ABSTRACT
DNA mismatch repair deficiency (MMRd) is associated with a high tumor mutational burden (TMB) and sensitivity to immune checkpoint blockade (ICB) therapy. Nevertheless, most MMRd tumors do not durably respond to ICB and critical questions remain about immunosurveillance and TMB in these tumors. In the present study, we developed autochthonous mouse models of MMRd lung and colon cancer. Surprisingly, these models did not display increased T cell infiltration or ICB response, which we showed to be the result of substantial intratumor heterogeneity of mutations. Furthermore, we found that immunosurveillance shapes the clonal architecture but not the overall burden of neoantigens, and T cell responses against subclonal neoantigens are blunted. Finally, we showed that clonal, but not subclonal, neoantigen burden predicts ICB response in clinical trials of MMRd gastric and colorectal cancer. These results provide important context for understanding immune evasion in cancers with a high TMB and have major implications for therapies aimed at increasing TMB.
Subject(s)
Brain Neoplasms , Colorectal Neoplasms , Neoplastic Syndromes, Hereditary , Animals , Mice , Colorectal Neoplasms/genetics , Antigens, Neoplasm/genetics , Mutation , DNA Mismatch Repair/genetics , Biomarkers, Tumor/geneticsABSTRACT
Tumor mutations can influence the surrounding microenvironment leading to suppression of anti-tumor immune responses and thereby contributing to tumor progression and failure of cancer therapies. Here we use genetically engineered lung cancer mouse models and patient samples to dissect how LKB1 mutations accelerate tumor growth by reshaping the immune microenvironment. Comprehensive immune profiling of LKB1 -mutant vs wildtype tumors revealed dramatic changes in myeloid cells, specifically enrichment of Arg1 + interstitial macrophages and SiglecF Hi neutrophils. We discovered a novel mechanism whereby autocrine LIF signaling in Lkb1 -mutant tumors drives tumorigenesis by reprogramming myeloid cells in the immune microenvironment. Inhibiting LIF signaling in Lkb1 -mutant tumors, via gene targeting or with a neutralizing antibody, resulted in a striking reduction in Arg1 + interstitial macrophages and SiglecF Hi neutrophils, expansion of antigen specific T cells, and inhibition of tumor progression. Thus, targeting LIF signaling provides a new therapeutic approach to reverse the immunosuppressive microenvironment of LKB1 -mutant tumors.
ABSTRACT
Lung cancer is the leading cause of cancer-related death worldwide. Lung adenocarcinoma (LUAD), the most common histological subtype, accounts for 40% of all cases. While existing genetically engineered mouse models (GEMMs) recapitulate the histological progression and transcriptional evolution of human LUAD, they are time-consuming and technically demanding. In contrast, cell line transplant models are fast and flexible, but these models fail to capture the full spectrum of disease progression. Organoid technologies provide a means to create next-generation cancer models that integrate the most advantageous features of autochthonous and transplant-based systems. However, robust and faithful LUAD organoid platforms are currently lacking. Here, we describe optimized conditions to continuously expand murine alveolar type 2 (AT2) cells, a prominent cell of origin for LUAD, in organoid culture. These organoids display canonical features of AT2 cells, including marker gene expression, the presence of lamellar bodies, and an ability to differentiate into the AT1 lineage. We used this system to develop flexible and versatile immunocompetent organoid-based models of KRAS, BRAF, and ALK mutant LUAD. Notably, organoid-based tumors display extensive burden and complete penetrance and are histopathologically indistinguishable from their autochthonous counterparts. Altogether, this organoid platform is a powerful, versatile new model system to study LUAD.
Subject(s)
Adenocarcinoma of Lung , Lung Neoplasms , Adenocarcinoma of Lung/genetics , Adenocarcinoma of Lung/metabolism , Adenocarcinoma of Lung/pathology , Animals , Humans , Lung Neoplasms/metabolism , Mice , Organoids , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , Receptor Protein-Tyrosine Kinases/metabolismABSTRACT
Intratumoral heterogeneity and cellular plasticity have emerged as hallmarks of cancer, including pancreatic ductal adenocarcinoma (PDAC). As PDAC portends a dire prognosis, a better understanding of the mechanisms underpinning cellular diversity in PDAC is crucial. Here, we investigated the cellular heterogeneity of PDAC cancer cells across a range of in vitro and in vivo growth conditions using single-cell genomics. Heterogeneity contracted significantly in two-dimensional and three-dimensional cell culture models but was restored upon orthotopic transplantation. Orthotopic transplants reproducibly acquired cell states identified in autochthonous PDAC tumors, including a basal state exhibiting coexpression and coaccessibility of epithelial and mesenchymal genes. Lineage tracing combined with single-cell transcriptomics revealed that basal cells display high plasticity in situ. This work defines the impact of cellular growth conditions on phenotypic diversity and uncovers a highly plastic cell state with the capacity to facilitate state transitions and promote intratumoral heterogeneity in PDAC. SIGNIFICANCE: This work provides important insights into how different model systems of pancreatic ductal adenocarcinoma mold the phenotypic space of cancer cells, highlighting the power of in vivo models.
Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/pathology , Humans , Pancreatic Ducts , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Plastics , Pancreatic NeoplasmsABSTRACT
The GATA4 transcription factor acts as a master regulator of development of multiple tissues. GATA4 also acts in a distinct capacity to control a stress-inducible pro-inflammatory secretory program that is associated with senescence, a potent tumor suppression mechanism, but also operates in non-senescent contexts such as tumorigenesis. This secretory pathway is composed of chemokines, cytokines, growth factors, and proteases. Since GATA4 is deleted or epigenetically silenced in cancer, here we examine the role of GATA4 in tumorigenesis in mouse models through both loss-of-function and overexpression experiments. We find that GATA4 promotes non-cell autonomous tumor suppression in multiple model systems. Mechanistically, we show that Gata4-dependent tumor suppression requires cytotoxic CD8 T cells and partially requires the secreted chemokine CCL2. Analysis of transcriptome data in human tumors reveals reduced lymphocyte infiltration in GATA4-deficient tumors, consistent with our murine data. Notably, activation of the GATA4-dependent secretory program combined with an anti-PD-1 antibody robustly abrogates tumor growth in vivo.
Subject(s)
Biological Transport/physiology , GATA4 Transcription Factor/metabolism , Neoplasms/metabolism , T-Lymphocytes, Cytotoxic/metabolism , Animals , Antibodies, Monoclonal, Humanized , Chemokine CCL2/metabolism , GATA4 Transcription Factor/genetics , Gene Expression Regulation, Neoplastic , Homeodomain Proteins , Humans , Immune Evasion , Lung/pathology , Melanoma , Mice , Mice, Inbred C57BL , Myocytes, Cardiac/metabolism , Neoplasms/immunology , Neoplasms/pathology , TranscriptomeABSTRACT
Tumor-infiltrating dendritic cells (DCs) assume varied functional states that impact anti-tumor immunity. To delineate the DC states associated with productive anti-tumor T cell immunity, we compared spontaneously regressing and progressing tumors. Tumor-reactive CD8+ T cell responses in Batf3-/- mice lacking type 1 DCs (DC1s) were lost in progressor tumors but preserved in regressor tumors. Transcriptional profiling of intra-tumoral DCs within regressor tumors revealed an activation state of CD11b+ conventional DCs (DC2s) characterized by expression of interferon (IFN)-stimulated genes (ISGs) (ISG+ DCs). ISG+ DC-activated CD8+ T cells ex vivo comparably to DC1. Unlike cross-presenting DC1, ISG+ DCs acquired and presented intact tumor-derived peptide-major histocompatibility complex class I (MHC class I) complexes. Constitutive type I IFN production by regressor tumors drove the ISG+ DC state, and activation of MHC class I-dressed ISG+ DCs by exogenous IFN-ß rescued anti-tumor immunity against progressor tumors in Batf3-/- mice. The ISG+ DC gene signature is detectable in human tumors. Engaging this functional DC state may present an approach for the treatment of human disease.
Subject(s)
CD8-Positive T-Lymphocytes/immunology , Dendritic Cells/immunology , Histocompatibility Antigens Class I/immunology , Interferon Type I/immunology , Lymphocytes, Tumor-Infiltrating/immunology , Animals , Antigens, Neoplasm/immunology , CD11b Antigen/immunology , Cross-Priming , Dendritic Cells/drug effects , Interferon-beta/administration & dosage , Interferon-beta/pharmacology , Mice , Neoplasms/immunology , Receptors, Interferon/immunology , Signal Transduction/immunology , Tumor Microenvironment/immunologyABSTRACT
SMARCA4/BRG1 encodes for one of two mutually exclusive ATPases present in mammalian SWI/SNF chromatin remodeling complexes and is frequently mutated in human lung adenocarcinoma. However, the functional consequences of SMARCA4 mutation on tumor initiation, progression, and chromatin regulation in lung cancer remain poorly understood. Here, we demonstrate that loss of Smarca4 sensitizes club cell secretory protein-positive cells within the lung in a cell type-dependent fashion to malignant transformation and tumor progression, resulting in highly advanced dedifferentiated tumors and increased metastatic incidence. Consistent with these phenotypes, Smarca4-deficient primary tumors lack lung lineage transcription factor activities and resemble a metastatic cell state. Mechanistically, we show that Smarca4 loss impairs the function of all three classes of SWI/SNF complexes, resulting in decreased chromatin accessibility at lung lineage motifs and ultimately accelerating tumor progression. Thus, we propose that the SWI/SNF complex via Smarca4 acts as a gatekeeper for lineage-specific cellular transformation and metastasis during lung cancer evolution. SIGNIFICANCE: We demonstrate cell-type specificity in the tumor-suppressive functions of SMARCA4 in the lung, pointing toward a critical role of the cell-of-origin in driving SWI/SNF-mutant lung adenocarcinoma. We further show the direct effects of SMARCA4 loss on SWI/SNF function and chromatin regulation that cause aggressive malignancy during lung cancer evolution.This article is highlighted in the In This Issue feature, p. 275.
Subject(s)
Adenocarcinoma of Lung/genetics , Cell Transformation, Neoplastic , DNA Helicases/genetics , Lung Neoplasms/genetics , Neoplasm Metastasis , Nuclear Proteins/genetics , Transcription Factors/genetics , Adenocarcinoma of Lung/secondary , Animals , Disease Models, Animal , Humans , Lung Neoplasms/pathology , MiceABSTRACT
The epithelial-mesenchymal transition (EMT) and primary ciliogenesis induce stem cell properties in basal mammary stem cells (MaSCs) to promote mammogenesis, but the underlying mechanisms remain incompletely understood. Here, we show that EMT transcription factors promote ciliogenesis upon entry into intermediate EMT states by activating ciliogenesis inducers, including FGFR1. The resulting primary cilia promote ubiquitination and inactivation of a transcriptional repressor, GLIS2, which localizes to the ciliary base. We show that GLIS2 inactivation promotes MaSC stemness, and GLIS2 is required for normal mammary gland development. Moreover, GLIS2 inactivation is required to induce the proliferative and tumorigenic capacities of the mammary tumorinitiating cells (MaTICs) of claudin-low breast cancers. Claudin-low breast tumors can be segregated from other breast tumor subtypes based on a GLIS2-dependent gene expression signature. Collectively, our findings establish molecular mechanisms by which EMT programs induce ciliogenesis to control MaSC and MaTIC stemness, mammary gland development, and claudin-low breast cancer formation.
ABSTRACT
CD8 T cell responses against different tumor neoantigens occur simultaneously, yet little is known about the interplay between responses and its impact on T cell function and tumor control. In mouse lung adenocarcinoma, we found that immunodominance is established in tumors, wherein CD8 T cell expansion is predominantly driven by the antigen that most stably binds MHC. T cells responding to subdominant antigens were enriched for a TCF1+ progenitor phenotype correlated with response to immune checkpoint blockade (ICB) therapy. However, the subdominant T cell response did not preferentially benefit from ICB due to a dysfunctional subset of TCF1+ cells marked by CCR6 and Tc17 differentiation. Analysis of human samples and sequencing datasets revealed that CCR6+ TCF1+ cells exist across human cancers and are not correlated with ICB response. Vaccination eliminated CCR6+ TCF1+ cells and dramatically improved the subdominant response, highlighting a strategy to optimally engage concurrent neoantigen responses against tumors.
Subject(s)
Adenocarcinoma of Lung/immunology , Antigens, Neoplasm/immunology , CD8-Positive T-Lymphocytes/immunology , Hepatocyte Nuclear Factor 1-alpha/metabolism , Lung Neoplasms/immunology , Stem Cells/immunology , Amino Acid Sequence , Animals , CTLA-4 Antigen/metabolism , Epitopes , Female , Humans , Immune Checkpoint Inhibitors/pharmacology , Lung Neoplasms/pathology , Mice , Peptides/chemistry , Phenotype , Programmed Cell Death 1 Receptor/metabolism , RNA-Seq , Receptors, Antigen, T-Cell/metabolism , Receptors, CCR6/metabolism , Single-Cell Analysis , VaccinationABSTRACT
The CD155/TIGIT axis can be co-opted during immune evasion in chronic viral infections and cancer. Pancreatic adenocarcinoma (PDAC) is a highly lethal malignancy, and immune-based strategies to combat this disease have been largely unsuccessful to date. We corroborate prior reports that a substantial portion of PDAC harbors predicted high-affinity MHC class I-restricted neoepitopes and extend these findings to advanced/metastatic disease. Using multiple preclinical models of neoantigen-expressing PDAC, we demonstrate that intratumoral neoantigen-specific CD8+ T cells adopt multiple states of dysfunction, resembling those in tumor-infiltrating lymphocytes of PDAC patients. Mechanistically, genetic and/or pharmacologic modulation of the CD155/TIGIT axis was sufficient to promote immune evasion in autochthonous neoantigen-expressing PDAC. Finally, we demonstrate that the CD155/TIGIT axis is critical in maintaining immune evasion in PDAC and uncover a combination immunotherapy (TIGIT/PD-1 co-blockade plus CD40 agonism) that elicits profound anti-tumor responses in preclinical models, now poised for clinical evaluation.
Subject(s)
Immune Evasion/immunology , Immunotherapy/methods , Lymphocytes, Tumor-Infiltrating/metabolism , Pancreatic Neoplasms/immunology , Receptors, Virus/immunology , Animals , Humans , Mice , Pancreatic NeoplasmsABSTRACT
Inactivation of SMARCA4/BRG1, the core ATPase subunit of mammalian SWI/SNF complexes, occurs at very high frequencies in non-small cell lung cancers (NSCLC). There are no targeted therapies for this subset of lung cancers, nor is it known how mutations in BRG1 contribute to lung cancer progression. Using a combination of gain- and loss-of-function approaches, we demonstrate that deletion of BRG1 in lung cancer leads to activation of replication stress responses. Single-molecule assessment of replication fork dynamics in BRG1-deficient cells revealed increased origin firing mediated by the prelicensing protein, CDC6. Quantitative mass spectrometry and coimmunoprecipitation assays showed that BRG1-containing SWI/SNF complexes interact with RPA complexes. Finally, BRG1-deficient lung cancers were sensitive to pharmacologic inhibition of ATR. These findings provide novel mechanistic insight into BRG1-mutant lung cancers and suggest that their dependency on ATR can be leveraged therapeutically and potentially expanded to BRG1-mutant cancers in other tissues. SIGNIFICANCE: These findings indicate that inhibition of ATR is a promising therapy for the 10% of non-small cell lung cancer patients harboring mutations in SMARCA4/BRG1. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/18/3841/F1.large.jpg.
Subject(s)
Ataxia Telangiectasia Mutated Proteins/antagonists & inhibitors , Carcinoma, Non-Small-Cell Lung/genetics , DNA Helicases/genetics , Gene Deletion , Lung Neoplasms/genetics , Nuclear Proteins/genetics , Transcription Factors/genetics , Animals , Cell Cycle Proteins/metabolism , Chromosomal Proteins, Non-Histone , DNA Helicases/deficiency , Disease Progression , Female , Forkhead Transcription Factors , Gene Editing , Humans , Immunoprecipitation , Mass Spectrometry , Mice , Mice, Inbred C57BL , Mice, Nude , Nuclear Proteins/deficiency , Nuclear Proteins/metabolism , Sequence Analysis, RNA , Transcription Factors/deficiencyABSTRACT
Obesity is a major modifiable risk factor for pancreatic ductal adenocarcinoma (PDAC), yet how and when obesity contributes to PDAC progression is not well understood. Leveraging an autochthonous mouse model, we demonstrate a causal and reversible role for obesity in early PDAC progression, showing that obesity markedly enhances tumorigenesis, while genetic or dietary induction of weight loss intercepts cancer development. Molecular analyses of human and murine samples define microenvironmental consequences of obesity that foster tumorigenesis rather than new driver gene mutations, including significant pancreatic islet cell adaptation in obesity-associated tumors. Specifically, we identify aberrant beta cell expression of the peptide hormone cholecystokinin (Cck) in response to obesity and show that islet Cck promotes oncogenic Kras-driven pancreatic ductal tumorigenesis. Our studies argue that PDAC progression is driven by local obesity-associated changes in the tumor microenvironment and implicate endocrine-exocrine signaling beyond insulin in PDAC development.
Subject(s)
Carcinoma, Pancreatic Ductal/etiology , Carcinoma, Pancreatic Ductal/metabolism , Obesity/metabolism , Animals , Carcinogenesis/genetics , Carcinoma, Pancreatic Ductal/pathology , Cell Line , Cell Line, Tumor , Cell Transformation, Neoplastic/genetics , Disease Models, Animal , Disease Progression , Endocrine Cells/metabolism , Exocrine Glands/metabolism , Female , Gene Expression Regulation, Neoplastic/genetics , Humans , Male , Mice , Mice, Inbred C57BL , Mutation/genetics , Obesity/genetics , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Signal Transduction/genetics , Tumor Microenvironment/physiology , Pancreatic NeoplasmsABSTRACT
Approximately 20-30% of human lung adenocarcinomas (LUAD) harbor loss-of-function (LOF) mutations in Kelch-like ECH Associated-Protein 1 (KEAP1), which lead to hyperactivation of the nuclear factor, erythroid 2-like 2 (NRF2) antioxidant pathway and correlate with poor prognosis1-3. We previously showed that Keap1 mutation accelerates KRAS-driven LUAD and produces a marked dependency on glutaminolysis4. To extend the investigation of genetic dependencies in the context of Keap1 mutation, we performed a druggable genome CRISPR-Cas9 screen in Keap1-mutant cells. This analysis uncovered a profound Keap1 mutant-specific dependency on solute carrier family 33 member 1 (Slc33a1), an endomembrane-associated protein with roles in autophagy regulation5, as well as a series of functionally-related genes implicated in the unfolded protein response. Targeted genetic and biochemical experiments using mouse and human Keap1-mutant tumor lines, as well as preclinical genetically-engineered mouse models (GEMMs) of LUAD, validate Slc33a1 as a robust Keap1-mutant-specific dependency. Furthermore, unbiased genome-wide CRISPR screening identified additional genes related to Slc33a1 dependency. Overall, our study provides a strong rationale for stratification of patients harboring KEAP1-mutant or NRF2-hyperactivated tumors as likely responders to targeted SLC33A1 inhibition and underscores the value of integrating functional genetic approaches with GEMMs to identify and validate genotype-specific therapeutic targets.
Subject(s)
Adenocarcinoma of Lung , Kelch-Like ECH-Associated Protein 1 , Lung Neoplasms , Membrane Transport Proteins , Adenocarcinoma of Lung/genetics , Animals , Humans , Kelch-Like ECH-Associated Protein 1/genetics , Lung Neoplasms/genetics , Membrane Transport Proteins/genetics , Mice , Mutation , NF-E2-Related Factor 2/geneticsABSTRACT
Small cell lung cancer (SCLC) is a highly aggressive subtype of lung cancer that remains among the most lethal of solid tumor malignancies. Recent genomic sequencing studies have identified many recurrently mutated genes in human SCLC tumors. However, the functional roles of most of these genes remain to be validated. Here, we have adapted the CRISPR-Cas9 system to a well-established murine model of SCLC to rapidly model loss-of-function mutations in candidate genes identified from SCLC sequencing studies. We show that loss of the gene p107 significantly accelerates tumor progression. Notably, compared with loss of the closely related gene p130, loss of p107 results in fewer but larger tumors as well as earlier metastatic spread. In addition, we observe differences in proliferation and apoptosis as well as altered distribution of initiated tumors in the lung, resulting from loss of p107 or p130 Collectively, these data demonstrate the feasibility of using the CRISPR-Cas9 system to model loss of candidate tumor suppressor genes in SCLC, and we anticipate that this approach will facilitate efforts to investigate mechanisms driving tumor progression in this deadly disease.
Subject(s)
Gene Editing/methods , Gene Expression Regulation, Neoplastic , Genes, Tumor Suppressor , Lung Neoplasms/genetics , Small Cell Lung Carcinoma/genetics , Animals , Apoptosis/genetics , CRISPR-Cas Systems/genetics , Cell Line , Cell Proliferation/genetics , Disease Models, Animal , Disease Progression , Feasibility Studies , Humans , Loss of Function Mutation , Lung/pathology , Lung Neoplasms/pathology , Mice , Mice, Transgenic , Neoplasm Staging , Retinoblastoma-Like Protein p107/genetics , Retinoblastoma-Like Protein p130/genetics , Small Cell Lung Carcinoma/pathology , Tumor Burden/genetics , Tumor Suppressor Protein p53/geneticsABSTRACT
Regulatory T cells (Tregs) can impair anti-tumor immune responses and are associated with poor prognosis in multiple cancer types. Tregs in human tumors span diverse transcriptional states distinct from those of peripheral Tregs, but their contribution to tumor development remains unknown. Here, we use single-cell RNA sequencing (RNA-seq) to longitudinally profile dynamic shifts in the distribution of Tregs in a genetically engineered mouse model of lung adenocarcinoma. In this model, interferon-responsive Tregs are more prevalent early in tumor development, whereas a specialized effector phenotype characterized by enhanced expression of the interleukin-33 receptor ST2 is predominant in advanced disease. Treg-specific deletion of ST2 alters the evolution of effector Treg diversity, increases infiltration of CD8+ T cells into tumors, and decreases tumor burden. Our study shows that ST2 plays a critical role in Treg-mediated immunosuppression in cancer, highlighting potential paths for therapeutic intervention.
Subject(s)
Interleukin-33/immunology , Signal Transduction/immunology , T-Lymphocytes, Regulatory/immunology , Animals , CD8-Positive T-Lymphocytes/immunology , Female , Immune Tolerance/immunology , Immunosuppression Therapy/methods , Male , Mice , Mice, Inbred C57BL , Neoplasms/immunology , Tumor Microenvironment/immunologyABSTRACT
Small cell lung cancer (SCLC) is an aggressive lung cancer subtype with extremely poor prognosis. No targetable genetic driver events have been identified, and the treatment landscape for this disease has remained nearly unchanged for over 30 years. Here, we have taken a CRISPR-based screening approach to identify genetic vulnerabilities in SCLC that may serve as potential therapeutic targets. We used a single-guide RNA (sgRNA) library targeting ~5000 genes deemed to encode "druggable" proteins to perform loss-of-function genetic screens in a panel of cell lines derived from autochthonous genetically engineered mouse models (GEMMs) of SCLC, lung adenocarcinoma (LUAD), and pancreatic ductal adenocarcinoma (PDAC). Cross-cancer analyses allowed us to identify SCLC-selective vulnerabilities. In particular, we observed enhanced sensitivity of SCLC cells toward disruption of the pyrimidine biosynthesis pathway. Pharmacological inhibition of dihydroorotate dehydrogenase (DHODH), a key enzyme in this pathway, reduced the viability of SCLC cells in vitro and strongly suppressed SCLC tumor growth in human patient-derived xenograft (PDX) models and in an autochthonous mouse model. These results indicate that DHODH inhibition may be an approach to treat SCLC.
Subject(s)
Lung Neoplasms/drug therapy , Lung Neoplasms/enzymology , Molecular Targeted Therapy , Oxidoreductases Acting on CH-CH Group Donors/antagonists & inhibitors , Small Cell Lung Carcinoma/drug therapy , Small Cell Lung Carcinoma/enzymology , Adenocarcinoma/drug therapy , Adenocarcinoma/enzymology , Adenocarcinoma/pathology , Animals , Biphenyl Compounds/pharmacology , Biphenyl Compounds/therapeutic use , Carcinoma, Pancreatic Ductal/drug therapy , Carcinoma, Pancreatic Ductal/enzymology , Carcinoma, Pancreatic Ductal/pathology , Cell Line, Tumor , DCMP Deaminase/metabolism , Dihydroorotate Dehydrogenase , Disease Progression , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Humans , Lung Neoplasms/pathology , Mice , Oxidoreductases Acting on CH-CH Group Donors/metabolism , Pancreatic Neoplasms/metabolism , Pyrimidines/biosynthesis , Small Cell Lung Carcinoma/pathology , Survival Analysis , Xenograft Model Antitumor Assays , Pancreatic NeoplasmsABSTRACT
Approximately 30% of human lung cancers acquire mutations in either Keap1 or Nfe2l2, resulting in the stabilization of Nrf2, the Nfe2l2 gene product, which controls oxidative homeostasis. Here, we show that heme triggers the degradation of Bach1, a pro-metastatic transcription factor, by promoting its interaction with the ubiquitin ligase Fbxo22. Nrf2 accumulation in lung cancers causes the stabilization of Bach1 by inducing Ho1, the enzyme catabolizing heme. In mouse models of lung cancers, loss of Keap1 or Fbxo22 induces metastasis in a Bach1-dependent manner. Pharmacological inhibition of Ho1 suppresses metastasis in a Fbxo22-dependent manner. Human metastatic lung cancer display high levels of Ho1 and Bach1. Bach1 transcriptional signature is associated with poor survival and metastasis in lung cancer patients. We propose that Nrf2 activates a metastatic program by inhibiting the heme- and Fbxo22-mediated degradation of Bach1, and that Ho1 inhibitors represent an effective therapeutic strategy to prevent lung cancer metastasis.
Subject(s)
Basic-Leucine Zipper Transcription Factors/metabolism , Lung Neoplasms/pathology , NF-E2-Related Factor 2/metabolism , Animals , Basic-Leucine Zipper Transcription Factors/antagonists & inhibitors , Basic-Leucine Zipper Transcription Factors/genetics , Cell Line, Tumor , Cell Movement , F-Box Proteins/antagonists & inhibitors , F-Box Proteins/genetics , F-Box Proteins/metabolism , Female , Heme Oxygenase-1/antagonists & inhibitors , Heme Oxygenase-1/genetics , Heme Oxygenase-1/metabolism , Humans , Kaplan-Meier Estimate , Kelch-Like ECH-Associated Protein 1/antagonists & inhibitors , Kelch-Like ECH-Associated Protein 1/genetics , Kelch-Like ECH-Associated Protein 1/metabolism , Lung Neoplasms/metabolism , Lung Neoplasms/mortality , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , NF-E2-Related Factor 2/genetics , Neoplasm Metastasis , RNA Interference , RNA, Small Interfering/metabolism , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Receptors, Cytoplasmic and Nuclear/genetics , Receptors, Cytoplasmic and Nuclear/metabolism , Transcriptional ActivationABSTRACT
Lung cancer is closely associated with chronic inflammation, but the causes of inflammation and the specific immune mediators have not been fully elucidated. The lung is a mucosal tissue colonized by a diverse bacterial community, and pulmonary infections commonly present in lung cancer patients are linked to clinical outcomes. Here, we provide evidence that local microbiota provoke inflammation associated with lung adenocarcinoma by activating lung-resident γδ T cells. Germ-free or antibiotic-treated mice were significantly protected from lung cancer development induced by Kras mutation and p53 loss. Mechanistically, commensal bacteria stimulated Myd88-dependent IL-1ß and IL-23 production from myeloid cells, inducing proliferation and activation of Vγ6+Vδ1+ γδ T cells that produced IL-17 and other effector molecules to promote inflammation and tumor cell proliferation. Our findings clearly link local microbiota-immune crosstalk to lung tumor development and thereby define key cellular and molecular mediators that may serve as effective targets in lung cancer intervention.
Subject(s)
Host Microbial Interactions/immunology , Intraepithelial Lymphocytes/immunology , Lung Neoplasms/immunology , Animals , Cell Proliferation , Female , Interleukin-17/immunology , Interleukin-1beta/metabolism , Interleukin-23/metabolism , Intraepithelial Lymphocytes/metabolism , Intraepithelial Lymphocytes/physiology , Lung/immunology , Lung Neoplasms/metabolism , Male , Mice , Mice, Inbred C57BL , Microbiota/immunology , Myeloid Differentiation Factor 88/metabolism , Neutrophils/immunology , Receptors, Antigen, T-Cell, gamma-delta , Symbiosis/immunology , T-Lymphocytes/immunologyABSTRACT
The major types of non-small-cell lung cancer (NSCLC)-squamous cell carcinoma and adenocarcinoma-have distinct immune microenvironments. We developed a genetic model of squamous NSCLC on the basis of overexpression of the transcription factor Sox2, which specifies lung basal cell fate, and loss of the tumor suppressor Lkb1 (SL mice). SL tumors recapitulated gene-expression and immune-infiltrate features of human squamous NSCLC; such features included enrichment of tumor-associated neutrophils (TANs) and decreased expression of NKX2-1, a transcriptional regulator that specifies alveolar cell fate. In Kras-driven adenocarcinomas, mis-expression of Sox2 or loss of Nkx2-1 led to TAN recruitment. TAN recruitment involved SOX2-mediated production of the chemokine CXCL5. Deletion of Nkx2-1 in SL mice (SNL) revealed that NKX2-1 suppresses SOX2-driven squamous tumorigenesis by repressing adeno-to-squamous transdifferentiation. Depletion of TANs in SNL mice reduced squamous tumors, suggesting that TANs foster squamous cell fate. Thus, lineage-defining transcription factors determine the tumor immune microenvironment, which in turn might impact the nature of the tumor.