Edward C. and Amy H. Sewall Professor in the School of Medicine and Professor, by courtesy, of Dermatology


Dr. Sunwoo was born and raised in St. Louis, Missouri. He received his undergraduate degree from Brown University in Providence, Rhode Island and his medical degree from Washington University in St. Louis, Missouri. He completed his training in Otolaryngology – Head and Neck Surgery at Washington University. Dr. Sunwoo has been at Stanford University since 2008, and his clinical focus is on the surgical management of head and neck cancer, specifically focusing on melanoma and neoplasms of the thyroid and parathyroid glands. He is a member of the Pigmented Lesions and Melanoma Clinic and the Melanoma Working Group at Stanford. He is also the co-founder of the Stanford Thyroid and Parathyroid Tumor Board. In addition to his clinical work, Dr. Sunwoo is the Director of Head and Neck Cancer Research at Stanford University and the principal investigator of an NIH-funded laboratory in the Stanford Cancer Institute. His research is focused on three primary areas: (1) the immune response to cancer, particularly a tumorigenic population of cells within malignancies called cancer stem cells; (2) the biology and developmental programs of a special lymphocyte population involved in innate immunity called natural killer (NK) cells; and (3) intra-tumor and inter-tumor heterogeneity in head and neck cancer.


  • Landscape of innate lymphoid cells in human head and neck cancer reveals divergent NK cell states in the tumor microenvironment. Proceedings of the National Academy of Sciences of the United States of America Moreno-Nieves, U. Y., Tay, J. K., Saumyaa, S., Horowitz, N. B., Shin, J. H., Mohammad, I. A., Luca, B., Mundy, D. C., Gulati, G. S., Bedi, N., Chang, S., Chen, C., Kaplan, M. J., Rosenthal, E. L., Holsinger, F. C., Divi, V., Baik, F. M., Sirjani, D. B., Gentles, A. J., Newman, A. M., Freud, A. G., Sunwoo, J. B. 2021; 118 (28)


    Natural killer (NK) cells comprise one subset of the innate lymphoid cell (ILC) family. Despite reported antitumor functions of NK cells, their tangible contribution to tumor control in humans remains controversial. This is due to incomplete understanding of the NK cell states within the tumor microenvironment (TME). Here, we demonstrate that peripheral circulating NK cells differentiate down two divergent pathways within the TME, resulting in different end states. One resembles intraepithelial ILC1s (ieILC1) and possesses potent in vivo antitumor activity. The other expresses genes associated with immune hyporesponsiveness and has poor antitumor functional capacity. Interleukin-15 (IL-15) and direct contact between the tumor cells and NK cells are required for the differentiation into CD49a+CD103+ cells, resembling ieILC1s. These data explain the similarity between ieILC1s and tissue-resident NK cells, provide insight into the origin of ieILC1s, and identify the ieILC1-like cell state within the TME to be the NK cell phenotype with the greatest antitumor activity. Because the proportions of the different ILC states vary between tumors, these findings provide a resource for the clinical study of innate immune responses against tumors and the design of novel therapy.

    View details for DOI 10.1073/pnas.2101169118

    View details for PubMedID 34244432

  • AHR Regulates NK Cell Migration via ASB2-Mediated Ubiquitination of Filamin A. Frontiers in immunology Shin, J. H., Moreno-Nieves, U. Y., Zhang, L. H., Chen, C., Dixon, A. L., Linde, M. H., Mace, E. M., Sunwoo, J. B. 2021; 12: 624284


    Natural killer (NK) cells are effector cells of the innate immune system involved in defense against virus-infected and transformed cells. The effector function of NK cells is linked to their ability to migrate to sites of inflammation or damage. Therefore, understanding the factors regulating NK cell migration is of substantial interest. Here, we show that in the absence of aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, NK cells have reduced capacity to migrate and infiltrate tumors in vivo. Analysis of differentially expressed genes revealed that ankyrin repeat and SOCS Box containing 2 (Asb2) expression was dramatically decreased in Ahr -/- NK cells and that AhR ligands modulated its expression. Further, AhR directly regulated the promoter region of the Asb2 gene. Similar to what was observed with murine Ahr -/- NK cells, ASB2 knockdown inhibited the migration of human NK cells. Activation of AHR by its agonist FICZ induced ASB2-dependent filamin A degradation in NK cells; conversely, knockdown of endogenous ASB2 inhibited filamin A degradation. Reduction of filamin A increased the migration of primary NK cells and restored the invasion capacity of AHR-deficient NK cells. Our study introduces AHR as a new regulator of NK cell migration, through an AHR-ASB2-filamin A axis and provides insight into a potential therapeutic target for NK cell-based immunotherapies.

    View details for DOI 10.3389/fimmu.2021.624284

    View details for PubMedID 33717133

  • Humanized Mouse Models for the Advancement of Innate Lymphoid Cell-Based Cancer Immunotherapies. Frontiers in immunology Horowitz, N. B., Mohammad, I., Moreno-Nieves, U. Y., Koliesnik, I., Tran, Q., Sunwoo, J. B. 2021; 12: 648580


    Innate lymphoid cells (ILCs) are a branch of the immune system that consists of diverse circulating and tissue-resident cells, which carry out functions including homeostasis and antitumor immunity. The development and behavior of human natural killer (NK) cells and other ILCs in the context of cancer is still incompletely understood. Since NK cells and Group 1 and 2 ILCs are known to be important for mediating antitumor immune responses, a clearer understanding of these processes is critical for improving cancer treatments and understanding tumor immunology as a whole. Unfortunately, there are some major differences in ILC differentiation and effector function pathways between humans and mice. To this end, mice bearing patient-derived xenografts or human cell line-derived tumors alongside human genes or human immune cells represent an excellent tool for studying these pathways in vivo. Recent advancements in humanized mice enable unparalleled insights into complex tumor-ILC interactions. In this review, we discuss ILC behavior in the context of cancer, the humanized mouse models that are most commonly employed in cancer research and their optimization for studying ILCs, current approaches to manipulating human ILCs for antitumor activity, and the relative utility of various mouse models for the development and assessment of these ILC-related immunotherapies.

    View details for DOI 10.3389/fimmu.2021.648580

    View details for PubMedID 33968039

  • Malignant cell-specific CXCL14 promotes tumor lymphocyte infiltration in oral cavity squamous cell carcinoma. Journal for immunotherapy of cancer Parikh, A., Shin, J., Faquin, W., Lin, D. T., Tirosh, I., Sunwoo, J. B., Puram, S. V. 2020; 8 (2)


    OBJECTIVES: To explore lymphocyte infiltration as a potential mechanism behind CXCL14-mediated tumor growth suppression in oral cavity squamous cell carcinoma (OSCC).METHODS: We analyzed single cell RNA-sequencing (scRNA-seq) data from OSCC to identify expression changes among malignant cells in lymph nodes (LN) versus primary tumors. CXCL14 expression in murine OSCC cell lines was quantified using qRT-PCR. Short hairpin RNA knockdown of CXCL14 was performed in mouse oral cavity (MOC)1 cells, and CXCL14 overexpression was performed in MOC2 cells. Cells in each condition were injected into C57BL/6 mice with and without T cell depletion, and tumor volume was measured. At 30 days, tumors were dissociated and analyzed by flow cytometry for CD45+CD3+ T cells. CXCL14 expression was correlated with gene expression signatures of tumor infiltrating lymphocytes (TIL) in scRNA-seq data, as well as TCGA tumors.RESULTS: scRNA-seq revealed CXCL14 as the most significantly downregulated gene among malignant cells in LNs relative to primary tumor, supporting a role in preventing invasion and/or metastasis. In a murine immunocompetent model, CXCL14 expression was higher in indolent MOC1 cells than in more aggressive MOC2 cells. Tumor growth in vivo was significantly increased by CXCL14 knockdown in MOC1 cells relative to control, with a corresponding decrease in TIL. In MOC2 cells, tumor growth was significantly reduced by CXCL14 overexpression relative to control and TIL were increased. Both effects were lost with T cell depletion. In a human tumor scRNA-seq cohort, we found that only malignant cell CXCL14, but not non-malignant cell or fibroblast CXCL14, was associated with TIL. Bulk CXCL14 from the TCGA cohort had no association with TIL.CONCLUSIONS: Higher CXCL14 expression by tumor cells is associated with reduced tumor growth and increased TIL, supporting immune-mediated suppression of tumor growth in OSCC. Given that CXCL14 is downregulated in LN metastases compared with primary tumors, our data raise the possibility that CXCL14-mediated immune infiltration may discourage invasion and metastasis. In human scRNA-seq data, only malignant cell-specific CXCL14 was associated with TIL, suggesting a critical context-dependent effect of CXCL14 expression.

    View details for DOI 10.1136/jitc-2020-001048

    View details for PubMedID 32958684

  • Organoid Modeling of the Tumor Immune Microenvironment. Cell Neal, J. T., Li, X., Zhu, J., Giangarra, V., Grzeskowiak, C. L., Ju, J., Liu, I. H., Chiou, S., Salahudeen, A. A., Smith, A. R., Deutsch, B. C., Liao, L., Zemek, A. J., Zhao, F., Karlsson, K., Schultz, L. M., Metzner, T. J., Nadauld, L. D., Tseng, Y., Alkhairy, S., Oh, C., Keskula, P., Mendoza-Villanueva, D., De La Vega, F. M., Kunz, P. L., Liao, J. C., Leppert, J. T., Sunwoo, J. B., Sabatti, C., Boehm, J. S., Hahn, W. C., Zheng, G. X., Davis, M. M., Kuo, C. J. 2018; 175 (7): 1972


    Invitro cancer cultures, including three-dimensional organoids, typically contain exclusively neoplastic epithelium but require artificial reconstitution to recapitulate the tumor microenvironment (TME). The co-culture of primary tumor epithelia with endogenous, syngeneic tumor-infiltrating lymphocytes (TILs) as a cohesive unit has been particularly elusive. Here, an air-liquid interface (ALI) method propagated patient-derived organoids (PDOs) from >100 human biopsies or mouse tumors in syngeneic immunocompetent hosts as tumor epithelia with native embedded immune cells (T, B, NK, macrophages). Robust droplet-based, single-cell simultaneous determination of gene expression and immune repertoire indicated that PDO TILs accurately preserved the original tumor Tcell receptor (TCR) spectrum. Crucially, human and murine PDOs successfully modeled immune checkpoint blockade (ICB) with anti-PD-1- and/or anti-PD-L1 expanding and activating tumor antigen-specific TILs and eliciting tumor cytotoxicity. Organoid-based propagation of primary tumor epithelium en bloc with endogenous immune stroma should enable immuno-oncology investigations within the TME and facilitate personalized immunotherapy testing.

    View details for PubMedID 30550791

  • The aryl hydrocarbon receptor modulates the function of human CD56bright NK cells. European journal of immunology Moreno-Nieves, U. Y., Mundy, D. C., Shin, J. H., Tam, K. n., Sunwoo, J. B. 2018


    Human natural killer (NK) cells are divided into two subsets: CD56bright and CD56dim NK cells, which differ in maturation, function and distribution. Mechanisms regulating NK cell functions are not completely understood. Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor, that binds to a variety of endogenous and exogenous molecules, and that has recently been shown to modulate the function and differentiation of immune cells. Here, we studied the expression of AhR and its involvement in the regulation of NK cell functions. We found that AhR mRNA is highly expressed in peripheral CD56bright NK cells and that AhR mRNA expression gradually decreases as NK cells display a more mature phenotype. CD56bright NK cells were highly sensitive to AhR ligands. Specifically, AhR ligands modulated their activation and their expression of NK cell receptors, as well as cytokine secretion which is the major function of these cells. As CD56bright NK cells are highly enriched in tissues and in tumors, our observations point to a possible effect of local AhR ligands in the regulation of the function of CD56bright tissue-resident or intratumoral NK cells. This article is protected by copyright. All rights reserved.

    View details for PubMedID 29336030

  • NSD1 inactivation defines an immune cold, DNA hypomethylated subtype in squamous cell carcinoma. Scientific reports Brennan, K. n., Shin, J. H., Tay, J. K., Prunello, M. n., Gentles, A. J., Sunwoo, J. B., Gevaert, O. n. 2017; 7 (1): 17064


    Chromatin modifying enzymes are frequently mutated in cancer, resulting in widespread epigenetic deregulation. Recent reports indicate that inactivating mutations in the histone methyltransferase NSD1 define an intrinsic subtype of head and neck squamous cell carcinoma (HNSC) that features pronounced DNA hypomethylation. Here, we describe a similar hypomethylated subtype of lung squamous cell carcinoma (LUSC) that is enriched for both inactivating mutations and deletions in NSD1. The 'NSD1 subtypes' of HNSC and LUSC are highly correlated at the DNA methylation and gene expression levels, featuring ectopic expression of developmental transcription factors and genes that are also hypomethylated in Sotos syndrome, a congenital disorder caused by germline NSD1 mutations. Further, the NSD1 subtype of HNSC displays an 'immune cold' phenotype characterized by low infiltration of tumor-associated leukocytes, particularly macrophages and CD8+ T cells, as well as low expression of genes encoding the immunotherapy target PD-1 immune checkpoint receptor and its ligands. Using an in vivo model, we demonstrate that NSD1 inactivation results in reduced T cell infiltration into the tumor microenvironment, implicating NSD1 as a tumor cell-intrinsic driver of an immune cold phenotype. NSD1 inactivation therefore causes epigenetic deregulation across cancer sites, and has implications for immunotherapy.

    View details for PubMedID 29213088

  • CD271 Confers an Invasive and Metastatic Phenotype of Head and Neck Squamous Cell Carcinoma Through the Upregulation of Slug. Clinical cancer research : an official journal of the American Association for Cancer Research Chung, M. K., Jung, Y. H., Lee, J. K., Cho, S. Y., Murillo-Sauca, O. J., Uppaluri, R. n., Shin, J. H., Sunwoo, J. B. 2017


    Head and neck squamous cell carcinoma (HNSCC) is comprised of heterogeneous populations of cells, and CD271 (NGFR; p75NTR) has been associated with a tumor-initiating cell subpopulation. This study assessed the role of CD271 in modulating metastatic behavior in HNSCC.CD271 was overexpressed in murine and human oral squamous cell carcinoma cells to assess the impact of CD271 activation on the invasive and metastatic phenotype of these cells, using in vitro and orthotopic in vivo modeling. Treatment with human nerve growth factor (NGF) to activate CD271, as well as shRNA knockdown of the CD271-upregulated Snai2 expression, was used to assess the mechanism of the CD271-induced invasive phenotype. Relevance of CD271 expression in human HNSCC was evaluated in patient derived xenografts (PDXs) and primary human oral cancers, annotated with clinical behavior characteristics and survival data.Forced expression of CD271 resulted in a more invasive and metastatic phenotype. Slug, an epithelial-to-mesenchymal transition (EMT)-related transcription factor, encoded by Snai2, was highly expressed in MOC2-CD271 and HSC3-CD271, compared to respective parental cells. CD271 activation by NGF conferred enhanced invasiveness in CD271-overexpressing cells, which was abrogated by Snai2 knockdown. In PDXs and primary human HNSCC, CD271 expression correlated with higher Snai2 expression, greater nodal metastasis, and shorter disease-free survival.Activation of CD271 results in upregulation of Snai2/Slug, which, in turn, results in a more invasive phenotype and an enhanced capacity for metastasis to regional lymph nodes. These findings point to CD271 as a promising, therapeutic target for oral cancer metastasis.

    View details for PubMedID 29208672

  • The aryl hydrocarbon receptor is required for the maintenance of liver-resident natural killer cells. journal of experimental medicine Zhang, L. H., Shin, J. H., Haggadone, M. D., Sunwoo, J. B. 2016; 213 (11): 2249-2257


    A tissue-resident population of natural killer cells (NK cells) in the liver has recently been described to have the unique capacity to confer immunological memory in the form of hapten-specific contact hypersensitivity independent of T and B cells. Factors regulating the development and maintenance of these liver-resident NK cells are poorly understood. The aryl hydrocarbon receptor (AhR) is a transcription factor modulated by exogenous and endogenous ligands that is important in the homeostasis of immune cells at barrier sites, such as the skin and gut. In this study, we show that liver-resident NK (NK1.1(+)CD3(-)) cells, defined as CD49a(+)TRAIL(+)CXCR6(+)DX5(-) cells in the mouse liver, constitutively express AhR. In AhR(-/-) mice, there is a significant reduction in the proportion and absolute number of these cells, which results from a cell-intrinsic dependence on AhR. This deficiency in liver-resident NK cells appears to be the result of higher turnover and increased susceptibility to cytokine-induced cell death. Finally, we show that this deficiency has functional implications in vivo. Upon hapten exposure, AhR(-/-) mice are not able to mount an NK cell memory response to hapten rechallenge. Together, these data demonstrate the requirement of AhR for the maintenance of CD49a(+)TRAIL(+)CXCR6(+)DX5(-) liver-resident NK cells and their hapten memory function.

    View details for PubMedID 27670593

  • CD44+ Cells in Head and Neck Squamous Cell Carcinoma Suppress T-Cell-Mediated Immunity by Selective Constitutive and Inducible Expression of PD-L1. Clinical cancer research Lee, Y., Shin, J. H., Longmire, M., Wang, H., Kohrt, H. E., Chang, H. Y., Sunwoo, J. B. 2016; 22 (14): 3571-3581


    Human tumors consist of heterogeneous populations of cells with distinct marker expression and functional properties. In squamous cell carcinoma of the head and neck (SCCHN), CD44 is a well-characterized marker of a resilient subpopulation of cells associated with increased tumorigenesis, radioresistance, and chemoresistance. Evidence indicates that these cells have an immune suppressive phenotype; however, mechanisms have been elusive.Using primary human SCCHN tumor samples and patient-derived xenografts, we examined the phenotypes of subsets of tumor cells and investigated mechanisms regulating their immunogenicity.CD44+ cells in primary human SCCHN were found to have an epithelial-to-mesenchymal (EMT) phenotype and were less immunogenic than CD44- cells when cultured with autologous CD8+ tumor-infiltrating T cells. Selective expression of the programmed death-ligand 1 (PD-L1) was observed on CD44+ cells compared to CD44- cells and was associated with constitutive phosphorylation of STAT3 on CD44+ cells. Importantly, inhibition of STAT3 decreased expression of PD-L1 on CD44+ cells. Interferon-γ (IFNγ) treatment preferentially induced even further PD-L1 expression on CD44+ cells and was associated with enhanced IFNγ receptor expression and phosphorylation of STAT1. Finally, the decreased immunogenicity of CD44+ cells was partially reversed by antibody blockade of the programmed death 1 (PD-1) receptor, indicating that the differences in PD-L1 expression between CD44+ and CD44- cells are biologically and clinically relevant.Our findings provide a mechanism by which long-lived CD44+ tumor-initiating cells can selectively evade host immune responses and provide rationale for targeting the PD-1 pathway in the adjuvant therapy setting of SCCHN.

    View details for DOI 10.1158/1078-0432.CCR-15-2665

    View details for PubMedID 26864211