Honors & Awards


  • AZKK Science Promotion Grant, Astra Zeneca (2013)
  • Single Cell Gene Expression Analysis Awards, WAT-NeW, TakaraBio and Fluidigm (2014)
  • Research grant, Fukuoka Foundation for Sound Health Cancer Research Fund (2018)
  • Research grant, The Shin-Nihon Foundation of Advanced Medical Research (2018)
  • Paper of the year 2019, Department of Medicine and Biosystemic Science, Kyushu University (2019)

Boards, Advisory Committees, Professional Organizations


  • Board Certified Fellow, Japanese Society of Internal Medicine (2018 - Present)
  • Board Certified Fellow, Japanese Society of Medical Oncology (2018 - Present)

Professional Education


  • Ph.D., Kyushu University (2019)
  • Fellowship, Kyushu University/National Kyushu Cancer Center, Oncology (2018)
  • Residency, Aso Iizuka Hospital (2011)
  • M.D., Kyushu University (2009)

Stanford Advisors


Current Research and Scholarly Interests


Understanding of tumor biology using cancer organoid as the medical oncologist.

Graduate and Fellowship Programs


  • Oncology (Fellowship Program)

All Publications


  • Dedifferentiation process driven by TGF-beta signaling enhances stem cell properties in human colorectal cancer ONCOGENE Nakano, M., Kikushige, Y., Miyawaki, K., Kunisaki, Y., Mizuno, S., Takenaka, K., Tamura, S., Okumura, Y., Ito, M., Ariyama, H., Kusaba, H., Nakamura, M., Maeda, T., Baba, E., Akashi, K. 2019; 38 (6): 780–93

    Abstract

    Cancer stem cells (CSCs) possess the capacity for self-renewal and the potential to differentiate into non-CSCs. The recent discoveries of dynamic equilibrium between CSCs and non-CSCs revealed the significance of acquiring CSC-like properties in non-CSCs as an important process in progression of cancer. The mechanism underlying acquisition of CSC-like properties has mainly been investigated in the context of epithelial-mesenchymal transition. Here, we demonstrate the dedifferentiation process may be an alternative mechanism in acquisition of CSC-like properties in human colorectal cancer cells. By exploring the single-cell gene expression analysis of organoids developed from CD44+ CSCs, we identified TWIST1 as a key molecule for maintaining the undifferentiated state of cancer cells. Consistent with the finding, we found that TGF-beta signaling pathway, a regulator of TWIST1, was specifically activated in the undifferentiated CD44+ CSCs in human colorectal cancer using microarray-based gene expression analysis and quantitative pathology imaging system. Furthermore, we showed that external stimulation with TGF-beta and the induction of TWIST1 converted CD44- non-CSCs into the undifferentiated CD44+ CSCs, leading to the significant increment of CSCs in xenograft models. This study strongly suggests dedifferentiation driven by TGF-beta signaling enhances stem cell properties in human colorectal cancer.

    View details for DOI 10.1038/s41388-018-0480-0

    View details for Web of Science ID 000458006300002

    View details for PubMedID 30181548

  • Epithelial-mesenchymal transition is activated in CD44-positive malignant ascites tumor cells of gastrointestinal cancer CANCER SCIENCE Nakano, M., Ito, M., Tanaka, R., Ariyama, H., Mitsugi, K., Makiyama, A., Uchino, K., Esaki, T., Tsuruta, N., Hanamura, F., Yamaguchi, K., Okumura, Y., Sagara, K., Takayoshi, K., Nio, K., Tsuchihashi, K., Tamura, S., Shimokawa, H., Arita, S., Miyawaki, K., Kusaba, H., Akashi, K., Baba, E. 2018; 109 (11): 3461–70

    Abstract

    Disseminated cancer cells in malignant ascites possess unique properties that differ from primary tumors. However, the biological features of ascites tumor cells (ATC) have not been fully investigated. By analyzing ascites fluid from 65 gastrointestinal cancer patients, the distinguishing characteristics of ATC were identified. High frequency of CD44+ cells was observed in ATC using flow cytometry (n = 48). Multiplex quantitative PCR (n = 15) showed higher gene expression of epithelial-mesenchymal transition (EMT)-related genes and transforming growth factor beta (TGF-beta)-related genes in ATC than in the primary tissues. Immunohistochemistry (n = 10) showed that ATC also had much higher expression of phosphorylated SMAD2 than that in the corresponding primary tissues. TGF-beta 1 was detected in all cases of malignant ascites by enzyme-linked immunoassay (n = 38), suggesting the possible interaction of ATC and the ascites microenvironment. In vitro experiments revealed that these ATC properties were maintained by TGF-beta 1 in cultured ATC(n = 3). Here, we showed that ATCrevealed high frequencies of CD44 and possessed distinct EMT features from primary tissues that were mainly maintained by TGF-beta 1 in the ascites.

    View details for DOI 10.1111/cas.13777

    View details for Web of Science ID 000449711400011

    View details for PubMedID 30142697

    View details for PubMedCentralID PMC6215886

  • PD-1+TIM-3+T cells in malignant ascites predict prognosis of gastrointestinal cancer CANCER SCIENCE Nakano, M., Ito, M., Tanaka, R., Yamaguchi, K., Ariyama, H., Mitsugi, K., Yoshihiro, T., Ohmura, H., Tsuruta, N., Hanamura, F., Sagara, K., Okumura, Y., Nio, K., Tsuchihashi, K., Arita, S., Kusaba, H., Akashi, K., Baba, E. 2018; 109 (9): 2986–92

    Abstract

    The liquid biopsy of ascites fluid could be an excellent source of tumor and microenvironment for the study of prognostic biomarkers because of its accessibility. Tumor-infiltrating lymphocytes (TILs) can predict prognosis in multiple malignancies, including the response to immune checkpoint inhibitors, a breakthrough cancer therapy. However, TILs' profiles from malignant ascites have not been extensively studied. Using flow cytometric analysis, we quantified the proportion of exhausted T cells and memory/naive/effector T-cell subsets, among the CD4+ and CD8+ T-cell populations of paired TILs and peripheral blood T cell samples (n = 22). The correlation between CD4+ and CD8+ subset profiles suggested that the combined analysis of CD4+ and CD8+ cells in malignant ascites was clinically significant. We found that cells positive for the exhaustion markers programmed cell death-1 (PD-1), and T-cell immunoglobulin and mucin domain 3 (TIM-3), and cells coexpressing PD-1 and TIM-3 abundantly exist among malignant ascites TILs. Furthermore, patients with high frequency of PD-1+ TIM-3+ cells among the CD4+ and CD8+ T-cell population showed worse clinical outcome in multivariate analysis (n = 27). We propose that exhausted ascites TILs represent a clinically significant prognostic biomarker in advanced gastrointestinal cancer and represent an important target for immune checkpoint inhibitors.

    View details for DOI 10.1111/cas.13723

    View details for Web of Science ID 000443802900035

    View details for PubMedID 30187676

    View details for PubMedCentralID PMC6125472

  • Pemetrexed combined with platinum-based chemotherapy for advanced malignant peritoneal mesothelioma: retrospective analysis of six cases. Anticancer research Nakano, M., Kusaba, H., Makiyama, A., Ariyama, H., Arita, S., Oda, H., Esaki, T., Takayoshi, K., Uchino, K., Tamura, S., Kumagai, H., Iwama, E., Shirakawa, T., Mitsugi, K., Takaishi, S., Akashi, K., Baba, E. 2014; 34 (1): 215–20

    Abstract

    Malignant peritoneal mesothelioma (PM) is an extremely rare disease. Pemetrexed and platinum have been used for advanced PM following malignant pleural mesothelioma (PLM). Because PM differs considerably from PLM in clinical features, the efficacy and safety of these therapies have yet to be established.Six Japanese patients with PM who had been treated with pemetrexed-based chemotherapy in four Institutions were retrospectively identified. Treatment response, progression-free survival, and overall survival were examined. Toxicities of therapy were also evaluated.Three patients with mild ascites achieved clinical benefits (one with partial response and two with stable disease). Treatments with reduced cisplatin or carboplatin for patients with massive ascites were safely performed. Median PFS and OS were 7.2 and 13.1 months, respectively. Grade 3 hematological toxicities appeared in two patients with massive ascites.Selection of chemotherapy based on the patient's condition, such as ascites, might be important for advanced PM.

    View details for PubMedID 24403465

  • Activation of central/effector memory T cells and T-helper 1 polarization in malignant melanoma patients treated with anti-programmed death-1 antibody CANCER SCIENCE Yamaguchi, K., Mishima, K., Ohmura, H., Hanamura, F., Ito, M., Nakano, M., Tsuchihashi, K., Ota, S., Wada, N., Uchi, H., Ariyama, H., Kusaba, H., Niiro, H., Akashi, K., Baba, E. 2018; 109 (10): 3032–42

    Abstract

    Human anti-programmed death-1 (PD-1) antibody possesses the capability to revitalize host T cells and has been an effective therapy for metastatic malignant melanoma (MM). The precise subsets of T cells predominantly activated by anti-PD-1, however, have not yet been clarified. In this study, peripheral blood mononuclear cells obtained from MM patients scheduled to receive anti-PD-1 (nivolumab) therapy, and healthy subjects (HS), were systematically examined on flow cytometry to identify changes in the proportion of immune cell subsets. Compared with HS, MM patients prior to therapy had an increased proportion of activated CD8+ T cells with effector memory phenotypes (Tem), and PD-1 positive subsets of CD4+ central memory T cells (Tcm) and T-helper (Th)17 cells. After a single course of anti-PD-1 therapy, MM patients had an increase in activated Tem and Tcm subsets of CD4+ and CD8+ T cells, and activated Th1 plus T-helper follicular 1 cells. There was no consistent change in the proportion of Tfh cells, B cells, natural killer cells, or dendritic cells. The observed activated phenotypes were attenuated during the course of therapy, but regulatory T cells belonging to the CD3+CD4+CD45RO+CD25high fraction increased at disease progression. Taken together, anti-PD-1 therapy modulates systemic immune reactions and exerts anti-tumor effects, not only by revitalizing Tem and Tcm of CD4+ and CD8+ T cells, but also via a shift to a Th1 phenotype.

    View details for DOI 10.1111/cas.13758

    View details for Web of Science ID 000446319600005

    View details for PubMedID 30066977

    View details for PubMedCentralID PMC6172076

  • E-cadherin regulates proliferation of colorectal cancer stem cells through NANOG ONCOLOGY REPORTS Tamura, S., Isobe, T., Ariyama, H., Nakano, M., Kikushige, Y., Takaishi, S., Kusaba, H., Takenaka, K., Ueki, T., Nakamura, M., Akashi, K., Baba, E. 2018; 40 (2): 693–703

    Abstract

    Cancer stem cells (CSCs) possess a self‑renewal ability and display tumorigenic potential in immunodeficient mice. Colorectal CSCs are thought to be a uniform population and no functionally distinct subpopulations have been identified. Because E‑cadherin is an essential molecule for self‑renewal of embryonic stem cells, we examined E‑cadherin expression, which may play a role in maintaining the properties of CSCs, in EpCAMhigh/CD44+ colorectal CSCs from human primary colorectal cancers. We obtained 18 surgical specimens of human primary colorectal cancer. CD44, EpCAM, and E‑cadherin expression were analyzed by fluorescence‑activated cell sorting. Sorted EpCAMhigh/CD44+ colorectal CSCs were injected into immunodeficient mice to estimate the tumorigenic potential. Genetic profiles were analyzed by cDNA microarray. Notably, colorectal CSCs could be divided into two populations based on the E‑cadherin expression status, and they exhibited different pathological characteristics. Compared to E‑cadherin‑negative colorectal CSCs, E‑cadherin‑positive (EC+) colorectal CSCs demonstrated higher tumor growth potential in vivo. EC+ colorectal CSCs revealed a higher expression of the pluripotency factor NANOG, which contributed to the higher tumor growth potential of EC+ colorectal CSCs through control of cyclin D1 expression. These findings are the first demonstration of functionally distinct subpopulations of colorectal CSCs in human clinical samples.

    View details for DOI 10.3892/or.2018.6464

    View details for Web of Science ID 000440585500012

    View details for PubMedID 29845283

    View details for PubMedCentralID PMC6072297

  • Genome-wide CRISPR-Cas9 Screen Identifies Leukemia-Specific Dependence on a Pre-mRNA Metabolic Pathway Regulated by DCPS CANCER CELL Yamauchi, T., Masuda, T., Canver, M. C., Seiler, M., Semba, Y., Shboul, M., Al-Raqad, M., Maeda, M., Schoonenberg, V. C., Cole, M. A., Macias-Trevino, C., Ishikawa, Y., Yao, Q., Nakano, M., Arai, F., Orkin, S. H., Reversade, B., Buonamici, S., Pinello, L., Akashi, K., Bauer, D. E., Maeda, T. 2018; 33 (3): 386-+

    Abstract

    To identify novel targets for acute myeloid leukemia (AML) therapy, we performed genome-wide CRISPR-Cas9 screening using AML cell lines, followed by a second screen in vivo. Here, we show that the mRNA decapping enzyme scavenger (DCPS) gene is essential for AML cell survival. The DCPS enzyme interacted with components of pre-mRNA metabolic pathways, including spliceosomes, as revealed by mass spectrometry. RG3039, a DCPS inhibitor originally developed to treat spinal muscular atrophy, exhibited anti-leukemic activity via inducing pre-mRNA mis-splicing. Humans harboring germline biallelic DCPS loss-of-function mutations do not exhibit aberrant hematologic phenotypes, indicating that DCPS is dispensable for human hematopoiesis. Our findings shed light on a pre-mRNA metabolic pathway and identify DCPS as a target for AML therapy.

    View details for DOI 10.1016/j.ccell.2018.01.012

    View details for Web of Science ID 000427419400008

    View details for PubMedID 29478914

    View details for PubMedCentralID PMC5849534