RESUMO
Tandem repeats (TRs) are generated by DNA replication errors and retain a high level of instability, which in principle would make them unsuitable for integration into gene regulatory networks. However, the appearance of DNA sequence motifs recognized by transcription factors may turn TRs into functional cis-regulatory elements, thus favoring their stabilization in genomes. Here, we show that, in human cells, the transcriptional repressor ZEB1, which promotes the maintenance of mesenchymal features largely by suppressing epithelial genes and microRNAs, occupies TRs harboring dozens of copies of its DNA-binding motif within genomic loci relevant for maintenance of epithelial identity. The deletion of one such TR caused quasi-mesenchymal cancer cells to reacquire epithelial features, partially recapitulating the effects of ZEB1 gene deletion. These data demonstrate that the high density of identical motifs in TRs can make them suitable platforms for recruitment of transcriptional repressors, thus promoting their exaptation into pre-existing cis-regulatory networks.
Assuntos
Sequências de Repetição em Tandem/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Adulto , Animais , Sequência de Bases , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Feminino , Expressão Gênica , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Mucosa Bucal/metabolismo , Polimorfismo de Nucleotídeo Único , Ligação Proteica , Fatores de Transcrição/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/deficiência , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genéticaRESUMO
Pancreatic ductal adenocarcinoma (PDAC), one of the most highly lethal tumors, is characterized by complex histology, with a massive fibrotic stroma in which both pseudo-glandular structures and compact nests of abnormally differentiated tumor cells are embedded, in different proportions and with different mutual relationships in space. This complexity and the heterogeneity of the tumor component have hindered the development of a broadly accepted, clinically actionable classification of PDACs, either on a morphological or a molecular basis. Here, we discuss evidence suggesting that such heterogeneity can to a large extent, albeit not exclusively, be traced back to two main classes of PDAC cells that commonly coexist in the same tumor: cells that maintained their ability to differentiate toward endodermal, mucin-producing epithelia and epithelial cells unable to form glandular structures and instead characterized by various levels of squamous differentiation and the expression of mesenchymal lineage genes. The underlying gene regulatory networks and how they are controlled by distinct transcription factors, as well as the practical implications of these two different populations of tumor cells, are discussed.
Assuntos
Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Transcrição Gênica/genética , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Diferenciação Celular/genética , Células Epiteliais/patologia , Epitélio/patologia , Regulação Neoplásica da Expressão Gênica/genética , Redes Reguladoras de Genes/genética , Humanos , Fatores de Transcrição/genéticaRESUMO
BACKGROUND & AIMS: WNT signaling is central to spatial tissue arrangement and regulating stem cell activity, and it represents the hallmark of gastrointestinal cancers. Although its role in driving intestinal tumors is well characterized, WNT's role in gastric tumorigenesis remains elusive. METHODS: We have developed mouse models to control the specific expression of an oncogenic form of ß-catenin in combination with MYC activation in Lgr5+ cells of the gastric antrum. We used multiomics approaches applied in vivo and in organoid models to characterize their cooperation in driving gastric tumorigenesis. RESULTS: We report that constitutive ß-catenin stabilization in the stomach has negligible oncogenic effects and requires MYC activation to induce gastric tumor formation. Although physiologically low MYC levels in gastric glands limit ß-catenin transcriptional activity, increased MYC expression unleashes the WNT oncogenic transcriptional program, promoting ß-catenin enhancer invasion without a direct transcriptional cooperation. MYC activation induces a metabolic rewiring that suppresses lysosomal biogenesis through mTOR and ERK activation and MiT/TFE inhibition. This prevents EPCAM degradation by macropinocytosis, promoting ß-catenin chromatin accumulation and activation of WNT oncogenic transcription. CONCLUSION: Our results uncovered a new signaling framework with important implications for the control of gastric epithelial architecture and WNT-dependent oncogenic transformation.
RESUMO
OBJECTIVE: Pancreatic ductal adenocarcinomas (PDACs) include heterogeneous mixtures of low-grade cells forming pseudoglandular structures and compact nests of high-grade cells organised in non-glandular patterns. We previously reported that low-grade PDAC cells display high expression of interferon regulatory factor 1 (IRF1), a pivotal transcription factor of the interferon (IFN) system, suggesting grade-specific, cell-intrinsic activation of IFN responses. Here, we set out to determine the molecular bases and the functional impact of the activation of IFN-regulated responses in human PDACs. DESIGN: We first confirmed the correlation between glandular differentiation and molecular subtypes of PDAC on the one hand, and the expression of IRF1 and IFN-stimulated genes on the other. We next used unbiased omics approaches to systematically analyse basal and IFN-regulated responses in low-grade and high-grade PDAC cells, as well as the impact of IRF1 on gene expression programmes and metabolic profiles of PDAC cells. RESULTS: High-level expression of IRF1 in low-grade PDAC cells was controlled by endodermal lineage-determining transcription factors. IRF1-regulated gene expression equipped low-grade PDAC cells with distinctive properties related to antigen presentation and processing as well as responsiveness to IFN stimulation. Notably, IRF1 also controlled the characteristic metabolic profile of low-grade PDAC cells, suppressing both mitochondrial respiration and fatty acid synthesis, which may in part explain its growth-inhibiting activity. CONCLUSION: IRF1 links endodermal differentiation to the expression of genes controlling antigen presentation and processing as well as to the specification of the metabolic profile characteristic of classical PDAC cells.
Assuntos
Regulação da Expressão Gênica , Neoplasias Pancreáticas , Humanos , Fator Regulador 1 de Interferon/genética , Fator Regulador 1 de Interferon/metabolismo , Interferons , Neoplasias Pancreáticas/genética , Neoplasias PancreáticasRESUMO
Differentiation of normal and tumor cells is controlled by regulatory networks enforced by lineage-determining transcription factors (TFs). Among them, TFs such as FOXA1/2 bind naïve chromatin and induce its accessibility, thus establishing new gene regulatory networks. Pancreatic ductal adenocarcinoma (PDAC) is characterized by the coexistence of well- and poorly differentiated cells at all stages of disease. How the transcriptional networks determining such massive cellular heterogeneity are established remains to be determined. We found that FOXA2, a TF controlling pancreas specification, broadly contributed to the cis-regulatory networks of PDACs. Despite being expressed in both well- and poorly differentiated PDAC cells, FOXA2 displayed extensively different genomic distributions and controlled distinct gene expression programs. Grade-specific functions of FOXA2 depended on its partnership with TFs whose expression varied depending on the differentiation grade. These data suggest that FOXA2 contributes to the regulatory networks of heterogeneous PDAC cells via interactions with alternative partner TFs.
Assuntos
Diferenciação Celular , Regulação Neoplásica da Expressão Gênica , Fator 1-beta Nuclear de Hepatócito/metabolismo , Fator 3-beta Nuclear de Hepatócito/metabolismo , Proteínas de Homeodomínio/metabolismo , Neoplasias Pancreáticas/patologia , Elementos Reguladores de Transcrição , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Movimento Celular , Proliferação de Células , Redes Reguladoras de Genes , Fator 1-beta Nuclear de Hepatócito/genética , Fator 3-alfa Nuclear de Hepatócito/genética , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Fator 3-beta Nuclear de Hepatócito/genética , Proteínas de Homeodomínio/genética , Humanos , Gradação de Tumores , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Células Tumorais CultivadasRESUMO
Infective endocarditis (IE) on atrial septal defect (ASD) closure devices, while extremely rare, has been reported to be more frequent early after the procedure. We describe a case of late IE after percutaneous closure of patent foramen ovale (PFO). We also performed a literature review on this subject. We reviewed a total of 42,365 patients who were treated with percutaneous devices: 13,916 for ostium secundum (OS) (32%), 24,726 for PFO (58%) and 3,723 for OS+PFO (8%). Among these patients, we identified 50 cases of IE after atrial septal defect device closure (0.001%). In contrast to previous reports, nearly 66% of IE in this setting occurred late, after at least 6 months from the procedure (33/50 patients). A statistical analysis clearly showed that the mean time from the procedure to IE increased in the last five years, probably associated with a change in antiplatelet therapy after ASD closure. Management of IE on an ASD occluder should always be discussed in the setting of a multidisciplinary heart team that includes a cardiologist, cardiac surgeon, and anesthetist. While surgical strategies gave excellent results, conservative management might be considered in cases of small IE vegetations and for patients in good general condition. However, in these cases, the patient must be closely observed with repeated blood and instrumental tests.
RESUMO
Satellite cells (SCs) are muscle stem cells that remain quiescent during homeostasis and are activated in response to acute muscle damage or in chronic degenerative conditions such as Duchenne Muscular Dystrophy. The activity of SCs is supported by specialized cells which either reside in the muscle or are recruited in regenerating skeletal muscles, such as for instance macrophages (MΦs). By using a dystrophic mouse model of transient MΦ depletion, we describe a shift in identity of muscle stem cells dependent on the crosstalk between MΦs and SCs. Indeed MΦ depletion determines adipogenic conversion of SCs and exhaustion of the SC pool leading to an exacerbated dystrophic phenotype. The reported data could also provide new insights into therapeutic approaches targeting inflammation in dystrophic muscles.
Assuntos
Diferenciação Celular/genética , Macrófagos/metabolismo , Distrofia Muscular de Duchenne/genética , Regeneração/genética , Animais , Linhagem da Célula/genética , Modelos Animais de Doenças , Distrofina/genética , Humanos , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos mdx , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patologia , Mioblastos/metabolismo , Células Satélites de Músculo Esquelético/metabolismo , Células Satélites de Músculo Esquelético/patologiaRESUMO
Chronic inflammation promotes oncogenic transformation and tumor progression. Many inflammatory agents also generate a toxic microenvironment, implying that adaptive mechanisms must be deployed for cells to survive and undergo transformation in such unfavorable contexts. A paradigmatic case is represented by cancers occurring in pediatric patients with genetic defects of hepatocyte phosphatidylcholine transporters and in the corresponding mouse model (Mdr2-/- mice), in which impaired bile salt emulsification leads to chronic hepatocyte damage and inflammation, eventually resulting in oncogenic transformation. By combining genomics and metabolomics, we found that the transition from inflammation to cancer in Mdr2-/- mice was linked to the sustained transcriptional activation of metabolic detoxification systems and transporters by the Constitutive Androstane Receptor (CAR), a hepatocyte-specific nuclear receptor. Activation of CAR-dependent gene expression programs coincided with reduced content of toxic bile acids in cancer nodules relative to inflamed livers. Treatment of Mdr2-/- mice with a CAR inhibitor blocked cancer progression and caused a partial regression of existing tumors. These results indicate that the acquisition of resistance to endo- or xeno-biotic toxicity is critical for cancers that develop in toxic microenvironments.
Assuntos
Ácidos e Sais Biliares/metabolismo , Transformação Celular Neoplásica/genética , Inativação Metabólica/genética , Fígado/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Androstanóis/farmacologia , Animais , Transformação Celular Neoplásica/metabolismo , Receptor Constitutivo de Androstano , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Hepatite/genética , Hepatite/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Camundongos Knockout , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Receptores Citoplasmáticos e Nucleares/genética , Transdução de Sinais/genética , Ativação Transcricional/efeitos dos fármacos , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATPRESUMO
The histological grade of carcinomas describes the ability of tumor cells to organize in differentiated epithelial structures and has prognostic and therapeutic impact. Here, we show that differential usage of the genomic repertoire of transcriptional enhancers leads to grade-specific gene expression programs in human pancreatic ductal adenocarcinoma (PDAC). By integrating gene expression profiling, epigenomic footprinting, and loss-of-function experiments in PDAC cell lines of different grade, we identified the repertoires of enhancers specific to high- and low-grade PDACs and the cognate set of transcription factors acting to maintain their activity. Among the candidate regulators of PDAC differentiation, KLF5 was selectively expressed in pre-neoplastic lesions and low-grade primary PDACs and cell lines, where it maintained the acetylation of grade-specific enhancers, the expression of epithelial genes such as keratins and mucins, and the ability to organize glandular epithelia in xenografts. The identification of the transcription factors controlling differentiation in PDACs will help clarify the molecular bases of its heterogeneity and progression.
Assuntos
Adenocarcinoma/patologia , Carcinoma Ductal Pancreático/patologia , Regulação da Expressão Gênica , Linhagem Celular Tumoral , Epigênese Genética , Perfilação da Expressão Gênica , Marcadores Genéticos , Humanos , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genéticaRESUMO
Mitochondria are the energy-generating hubs of the cell. In spite of considerable advances, our understanding of the factors that regulate the molecular circuits that govern mitochondrial function remains incomplete. Using a genome-wide functional screen, we identify the poorly characterized protein Zinc finger CCCH-type containing 10 (Zc3h10) as regulator of mitochondrial physiology. We show that Zc3h10 is upregulated during physiological mitochondriogenesis as it occurs during the differentiation of myoblasts into myotubes. Zc3h10 overexpression boosts mitochondrial function and promotes myoblast differentiation, while the depletion of Zc3h10 results in impaired myoblast differentiation, mitochondrial dysfunction, reduced expression of electron transport chain (ETC) subunits, and blunted TCA cycle flux. Notably, we have identified a loss-of-function mutation of Zc3h10 in humans (Tyr105 to Cys105) that is associated with increased body mass index, fat mass, fasting glucose, and triglycerides. Isolated peripheral blood mononuclear cells from individuals homozygotic for Cys105 display reduced oxygen consumption rate, diminished expression of some ETC subunits, and decreased levels of some TCA cycle metabolites, which all together derive in mitochondrial dysfunction. Taken together, our study identifies Zc3h10 as a novel mitochondrial regulator.
Assuntos
Proteínas de Transporte/metabolismo , Mitocôndrias/metabolismo , Idoso , Animais , Proteínas de Transporte/genética , Diferenciação Celular , Linhagem Celular , Ciclo do Ácido Cítrico , Biologia Computacional/métodos , Metabolismo Energético , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Inativação Gênica , Humanos , Masculino , Camundongos , Mitocôndrias/genética , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Mutação , Mioblastos/citologia , Mioblastos/metabolismo , Proteoma , Proteômica/métodosRESUMO
Epigenetic aberrations have been recognized as important contributors to cancer onset and development, and increasing evidence suggests that linker histone H1 variants may serve as biomarkers useful for patient stratification, as well as play an important role as drivers in cancer. Although traditionally histone H1 levels have been studied using antibody-based methods and RNA expression, these approaches suffer from limitations. Mass spectrometry (MS)-based proteomics represents the ideal tool to accurately quantify relative changes in protein abundance within complex samples. In this study, we used a label-free quantification approach to simultaneously analyze all somatic histone H1 variants in clinical samples and verified its applicability to laser micro-dissected tissue areas containing as low as 1000 cells. We then applied it to breast cancer patient samples, identifying differences in linker histone variants patters in primary triple-negative breast tumors with and without relapse after chemotherapy. This study highlights how label-free quantitation by MS is a valuable option to accurately quantitate histone H1 levels in different types of clinical samples, including very low-abundance patient tissues.
Assuntos
Histonas/genética , Recidiva Local de Neoplasia/genética , Proteômica , Neoplasias de Mama Triplo Negativas/genética , Biomarcadores Tumorais/genética , Epigênese Genética/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/patologia , Processamento de Proteína Pós-Traducional/genética , Espectrometria de Massas em Tandem , Neoplasias de Mama Triplo Negativas/diagnóstico , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
mSEL-1L is a highly conserved ER-resident type I protein, involved in the degradation of misfolded peptides through the ubiquitin-proteasome system (UPS), a pathway known to control the plasticity of the vascular smooth muscle cells (VSMC) phenotype and survival. In this article, we demonstrate that mSEL-1L deficiency interferes with the murine embryonic vascular network, showing particular irregularities in the intracranic and intersomitic neurovascular units and in the cerebral capillary microcirculation. During murine embryogenesis, mSEL-1L is expressed in cerebral areas known to harbor progenitor neural cells, while in the adult brain the protein is specifically restricted to the stem cell niches, co-localizing with Sox2 and Nestin. Null mice are characterized by important defects in the development of telenchephalic regions, revealing conspicuous aberration in neural stem cell lineage commitment. Moreover, mSEL-1L depletion in vitro and in vivo appears to affect the harmonic differentiation of the NSCs, by negatively influencing the corticogenesis processes. Overall, the data presented suggests that the drastic phenotypic characteristics exhibited in mSEL-1L null mice can, in part, be explained by the negative influence it plays on Notch1 signaling pathway.
Assuntos
Linhagem da Célula , Neovascularização Fisiológica , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Proteínas/metabolismo , Animais , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Proliferação de Células , Autorrenovação Celular , Genoma , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos Knockout , Receptores Notch/metabolismo , Transcriptoma/genéticaRESUMO
Development of the endocrine compartment of the pancreas, as represented by the islets of Langerhans, occurs through a series of highly regulated events encompassing branching of the pancreatic epithelium, delamination and differentiation of islet progenitors from ductal domains, followed by expansion and three-dimensional organization into islet clusters. Cellular interactions with the extracellular matrix (ECM) mediated by receptors of the integrin family are postulated to regulate key functions in these processes. Yet, specific events regulated by these receptors in the developing pancreas remain unknown. Here, we show that ablation of the ß1 integrin gene in developing pancreatic ß-cells reduces their ability to expand during embryonic life, during the first week of postnatal life, and thereafter. Mice lacking ß1 integrin in insulin-producing cells exhibit a dramatic reduction of the number of ß-cells to only â¼18% of wild-type levels. Despite the significant reduction in ß-cell mass, these mutant mice are not diabetic. A thorough phenotypic analysis of ß-cells lacking ß1 integrin revealed a normal expression repertoire of ß-cell markers, normal architectural organization within islet clusters, and a normal ultrastructure. Global gene expression analysis revealed that ablation of this ECM receptor in ß-cells inhibits the expression of genes regulating cell cycle progression. Collectively, our results demonstrate that ß1 integrin receptors function as crucial positive regulators of ß-cell expansion.
Assuntos
Proliferação de Células , Regulação da Expressão Gênica no Desenvolvimento , Células Secretoras de Insulina/metabolismo , Integrina beta1/metabolismo , Animais , Adesão Celular , Contagem de Células , Ciclo Celular , Diferenciação Celular , Membrana Celular/metabolismo , Forma Celular , Células Cultivadas , Embrião de Mamíferos/metabolismo , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Insulina/genética , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/ultraestrutura , Integrina beta1/genética , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Transmissão , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosforilação , Regiões Promotoras GenéticasRESUMO
BACKGROUND: Thymic stromal lymphopoietin (TSLP) is a cytokine with pleiotropic functions in the immune system. It has been associated with allergic reactions in the skin and lungs but also homeostatic tolerogenic responses in the thymus and gut. OBJECTIVE: In human subjects TSLP is present in 2 isoforms, short and long. Here we wanted to investigate the differential expression of the TSLP isoforms and discern their biological implications under homeostatic or inflammatory conditions. METHODS: We evaluated the expression of TSLPs in tissues from healthy subjects, patients with ulcerative colitis, patients with celiac disease, and patients with atopic dermatitis and on epithelial cells and keratinocytes under steady-state conditions or after stimulation. We then tested the immune activity of TSLP isoforms both in vitro and in vivo. RESULTS: We showed that TSLP isoforms are responsible for 2 opposite immune functions. The short isoform is expressed under steady-state conditions and exerts anti-inflammatory activities by affecting the capacity of PBMCs and dendritic cells to produce inflammatory cytokines. Moreover, the short isoform TSLP ameliorates experimental colitis in mice and prevents endotoxin shock. The long isoform of TSLP is proinflammatory and is only expressed during inflammation. The isoforms are differentially regulated by pathogenic bacteria, such as Salmonella species and adhesive-invasive Escherichia coli. CONCLUSIONS: We have solved the dilemma of TSLP being both homeostatic and inflammatory. The TSLP isoform ratio is altered during several inflammatory disorders, with strong implications in disease treatment and prevention. Indeed, targeting of the long isoform of TSLP at the C-terminal portion, which is common to both isoforms, might lead to unwanted side effects caused by neutralization of the homeostatic short isoform.
Assuntos
Doença Celíaca/imunologia , Colite Ulcerativa/imunologia , Citocinas/imunologia , Dermatite Atópica/imunologia , Intestinos/imunologia , Pele/imunologia , Animais , Estudos de Casos e Controles , Doença Celíaca/genética , Doença Celíaca/microbiologia , Doença Celíaca/patologia , Colite Ulcerativa/genética , Colite Ulcerativa/microbiologia , Colite Ulcerativa/patologia , Citocinas/genética , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Células Dendríticas/patologia , Dermatite Atópica/genética , Dermatite Atópica/microbiologia , Dermatite Atópica/patologia , Modelos Animais de Doenças , Escherichia coli/imunologia , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Feminino , Regulação da Expressão Gênica/imunologia , Humanos , Intestinos/microbiologia , Intestinos/patologia , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/microbiologia , Leucócitos Mononucleares/patologia , Camundongos , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Salmonella/imunologia , Infecções por Salmonella/genética , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Infecções por Salmonella/patologia , Pele/microbiologia , Pele/patologia , Linfopoietina do Estroma do TimoRESUMO
We explored the dysregulation of G-protein-coupled receptor (GPCR) ligand systems in cancer transcriptomics datasets to uncover new therapeutics opportunities in oncology. We derived an interaction network of receptors with ligands and their biosynthetic enzymes. Multiple GPCRs are differentially regulated together with their upstream partners across cancer subtypes and are associated to specific transcriptional programs and to patient survival patterns. The expression of both receptor-ligand (or enzymes) partners improved patient stratification, suggesting a synergistic role for the activation of GPCR networks in modulating cancer phenotypes. Remarkably, we identified many such axes across several cancer molecular subtypes, including many involving receptor-biosynthetic enzymes for neurotransmitters. We found that GPCRs from these actionable axes, including, e.g., muscarinic, adenosine, 5-hydroxytryptamine, and chemokine receptors, are the targets of multiple drugs displaying anti-growth effects in large-scale, cancer cell drug screens, which we further validated. We have made the results generated in this study freely available through a webapp (gpcrcanceraxes.bioinfolab.sns.it).
Assuntos
Neoplasias , Receptores Acoplados a Proteínas G , Transdução de Sinais , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Neoplasias/metabolismo , Neoplasias/genética , Neoplasias/patologia , Ligantes , Regulação Neoplásica da Expressão GênicaRESUMO
While pancreatic ductal adenocarcinomas (PDACs) are addicted to KRAS-activating mutations, inhibitors of downstream KRAS effectors, such as the MEK1/2 kinase inhibitor trametinib, are devoid of therapeutic effects. However, the extensive rewiring of regulatory circuits driven by the attenuation of the KRAS pathway may induce vulnerabilities of therapeutic relevance. An in-depth molecular analysis of the transcriptional and epigenomic alterations occurring in PDAC cells in the initial hours after MEK1/2 inhibition by trametinib unveiled the induction of endogenous retroviruses (ERVs) escaping epigenetic silencing, leading to the production of double-stranded RNAs and the increased expression of interferon (IFN) genes. We tracked ERV activation to the early induction of the transcription factor ELF3, which extensively bound and activated nonsilenced retroelements and synergized with IRF1 (interferon regulatory factor 1) in the activation of IFNs and IFN-stimulated genes. Trametinib-induced viral mimicry in PDAC may be exploited in the rational design of combination therapies in immuno-oncology.
Assuntos
Carcinoma Ductal Pancreático , Retrovirus Endógenos , Neoplasias Pancreáticas , Humanos , Retrovirus Endógenos/genética , Transdução de Sinais , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismoRESUMO
Intratumor morphological heterogeneity of pancreatic ductal adenocarcinoma (PDAC) predicts clinical outcomes but is only partially understood at the molecular level. To elucidate the gene expression programs underpinning intratumor morphological variation in PDAC, we investigated and deconvoluted at single cell level the molecular profiles of histologically distinct clusters of PDAC cells. We identified three major morphological and functional variants that co-exist in varying proportions in all PDACs, display limited genetic diversity, and are associated with a distinct organization of the extracellular matrix: a glandular variant with classical ductal features; a transitional variant displaying abortive ductal structures and mixed endodermal and myofibroblast-like gene expression; and a poorly differentiated variant lacking ductal features and basement membrane, and showing neuronal lineage priming. Ex vivo and in vitro evidence supports the occurrence of dynamic transitions among these variants in part influenced by extracellular matrix composition and stiffness and associated with local, specifically neural, invasion.
Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/patologia , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Membrana Basal/metabolismo , Sistema NervosoRESUMO
Background: The inhibition of PCSK9 lowered LDL cholesterol levels, reducing the risk of cardiovascular events. However, the effect on patients who have undergone surgical myocardial revascularization has not yet been evaluated. Methods: From January 2017 to December 2022, 180 dyslipidemic patients who underwent coronary artery bypass were included in the study. Until December 2019, 100 patients optimized therapy with statin ± ezetimibe (SG). Since January 2020, 80 matched patients added treatment with Evolocumab every 2 weeks (EG). All 180 patients were followed-up at 3 and 12 months, comparing outcomes. Results: The two groups are homogenous. At 3 months and 1 year, a significant decrease in the parameter mean levels of LDL cholesterol and total cholesterol is detected in the Evolocumab group compared to the standard group. No mortality was detected in either group. No complications or drug discontinuation were recorded. In the SG group, five patients (5%) suffered a myocardial infarction during the 1-year follow-up. In the EG group, two patients (2.5%) underwent PTCA due to myocardial infarction. There is no significant difference in overall survival according to the new treatment (p-value = 0.9), and the hazard ratio is equal to 0.94 (95% C.I.: [0.16-5.43]; p-value = 0.9397). Conclusions: The use of Evolocumab, which was started immediately after coronary artery bypass graft surgery, significantly reduced LDL cholesterol and total cholesterol levels compared to statin treatment alone and is completely safe. However, at one year of follow-up, this result did not have impact on the reduction in major clinical events.
RESUMO
Background. The in-hospital reduction in low-density lipoprotein cholesterol (LDL-C) levels following acute coronary syndrome (ACS) is recommended in the current clinical guidelines. However, the efficacy of proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors in those patients undergoing coronary artery bypass graft (CABG) has never been demonstrated. Methods. From January 2022 to July 2023, we retrospectively analyzed 74 ACS patients characterized by higher LDL-C levels than guideline targets and who underwent coronary bypass surgery. In the first period (January 2022-January 2023), the patients increased their statin dosage and/or added Ezetimibe (Group STEZE, 43 patients). At a later time (February 2023-July 2023), the patients received not only statins and Ezetimibe but also Evolocumab 140 mg every 2 weeks starting as early as possible (Group STEVO, 31 patients). After one and three months post-discharge, the patients underwent clinical and laboratory controls with an evaluation of the efficacy lipid measurements and every adverse event. Results. The two groups did not differ in terms of preoperative risk factors and Euroscore II (STEVO: 2.14 ± 0.75 vs. STEZE: 2.05 ± 0.6, p = 0.29). Also, there was no difference between the groups in terms of ACS (ST-, Instable angina, or NSTE) and time of symptoms onset regarding total cholesterol, LDL-C, and HDL-C trends from the preprocedural period to 3-month follow-up, but there was a more significant reduction in LDL-C and total cholesterol in the STEVO group (p = 0.01 and p = 0.04, respectively) and no difference in HDL-C rise (p = 0.12). No deaths were reported. In three STEZE group patients, angina recurrence posed the need for percutaneous re-revascularization. No STEVO patients developed significant adverse events. The statistical difference in these serious events, 7% in STEZE vs. 0% in STEVO, was not significant (p = 0.26). Conclusions. Evolocumab initiated "as soon as possible" in ACS patients submitted to CABG with high-intensity statin therapy and Ezetimibe was well tolerated and resulted in a substantial and significant reduction in LDL-C levels at discharge, 1 month, and 3 months. This result is associated with a reduction but without a statistical difference between groups.