Publications


List of authored research works

Click on an abstract to view the description for the study.

  1. Sturgill IR, Raab JR, Hoadley KA. Expanded detection and impact of BAP1 alterations in cancer. NAR Cancer. 2024 Oct 3;6(4):zcae045.
    Abstract Aberrant expression of the BAP1 (BRCA associated protein 1) tumor suppressor gene is a prominent risk factor for several tumor types and is important in tumor evolution and progression. Here we performed integrated multi-omics analyses using data from The Cancer Genome Atlas for 33 cancer types and over 10,000 individuals to identify alterations leading to BAP1 disruption. We combined existing variant calls and new calls derived from a de novo local realignment pipeline across multiple independent variant callers, increasing somatic variant detection by 41% from 182 to 257, including 11 indels ≥40 bp. The expanded detection of mutations highlights the power of new tools to uncover longer indels and impactful mutations. We developed an expression-based BAP1 activity score and identified a transcriptional profile associated with BAP1 disruption in cancer. BAP1 has been proposed to play a critical role in controlling tumor plasticity and normal cell fate. Leveraging human and mouse liver datasets, BAP1 loss in normal cells resulted in lower BAP1 activity scores and lower scores were associated with a less-differentiated phenotype in embryonic cells. Together, our expanded BAP1 mutant samples revealed a transcriptional signature in cancer cells, supporting BAP1’s influences on cellular plasticity and cell identity maintenance.

    Link: https://doi.org/10.1093/narcan/zcae045

  2. Cruz SM, Iranpur KR, Judge SJ, Ames E, Sturgill IR, Farley LE, et al. Low-Dose Sorafenib Promotes Cancer Stem Cell Expansion and Accelerated Tumor Progression in Soft Tissue Sarcomas. Int J Mol Sci. 2024 Jan;25(6):3351.
    Abstract The cancer stem cell (CSC) hypothesis postulates that heterogeneous human cancers harbor a population of stem-like cells which are resistant to cytotoxic therapies, thus providing a reservoir of relapse following conventional therapies like chemotherapy and radiation (RT). CSCs have been observed in multiple human cancers, and their presence has been correlated with worse clinical outcomes. Here, we sought to evaluate the impact of drug dosing of the multi-tyrosine kinase inhibitor, sorafenib, on CSC and non-CSCs in soft tissue sarcoma (STS) models, hypothesizing differential effects of sorafenib based on dose and target cell population. In vitro, human cancer cell lines and primary STS from surgical specimens were exposed to escalating doses of sorafenib to determine cell viability and expression of CSC marker aldehyde dehydrogenase (ALDH). In vivo, ALDHbright CSCs were isolated, exposed to sorafenib, and xenograft growth and survival analyses were performed. We observed that sarcoma CSCs appear to paradoxically respond to the tyrosine kinase inhibitor sorafenib at low doses with increased proliferation and stem-like function of CSCs, whereas anti-viability effects dominated at higher doses. Importantly, STS patients receiving neoadjuvant sorafenib and RT on a clinical trial (NCT00864032) showed increased CSCs post therapy, and higher ALDH scores post therapy were associated with worse metastasis-free survival. These data suggest that low-dose sorafenib may promote the CSC phenotype in STS with clinically significant effects, including increased tumor growth and higher rates of metastasis formation in sarcoma patients.

    Link: https://doi.org/10.3390/ijms25063351

  3. Gingrich AA, Reiter TE, Judge SJ, York D, Yanagisawa M, Razmara A, Sturgill IR, et al. Comparative Immunogenomics of Canine Natural Killer Cells as Immunotherapy Target. Front Immunol. 2021 Sep 14;12.
    Abstract Natural killer (NK) cells are key effectors of the innate immune system, but major differences between human and murine NK cells have impeded translation. Outbred dogs offer an important link for studies of NK biology and immunotherapy. We analyzed gene expression of putative NK populations from healthy dogs and dogs with naturally-occurring cancers examining differential gene expression across multiple conditions, including steady-state, in vitro activation with cytokines and co-culture, and in vivo activation with inhaled IL-15 in dogs receiving IL-15 immunotherapy. We also compared dog, mouse and human CD3-NKp46+ NK cells using a novel orthologous transcriptome. Distinct transcriptional profiles between NK populations exist between conditions and in vitro versus in vivo treatments. In cross-species analysis, canine NK cells were globally more similar to human NK cells than mice. These data define canine NK cell gene expression under multiple conditions and across species, filling an important gap in translational NK studies.

    Link: https://doi.org/10.3389/fimmu.2021.670309

  4. Khuat LT, Le CT, Pai CCS, Shields-Cutler RR, Holtan SG, Rashidi A, Parker SL, Knights D, Luna JI, Dunai C, Wang Z, Sturgill IR, et al. Obesity induces gut microbiota alterations and augments acute graft-versus-host disease after allogeneic stem cell transplantation. Sci Transl Med. 2020 Nov 25;12(571):eaay7713.
    Abstract The efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is limited by acute and chronic graft-versus-host disease (GVHD). The impact of obesity on allo-HSCT outcomes is poorly understood. Here, we report that obesity had a negative and selective impact on acute gut GVHD after allo-HSCT in mice with diet-induced obesity (DIO). These animals exhibited increased gut permeability, endotoxin translocation across the gut, and radiation-induced gastrointestinal damage after allo-HSCT. After allo-HSCT, both male and female DIO mouse recipients showed increased proinflammatory cytokine production and expression of the GVHD marker ST2 (IL-33R) and MHC class II molecules; they also exhibited decreased survival associated with acute severe gut GVHD. This rapid-onset, obesity-associated gut GVHD depended on donor CD4+ T cells and occurred even with a minor MHC mismatch between donor and recipient animals. Retrospective analysis of clinical cohorts receiving allo-HSCT transplants from unrelated donors revealed that recipients with a high body mass index (BMI, >30) had reduced survival and higher serum ST2 concentrations compared with nonobese transplant recipients. Assessment of both DIO mice and allo-HSCT recipients with a high BMI revealed reduced gut microbiota diversity and decreased Clostridiaceae abundance. Prophylactic antibiotic treatment protected DIO mouse recipients from endotoxin translocation across the gut and increased inflammatory cytokine production, as well as gut pathology and mortality, but did not protect against later development of chronic skin GVHD. These results suggest that obesity-induced alterations of the gut microbiota may affect GVHD after allo-HSCT in DIO mice, which could be ameliorated by prophylactic antibiotic treatment.

    Link: https://doi.org/10.1126/scitranslmed.aay7713

  5. Judge SJ, Dunai C, Aguilar EG, Vick SC, Sturgill IR, Khuat LT, et al. Minimal PD-1 expression in mouse and human NK cells under diverse conditions. J Clin Invest. 2020 Jun 1;130(6):3051–68.
    Abstract PD-1 expression is a hallmark of both early antigen-specific T cell activation and later chronic stimulation, suggesting key roles in both naive T cell priming and memory T cell responses. Although significant similarities exist between T cells and NK cells, there are critical differences in their biology and functions reflecting their respective adaptive and innate immune effector functions. Expression of PD-1 on NK cells is controversial despite rapid incorporation into clinical cancer trials. Our objective was to stringently and comprehensively assess expression of PD-1 on both mouse and human NK cells under multiple conditions and using a variety of readouts. We evaluated NK cells from primary human tumor samples, after ex vivo culturing, and from multiple mouse tumor and viral models using flow cytometry, quantitative reverse-transcriptase PCR (qRT-PCR), and RNA-Seq for PD-1 expression. We demonstrate that, under multiple conditions, human and mouse NK cells consistently lack PD-1 expression despite the marked upregulation of other activation/regulatory markers, such as TIGIT. This was in marked contrast to T cells, which were far more prominent within all tumors and expressed PD-1. These data have important implications when attempting to discern NK from T cell effects and to determine whether PD-1 targeting can be expected to have direct effects on NK cell functions.

    Link: https://doi.org/10.1172/jci133353

  6. Judge SJ, Yanagisawa M, Sturgill IR, Bateni SB, Gingrich AA, Foltz JA, et al. Blood and tissue biomarker analysis in dogs with osteosarcoma treated with palliative radiation and intra-tumoral autologous natural killer cell transfer. PLOS ONE. 2020 Feb 21;15(2):e0224775.
    Abstract We have previously reported radiation-induced sensitization of canine osteosarcoma (OSA) to natural killer (NK) therapy, including results from a first-in-dog clinical trial. Here, we report correlative analyses of blood and tissue specimens for signals of immune activation in trial subjects. Among 10 dogs treated with palliative radiotherapy (RT) and intra-tumoral adoptive NK transfer, we performed ELISA on serum cytokines, flow cytometry for immune phenotype of PBMCs, and PCR on tumor tissue for immune-related gene expression. We then queried The Cancer Genome Atlas (TCGA) to evaluate the association of cytotoxic/immune-related gene expression with human sarcoma survival. Updated survival analysis revealed five 6-month survivors, including one dog who lived 17.9 months. Using feeder line co-culture for NK expansion, we observed maximal activation of dog NK cells on day 17–19 post isolation with near 100% expression of granzyme B and NKp46 and high cytotoxic function in the injected NK product. Among dogs on trial, we observed a trend for higher baseline serum IL-6 to predict worse lung metastasis-free and overall survival (P = 0.08). PCR analysis revealed low absolute gene expression of CD3, CD8, and NKG2D in untreated OSA. Among treated dogs, there was marked heterogeneity in the expression of immune-related genes pre- and post-treatment, but increases in CD3 and CD8 gene expression were higher among dogs that lived > 6 months compared to those who did not. Analysis of the TCGA confirmed significant differences in survival among human sarcoma patients with high and low expression of genes associated with greater immune activation and cytotoxicity (CD3e, CD8a, IFN-γ, perforin, and CD122/IL-2 receptor beta). Updated results from a first-in-dog clinical trial of palliative RT and autologous NK cell immunotherapy for OSA illustrate the translational relevance of companion dogs for novel cancer therapies. Similar to human studies, analyses of immune markers from canine serum, PBMCs, and tumor tissue are feasible and provide insight into potential biomarkers of response and resistance.

    Link: https://doi.org/10.1371/journal.pone.0224775

  7. Judge SJ, Darrow MA, Thorpe SW, Gingrich AA, O’Donnell EF, Bellini AR, Sturgill IR, et al. Analysis of tumor-infiltrating NK and T cells highlights IL-15 stimulation and TIGIT blockade as a combination immunotherapy strategy for soft tissue sarcomas. J Immunother Cancer. 2020 Nov 6;8(2):e001355.
    Abstract Purpose Given the unmet need for novel immunotherapy in soft tissue sarcoma (STS), we sought to characterize the phenotype and function of intratumoral natural killer (NK) and T cells to identify novel strategies to augment tumor-infiltrating lymphocyte (TIL) function. Experimental design Using prospectively collected specimens from dogs and humans with sarcomas, archived specimens, and The Cancer Genome Atlas (TCGA) data, we evaluated blood and tumor NK and T cell phenotype and function and correlated those with outcome. We then assessed the effects of interleukin 15 (IL-15) stimulation on both NK and T cell activation and TIGIT upregulation. Finally, we evaluated cytotoxic effects of IL-15 combined with TIGIT blockade using a novel anti-TIGIT antibody. Results TILs were strongly associated with survival outcome in both archived tissue and TCGA, but higher TIL content was also associated with higher TIGIT expression. Compared with blood, intratumoral NK and T cells showed significantly higher expression of both activation and exhaustion markers, in particular TIGIT. Ex vivo stimulation of blood and tumor NK and T cells from patients with STS with IL-15 further increased both activation and exhaustion markers, including TIGIT. Dogs with metastatic osteosarcoma receiving inhaled IL-15 also exhibited upregulation of activation markers and TIGIT. Ex vivo, combined IL-15 and TIGIT blockade using STS blood and tumor specimens significantly increased cytotoxicity against STS targets. Conclusion Intratumoral NK and T cells are prognostic in STS, but their activation is marked by significant upregulation of TIGIT. Our data suggest that combined IL-15 and TIGIT blockade may be a promising clinical strategy in STS.

    Link: https://doi.org/10.1136/jitc-2020-001355

  8. Khuat LT, Le CT, Pai CC, Shields-Cutler R, Holtan S, Rashidi A, Parker S, Knights D, Luna JI, Dunai C, Wang Z, Sturgill IR, et al. Obesity-Induced Microbiome Alterations Result in Severe Gastrointestinal Graft-Versus-Host Disease Following Allogeneic Hematopoietic Stem Cell Transplantation. Blood. 2019 Nov 13;134:1922.
    Abstract Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a viable treatment option for many cancers but its clinical utility is limited due to the occurrence of graft-versus-host disease (GVHD). Understanding the impact of obesity on immune function has become increasingly important in the setting of the current obesity pandemic. We report here that obesity has a negative and selective impact on acute gut GVHD. Diet-induced obese (DIO) mice exhibited increased gut permeability, endotoxin translocation and radiation-induced gastrointestinal damage. After allo-HSCT, DIO recipients across strains and sex had markedly increased pro-inflammatory cytokines (IL-6, TNF), GVHD biomarker ST2, MHC class II expression and exhibited rapid mortality associated with severe acute gut pathology. This obesity-associated lethal acute gut GVHD was dependent on donor CD4 T cells and occurred even in minor MHC mismatch strain combination in which only a delayed skin chronic GVHD resulted in lean recipients. Pro-inflammatory cytokine blockade targeting both IL-6 and TNF ameliorated obesity-associated acute gut GVHD while maintaining graft-versus-tumor (GVT) effects. Microbiome assessment of DIO mice revealed markedly reduced microbiome diversity and decreased Clostridiaceae abundance. Additionally, DIO mice had a significant increase of GVHD-associated Akkermansia muciniphila before and after allo-HSCT compared to the controls. Extended antibiotic treatment of DIO mice protected from the endotoxin translocation, cytokine storm as well as gut GVHD pathology but did not protect later development of chronic skin GVHD. These results demonstrate that obesity alters the microbiome and imparts differential effects on GVHD following allo-HSCT with decreased survival and this inferior outcome can be pre-empted by combined pro-inflammatory cytokine blockade or antibiotic pretreatment.

    Link: https://doi.org/10.1182/blood-2019-127743

  9. Luna JI, Grossenbacher SK, Sturgill IR, Ames E, Judge SJ, Bouzid LA, et al. Bortezomib Augments Natural Killer Cell Targeting of Stem-Like Tumor Cells. Cancers. 2019 Jan;11(1):85.
    Abstract Tumor cells harboring stem-like/cancer stem cell (CSC) properties have been identified and isolated from numerous hematological and solid malignancies. These stem-like tumor cells can persist following conventional cytoreductive therapies, such as chemotherapy and radiotherapy, thereby repopulating the tumor and seeding relapse and/or metastasis. We have previously shown that natural killer (NK) cells preferentially target stem-like tumor cells via non- major histocompatibility complex (MHC) restricted mechanisms. Here, we demonstrated that the proteasome inhibitor, bortezomib, augments NK cell targeting of stem cell-like tumor cells against multiple solid human tumor-derived cancer lines and primary tissue samples. Mechanistically, this was mediated by the upregulation of cell surface NK ligands MHC class I chain-related protein A and B (MICA and MICB) on aldehyde dehydrogenases (ALDH)-positive CSCs. The increased expression of MICA and MICB on CSC targets thereby enhanced NK cell mediated killing in vitro and ex vivo from both human primary tumor and patient-derived xenograft samples. In vivo, the combination of bortezomib and allogeneic NK cell adoptive transfer in immunodeficient mice led to increased elimination of CSCs as well as tumor growth delay of orthotopic glioblastoma tumors. Taken together, our data support the combination bortezomib and NK transfer as a strategy for both CSC targeting and potentially improved outcomes in clinical cancer patients.

    Link: https://doi.org/10.3390/cancers11010085

  10. Wang Z, Aguilar EG, Luna JI, Dunai C, Khuat LT, Le CT, Mirsoian A, Minnar CM, Stoffel KM, Sturgill IR, et al. Paradoxical effects of obesity on T cell function during tumor progression and PD-1 checkpoint blockade. Nat Med. 2019 Jan;25(1):141–51.
    Abstract The recent successes of immunotherapy have shifted the paradigm in cancer treatment, but because only a percentage of patients are responsive to immunotherapy, it is imperative to identify factors impacting outcome. Obesity is reaching pandemic proportions and is a major risk factor for certain malignancies, but the impact of obesity on immune responses, in general and in cancer immunotherapy, is poorly understood. Here, we demonstrate, across multiple species and tumor models, that obesity results in increased immune aging, tumor progression and PD-1-mediated T cell dysfunction which is driven, at least in part, by leptin. However, obesity is also associated with increased efficacy of PD-1/PD-L1 blockade in both tumor-bearing mice and clinical cancer patients. These findings advance our understanding of obesity-induced immune dysfunction and its consequences in cancer and highlight obesity as a biomarker for some cancer immunotherapies. These data indicate a paradoxical impact of obesity on cancer. There is heightened immune dysfunction and tumor progression but also greater anti-tumor efficacy and survival after checkpoint blockade which directly targets some of the pathways activated in obesity.

    Link: https://doi.org/10.1038/s41591-018-0221-5

  11. Canter RJ, Grossenbacher SK, Foltz JA, Sturgill IR, Park JS, Luna JI, et al. Radiotherapy enhances natural killer cell cytotoxicity and localization in pre-clinical canine sarcomas and first-in-dog clinical trial. J Immunother Cancer. 2017 Dec 19;5(1):98.
    Abstract Background We have previously shown that radiotherapy (RT) augments natural killer (NK) functions in pre-clinical models of human and mouse cancers, including sarcomas. Since dogs are an excellent outbred model for immunotherapy studies, we sought to assess RT plus local autologous NK transfer in canine sarcomas. Methods Dog NK cells (CD5dim, NKp46+) were isolated from PBMCs and expanded with irradiated K562-C9-mIL21 feeder cells and 100 IU/mL recombinant human IL-2. NK homing and cytotoxicity ± RT were evaluated using canine osteosarcoma tumor lines and dog patient-derived xenografts (PDX). In a first-in-dog clinical trial for spontaneous osteosarcoma, we evaluated RT and intra-tumoral autologous NK transfer. Results After 14 days, mean NK expansion and yield were 19.0-fold (±8.6) and 258.9(±76.1) ×106 cells, respectively. Post-RT, NK cytotoxicity increased in a dose-dependent fashion in vitro reaching ~ 80% at effector:target ratios of ≥10:1 (P < 0.001). In dog PDX models, allogeneic NK cells were cytotoxic in ex vivo killing assays and produced significant PDX tumor growth delay (P < 0.01) in vivo. After focal RT and intravenous NK transfer, we also observed significantly increased NK homing to tumors in vivo. Of 10 dogs with spontaneous osteosarcoma treated with focal RT and autologous NK transfer, 5 remain metastasis-free at the 6-month primary endpoint with resolution of suspicious pulmonary nodules in one patient. We also observed increased activation of circulating NK cells after treatment and persistence of labelled NK cells in vivo. Conclusions NK cell homing and cytotoxicity are increased following RT in canine models of sarcoma. Results from a first-in-dog clinical trial are promising, including possible abscopal effects.

    Link: https://doi.org/10.1186/s40425-017-0305-7

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