tomohiro Shibata, Kosuke Watari, Akihiko Kawahara, Tomoya Sudo, Satoshi Hattori, Yuichi Murakami, Hiroto Izumi, Junji Itou, Masakazu Toi, Jun Akiba, Yoshito Akagi, Maki Tanaka, Michihiko Kuwano, Mayumi Ono

    Molecular cancer therapeutics   19 ( 3 )   882 - 894   2020.3

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    Nuclear expression of Y-box-binding protein (YBX1) is closely correlated with clinical poor outcomes and drug resistance in breast cancer. Nuclear translocation of YBX1 is facilitated by YBX1 phosphorylation at serine 102 by AKT, p70S6K, and p90RSK, and the phosphorylated YBX1 (pYBX1) promotes expression of genes related to drug resistance and cell growth. A forthcoming problem to be addressed is whether targeting the phosphorylation of YBX1 overcomes antiestrogen resistance by progressive breast cancer. Here, we found that increased expression of pYBX1 was accompanied by acquired resistance to antiestrogens, fulvestrant and tamoxifen. Forced expression of YBX1/S102E, a constitutive phosphorylated form, resulted in acquired resistance to fulvestrant. Inversely, YBX1 silencing specifically overcame antiestrogen resistance. Furthermore, treatment with everolimus, an mTORC1 inhibitor, or TAS0612, a novel multikinase inhibitor of AKT, p70S6K, and p90RSK, suppressed YBX1 phosphorylation and overcame antiestrogen resistance in vitro and in vivo IHC analysis revealed that expression of pYBX1 and YBX1 was augmented in patients who experienced recurrence during treatment with adjuvant endocrine therapies. Furthermore, pYBX1 was highly expressed in patients with triple-negative breast cancer compared with other subtypes. TAS0612 also demonstrated antitumor effect against triple-negative breast cancer in vivo Taken together, our findings suggest that pYBX1 represents a potential therapeutic target for treatment of antiestrogen-resistant and progressive breast cancer.

    DOI: 10.1158/1535-7163.MCT-19-0690

    PubMed

    researchmap

  • Bidirectional Regulation between NDRG1 and GSK3β Controls Tumor Growth and Is Targeted by Differentiation Inducing Factor-1 in Glioblastoma Reviewed

    Hiroshi Ito, Kosuke Watari, Tomohiro Shibata, Tomofumi Miyamoto, Yuichi Murakami, Yukiko Nakahara, Hiroto Izumi, Hiroaki Wakimoto, Michihiko Kuwano, Tatsuya Abe, Mayumi Ono

    Cancer Research   80 ( 2 )   234 - 248   2020.1

     More details

    Publishing type:Research paper (scientific journal)   Publisher:American Association for Cancer Research (AACR)  

    DOI: 10.1158/0008-5472.can-19-0438

    PubMed

    researchmap

  • Oncogenic Y-box binding protein-1 as an effective therapeutic target in drug-resistant cancer Reviewed International journal

    Michihiko Kuwano, Tomohiro Shibata, Kosuke Watari, Mayumi Ono

    Cancer Science   110 ( 5 )   1536 - 1543   2019.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1111/cas.14006

    Scopus

    PubMed

    researchmap

  • Selective and reversible modification of kinase cysteines with chlorofluoroacetamides. Reviewed International journal

    Naoya Shindo, Hirokazu Fuchida, Mami Sato, Kosuke Watari, Tomohiro Shibata, Keiko Kuwata, Chizuru Miura, Kei Okamoto, Yuji Hatsuyama, Keisuke Tokunaga, Seiichi Sakamoto, Satoshi Morimoto, Yoshito Abe, Mitsunori Shiroishi, Jose M M Caaveiro, Tadashi Ueda, Tomonori Tamura, Naoya Matsunaga, Takaharu Nakao, Satoru Koyanagi, Shigehiro Ohdo, Yasuchika Yamaguchi, Itaru Hamachi, Mayumi Ono, Akio Ojida

    Nature chemical biology   15 ( 3 )   250 - 258   2019.3

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/s41589-018-0204-3

    Scopus

    PubMed

    researchmap

  • Y-box binding protein YBX1 and its correlated genes as biomarkers for poor outcomes in patients with breast cancer Reviewed

    Tomohiro Shibata, Eriko Tokunaga, Satoshi Hattori, Kosuke Watari, Yuichi Murakami, Nami Yamashita, Eiji Oki, Junji Itou, Masakazu Toi, Yoshihiko Maehara, Michihiko Kuwano, Mayumi Ono

    Oncotarget   9 ( 98 )   37216 - 37228   2018.12

     More details

    Authorship:Lead author   Publishing type:Research paper (scientific journal)   Publisher:Impact Journals, LLC  

    DOI: 10.18632/oncotarget.26469

    Scopus

    PubMed

    researchmap

  • Breast Cancer Resistance to Antiestrogens Is Enhanced by Increased ER Degradation and ERBB2 Expression Reviewed

    Tomohiro Shibata, Kosuke Watari, Hiroto Izumi, Akihiko Kawahara, Satoshi Hattori, Chihiro Fukumitsu, Yuichi Murakami, Ryuji Takahashi, Uhi Toh, Ken-ichi Ito, Shigehiro Ohdo, Maki Tanaka, Masayoshi Kage, Michihiko Kuwano, Mayumi Ono

    CANCER RESEARCH   77 ( 2 )   545 - 556   2017.1

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1158/0008-5472.CAN-16-1593

    Web of Science

    Scopus

    PubMed

    researchmap

  • Phosphorylation of mTOR Ser2481 is a key target limiting the efficacy of rapalogs for treating hepatocellular carcinoma Reviewed

    Kosuke Watari, Ayumi Nishitani, Tomohiro Shibata, Masaki Noda, Akihiko Kawahara, Jun Akiba, Yuichi Murakami, Hirohisa Yano, Michihiko Kuwano, Mayumi Ono

    ONCOTARGET   7 ( 30 )   47403 - 47417   2016.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.18632/oncotarget.10161

    Web of Science

    Scopus

    PubMed

    researchmap

  • Impaired differentiation of macrophage lineage cells attenuates bone remodeling and inflammatory angiogenesis in Ndrg1 deficient mice Reviewed

    Kosuke Watari, Tomohiro Shibata, Hiroshi Nabeshima, Ai Shinoda, Yuichi Fukunaga, Akihiko Kawahara, Kazuyuki Karasuyama, Jun-ichi Fukushi, Yukihide Iwamoto, Michihiko Kuwano, Mayumi Ono

    SCIENTIFIC REPORTS   6   2016.1

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/srep19470

    Web of Science

    Scopus

    PubMed

    researchmap

  • Tumor-Derived Interleukin-1 Promotes Lymphangiogenesis and Lymph Node Metastasis through M2-Type Macrophages Reviewed

    Kosuke Watari, Tomohiro Shibata, Akihiko Kawahara, Ken-ichi Sata, Hiroshi Nabeshima, Ai Shinoda, Hideyuki Abe, Koichi Azuma, Yuichi Murakami, Hiroto Izumi, Takashi Takahashi, Masayoshi Kage, Michihiko Kuwano, Mayumi Ono

    PLOS ONE   9 ( 6 )   2014.6

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1371/journal.pone.0099568

    Web of Science

    Scopus

    PubMed

    researchmap

  • N-myc downstream-regulated gene 1 promotes tumor inflammatory angiogenesis through JNK activation and autocrine loop of interleukin-1α by human gastric cancer cells Reviewed

    Yuichi Murakami, Kosuke Watari, Tomohiro Shibata, Manami Uba, Hiroki Ureshino, Akihiko Kawahara, Hideyuki Abe, Hiroto Izumi, Naofumi Mukaida, Michihiko Kuwano, Mayumi Ono

    Journal of Biological Chemistry   288 ( 35 )   25025 - 25037   2013.8

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1074/jbc.M113.472068

    Scopus

    PubMed

    researchmap

  • Y-box binding protein-1 contributes to both HER2/ErbB2 expression and lapatinib sensitivity in human gastric cancer cells Reviewed

    Tomohiro Shibata, Hitoshi Kan, Yuichi Murakami, Hiroki Ureshino, Kosuke Watari, Akihiko Kawahara, Masayoshi Kage, Satoshi Hattori, Mayumi Ono, Michihiko Kuwano

    Molecular Cancer Therapeutics   12 ( 5 )   737 - 746   2013.5

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1158/1535-7163.MCT-12-1125

    Scopus

    PubMed

    researchmap

  • The antitumor effect of a novel angiogenesis inhibitor (an octahydronaphthalene derivative) targeting both VEGF receptor and NF-kappa B pathway Reviewed

    Kosuke Watari, Mamiyo Nakamura, Yuichi Fukunaga, Ayana Furuno, Tomohiro Shibata, Akihiko Kawahara, Fumihito Hosoi, Takashi Kuwano, Michihiko Kuwano, Mayumi Ono

    INTERNATIONAL JOURNAL OF CANCER   131 ( 2 )   310 - 321   2012.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/ijc.26356

    Web of Science

    Scopus

    PubMed

    researchmap

  • NDRG1/Cap43/Drg-1 may Predict Tumor Angiogenesis and Poor Outcome in Patients with Lung Cancer Reviewed

    Koichi Azuma, Akihiko Kawahara, Satoshi Hattori, Tomoki Taira, Junji Tsurutani, Kosuke Watari, Tomohiro Shibata, Yuichi Murakami, Shinzo Takamori, Mayumi Ono, Hiroto Izumi, Masayoshi Kage, Takashi Yanagawa, Kazuhiko Nakagawa, Tomoaki Hoshino, Michihiko Kuwano

    JOURNAL OF THORACIC ONCOLOGY   7 ( 5 )   779 - 789   2012.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1097/JTO.0b013e31824c92b4

    Web of Science

    Scopus

    researchmap

▼display all

MISC

  • Y-BOX BINDING PROTEIN-1 ACTIVATION MAY MODIFY THE RESPONSES TO ENDOCRINE AND HER2-TARGETED THERAPEUTICS IN BREAST CANCER

    Michihiko Kuwano, Tomohiro Shibata, Akihiko Kawahara, Satoshi Hattori, Ryuji Takahashi, Kosuke Watari, Yuichi Murakami, Hiroto Izumi, Masayoshi Kage, Mayumi Ono

    ANNALS OF ONCOLOGY   25   2014.10

     More details

    Language:English   Publishing type:Research paper, summary (international conference)  

    DOI: 10.1093/annonc/mdu435.89

    Web of Science

    researchmap

  • Y-box binding protein-1 YB-1 negatively regulates ER alpha expression accompanying by enhanced HER2/ErbB2 expression in breast cancer

    Tomohiro Shibata, Hiroto Izumi, Akihiko Kawahara, Satoshi Hattori, Chihiro Fukumitsu, Ryuji Takahashi, Kosuke Watari, Yuichi Murakami, Kimitoshi Kohno, Ken-ichi Ito, Masayoshi Kage, Michihiko Kuwano, Mayumi Ono

    CANCER RESEARCH   74 ( 19 )   2014.10

     More details

    Language:English   Publishing type:Research paper, summary (international conference)  

    DOI: 10.1158/1538-7445.AM2014-LB-183

    Web of Science

    researchmap

  • Tumor-derived interleukin-1 promotes lymphangiogenesis and lymph node metastasis through activation of M2-type macrophages by lung cancer cells

    Kosuke Watari, Tomohiro Shibata, Akihiko Kawahara, Yuichi Murakami, Hiroshi Nabeshima, Ai Shinoda, Koichi Azuma, Hiroto Izumi, Masayoshi Kage, Michihiko Kuwano, Mayumi Ono

    CANCER RESEARCH   74 ( 19 )   2014.10

     More details

    Language:English   Publishing type:Research paper, summary (international conference)  

    DOI: 10.1158/1538-7445.AM2014-3662

    Web of Science

    researchmap

Presentations

  • The activated YB-1 as an effective therapeutic target in human progressive cancers Invited

    COLD SHOCK PROTEIN SYMPOSIUM 2019  2019.9 

     More details

    Language:English   Presentation type:Symposium, workshop panel (nominated)  

    researchmap

  • ERαとHER2発現のY-box binding protein-1 (YB-1)による制御と乳癌内分泌治療耐性 Invited

    柴田 智博, 渡 公佑, 河原 明彦, 和泉 弘人, 村上 雄一, 桑野 信彦, 小野 眞弓

    第21回日本がん分子標的治療学会学術集会  2017.6 

     More details

    Language:Japanese   Presentation type:Symposium, workshop panel (nominated)  

    researchmap

Awards

  • 2025年度 奨励賞

    2025.9   日本癌学会  

     More details

  • 2024年度 研究奨励賞

    2025.7   日本がん分子標的治療学会  

     More details

  • 優秀発表賞

    2019.6   第23回日本がん分子標的治療学会学術集会  

    柴田 智博

     More details

  • がん研究助成金 優秀賞

    2015.12   福岡県すこやか健康事業団  

    柴田 智博

     More details

Research Projects

  • 新規ペプチドによる好中球・マクロファージ分化促進メカニズムの解明

    2025.9 - 2026.8

    横浜市立大学  学長裁量事業 第5期 学術的研究推進事業 「国際共同研究プロジェクト」 

      More details

    Authorship:Principal investigator 

    Grant amount:\500000

    researchmap

  • 心臓ナトリウム利尿ペプチドの腫瘍血管成熟化作用を応用した画期的がん治療法の開発

    Grant number:25K10005  2025.4 - 2028.3

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    柴田 智博

      More details

    Grant amount:\4680000 ( Direct Cost: \3600000 、 Indirect Cost:\1080000 )

    researchmap

  • 進行性甲状腺癌の発症メカニズムの解明と画期的治療薬の創出

    2024.10 - 2026.3

    横浜総合医学振興財団  わかば研究助成 

      More details

    Authorship:Principal investigator 

    Grant amount:\1000000 ( Direct Cost: \1000000 )

    researchmap

  • ACEによる好中球及びマクロファージの活性化メカニズムの解明

    2023.4 - 2024.3

    公益財団法人 上原記念生命科学財団  海外留学助成 

      More details

    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\5600000 ( Direct Cost: \5600000 )

    researchmap

  • Development of therapeutic drug against TNBC based on mechanism of ERα induction

    Grant number:21KK0276  2022.4 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Fund for the Promotion of Joint International Research (Fostering Joint International Research (A))  Fund for the Promotion of Joint International Research (Fostering Joint International Research (A))

      More details

    Authorship:Principal investigator 

    Grant amount:\15600000 ( Direct Cost: \12000000 、 Indirect Cost:\3600000 )

    researchmap

  • Development of therapeutic drug against TNBC based on mechanism of ER induction

    Grant number:21K06641  2021.4 - 2024.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

      More details

    Authorship:Principal investigator 

    Grant amount:\4160000 ( Direct Cost: \3200000 、 Indirect Cost:\960000 )

    researchmap

  • 好中球の抗腫瘍活性を促進するアンジ オテンシン変換酵素(ACE)の関与メカニ ズムの解明

    2021.4 - 2022.3

    公益財団法人持田記念医学薬学振興財団  留学補助金 

    柴田 智博

      More details

    Authorship:Principal investigator 

    Grant amount:\500000 ( Direct Cost: \500000 )

    researchmap

  • Identification of progression mechanism and development of new therapeutic drugs in triple negative breast cancer

    Grant number:20J00393  2020.4 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows  Grant-in-Aid for JSPS Fellows

      More details

    Authorship:Principal investigator 

    Grant amount:\4810000 ( Direct Cost: \3700000 、 Indirect Cost:\1110000 )

    researchmap

  • Targeting YB-1 activation pathway overcomes progressive breast cancer

    Grant number:19K16449  2019.4 - 2021.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists  Grant-in-Aid for Early-Career Scientists

    Shibata Tomohiro

      More details

    Grant amount:\4160000 ( Direct Cost: \3200000 、 Indirect Cost:\960000 )

    Nuclear expression of Y-box binding protein-1 (YB-1) is closely correlated with clinical poor outcomes and drug resistance in breast cancer. Phosphorylated YB-1 (pYB-1) promotes expression of genes related to drug resistance and cell growth. A forthcoming problem to be addressed is whether targeting the phosphorylation of YB-1 overcomes antiestrogen resistance by progressive breast cancer. Here we found that increased expression of pYB-1 was accompanied by acquired resistance to antiestrogens, fulvestrant and tamoxifen. Forced expression of YB-1/S102E, a constitutive phosphorylated form, resulted in acquired resistance to fulvestrant. IHC analysis revealed that expression of pYB-1 and YB-1 was augmented in patients who experienced recurrence during treatment with adjuvant endocrine therapies. Taken together our findings suggest that pYB-1 represents a potential therapeutic target for treatment of antiestrogen resistant and progressive breast cancer.

    researchmap

  • Novel breast cancer therapeutic strategy by targeting Y-box binding protein 1 activation pathways

    Grant number:17K15508  2017.4 - 2019.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)  Grant-in-Aid for Young Scientists (B)

    Shibata Tomohiro

      More details

    Grant amount:\4160000 ( Direct Cost: \3200000 、 Indirect Cost:\960000 )

    Despite considerable advances in the treatment of estrogen receptor alpha (ERα)-positive breast cancer, numerous patients develop recurrence during endocrine therapy. Drug resistance to various anticancer drugs is often correlated with enhanced nuclear expression of the Y-box binding protein-1 (YB-1) in breast cancer. In this study, fulvestrant resistant breast cancer cell lines (FR-1 and FR-2) showed markedly reduced expression of ERα and increased expression levels of pYB-1, pmTOR, pAKT, pp70S6K, and pS6. FR-1 and FR-2 showed collateral sensitivity to everolimus (an mTORC1 inhibitor). Furthermore, we demonstrated that pYB-1 directly promoted the ERα-independent cell growth of breast cancer cells. Finally, treatment with everolimus could overcome acquired resistance to antiestrogens through reduction of pYB-1 expression in vivo,
    Based on these findings, we concluded that the pYB-1 represents an attractive therapeutic target for endocrine therapy resistant breast cancer.

    researchmap

  • YB-1依存性HER2発現のERαによる制御機構の解明-乳癌の適正化治療を目指し

    Grant number:15J03033  2015.4 - 2017.3

    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

    柴田 智博

      More details

    Grant amount:\1700000 ( Direct Cost: \1700000 )

    ERα陽性の乳癌患者は全乳癌患者の60%近くを占め、ERα標的の内分泌治療薬が臨床応用されている。しかし、内分泌治療耐性がんの出現が乳癌治療において大きな難関である。昨年度までに① ERα陽性乳癌細胞で、乳癌のオンコプロテインとして報告されているYB-1発現誘導によりHER2発現を亢進しERα発現を低下させること。② YB-1発現誘導は、ERαのユビキチン化の増加とERαのプロテアソームでの分解を亢進させること。を明らかにした。そこで、本年度は、YB-1発現誘導時の内分泌治療薬とHER2標的薬の治療効果を検討し、以下の点について明らかにすることができた。
    [1]ERα陽性乳癌細胞より、親株よりERα標的薬であるfulvestrantに対し約500倍の耐性を示すfulvestrant耐性株を樹立した。耐性株においてYB-1の活性化に加え、ERα発現の減少とHER2発現の上昇が観察された。
    [2]耐性株においてERαのプロテアソームでの分解が促進し、安定性が低下していることを明らかにした。さらに、親株及び耐性株についてYB-1発現を抑制した際のERα及びHER2発現を検討した。その結果、YB-1の発現抑制によりERαの発現が上昇しHER2発現が低下した。
    [3]Fulvestrant耐性株においてYB-1が耐性に関与するか否か明らかにするため、YB-1発現抑制時のfulvestrant及びlapatinib(EGFR/HER2標的薬)の感受性について検討した。YB-1発現抑制によりfulvestrantに対し感受性となり、lapatinibに対して耐性を示した。
    本年度の研究において、YB-1が内分泌治療薬とHER2標的薬の感受性を制御することを明らかにした。さらに、YB-1を標的とすることが内分泌治療薬の耐性克服に貢献できることを示した。

    researchmap

  • 抗ホルモン薬と抗HER2治療薬の適正化にむけた核内YB-1発現を基盤とした乳癌新規治療の創出

    2015.4 - 2016.3

    公益財団法人福岡県すこやか健康事業団  がん研究助成金 

    柴田 智博

      More details

    Authorship:Principal investigator 

    Grant amount:\500000 ( Direct Cost: \500000 )

    researchmap

▼display all