RESUMEN
Naive CD8+ T cells differentiating into effector T cells increase glucose uptake and shift from quiescent to anabolic metabolism. Although much is known about the metabolism of cultured T cells, how T cells use nutrients during immune responses in vivo is less well defined. Here, we combined bioenergetic profiling and 13C-glucose infusion techniques to investigate the metabolism of CD8+ T cells responding to Listeria infection. In contrast to in vitro-activated T cells, which display hallmarks of Warburg metabolism, physiologically activated CD8+ T cells displayed greater rates of oxidative metabolism, higher bioenergetic capacity, differential use of pyruvate, and prominent flow of 13C-glucose carbon to anabolic pathways, including nucleotide and serine biosynthesis. Glucose-dependent serine biosynthesis mediated by the enzyme Phgdh was essential for CD8+ T cell expansion in vivo. Our data highlight fundamental differences in glucose use by pathogen-specific T cells in vivo, illustrating the impact of environment on T cell metabolic phenotypes.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Metabolismo Energético , Glucosa/metabolismo , Activación de Linfocitos/inmunología , Metaboloma , Metabolómica , Animales , Proliferación Celular , Cromatografía de Gases y Espectrometría de Masas , Glucólisis , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Activación de Linfocitos/genética , Metabolómica/métodos , Ratones , Estrés Oxidativo , Virosis/genética , Virosis/inmunología , Virosis/metabolismo , Virosis/virologíaRESUMEN
The microRNAs encoded by the miR-17â¼92 polycistron are commonly overexpressed in cancer and orchestrate a wide range of oncogenic functions. Here, we identify a mechanism for miR-17â¼92 oncogenic function through the disruption of endogenous microRNA (miRNA) processing. We show that, upon oncogenic overexpression of the miR-17â¼92 primary transcript (pri-miR-17â¼92), the microprocessor complex remains associated with partially processed intermediates that aberrantly accumulate. These intermediates reflect a series of hierarchical and conserved steps in the early processing of the pri-miR-17â¼92 transcript. Encumbrance of the microprocessor by miR-17â¼92 intermediates leads to the broad but selective downregulation of co-expressed polycistronic miRNAs, including miRNAs derived from tumor-suppressive miR-34b/c and from the Dlk1-Dio3 polycistrons. We propose that the identified steps of polycistronic miR-17â¼92 biogenesis contribute to the oncogenic re-wiring of gene regulation networks. Our results reveal previously unappreciated functional paradigms for polycistronic miRNAs in cancer.
Asunto(s)
Carcinogénesis/genética , MicroARNs/genética , Procesamiento Postranscripcional del ARN/genética , Proteínas de Unión al Calcio/genética , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Yoduro Peroxidasa/genética , Proteínas de la Membrana/genética , MicroARNs/biosíntesis , Conformación de Ácido NucleicoRESUMEN
During V(D)J recombination of immunoglobulin genes, p53 and nonhomologous end-joining (NHEJ) suppress aberrant rejoining of DNA double-strand breaks induced by recombinase-activating genes (Rags)-1/2, thus maintaining genomic stability and limiting malignant transformation during B-cell development. However, Rag deficiency does not prevent B-cell leukemogenesis in p53/NHEJ mutant mice, revealing that p53 and NHEJ also suppress Rag-independent mechanisms of B-cell leukemogenesis. Using several cytogenomic approaches, we identified a novel class of activating mutations in Fms-like tyrosine kinase 3 (Flt3), a receptor tyrosine kinase important for normal hematopoiesis in Rag/p53/NHEJ triple-mutant (TM) B-cell leukemias. These mutant Flt3 alleles were created by complex genomic rearrangements with Moloney leukemia virus (MuLV)-related endogenous retroviral (ERV) elements, generating ERV-Flt3 fusion genes encoding an N-terminally truncated mutant form of Flt3 (trFlt3) that was transcribed from ERV long terminal repeats. trFlt3 protein lacked most of the Flt3 extracellular domain and induced ligand-independent STAT5 phosphorylation and proliferation of hematopoietic progenitor cells. Furthermore, expression of trFlt3 in p53/NHEJ mutant hematopoietic progenitor cells promoted development of clinically aggressive B-cell leukemia. Thus, repetitive MuLV-related ERV sequences can participate in aberrant end-joining events that promote development of aggressive B-cell leukemia.
Asunto(s)
Linfocitos B/citología , Leucemia/genética , Virus de la Leucemia Murina de Moloney/genética , Recombinación Genética , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismo , Animales , Linfocitos B/patología , Proliferación Celular , Reparación del ADN por Unión de Extremidades/genética , Regulación Leucémica de la Expresión Génica , Células Madre Hematopoyéticas/citología , Leucemia/patología , Ratones , Virus de la Leucemia Murina de Moloney/metabolismo , Mutación , Fosforilación , Estructura Terciaria de Proteína , Factor de Transcripción STAT5/metabolismo , Transducción de Señal , Células Tumorales CultivadasRESUMEN
Atypical teratoid rhabdoid tumor (ATRT) is a fatal pediatric malignancy of the central neural system lacking effective treatment options. It belongs to the rhabdoid tumor family and is usually caused by biallelic inactivation of SMARCB1, encoding a key subunit of SWI/SNF chromatin remodeling complexes. Previous studies proposed that SMARCB1 loss drives rhabdoid tumor by promoting cell cycle through activating transcription of cyclin D1 while suppressing p16. However, low cyclin D1 protein expression is observed in most ATRT patient tumors. The underlying mechanism and therapeutic implication of this molecular trait remain unknown. Here, we show that SMARCB1 loss in ATRT leads to the reduction of cyclin D1 expression by upregulating MIR17HG, a microRNA (miRNA) cluster known to generate multiple miRNAs targeting CCND1. Furthermore, we find that this cyclin D1 deficiency in ATRT results in marked in vitro and in vivo sensitivity to the CDK4/6 inhibitor palbociclib as a single agent. Our study identifies a novel genetic interaction between SMARCB1 and MIR17HG in regulating cyclin D1 in ATRT and suggests a rationale to treat ATRT patients with FDA-approved CDK4/6 inhibitors. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Asunto(s)
Ciclina D1/genética , Regulación Neoplásica de la Expresión Génica , Proteínas/genética , Tumor Rabdoide/genética , Proteína SMARCB1/genética , Teratoma/genética , Línea Celular Tumoral , Supervivencia Celular , Ciclina D1/metabolismo , Humanos , Proteínas/metabolismo , Tumor Rabdoide/metabolismo , Tumor Rabdoide/patología , Proteína SMARCB1/metabolismo , Teratoma/metabolismo , Teratoma/patología , Regulación hacia ArribaRESUMEN
BACKGROUND: Triple negative breast cancer (TNBC) is aggressive with limited treatment options upon recurrence. Molecular discordance between primary and metastatic TNBC has been observed, but the degree of biological heterogeneity has not been fully explored. Furthermore, genomic evolution through treatment is poorly understood. In this study, we aim to characterize the genomic changes between paired primary and metastatic TNBCs through transcriptomic and genomic profiling, and to identify genomic alterations which may contribute to chemotherapy resistance. METHODS: Genomic alterations and mRNA expression of 10 paired primary and metastatic TNBCs were determined through targeted sequencing, microarray analysis, and RNA sequencing. Commonly mutated genes, as well as differentially expressed and co-expressed genes were identified. We further explored the clinical relevance of differentially expressed genes between primary and metastatic tumors to patient survival using large public datasets. RESULTS: Through gene expression profiling, we observed a shift in TNBC subtype classifications between primary and metastatic TNBCs. A panel of eight cancer driver genes (CCNE1, TPX2, ELF3, FANCL, JAK2, GSK3B, CEP76, and SYK) were differentially expressed in recurrent TNBCs, and were also overexpressed in TCGA and METABRIC. CCNE1 and TPX2 were co-overexpressed in TNBCs. DNA mutation profiling showed that multiple mutations occurred in genes comprising a number of potentially targetable pathways including PI3K/AKT/mTOR, RAS/MAPK, cell cycle, and growth factor receptor signaling, reaffirming the wide heterogeneity of mechanisms driving TNBC. CCNE1 amplification was associated with poor overall survival in patients with metastatic TNBC. CONCLUSIONS: CCNE1 amplification may confer resistance to chemotherapy and is associated with poor overall survival in TNBC.
Asunto(s)
Ciclina E/genética , Amplificación de Genes , Perfilación de la Expresión Génica/métodos , Proteínas Oncogénicas/genética , Neoplasias de la Mama Triple Negativas/genética , Adulto , Anciano , Ciclina E/metabolismo , Resistencia a Antineoplásicos/genética , Femenino , Predisposición Genética a la Enfermedad/genética , Humanos , Persona de Mediana Edad , Proteínas Oncogénicas/metabolismo , Pronóstico , Análisis de Supervivencia , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/metabolismo , Secuenciación del ExomaRESUMEN
BACKGROUND: Cancer genomics projects are producing ever-increasing amounts of rich and diverse data from patient samples. The ability to easily visualize this data in an integrated an intuitive way is currently limited by the current software available. As a result, users typically must use several different tools to view the different data types for their cohort, making it difficult to have a simple unified view of their data. RESULTS: Here we present Cascade, a novel web based tool for the intuitive 3D visualization of RNA-seq data from cancer genomics experiments. The Cascade viewer allows multiple data types (e.g. mutation, gene expression, alternative splicing frequency) to be simultaneously displayed, allowing a simplified view of the data in a way that is tuneable based on user specified parameters. The main webpage of Cascade provides a primary view of user data which is overlaid onto known biological pathways that are either predefined or added by users. A space-saving menu for data selection and parameter adjustment allows users to access an underlying MySQL database and customize the features presented in the main view. CONCLUSIONS: There is currently a pressing need for new software tools to allow researchers to easily explore large cancer genomics datasets and generate hypotheses. Cascade represents a simple yet intuitive interface for data visualization that is both scalable and customizable.
Asunto(s)
Genómica/métodos , Neoplasias/genética , Programas Informáticos , HumanosRESUMEN
Infusion of 13C-labeled metabolites provides a gold standard for understanding the metabolic processes used by T cells during immune responses in vivo. Through infusion of 13C-labeled metabolites (glucose, glutamine, and acetate) in Listeria monocytogenes-infected mice, we demonstrate that CD8 T effector (Teff) cells use metabolites for specific pathways during specific phases of activation. Highly proliferative early Teff cells in vivo shunt glucose primarily toward nucleotide synthesis and leverage glutamine anaplerosis in the tricarboxylic acid (TCA) cycle to support adenosine triphosphate and de novo pyrimidine synthesis. In addition, early Teff cells rely on glutamic-oxaloacetic transaminase 1 (Got1)-which regulates de novo aspartate synthesis-for effector cell expansion in vivo. CD8 Teff cells change fuel preference over the course of infection, switching from glutamine- to acetate-dependent TCA cycle metabolism late in infection. This study provides insights into the dynamics of Teff metabolism, illuminating distinct pathways of fuel consumption associated with CD8 Teff cell function in vivo.
Asunto(s)
Acetatos , Linfocitos T CD8-positivos , Isótopos de Carbono , Glutamina , Glutamina/metabolismo , Animales , Linfocitos T CD8-positivos/metabolismo , Acetatos/metabolismo , Ratones , Listeriosis/metabolismo , Listeriosis/inmunología , Listeriosis/microbiología , Listeria monocytogenes , Ciclo del Ácido Cítrico , Glucosa/metabolismo , Ratones Endogámicos C57BLRESUMEN
Infusion of 13C-labeled metabolites provides a gold-standard for understanding the metabolic processes used by T cells during immune responses in vivo. Through infusion of 13C-labeled metabolites (glucose, glutamine, acetate) in Listeria monocytogenes (Lm)-infected mice, we demonstrate that CD8+ T effector (Teff) cells utilize metabolites for specific pathways during specific phases of activation. Highly proliferative early Teff cells in vivo shunt glucose primarily towards nucleotide synthesis and leverage glutamine anaplerosis in the tricarboxylic acid (TCA) cycle to support ATP and de novo pyrimidine synthesis. Additionally, early Teff cells rely on glutamic-oxaloacetic transaminase 1 (Got1)-which regulates de novo aspartate synthesis-for effector cell expansion in vivo. Importantly, Teff cells change fuel preference over the course of infection, switching from glutamine- to acetate-dependent TCA cycle metabolism late in infection. This study provides insights into the dynamics of Teff metabolism, illuminating distinct pathways of fuel consumption associated with Teff cell function in vivo.
RESUMEN
Most colorectal (CRC) tumors are dependent on EGFR/KRAS/BRAF/MAPK signaling activation. ARID1A is an epigenetic regulator mutated in approximately 5% of non-hypermutated CRC tumors. Here we show that anti-EGFR but not anti-VEGF treatment enriches for emerging ARID1A mutations in CRC patients. In addition, we find that patients with ARID1A mutations, at baseline, are associated with worse outcome when treated with cetuximab- but not bevacizumab-containing therapies; thus, this suggests that ARID1A mutations may provide both an acquired and intrinsic mechanism of resistance to anti-EGFR therapies. We find that, ARID1A and EGFR-pathway genetic alterations are mutually exclusive across lung and colorectal cancers, further supporting a functional connection between these pathways. Our results not only suggest that ARID1A could be potentially used as a predictive biomarker for cetuximab treatment decisions but also provide a rationale for exploring therapeutic MAPK inhibition in an unexpected but genetically defined segment of CRC patients.
Asunto(s)
Antineoplásicos Inmunológicos , Cetuximab , Neoplasias Colorrectales , Proteínas de Unión al ADN , Resistencia a Antineoplásicos , Factores de Transcripción , Antineoplásicos Inmunológicos/efectos adversos , Antineoplásicos Inmunológicos/farmacología , Antineoplásicos Inmunológicos/uso terapéutico , Cetuximab/efectos adversos , Cetuximab/farmacología , Cetuximab/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Proteínas de Unión al ADN/genética , Resistencia a Antineoplásicos/genética , Humanos , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Factores de Transcripción/genéticaRESUMEN
Transmembrane glycoprotein NMB (GPNMB) is a prognostic marker of poor outcome in patients with triple-negative breast cancer (TNBC). Glembatumumab Vedotin, an antibody drug conjugate targeting GPNMB, exhibits variable efficacy against GPNMB-positive metastatic TNBC as a single agent. We show that GPNMB levels increase in response to standard-of-care and experimental therapies for multiple breast cancer subtypes. While these therapeutic stressors induce GPNMB expression through differential engagement of the MiTF family of transcription factors, not all are capable of increasing GPNMB cell-surface localization required for Glembatumumab Vedotin inhibition. Using a FACS-based genetic screen, we discovered that suppression of heat shock protein 90 (HSP90) concomitantly increases GPNMB expression and cell-surface localization. Mechanistically, HSP90 inhibition resulted in lysosomal dispersion towards the cell periphery and fusion with the plasma membrane, which delivers GPNMB to the cell surface. Finally, treatment with HSP90 inhibitors sensitizes breast cancers to Glembatumumab Vedotin in vivo, suggesting that combination of HSP90 inhibitors and Glembatumumab Vedotin may be a viable treatment strategy for patients with metastatic TNBC.
Asunto(s)
Antineoplásicos , Inmunoconjugados , Neoplasias de la Mama Triple Negativas , Anticuerpos Monoclonales , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Membrana Celular/metabolismo , Humanos , Inmunoconjugados/efectos adversos , Lisosomas/metabolismo , Glicoproteínas de Membrana/genética , Factores de Transcripción , Neoplasias de la Mama Triple Negativas/tratamiento farmacológicoRESUMEN
Triple-negative breast cancer (TNBC) is a heterogeneous disease that lacks both effective patient stratification strategies and therapeutic targets. Whilst elevated levels of the MET receptor tyrosine kinase are associated with TNBCs and predict poor clinical outcome, the functional role of MET in TNBC is still poorly understood. In this study, we utilise an established Met-dependent transgenic mouse model of TNBC, human cell lines and patient-derived xenografts to investigate the role of MET in TNBC tumorigenesis. We find that in TNBCs with mesenchymal signatures, MET participates in a compensatory interplay with FGFR1 to regulate tumour-initiating cells (TICs). We demonstrate a requirement for the scaffold protein FRS2 downstream from both Met and FGFR1 and find that dual inhibition of MET and FGFR1 signalling results in TIC depletion, hindering tumour progression. Importantly, basal breast cancers that display elevated MET and FGFR1 signatures are associated with poor relapse-free survival. Our results support a role for MET and FGFR1 as potential co-targets for anti-TIC therapies in TNBC.
RESUMEN
Claudin-2 promotes breast cancer liver metastasis by enabling seeding and early cancer cell survival. We now demonstrate that Claudin-2 is functionally required for colorectal cancer liver metastasis and that Claudin-2 expression in primary colorectal cancers is associated with poor overall and liver metastasis-free survival. We have examined the role of Claudin-2, and other claudin family members, as potential prognostic biomarkers of the desmoplastic and replacement histopathological growth pattern associated with colorectal cancer liver metastases. Immunohistochemical analysis revealed higher Claudin-2 levels in replacement type metastases when compared to those with desmoplastic features. In contrast, Claudin-8 was highly expressed in desmoplastic colorectal cancer liver metastases. Similar observations were made following immunohistochemical staining of patient-derived xenografts (PDXs) that we have established, which faithfully retain the histopathology of desmoplastic or replacement type colorectal cancer liver metastases. We provide evidence that Claudin-2 status in patient-derived extracellular vesicles may serve as a relevant prognostic biomarker to predict whether colorectal cancer patients have developed replacement type liver metastases. Such a biomarker will be a valuable tool in designing optimal treatment strategies to better manage patients with colorectal cancer liver metastases.
Asunto(s)
Biomarcadores de Tumor/fisiología , Claudinas/fisiología , Neoplasias Colorrectales/secundario , Neoplasias Hepáticas/patología , Animales , Biomarcadores de Tumor/antagonistas & inhibidores , Biomarcadores de Tumor/genética , Adhesión Celular/genética , Adhesión Celular/fisiología , Claudinas/antagonistas & inhibidores , Claudinas/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/fisiopatología , Femenino , Regulación Neoplásica de la Expresión Génica , Técnicas de Inactivación de Genes , Células HT29 , Hepatocitos/patología , Xenoinjertos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/fisiopatología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/fisiopatología , Neoplasias Pulmonares/secundario , Ratones , Ratones SCID , Dominios PDZ/genética , Pronóstico , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
BACKGROUND: We aimed to develop a gene expression-based prognostic signature for isocitrate dehydrogenase (IDH) wild-type glioblastoma using clinical trial datasets representative of glioblastoma clinical trial populations. METHODS: Samples were collected from newly diagnosed patients with IDH wild-type glioblastoma in the ARTE, TAMIGA, EORTC 26101 (referred to as "ATE"), AVAglio, and GLARIUS trials, or treated at UCLA. Transcriptional profiling was achieved with the NanoString gene expression platform. To identify genes prognostic for overall survival (OS), we built an elastic net penalized Cox proportional hazards regression model using the discovery ATE dataset. For validation in independent datasets (AVAglio, GLARIUS, UCLA), we combined elastic net-selected genes into a robust z-score signature (ATE score) to overcome gene expression platform differences between discovery and validation cohorts. RESULTS: NanoString data were available from 512 patients in the ATE dataset. Elastic net identified a prognostic signature of 9 genes (CHEK1, GPR17, IGF2BP3, MGMT, MTHFD1L, PTRH2, SOX11, S100A9, and TFRC). Translating weighted elastic net scores to the ATE score conserved the prognostic value of the genes. The ATE score was prognostic for OS in the ATE dataset (Pâ <â 0.0001), as expected, and in the validation cohorts (AVAglio, Pâ <â 0.0001; GLARIUS, Pâ =â 0.02; UCLA, Pâ =â 0.004). The ATE score remained prognostic following adjustment for O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status and corticosteroid use at baseline. A positive correlation between ATE score and proneural/proliferative subtypes was observed in patients with MGMT non-methylated promoter status. CONCLUSIONS: The ATE score showed prognostic value and may enable clinical trial stratification for IDH wild-type glioblastoma.
Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/genética , Metilación de ADN , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Glioblastoma/genética , Humanos , Isocitrato Deshidrogenasa/genética , Pronóstico , Receptores Acoplados a Proteínas GRESUMEN
Epigenetic modifications on DNA and histones regulate gene expression by modulating chromatin accessibility to transcription machinery. Here we identify methionine as a key nutrient affecting epigenetic reprogramming in CD4+ T helper (Th) cells. Using metabolomics, we showed that methionine is rapidly taken up by activated T cells and serves as the major substrate for biosynthesis of the universal methyl donor S-adenosyl-L-methionine (SAM). Methionine was required to maintain intracellular SAM pools in T cells. Methionine restriction reduced histone H3K4 methylation (H3K4me3) at the promoter regions of key genes involved in Th17 cell proliferation and cytokine production. Applied to the mouse model of multiple sclerosis (experimental autoimmune encephalomyelitis), dietary methionine restriction reduced the expansion of pathogenic Th17 cells in vivo, leading to reduced T cell-mediated neuroinflammation and disease onset. Our data identify methionine as a key nutritional factor shaping Th cell proliferation and function in part through regulation of histone methylation.
Asunto(s)
Encefalomielitis Autoinmune Experimental , Epigénesis Genética/efectos de los fármacos , Histonas/metabolismo , Metionina , Esclerosis Múltiple , Células Th17/metabolismo , Animales , Proliferación Celular , Citocinas/metabolismo , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/metabolismo , Células HEK293 , Humanos , Metionina/metabolismo , Metionina/farmacología , Metilación , Ratones Endogámicos C57BL , Ratones Noqueados , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/metabolismo , Células Th17/citologíaRESUMEN
Neutrophils are phenotypically heterogeneous and exert either anti- or pro-metastatic functions. We show that cancer-cell-derived G-CSF is necessary, but not sufficient, to mobilize immature low-density neutrophils (iLDNs) that promote liver metastasis. In contrast, mature high-density neutrophils inhibit the formation of liver metastases. Transcriptomic and metabolomic analyses of high- and low-density neutrophils reveal engagement of numerous metabolic pathways specifically in low-density neutrophils. iLDNs exhibit enhanced global bioenergetic capacity, through their ability to engage mitochondrial-dependent ATP production, and remain capable of executing pro-metastatic neutrophil functions, including NETosis, under nutrient-deprived conditions. We demonstrate that NETosis is an important neutrophil function that promotes breast cancer liver metastasis. iLDNs rely on the catabolism of glutamate and proline to support mitochondrial-dependent metabolism in the absence of glucose, which enables sustained NETosis. These data reveal that distinct pro-metastatic neutrophil populations exhibit a high degree of metabolic flexibility, which facilitates the formation of liver metastases.
Asunto(s)
Neoplasias Hepáticas/metabolismo , Neoplasias Mamarias Experimentales/metabolismo , Neutrófilos/metabolismo , Animales , Línea Celular Tumoral , Femenino , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/secundario , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos BALB C , Metástasis de la Neoplasia , Neutrófilos/patologíaRESUMEN
Inactivating mutations in SMARCA4 (BRG1), a key SWI/SNF chromatin remodelling gene, underlie small cell carcinoma of the ovary, hypercalcemic type (SCCOHT). To reveal its druggable vulnerabilities, we perform kinase-focused RNAi screens and uncover that SMARCA4-deficient SCCOHT cells are highly sensitive to the inhibition of cyclin-dependent kinase 4/6 (CDK4/6). SMARCA4 loss causes profound downregulation of cyclin D1, which limits CDK4/6 kinase activity in SCCOHT cells and leads to in vitro and in vivo susceptibility to CDK4/6 inhibitors. SCCOHT patient tumors are deficient in cyclin D1 yet retain the retinoblastoma-proficient/p16INK4a-deficient profile associated with positive responses to CDK4/6 inhibitors. Thus, our findings indicate that CDK4/6 inhibitors, approved for a breast cancer subtype addicted to CDK4/6 activation, could be repurposed to treat SCCOHT. Moreover, our study suggests a novel paradigm whereby critically low oncogene levels, caused by loss of a driver tumor suppressor, may also be exploited therapeutically.
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Carcinoma de Células Pequeñas/tratamiento farmacológico , Carcinoma de Células Pequeñas/metabolismo , Ciclina D1/deficiencia , ADN Helicasas/metabolismo , Proteínas Nucleares/metabolismo , Inhibidores de Proteínas Quinasas/uso terapéutico , Factores de Transcripción/metabolismo , Aminopiridinas/uso terapéutico , Animales , Bencimidazoles/uso terapéutico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Inmunoprecipitación de Cromatina , Ciclina D1/metabolismo , ADN Helicasas/genética , Femenino , Humanos , Hipercalcemia/tratamiento farmacológico , Hipercalcemia/metabolismo , Ratones , Ratones SCID , Proteínas Nucleares/genética , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/metabolismo , Piperazinas/uso terapéutico , Purinas/uso terapéutico , Piridinas/uso terapéutico , ARN Interferente Pequeño/genética , Factores de Transcripción/genéticaRESUMEN
Emerging evidence has illustrated the importance of epigenomic reprogramming in cancer, with altered post-translational modifications of histones contributing to pathogenesis. However, the contributions of histone modifiers to breast cancer progression are unclear, and how these processes vary between molecular subtypes has yet to be adequately addressed. Here we report that genetic or pharmacological targeting of the epigenetic modifier Ezh2 dramatically hinders metastatic behaviour in both a mouse model of breast cancer and patient-derived xenografts reflective of the Luminal B subtype. We further define a subtype-specific molecular mechanism whereby EZH2 maintains H3K27me3-mediated repression of the FOXC1 gene, thereby inactivating a FOXC1-driven, anti-invasive transcriptional program. We demonstrate that higher FOXC1 is predictive of favourable outcome specifically in Luminal B breast cancer patients and establish the use of EZH2 methyltransferase inhibitors as a viable strategy to block metastasis in Luminal B breast cancer, where options for targeted therapy are limited.
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Neoplasias de la Mama/tratamiento farmacológico , Proteína Potenciadora del Homólogo Zeste 2/genética , Factores de Transcripción Forkhead/genética , Regulación Neoplásica de la Expresión Génica , Histonas/genética , Indoles/farmacología , Neoplasias Pulmonares/tratamiento farmacológico , Piridonas/farmacología , Animales , Antineoplásicos/farmacología , Neoplasias de la Mama/genética , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Línea Celular Tumoral , Doxiciclina/farmacología , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Proteína Potenciadora del Homólogo Zeste 2/deficiencia , Inhibidores Enzimáticos/farmacología , Femenino , Factores de Transcripción Forkhead/agonistas , Factores de Transcripción Forkhead/metabolismo , Histonas/metabolismo , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/secundario , Ratones , Ratones Noqueados , Terapia Molecular Dirigida , Procesamiento Proteico-Postraduccional , Transducción de Señal , Transcripción Genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Triple-negative breast cancers (TNBCs) display a complex spectrum of mutations and chromosomal aberrations. Chromosome 5q (5q) loss is detected in up to 70% of TNBCs, but little is known regarding the genetic drivers associated with this event. Here, we show somatic deletion of a region syntenic with human 5q33.2-35.3 in a mouse model of TNBC. Mechanistically, we identify KIBRA as a major factor contributing to the effects of 5q loss on tumor growth and metastatic progression. Re-expression of KIBRA impairs metastasis in vivo and inhibits tumorsphere formation by TNBC cells in vitro. KIBRA functions co-operatively with the protein tyrosine phosphatase PTPN14 to trigger mechanotransduction-regulated signals that inhibit the nuclear localization of oncogenic transcriptional co-activators YAP/TAZ. Our results argue that the selective advantage produced by 5q loss involves reduced dosage of KIBRA, promoting oncogenic functioning of YAP/TAZ in TNBC.
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Anemia Macrocítica/genética , Genes Supresores de Tumor , Péptidos y Proteínas de Señalización Intracelular/genética , Neoplasias Mamarias Experimentales/genética , Fosfoproteínas/genética , Neoplasias de la Mama Triple Negativas/genética , Animales , Deleción Cromosómica , Cromosomas Humanos Par 5/genética , Modelos Animales de Enfermedad , Femenino , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Metástasis de la Neoplasia , Fosfoproteínas/metabolismo , Neoplasias de la Mama Triple Negativas/metabolismo , Neoplasias de la Mama Triple Negativas/patologíaRESUMEN
Metabolic adaptations play a key role in fueling tumor growth. However, less is known regarding the metabolic changes that promote cancer progression to metastatic disease. Herein, we reveal that breast cancer cells that preferentially metastasize to the lung or bone display relatively high expression of PGC-1α compared with those that metastasize to the liver. PGC-1α promotes breast cancer cell migration and invasion in vitro and augments lung metastasis in vivo. Pro-metastatic capabilities of PGC-1α are linked to enhanced global bioenergetic capacity, facilitating the ability to cope with bioenergetic disruptors like biguanides. Indeed, biguanides fail to mitigate the PGC-1α-dependent lung metastatic phenotype and PGC-1α confers resistance to stepwise increases in metformin concentration. Overall, our results reveal that PGC-1α stimulates bioenergetic potential, which promotes breast cancer metastasis and facilitates adaptation to metabolic drugs.
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Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Metabolismo Energético , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Animales , Línea Celular Tumoral , Movimiento Celular , Metabolismo Energético/efectos de los fármacos , Femenino , Humanos , Hipoglucemiantes/farmacología , Metabolómica , Metformina/farmacología , Ratones , Ratones SCID , Mitocondrias/metabolismo , Invasividad Neoplásica , Metástasis de la Neoplasia , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genéticaRESUMEN
During immune challenge, T lymphocytes engage pathways of anabolic metabolism to support clonal expansion and the development of effector functions. Here we report a critical role for the non-essential amino acid serine in effector T cell responses. Upon activation, T cells upregulate enzymes of the serine, glycine, one-carbon (SGOC) metabolic network, and rapidly increase processing of serine into one-carbon metabolism. We show that extracellular serine is required for optimal T cell expansion even in glucose concentrations sufficient to support T cell activation, bioenergetics, and effector function. Restricting dietary serine impairs pathogen-driven expansion of T cells in vivo, without affecting overall immune cell homeostasis. Mechanistically, serine supplies glycine and one-carbon units for de novo nucleotide biosynthesis in proliferating T cells, and one-carbon units from formate can rescue T cells from serine deprivation. Our data implicate serine as a key immunometabolite that directly modulates adaptive immunity by controlling T cell proliferative capacity.