Oncogenic FOXO1 gene fusions drive a subset of rhabdomyosarcoma (RMS) with poor survival and to date these cancer drivers are therapeutically intractable. To identify new therapies for this disease, we undertook an isogenic CRISPR-interference screen to define PAX3-FOXO1 specific genetic dependencies and identified genes in the GATOR2 complex. GATOR2 loss in RMS abrogated amino acid-induced lysosomal localization of mTORC1 and consequent downstream signaling, slowing G1-S cell cycle transition. In vivo suppression of GATOR2 impaired the growth of tumor xenografts and favored the outgrowth of cells lacking PAX3-FOXO1. Loss of a subset of GATOR2 members can be compensated by direct genetic activation of mTORC1. RAS mutations are also sufficient to decouple mTORC1 activation from GATOR2, and indeed fusion negative RMS harboring such mutations exhibit amino acid-independent mTORC1 activity. A bi-steric, mTORC1-selective small molecule induced tumor regressions in fusion positive patient-derived tumor xenografts. These findings highlight a vulnerability in FOXO1 fusion positive RMS and provide rationale for the clinical evaluation of bi-steric mTORC1 inhibitors, currently in phase 1 testing, to treat this disease. Isogenic genetic screens can thus identify potentially exploitable vulnerabilities in fusion driven pediatric cancers which otherwise remain mostly undruggable.
Jacqueline Morales, David V. Allegakoen, José A. Garcia, Kristen Kwong, Pushpendra K. Sahu, Drew A. Fajardo, Yue Pan, Max A. Horlbeck, Jonathan S. Weissman, W. Clay Gustafson, Trever G. Bivona, Amit J. Sabnis
Peritoneal metastases are associated with a low response rate to immune checkpoint blockade (ICB) therapy. The numbers of peritoneal resident macrophages (PRMs) are reversely correlated with the response rate to ICB therapy. We have previously shown that TLR9 in fibroblastic reticular cells (FRCs) plays a critical role in regulating peritoneal immune cell recruitment. However, the role of TLR9 in FRCs in regulating PRMs is unclear. Here, we demonstrated that the class A TLR9 agonist, ODN1585, markedly enhanced the efficacy of anti–PD-1 therapy in mouse models of colorectal peritoneal metastases. ODN1585 injected i.p. reduced the numbers of Tim4+ PRMs and enhanced CD8+ T cell antitumor immunity. Mechanistically, treatment of ODN1585 suppressed the expression of genes required for retinoid metabolism in FRCs, and this was associated with reduced expression of the PRM lineage–defining transcription factor GATA6. Selective deletion of TLR9 in FRCs diminished the benefit of ODN1585 in anti–PD-1 therapy in reducing peritoneal metastases. The crosstalk between PRMs and FRCs may be utilized to develop new strategies to improve the efficacy of ICB therapy for peritoneal metastases.
Ting Jiang, Hongji Zhang, Yiming Li, Preethi Jayakumar, Hong Liao, Hai Huang, Timothy R. Billiar, Meihong Deng
Docetaxel (DTX) combined with cisplatin and 5-FU has been used as induction chemotherapy for head and neck squamous cell carcinoma (HNSCC). However, the development of acquired resistance remains a major obstacle to treatment response. Tumor-associated macrophages are associated with chemotherapeutic resistance. In the present study, increased infiltration of macrophages into the tumor microenvironment was significantly associated with shorter overall survival and increased resistance to chemotherapeutic drugs, particularly DTX in HNSCC patients. Macrophage co-culture induced expression of intercellular adhesion molecule 1 (ICAM1), which promotes stemness and the formation of polyploid giant cancer cells, thereby reducing the efficacy of DTX. Both genetic silencing and pharmacological inhibition of ICAM1 sensitized HNSCC to DTX. Macrophage secretion of IL-1β was found to induce tumor expression of ICAM1. IL-1β neutralization and IL-1 receptor blockade reversed DTX resistance induced by macrophage co-culture. IL-1β activated superoxide dismutase 2 and inhibited catalase, thereby modulating intracellular levels of reactive oxygen species (ROS) and inducing ICAM1 expression. Arsenic trioxide (ATO) reduced macrophage infiltration into the TME and impaired IL-1β secretion by macrophages. The combinatorial use of ATO enhanced the in vivo efficacy of DTX in a mouse model, which may provide a revolutionary approach to overcoming acquired therapeutic resistance in HNSCC.
Ching-Yun Hsieh, Ching-Chan Lin, Yu-Wen Huang, Jong-Hang Chen, Yung-An Tsou, Ling-Chu Chang, Chi-Chen Fan, Chen-Yuan Lin, Wei-Chao Chang
BACKGROUND. A patient-derived organoid (PDO) platform may serve as a promising tool for translational cancer research. In this study, we evaluated PDO’s ability to predict clinical response to gastrointestinal (GI) cancers. METHODS. We generated PDOs from primary and metastatic lesions of patients with GI cancers, including pancreatic ductal adenocarcinoma, colorectal adenocarcinoma, and cholangiocarcinoma. We compared PDO response with the observed clinical response for donor patients to the same treatments. RESULTS. We reported an approximately 80% concordance rate between PDO and donor tumor response. Importantly, we found a profound influence of culture media on PDO phenotype, where we showed significant difference in response to standard of care chemotherapies, distinct morphologies, and transcriptomes between media within the same PDOs cultures. CONCLUSION. While we demonstrate a high concordance rate between donor tumor and PDO, these studies also showed the important role of culture media when using PDOs to inform treatment selection and predict response across a spectrum of GI cancers. TRIAL REGISTRATION. Not applicable. FUNDING. This work was supported by the Joan F. & Richard A. Abdoo Family Fund in Colorectal Cancer Research, CA265050, GI Cancer program of the Mayo Clinic Cancer Center, Mayo Clinic SPORE in Pancreatic Cancer, Center of Individualized Medicine (Mayo Clinic), Department of Laboratory Medicine and Pathology (Mayo Clinic), Incyte Pharmaceuticals and Mayo Clinic Hepatobiliary SPORE, a University of Minnesota-Mayo Clinic Partnership grant, and the Early Therapeutic program (Department of Oncology, Mayo Clinic).
Tara L. Hogenson, Hao Xie, William J. Phillips, Merih D. Toruner, Jenny J. Li, Isaac P. Horn, Devin J. Kennedy, Luciana L. Almada, David L. Marks, Ryan M. Carr, Murat Toruner, Ashley N. Sigafoos, Amanda N. Koenig-Kappes, Rachel L.O. Olson, Ezequiel J. Tolosa, Cheng Zhang, Hu Li, Jason D. Doles, Jonathan Bleeker, Michael T. Barrett, James H. Boyum, Benjamin R. Kipp, Amit Mahipal, Joleen M. Hubbard, Temperance J. Scheffler Hanson, Gloria M. Petersen, Surendra Dasari, Ann L. Oberg, Mark J. Truty, Rondell P. Graham, Michael J. Levy, Mojun Zhu, Daniel D. Billadeau, Alex A. Adjei, Nelson Dusetti, Juan L. Iovanna, Tanios S. Bekaii-Saab, Wen Wee Ma, Martin E. Fernandez-Zapico
Pancreatic ductal adenocarcinoma (PDA) remains resistant to immune therapies, largely due to robustly fibrotic and immunosuppressive tumor microenvironments. It has been postulated that excessive accumulation of immunosuppressive myeloid cells influences immunotherapy resistance and recent studies targeting macrophages in combination with checkpoint blockade have demonstrated promising preclinical results. Yet, our understanding of tumor-associated macrophage (TAM) function, complexity, and diversity in PDA remains limited. Here, analysis reveals significant macrophage heterogeneity, with bone marrow-derived monocytes serving as the primary source for immunosuppressive TAMs. These cells also serve as a primary source of TNF-α, which suppresses expression of the alarmin IL33 in carcinoma cells. Deletion of Ccr2 in genetically engineered mice decreases monocyte recruitment resulting in profoundly decreased TNF-α and increased IL33 expression, decreased metastasis, and increased survival. Moreover, intervention studies targeting CCR2 with a new orthosteric inhibitor (CCX598) renders PDA susceptible to checkpoint blockade resulting in reduced metastatic burden and increased survival. Our data indicate that this shift in anti-tumor immunity is influenced by increased levels of IL-33, which increases dendritic cell and cytotoxic T cell activity. These data demonstrate that interventions to disrupt infiltration of immunosuppressive macrophages, or their signaling, have the potential to overcome barriers to effective immunotherapeutics for PDA.
Ajay Dixit, Aaron L. Sarver, Jon Zettervall, Huocong Huang, Kexin Zheng, Rolf A. Brekken, Paolo Provenzano
The DNA methyltransferase inhibitor decitabine has classically been used to reactivate silenced genes and as a pre-treatment for anti-cancer therapies. In a new variation of this idea, this study explores the concept of adding low-dose decitabine following administration of chemotherapy to bolster therapeutic efficacy. We find that addition of decitabine following treatment with the chemotherapy gemcitabine improves survival and slows tumor growth in a mouse model of high-grade sarcoma. Unlike prior studies in epithelial tumor models, low-dose decitabine did not induce a robust anti-tumor T cell response in sarcoma. Furthermore, low-dose decitabine synergizes with gemcitabine independently of the immune system. Mechanistic analyses demonstrate that the combination therapy induces bi-phasic cell cycle arrest and apoptosis. Therapeutic efficacy was found to be sequence dependent, with gemcitabine priming cells for treatment with decitabine through inhibition of ribonucleotide reductase. This study identifies a unique application of low-dose decitabine to augment the cytotoxic effects of conventional chemotherapy in an immune-independent manner. The concepts explored in this study represent a promising new paradigm for cancer treatment by augmenting chemotherapy through addition of low-dose decitabine to increase tolerability and improve patient response. These findings have widespread implications for the treatment of sarcomas and other aggressive malignancies.
Wade R. Gutierrez, Amanda Scherer, Jeffrey D. Rytlewski, Emily A. Laverty, Alexa P. Sheehan, Gavin R. McGivney, Qierra R. Brockman, Vickie Knepper-Adrian, Grace A. Roughton, Dawn E. Quelle, David J. Gordon, Varun Monga, Rebecca D. Dodd
Mass cytometry, or cytometry by TOF (CyTOF), provides a robust means of determining protein-level measurements of more than 40 markers simultaneously. While the functional states of immune cells occur along continuous phenotypic transitions, cytometric studies surveying cell phenotypes often rely on static metrics, such as discrete cell-type abundances, based on canonical markers and/or restrictive gating strategies. To overcome this limitation, we applied single-cell trajectory inference and nonnegative matrix factorization methods to CyTOF data to trace the dynamics of T cell states. In the setting of cancer immunotherapy, we showed that patient-specific summaries of continuous phenotypic shifts in T cells could be inferred from peripheral blood–derived CyTOF mass cytometry data. We further illustrated that transfer learning enabled these T cell continuous metrics to be used to estimate patient-specific cell states in new sample cohorts from a reference patient data set. Our work establishes the utility of continuous metrics for CyTOF analysis as tools for translational discovery.
Dimitrios N. Sidiropoulos, Genevieve L. Stein-O’Brien, Ludmila Danilova, Nicole E. Gross, Soren Charmsaz, Stephanie Xavier, James Leatherman, Hao Wang, Mark Yarchoan, Elizabeth M. Jaffee, Elana J. Fertig, Won Jin Ho
Immune-related adverse events are a major hurdle to the success of immunotherapy. The immunological mechanisms underlying their development and relation to anti-tumour responses are poorly understood. By examining both systemic and tissue-specific immune changes induced by combination anti-CTLA-4 and anti-PD-1 immunotherapy, we found distinct repertoire changes in patients who developed moderate-severe colitis irrespective of their anti-tumour response to therapy. The proportion of circulating monocytes were significantly increased at baseline in patients who subsequently developed colitis compared to patients who did not develop colitis and biopsies from patients with colitis showed monocytic infiltration of both endoscopically and histopathologically normal and inflamed regions of colon. The magnitude of systemic expansion of T cells following commencement of immunotherapy was also greater in patients who developed colitis. Importantly, we show expansion of specific T cell subsets within inflamed regions of the colon, including tissue-resident memory CD8+ T cells and Th1 CD4+ T cells in patients who developed colitis. Our data also suggest that CD8+ T cell expansion was locally induced, while Th1 cell expansion was systemic. Together our data show exaggerated innate and T cell responses to combination immunotherapy synergise to propel colitis in susceptible patients.
Kazi J. Nahar, Felix Marsh-Wakefield, Robert V. Rawson, Tuba N. Gide, Angela L. Ferguson, Ruth O. Allen, Camelia Quek, Ines Pires da Silva, Stephen Tattersall, Christopher J. Kiely, Neomal Sandanayake, Matteo S. Carlino, Geoff McCaughan, James S. Wilmott, Richard A. Scolyer, Georgina V. Long, Alexander M. Menzies, Umaimainthan Palendira
Therapy with radiation plus cisplatin kills HPV+ oropharyngeal squamous cell carcinomas (OPSCCs) by increasing reactive oxygen species beyond cellular antioxidant capacity. To explore why these standard treatments fail for some patients, we evaluated whether the variation in HPV oncoprotein levels among HPV+ OPSCCs affects mitochondrial metabolism, a source of antioxidant capacity. In cell line and patient-derived xenograft models, levels of HPV full-length E6 (fl-E6) inversely correlated with oxidative phosphorylation, antioxidant capacity, and therapy resistance, and fl-E6 was the only HPV oncoprotein to display such correlations. Ectopically expressing fl-E6 in models with low baseline levels reduced mitochondrial mass, depleted antioxidant capacity, and sensitized to therapy. In this setting, fl-E6 repressed the peroxisome proliferator–activated receptor gamma co-activator 1α/estrogen-related receptor α (PGC-1α/ERRα) pathway for mitochondrial biogenesis by reducing p53-dependent PGC-1α transcription. Concordant observations were made in 3 clinical cohorts, where expression of mitochondrial components was higher in tumors of patients with reduced survival. These tumors contained the lowest fl-E6 levels, the highest p53 target gene expression, and an activated PGC-1α/ERRα pathway. Our findings demonstrate that E6 can potentiate treatment responses by depleting mitochondrial antioxidant capacity and provide evidence for low E6 negatively affecting patient survival. E6’s interaction with the PGC-1α/ERRα axis has implications for predicting and targeting treatment resistance in OPSCC.
Malay K. Sannigrahi, Pavithra Rajagopalan, Ling Lai, Xinyi Liu, Varun Sahu, Hiroshi Nakagawa, Jalal B. Jalaly, Robert M. Brody, Iain M. Morgan, Bradford E. Windle, Xiaowei Wang, Phyllis A. Gimotty, Daniel P. Kelly, Elizabeth A. White, Devraj Basu
To define alterations early in tumor formation, we studied nerve tumors in neurofibromatosis 1 (NF1), a tumor predisposition syndrome. Affected individuals develop neurofibromas, benign tumors driven by NF1 loss in Schwann cells (SCs). By comparing normal nerve cells to plexiform neurofibroma (PN) cells using single-cell and bulk RNA sequencing, we identified changes in 5 SC populations, including a de novo SC progenitor–like (SCP-like) population. Long after Nf1 loss, SC populations developed PN-specific expression of Dcn, Postn, and Cd74, with sustained expression of the injury response gene Postn and showed dramatic expansion of immune and stromal cell populations; in corresponding human PNs, the immune and stromal cells comprised 90% of cells. Comparisons between injury-related and tumor monocytes/macrophages support early monocyte recruitment and aberrant macrophage differentiation. Cross-species analysis verified each SC population and unique conserved patterns of predicted cell-cell communication in each SC population. This analysis identified PROS1-AXL, FGF-FGFR, and MIF-CD74 and its effector pathway NF-κB as deregulated in NF1 SC populations, including SCP-like cells predicted to influence other types of SCs, stromal cells, and/or immune cells in mouse and human. These findings highlight remarkable changes in multiple types of SCs and identify therapeutic targets for PN.
Leah J. Kershner, Kwangmin Choi, Jianqiang Wu, Xiyuan Zhang, Melissa Perrino, Nathan Salomonis, Jack F. Shern, Nancy Ratner
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