RESUMO
The coronavirus disease 2019 (COVID-19) pandemic has claimed the lives of over one million people worldwide. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a member of the Coronaviridae family of viruses that can cause respiratory infections of varying severity. The cellular host factors and pathways co-opted during SARS-CoV-2 and related coronavirus life cycles remain ill defined. To address this gap, we performed genome-scale CRISPR knockout screens during infection by SARS-CoV-2 and three seasonal coronaviruses (HCoV-OC43, HCoV-NL63, and HCoV-229E). These screens uncovered host factors and pathways with pan-coronavirus and virus-specific functional roles, including major dependency on glycosaminoglycan biosynthesis, sterol regulatory element-binding protein (SREBP) signaling, bone morphogenetic protein (BMP) signaling, and glycosylphosphatidylinositol biosynthesis, as well as a requirement for several poorly characterized proteins. We identified an absolute requirement for the VMP1, TMEM41, and TMEM64 (VTT) domain-containing protein transmembrane protein 41B (TMEM41B) for infection by SARS-CoV-2 and three seasonal coronaviruses. This human coronavirus host factor compendium represents a rich resource to develop new therapeutic strategies for acute COVID-19 and potential future coronavirus pandemics.
Assuntos
Infecções por Coronavirus/genética , Estudo de Associação Genômica Ampla , SARS-CoV-2/fisiologia , Células A549 , Linhagem Celular , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Coronavirus Humano 229E/fisiologia , Infecções por Coronavirus/virologia , Coronavirus Humano NL63/fisiologia , Coronavirus Humano OC43/fisiologia , Técnicas de Inativação de Genes , Células HEK293 , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Humanos , Proteínas de Membrana/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Mapeamento de Interação de ProteínasRESUMO
KRAS mutant pancreatic ductal adenocarcinoma (PDAC) is characterized by a desmoplastic response that promotes hypovascularity, immunosuppression, and resistance to chemo- and immunotherapies. We show that a combination of MEK and CDK4/6 inhibitors that target KRAS-directed oncogenic signaling can suppress PDAC proliferation through induction of retinoblastoma (RB) protein-mediated senescence. In preclinical mouse models of PDAC, this senescence-inducing therapy produces a senescence-associated secretory phenotype (SASP) that includes pro-angiogenic factors that promote tumor vascularization, which in turn enhances drug delivery and efficacy of cytotoxic gemcitabine chemotherapy. In addition, SASP-mediated endothelial cell activation stimulates the accumulation of CD8+ T cells into otherwise immunologically "cold" tumors, sensitizing tumors to PD-1 checkpoint blockade. Therefore, in PDAC models, therapy-induced senescence can establish emergent susceptibilities to otherwise ineffective chemo- and immunotherapies through SASP-dependent effects on the tumor vasculature and immune system.
Assuntos
Envelhecimento/fisiologia , Carcinoma Ductal Pancreático/patologia , Remodelação Vascular/fisiologia , Animais , Linfócitos T CD8-Positivos/imunologia , Carcinoma Ductal Pancreático/microbiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Genes ras/genética , Humanos , Imunoterapia/métodos , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Neoplasias Pancreáticas/patologia , Proteína do Retinoblastoma/imunologia , Transdução de Sinais/genética , Microambiente Tumoral , Remodelação Vascular/genéticaRESUMO
The NRF2 transcription factor controls a cell stress program that is implicated in cancer and there is great interest in targeting NRF2 for therapy. We show that NRF2 activity depends on Fructosamine-3-kinase (FN3K)-a kinase that triggers protein de-glycation. In its absence, NRF2 is extensively glycated, unstable, and defective at binding to small MAF proteins and transcriptional activation. Moreover, the development of hepatocellular carcinoma triggered by MYC and Keap1 inactivation depends on FN3K in vivo. N-acetyl cysteine treatment partially rescues the effects of FN3K loss on NRF2 driven tumor phenotypes indicating a key role for NRF2-mediated redox balance. Mass spectrometry reveals that other proteins undergo FN3K-sensitive glycation, including translation factors, heat shock proteins, and histones. How glycation affects their functions remains to be defined. In summary, our study reveals a surprising role for the glycation of cellular proteins and implicates FN3K as targetable modulator of NRF2 activity in cancer.
Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Feminino , Técnicas de Silenciamento de Genes , Glucose/metabolismo , Glicosilação , Células HEK293 , Células Hep G2 , Xenoenxertos , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução GenéticaRESUMO
There are still gaps in our understanding of the complex processes by which p53 suppresses tumorigenesis. Here we describe a novel role for p53 in suppressing the mevalonate pathway, which is responsible for biosynthesis of cholesterol and nonsterol isoprenoids. p53 blocks activation of SREBP-2, the master transcriptional regulator of this pathway, by transcriptionally inducing the ABCA1 cholesterol transporter gene. A mouse model of liver cancer reveals that downregulation of mevalonate pathway gene expression by p53 occurs in premalignant hepatocytes, when p53 is needed to actively suppress tumorigenesis. Furthermore, pharmacological or RNAi inhibition of the mevalonate pathway restricts the development of murine hepatocellular carcinomas driven by p53 loss. Like p53 loss, ablation of ABCA1 promotes murine liver tumorigenesis and is associated with increased SREBP-2 maturation. Our findings demonstrate that repression of the mevalonate pathway is a crucial component of p53-mediated liver tumor suppression and outline the mechanism by which this occurs.
Assuntos
Ácido Mevalônico/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Animais , Linhagem Celular , Colesterol/metabolismo , Feminino , Genes Supressores de Tumor , Células HCT116 , Hepatócitos/metabolismo , Humanos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/genética , Regiões Promotoras Genéticas , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Terpenos/metabolismoRESUMO
MLL/SET methyltransferases catalyze methylation of histone 3 lysine 4 and play critical roles in development and cancer. We assessed MLL/SET proteins and found that SETD1A is required for survival of acute myeloid leukemia (AML) cells. Mutagenesis studies and CRISPR-Cas9 domain screening show the enzymatic SET domain is not necessary for AML cell survival but that a newly identified region termed the "FLOS" (functional location on SETD1A) domain is indispensable. FLOS disruption suppresses DNA damage response genes and induces p53-dependent apoptosis. The FLOS domain acts as a cyclin-K-binding site that is required for chromosomal recruitment of cyclin K and for DNA-repair-associated gene expression in S phase. These data identify a connection between the chromatin regulator SETD1A and the DNA damage response that is independent of histone methylation and suggests that targeting SETD1A and cyclin K complexes may represent a therapeutic opportunity for AML and, potentially, for other cancers.
Assuntos
Ciclinas/metabolismo , Dano ao DNA , Histona-Lisina N-Metiltransferase/metabolismo , Animais , Biocatálise , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Ciclinas/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Regulação Leucêmica da Expressão Gênica , Técnicas de Silenciamento de Genes , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/genética , Histonas , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Camundongos , Ligação Proteica , Domínios Proteicos , Estabilidade Proteica , Transcrição GênicaRESUMO
Nuclear pore complexes (NPCs) regulate nuclear-cytoplasmic transport, transcription, and genome integrity in eukaryotic cells. However, their functional roles in cancer remain poorly understood. We interrogated the evolutionary transcriptomic landscape of NPC components, nucleoporins (Nups), from primary to advanced metastatic human prostate cancer (PC). Focused loss-of-function genetic screen of top-upregulated Nups in aggressive PC models identified POM121 as a key contributor to PC aggressiveness. Mechanistically, POM121 promoted PC progression by enhancing importin-dependent nuclear transport of key oncogenic (E2F1, MYC) and PC-specific (AR-GATA2) transcription factors, uncovering a pharmacologically targetable axis that, when inhibited, decreased tumor growth, restored standard therapy efficacy, and improved survival in patient-derived pre-clinical models. Our studies molecularly establish a role of NPCs in PC progression and give a rationale for NPC-regulated nuclear import targeting as a therapeutic strategy for lethal PC. These findings may have implications for understanding how NPC deregulation contributes to the pathogenesis of other tumor types.
Assuntos
Fator de Transcrição E2F1/metabolismo , Glicoproteínas de Membrana/metabolismo , Poro Nuclear/fisiologia , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fatores de Transcrição/metabolismo , Transporte Ativo do Núcleo Celular , Carcinogênese , Núcleo Celular/metabolismo , Proliferação de Células , Fator de Transcrição GATA2/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Membrana Nuclear , Complexo de Proteínas Formadoras de Poros Nucleares , Transdução de SinaisRESUMO
TP53 is the most frequently mutated gene in human cancer. Functionally, p53 is activated by a host of stress stimuli and, in turn, governs an exquisitely complex anti-proliferative transcriptional program that touches upon a bewildering array of biological responses. Despite the many unveiled facets of the p53 network, a clear appreciation of how and in what contexts p53 exerts its diverse effects remains unclear. How can we interpret p53's disparate activities and the consequences of its dysfunction to understand how cell type, mutation profile, and epigenetic cell state dictate outcomes, and how might we restore its tumor-suppressive activities in cancer?
Assuntos
Neoplasias/genética , Proteína Supressora de Tumor p53/metabolismo , Animais , Epigênese Genética , Genes p53 , Humanos , Mutação , Neoplasias/metabolismo , Proteína Supressora de Tumor p53/genéticaRESUMO
Germinal center (GC) B cells feature repression of many gene enhancers to establish their characteristic transcriptome. Here we show that conditional deletion of Lsd1 in GCs significantly impaired GC formation, associated with failure to repress immune synapse genes linked to GC exit, which are also direct targets of the transcriptional repressor BCL6. We found that BCL6 directly binds LSD1 and recruits it primarily to intergenic and intronic enhancers. Conditional deletion of Lsd1 suppressed GC hyperplasia caused by constitutive expression of BCL6 and significantly delayed BCL6-driven lymphomagenesis. Administration of catalytic inhibitors of LSD1 had little effect on GC formation or GC-derived lymphoma cells. Using a CRISPR-Cas9 domain screen, we found instead that the LSD1 Tower domain was critical for dependence on LSD1 in GC-derived B cells. These results indicate an essential role for LSD1 in the humoral immune response, where it modulates enhancer function by forming repression complexes with BCL6.
Assuntos
Linfócitos B/fisiologia , Centro Germinativo/patologia , Histona Desmetilases/metabolismo , Linfoma/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Animais , Sistemas CRISPR-Cas , Carcinogênese , DNA Intergênico/genética , Centro Germinativo/imunologia , Histona Desmetilases/genética , Hiperplasia , Sinapses Imunológicas/genética , Íntrons/genética , Linfoma/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Proto-Oncogênicas c-bcl-6/genéticaRESUMO
The adenomatous polyposis coli (APC) tumor suppressor is mutated in the vast majority of human colorectal cancers (CRC) and leads to deregulated Wnt signaling. To determine whether Apc disruption is required for tumor maintenance, we developed a mouse model of CRC whereby Apc can be conditionally suppressed using a doxycycline-regulated shRNA. Apc suppression produces adenomas in both the small intestine and colon that, in the presence of Kras and p53 mutations, can progress to invasive carcinoma. In established tumors, Apc restoration drives rapid and widespread tumor-cell differentiation and sustained regression without relapse. Tumor regression is accompanied by the re-establishment of normal crypt-villus homeostasis, such that once aberrantly proliferating cells reacquire self-renewal and multi-lineage differentiation capability. Our study reveals that CRC cells can revert to functioning normal cells given appropriate signals and provide compelling in vivo validation of the Wnt pathway as a therapeutic target for treatment of CRC.
Assuntos
Proteína da Polipose Adenomatosa do Colo/metabolismo , Neoplasias Colorretais/genética , Modelos Animais de Doenças , Intestino Grosso/patologia , Intestino Delgado/patologia , Proteína da Polipose Adenomatosa do Colo/genética , Animais , Proliferação de Células , Neoplasias Colorretais/patologia , Doxiciclina/administração & dosagem , Genes p53 , Pólipos Intestinais/metabolismo , Pólipos Intestinais/patologia , Intestino Grosso/metabolismo , Intestino Delgado/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas Proto-Oncogênicas p21(ras)/genética , Interferência de RNA , Via de Sinalização WntRESUMO
Missense mutations in the p53 tumor suppressor inactivate its antiproliferative properties but can also promote metastasis through a gain-of-function activity. We show that sustained expression of mutant p53 is required to maintain the prometastatic phenotype of a murine model of pancreatic cancer, a highly metastatic disease that frequently displays p53 mutations. Transcriptional profiling and functional screening identified the platelet-derived growth factor receptor b (PDGFRb) as both necessary and sufficient to mediate these effects. Mutant p53 induced PDGFRb through a cell-autonomous mechanism involving inhibition of a p73/NF-Y complex that represses PDGFRb expression in p53-deficient, noninvasive cells. Blocking PDGFRb signaling by RNA interference or by small molecule inhibitors prevented pancreatic cancer cell invasion in vitro and metastasis formation in vivo. Finally, high PDGFRb expression correlates with poor disease-free survival in pancreatic, colon, and ovarian cancer patients, implicating PDGFRb as a prognostic marker and possible target for attenuating metastasis in p53 mutant tumors.
Assuntos
Carcinoma Ductal Pancreático/metabolismo , Metástase Neoplásica , Neoplasias Pancreáticas/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Carcinoma Ductal Pancreático/patologia , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Camundongos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Proteína Supressora de Tumor p53/genéticaRESUMO
The p53 tumor suppressor coordinates a series of antiproliferative responses that restrict the expansion of malignant cells, and as a consequence, p53 is lost or mutated in the majority of human cancers. Here, we show that p53 restricts expression of the stem and progenitor-cell-associated protein nestin in an Sp1/3 transcription-factor-dependent manner and that Nestin is required for tumor initiation in vivo. Moreover, loss of p53 facilitates dedifferentiation of mature hepatocytes into nestin-positive progenitor-like cells, which are poised to differentiate into hepatocellular carcinomas (HCCs) or cholangiocarcinomas (CCs) in response to lineage-specific mutations that target Wnt and Notch signaling, respectively. Many human HCCs and CCs show elevated nestin expression, which correlates with p53 loss of function and is associated with decreased patient survival. Therefore, transcriptional repression of Nestin by p53 restricts cellular plasticity and tumorigenesis in liver cancer.
Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Nestina/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Transformação Celular Neoplásica , Hepatócitos/metabolismo , Humanos , Neoplasias Hepáticas/patologia , Camundongos , Prognóstico , Fator de Transcrição Sp1/metabolismo , Fator de Transcrição Sp3/metabolismo , Transcrição Gênica , Proteína Supressora de Tumor p53/metabolismoRESUMO
Metastasis frequently develops from disseminated cancer cells that remain dormant after the apparently successful treatment of a primary tumour. These cells fluctuate between an immune-evasive quiescent state and a proliferative state liable to immune-mediated elimination1-6. Little is known about the clearing of reawakened metastatic cells and how this process could be therapeutically activated to eliminate residual disease in patients. Here we use models of indolent lung adenocarcinoma metastasis to identify cancer cell-intrinsic determinants of immune reactivity during exit from dormancy. Genetic screens of tumour-intrinsic immune regulators identified the stimulator of interferon genes (STING) pathway as a suppressor of metastatic outbreak. STING activity increases in metastatic progenitors that re-enter the cell cycle and is dampened by hypermethylation of the STING promoter and enhancer in breakthrough metastases or by chromatin repression in cells re-entering dormancy in response to TGFß. STING expression in cancer cells derived from spontaneous metastases suppresses their outgrowth. Systemic treatment of mice with STING agonists eliminates dormant metastasis and prevents spontaneous outbreaks in a T cell- and natural killer cell-dependent manner-these effects require cancer cell STING function. Thus, STING provides a checkpoint against the progression of dormant metastasis and a therapeutically actionable strategy for the prevention of disease relapse.
Assuntos
Neoplasias Pulmonares , Metástase Neoplásica , Animais , Camundongos , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/patologia , Ciclo Celular , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/genética , Metástase Neoplásica/imunologia , Metástase Neoplásica/patologia , Recidiva Local de Neoplasia/tratamento farmacológico , Linfócitos T/imunologia , Fator de Crescimento Transformador beta , Células Matadoras Naturais/imunologiaRESUMO
Cellular senescence is implicated in several pathological responses in the adult, with important repercussions in tumor suppression, wound healing, and aging. Two studies by Muñoz-Espín et al. and Storer et al. now reveal that senescence contributes to embryonic development, suggesting a primordial role in normal physiology.
Assuntos
Senescência Celular , Desenvolvimento Embrionário , Saco Endolinfático/embriologia , Mesonefro/embriologia , Animais , Feminino , Humanos , MasculinoRESUMO
The p53 tumor suppressor can restrict malignant transformation by triggering cell-autonomous programs of cell-cycle arrest or apoptosis. p53 also promotes cellular senescence, a tumor-suppressive program that involves stable cell-cycle arrest and secretion of factors that modify the tissue microenvironment. In the presence of chronic liver damage, we show that ablation of a p53-dependent senescence program in hepatic stellate cells increases liver fibrosis and cirrhosis associated with reduced survival and enhances the transformation of adjacent epithelial cells into hepatocellular carcinoma. p53-expressing senescent stellate cells release factors that skew macrophage polarization toward a tumor-inhibiting M1-state capable of attacking senescent cells in culture, whereas proliferating p53-deficient stellate cells secrete factors that stimulate polarization of macrophages into a tumor-promoting M2-state and enhance the proliferation of premalignant cells. Hence, p53 can act non-cell autonomously to suppress tumorigenesis by promoting an antitumor microenvironment, in part, through secreted factors that modulate macrophage function.
Assuntos
Transformação Celular Neoplásica , Senescência Celular , Células Estreladas do Fígado/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Microambiente Celular , Fibrose/patologia , Células Estreladas do Fígado/citologia , Humanos , Inflamação/metabolismo , Células de Kupffer/metabolismo , Células de Kupffer/patologia , Fígado/citologia , Fígado/patologia , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , NF-kappa BRESUMO
CD8 T cell-mediated autoimmune diseases result from the breakdown of self-tolerance mechanisms in autoreactive CD8 T cells1. How autoimmune T cell populations arise and are sustained, and the molecular programmes defining the autoimmune T cell state, are unknown. In type 1 diabetes, ß-cell-specific CD8 T cells destroy insulin-producing ß-cells. Here we followed the fate of ß-cell-specific CD8 T cells in non-obese diabetic mice throughout the course of type 1 diabetes. We identified a stem-like autoimmune progenitor population in the pancreatic draining lymph node (pLN), which self-renews and gives rise to pLN autoimmune mediators. pLN autoimmune mediators migrate to the pancreas, where they differentiate further and destroy ß-cells. Whereas transplantation of as few as 20 autoimmune progenitors induced type 1 diabetes, as many as 100,000 pancreatic autoimmune mediators did not. Pancreatic autoimmune mediators are short-lived, and stem-like autoimmune progenitors must continuously seed the pancreas to sustain ß-cell destruction. Single-cell RNA sequencing and clonal analysis revealed that autoimmune CD8 T cells represent unique T cell differentiation states and identified features driving the transition from autoimmune progenitor to autoimmune mediator. Strategies aimed at targeting the stem-like autoimmune progenitor pool could emerge as novel and powerful immunotherapeutic interventions for type 1 diabetes.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Células Secretoras de Insulina/imunologia , Células-Tronco/patologia , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/transplante , Autorrenovação Celular , Células Clonais/imunologia , Células Clonais/metabolismo , Células Clonais/patologia , Modelos Animais de Doenças , Feminino , Glucose-6-Fosfatase/imunologia , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Células Secretoras de Insulina/patologia , Linfonodos/imunologia , Masculino , Camundongos , Receptores de Antígenos de Linfócitos T/metabolismo , Análise de Célula Única , Transplante de Células-Tronco , Células-Tronco/imunologia , Células-Tronco/metabolismo , TranscriptomaRESUMO
Although p53 inactivation promotes genomic instability1 and presents a route to malignancy for more than half of all human cancers2,3, the patterns through which heterogenous TP53 (encoding human p53) mutant genomes emerge and influence tumorigenesis remain poorly understood. Here, in a mouse model of pancreatic ductal adenocarcinoma that reports sporadic p53 loss of heterozygosity before cancer onset, we find that malignant properties enabled by p53 inactivation are acquired through a predictable pattern of genome evolution. Single-cell sequencing and in situ genotyping of cells from the point of p53 inactivation through progression to frank cancer reveal that this deterministic behaviour involves four sequential phases-Trp53 (encoding mouse p53) loss of heterozygosity, accumulation of deletions, genome doubling, and the emergence of gains and amplifications-each associated with specific histological stages across the premalignant and malignant spectrum. Despite rampant heterogeneity, the deletion events that follow p53 inactivation target functionally relevant pathways that can shape genomic evolution and remain fixed as homogenous events in diverse malignant populations. Thus, loss of p53-the 'guardian of the genome'-is not merely a gateway to genetic chaos but, rather, can enable deterministic patterns of genome evolution that may point to new strategies for the treatment of TP53-mutant tumours.
Assuntos
Carcinogênese , Progressão da Doença , Genes p53 , Genoma , Perda de Heterozigosidade , Neoplasias Pancreáticas , Proteína Supressora de Tumor p53 , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Carcinogênese/genética , Carcinogênese/patologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Evolução Molecular , Deleção de Genes , Genes p53/genética , Genoma/genética , Camundongos , Modelos Genéticos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Proteína Supressora de Tumor p53/genéticaRESUMO
Although TP53 is the most commonly mutated gene in human cancers, the p53-dependent transcriptional programs mediating tumor suppression remain incompletely understood. Here, to uncover critical components downstream of p53 in tumor suppression, we perform unbiased RNAi and CRISPR-Cas9-based genetic screens in vivo. These screens converge upon the p53-inducible gene Zmat3, encoding an RNA-binding protein, and we demonstrate that ZMAT3 is an important tumor suppressor downstream of p53 in mouse KrasG12D-driven lung and liver cancers and human carcinomas. Integrative analysis of the ZMAT3 RNA-binding landscape and transcriptomic profiling reveals that ZMAT3 directly modulates exon inclusion in transcripts encoding proteins of diverse functions, including the p53 inhibitors MDM4 and MDM2, splicing regulators, and components of varied cellular processes. Interestingly, these exons are enriched in NMD signals, and, accordingly, ZMAT3 broadly affects target transcript stability. Collectively, these studies reveal ZMAT3 as a novel RNA-splicing and homeostasis regulator and a key component of p53-mediated tumor suppression.
Assuntos
Proteínas de Ligação a RNA/genética , Proteína Supressora de Tumor p53/genética , Adenocarcinoma/genética , Processamento Alternativo , Animais , Proteínas de Ciclo Celular/metabolismo , Éxons , Perfilação da Expressão Gênica/métodos , Genes Supressores de Tumor , Humanos , Neoplasias Hepáticas/genética , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos SCID , Interferência de RNA , Splicing de RNA , Proteínas de Ligação a RNA/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
The biological and functional heterogeneity between tumors-both across and within cancer types-poses a challenge for immunotherapy. To understand the factors underlying tumor immune heterogeneity and immunotherapy sensitivity, we established a library of congenic tumor cell clones from an autochthonous mouse model of pancreatic adenocarcinoma. These clones generated tumors that recapitulated T cell-inflamed and non-T-cell-inflamed tumor microenvironments upon implantation in immunocompetent mice, with distinct patterns of infiltration by immune cell subsets. Co-injecting tumor cell clones revealed the non-T-cell-inflamed phenotype is dominant and that both quantitative and qualitative features of intratumoral CD8+ T cells determine response to therapy. Transcriptomic and epigenetic analyses revealed tumor-cell-intrinsic production of the chemokine CXCL1 as a determinant of the non-T-cell-inflamed microenvironment, and ablation of CXCL1 promoted T cell infiltration and sensitivity to a combination immunotherapy regimen. Thus, tumor cell-intrinsic factors shape the tumor immune microenvironment and influence the outcome of immunotherapy.
Assuntos
Adenocarcinoma/terapia , Fatores Imunológicos/imunologia , Imunoterapia , Subpopulações de Linfócitos/imunologia , Linfócitos do Interstício Tumoral/imunologia , Neoplasias Pancreáticas/terapia , Microambiente Tumoral/imunologia , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Animais , Linfócitos T CD8-Positivos/imunologia , Epigenômica , Feminino , Perfilação da Expressão Gênica , Humanos , Fatores Imunológicos/genética , Masculino , Camundongos , Pessoa de Meia-Idade , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologia , Cultura Primária de Células , Neoplasias PancreáticasRESUMO
Analyses of the human genome have proven extremely successful in identifying changes that contribute to human disease. Genetically engineered mice provide a powerful tool to analyze these changes, although they are slow and costly and do not always recapitulate human biology. Recent advances in genomic technologies, rodent-modeling approaches, and the production of patient-derived reprogrammed cell lines now provide a plethora of complementary systems to study disease states and test new therapies. Continued evolution and integration of these model systems will be the key to realizing the benefits of the genomic revolution and refining our understanding and treatment of human diseases.