Oba, Junna



School of Medicine, Department of Extended Intelligence for Medicine, The Ishii-Ishibashi Laboratory (Shinanomachi)


Senior Assistant Professor (Non-tenured)/Assistant Professor (Non-tenured)

Related Websites


Maiden name: Okada

Career 【 Display / hide

  • 2022.04

    Keio University School of Medicine, Department of Extended Intelligence for Medicine, The Ishii-Ishibashi Laboratory, Assistant Professor

  • 2021.11

    Keio University School of Medicine, Department of Extended Intelligence for Medicine, The Ishii-Ishibashi Laboratory, Assistant Professor

  • 2019.10

    Keio University School of Medicine, Genomics Unit, Cancer Center, Project lecturer

  • 2018.05

    The University of Texas MD Anderson Cancer Center, Department of Melanoma Medical Oncology, Instructor

  • 2016.07

    The University of Texas MD Anderson Cancer Center, Department of Melanoma Medical Oncology, Senior Research Scientist

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Academic Background 【 Display / hide

  • 1996.04

    Kumamoto University, School of Medicine

    University, Graduated, Other

  • 2007.04

    Kyushu University, Graduate School of Medicine

    Graduate School, Graduated, Doctoral course

Academic Degrees 【 Display / hide

  • Medical Doctor (MD), Kumamoto University School of Medicine, Coursework, 2003.04

  • Doctor of Philosophy (PhD), Kyushu University Graduate School of Medicine, Coursework, 2012.03

Licenses and Qualifications 【 Display / hide

  • Board-Certificated Japanese Medical License, 2003.04

  • Board-Certificated Dermatology Specialist, 2009.10


Papers 【 Display / hide

  • Building a versatile medical test system in a pandemic

    Oba J., Toriya M., Matsuo K.

    (Science Impact Ltd)   ( 2 ) 42 - 44 2023.04

    Joint Work, Lead author

     View Summary

    The COVID-19 pandemic was unprecedented and forced countries to organise and combine resources and develop coordinated responses. Temporary systems were established with the support of researchers and other stakeholders. Dr Junna Oba, Assistant Professor at the Department of Extended Intelligence for Medicine at Keio University School of Medicine (KUSM) is devising methodologies for developing adjustable temporary systems that are quick and efficient to build, apply and dissemble when emergency situations have passed. KUSM helped to respond to the COVID-19 crisis by collaborating with basic science researches to reinforce the PCR testing system in hospitals. Among those involved in this effort were Professor Masako Toriya of Keio University Global Research Institute (KGRI) and Professor Koichi Matsuo from the KUSM's Collaborative Research Resources group. The researchers built from scratch a workflow for effective testing and information sharing. Since this time, the team has been working to build a cooperative network, developing a novel approach to planning, analysing and recording various processes and strategies to address emergency situations that will be shared with the wider healthcare community and policy makers. The researchers used systems engineering methods to launch an unprecedented collaborative system that offers the ability to gain an overall picture of the interrelationships between departments that are working together on the diagnosis, treatment and management of COVID-19.


  • Multi-modal molecular programs regulate melanoma cell state

    Andrews M.C., Oba J., Wu C.J., Zhu H., Karpinets T., Creasy C.A., Forget M.A., Yu X., Song X., Mao X., Robertson A.G., Romano G., Li P., Burton E.M., Lu Y., Sloane R.S., Wani K.M., Rai K., Lazar A.J., Haydu L.E., Bustos M.A., Shen J., Chen Y., Morgan M.B., Wargo J.A., Kwong L.N., Haymaker C.L., Grimm E.A., Hwu P., Hoon D.S.B., Zhang J., Gershenwald J.E., Davies M.A., Futreal P.A., Bernatchez C., Woodman S.E.

    Nature Communications 13 ( 1 ) 4000 2022.07

    Research paper (scientific journal), Joint Work, Lead author, Accepted

     View Summary

    Melanoma cells display distinct intrinsic phenotypic states. Here, we seek to characterize the molecular regulation of these states using multi-omic analyses of whole exome, transcriptome, microRNA, long non-coding RNA and DNA methylation data together with reverse-phase protein array data on a panel of 68 highly annotated early passage melanoma cell lines. We demonstrate that clearly defined cancer cell intrinsic transcriptomic programs are maintained in melanoma cells ex vivo and remain highly conserved within melanoma tumors, are associated with distinct immune features within tumors, and differentially correlate with checkpoint inhibitor and adoptive T cell therapy efficacy. Through integrative analyses we demonstrate highly complex multi-omic regulation of melanoma cell intrinsic programs that provide key insights into the molecular maintenance of phenotypic states. These findings have implications for cancer biology and the identification of new therapeutic strategies. Further, these deeply characterized cell lines will serve as an invaluable resource for future research in the field.

  • SARS-CoV-2 RT-qPCR testing of pooled saliva samples: A case study of 824 asymptomatic individuals and a questionnaire survey in Japan

    Oba J., Taniguchi H., Sato M., Takanashi M., Yokemura M., Sato Y., Nishihara H.

    PLoS ONE 17 ( 5 May ) e0263700 2022.05

    Research paper (scientific journal), Joint Work, Lead author, Accepted

     View Summary

    From the beginning of the COVID-19 pandemic, the demand for diagnostic and screening tests has exceeded supply. Although the proportion of vaccinated people has increased in wealthier countries, breakthrough infections have occurred amid the emergence of new variants. Pooled-sample COVID-19 testing using saliva has been proposed as an efficient, inexpensive, and non-invasive method to allow larger-scale testing, especially in a screening setting. In this study, we aimed to evaluate pooled RT-qPCR saliva testing and to compare the results with individual tests. Employees of Philips Japan, Ltd. were recruited to participate in COVID-19 screening from October to December 2020. Asymptomatic individuals (n = 824) submitted self-collected saliva samples. Samples were tested for the presence of SARS-CoV-2 by RT-qPCR in both 10-sample pools and individual tests. We also surveyed participants regarding their thoughts and behaviors after the PCR screening project. Two of the 824 individuals were positive by RT-qPCR. In the pooled testing, one of these two had no measurable Ct value, but showed an amplification trend at the end of the PCR cycle. Both positive individuals developed cold-like symptoms, but neither required hospitalization. Of the 824 participants, 471 responded to our online questionnaire. Overall, while respondents agreed that PCR screening should be performed regularly, the majority were willing to undergo PCR testing only when it was provided for free or at low cost. In conclusion, pooled testing of saliva samples can support frequent large-scale screening that is rapid, efficient, and inexpensive.

  • Reprogramming of bivalent chromatin states in NRAS mutant melanoma suggests PRC2 inhibition as a therapeutic strategy

    Terranova C.J., Tang M., Maitituoheti M., Raman A.T., Ghosh A.K., Schulz J., Amin S.B., Orouji E., Tomczak K., Sarkar S., Oba J., Creasy C., Wu C.J., Khan S., Lazcano R., Wani K., Singh A., Barrodia P., Zhao D., Chen K., Haydu L.E., Wang W.L., Lazar A.J., Woodman S.E., Bernatchez C., Rai K.

    Cell Reports (Cell Reports)  36 ( 3 ) 109410 2021.07

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  2211-1247

     View Summary

    The dynamic evolution of chromatin state patterns during metastasis, their relationship with bona fide genetic drivers, and their therapeutic vulnerabilities are not completely understood. Combinatorial chromatin state profiling of 46 melanoma samples reveals an association of NRAS mutants with bivalent histone H3 lysine 27 trimethylation (H3K27me3) and Polycomb repressive complex 2. Reprogramming of bivalent domains during metastasis occurs on master transcription factors of a mesenchymal phenotype, including ZEB1, TWIST1, and CDH1. Resolution of bivalency using pharmacological inhibition of EZH2 decreases invasive capacity of melanoma cells and markedly reduces tumor burden in vivo, specifically in NRAS mutants. Coincident with bivalent reprogramming, the increased expression of pro-metastatic and melanocyte-specific cell-identity genes is associated with exceptionally wide H3K4me3 domains, suggesting a role for this epigenetic element. Overall, we demonstrate that reprogramming of bivalent and broad domains represents key epigenetic alterations in metastatic melanoma and that EZH2 plus MEK inhibition may provide a promising therapeutic strategy for NRAS mutant melanoma patients.

  • The genetic and epigenetic basis of distinct melanoma types

    Oba J., Woodman S.E.

    Journal of Dermatology 48 ( 7 ) 925 - 939 2021.07

    Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  03852407

     View Summary

    Melanoma represents the deadliest skin cancer. Recent therapeutic developments, including targeted and immune therapies have revolutionized clinical management and improved patient outcome. This progress was achieved by rigorous molecular and functional studies followed by robust clinical trials. The identification of key genomic alterations and gene expression profiles have propelled the understanding of distinct characteristics within melanoma subtypes. The aim of this review is to summarize and highlight the main genetic and epigenetic findings of melanomas and highlight their pathological and therapeutic importance.

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

  • Building a versatile medical test system in a pandemic


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