RESUMO
Therapies that boost the anti-tumor responses of cytotoxic T lymphocytes (CTLs) have shown promise; however, clinical responses to the immunotherapeutic agents currently available vary considerably, and the molecular basis of this is unclear. We performed transcriptomic profiling of tumor-infiltrating CTLs from treatment-naive patients with lung cancer to define the molecular features associated with the robustness of anti-tumor immune responses. We observed considerable heterogeneity in the expression of molecules associated with activation of the T cell antigen receptor (TCR) and of immunological-checkpoint molecules such as 4-1BB, PD-1 and TIM-3. Tumors with a high density of CTLs showed enrichment for transcripts linked to tissue-resident memory cells (TRM cells), such as CD103, and CTLs from CD103hi tumors displayed features of enhanced cytotoxicity. A greater density of TRM cells in tumors was predictive of a better survival outcome in lung cancer, and this effect was independent of that conferred by CTL density. Here we define the 'molecular fingerprint' of tumor-infiltrating CTLs and identify potentially new targets for immunotherapy.
Assuntos
Adenocarcinoma/imunologia , Carcinoma de Células Escamosas/imunologia , Neoplasias de Cabeça e Pescoço/imunologia , Memória Imunológica/imunologia , Neoplasias Pulmonares/imunologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos T Citotóxicos/imunologia , Adenocarcinoma/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/genética , Carcinoma de Células Escamosas/mortalidade , Feminino , Perfilação da Expressão Gênica , Receptor Celular 2 do Vírus da Hepatite A/genética , Humanos , Imunoterapia , Cadeias alfa de Integrinas/genética , Neoplasias Pulmonares/mortalidade , Linfócitos do Interstício Tumoral/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico , Receptor de Morte Celular Programada 1/genética , Receptores de Antígenos de Linfócitos T/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço , Taxa de Sobrevida , Linfócitos T Citotóxicos/metabolismo , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/genéticaRESUMO
RATIONALE: Activin receptor-like kinase-1 (ALK1) is an endothelial transforming growth factor ß receptor involved in angiogenesis. ALK1 expression is high in the embryo vasculature, becoming less detectable in the quiescent endothelium of adult stages. However, ALK1 expression becomes rapidly increased after angiogenic stimuli such as vascular injury. OBJECTIVE: To characterize the molecular mechanisms underlying the regulation of ALK1 on vascular injury. METHODS AND RESULTS: Alk1 becomes strongly upregulated in endothelial (EC) and vascular smooth muscle cells of mouse femoral arteries after wire-induced endothelial denudation. In vitro denudation of monolayers of human umbilical vein ECs also leads to an increase in ALK1. Interestingly, a key factor in tissue remodeling, Krüppel-like factor 6 (KLF6) translocates to the cell nucleus during wound healing, concomitantly with an increase in the ALK1 gene transcriptional rate. KLF6 knock down in human umbilical vein ECs promotes ALK1 mRNA downregulation. Moreover, Klf6(+/-) mice have lower levels of Alk1 in their vasculature compared with their wild-type siblings. Chromatin immunoprecipitation assays show that KLF6 interacts with ALK1 promoter in ECs, and this interaction is enhanced during wound healing. We demonstrate that KLF6 is transactivating ALK1 gene, and this transactivation occurs by a synergistic cooperative mechanism with specificity protein 1. Finally, Alk1 levels in vascular smooth muscle cells are not directly upregulated in response to damage, but in response to soluble factors, such as interleukin 6, released from ECs after injury. CONCLUSIONS: ALK1 is upregulated in ECs during vascular injury by a synergistic cooperative mechanism between KLF6 and specificity protein 1, and in vascular smooth muscle cells by an EC-vascular smooth muscle cell paracrine communication during vascular remodeling.
Assuntos
Receptores de Activinas Tipo II/metabolismo , Receptores de Ativinas Tipo I/metabolismo , Células Endoteliais/metabolismo , Artéria Femoral/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Lesões do Sistema Vascular/metabolismo , Cicatrização , Receptores de Ativinas Tipo I/genética , Receptores de Activinas Tipo II/genética , Animais , Sítios de Ligação , Modelos Animais de Doenças , Células Endoteliais/patologia , Artéria Femoral/lesões , Artéria Femoral/patologia , Regulação da Expressão Gênica , Células HEK293 , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Interleucina-6/metabolismo , Fator 6 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Comunicação Parácrina , Regiões Promotoras Genéticas , Transporte Proteico , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Interferência de RNA , RNA Mensageiro/metabolismo , Fator de Transcrição Sp1/metabolismo , Fatores de Tempo , Transcrição Gênica , Ativação Transcricional , Transfecção , Lesões do Sistema Vascular/genética , Lesões do Sistema Vascular/patologiaRESUMO
OBJECTIVE: Hereditary hemorrhagic telangiectasia is a genetic disorder characterized by visceral and mucocutaneous arteriovenous malformations (AVMs). Clinically indistinguishable hereditary hemorrhagic telangiectasia 1 and hereditary hemorrhagic telangiectasia 2 are caused by mutations in ENG and ALK1, respectively. In this study, we have compared the development of visceral and mucocutaneous AVMs in adult stages between Eng- and Alk1-inducible knockout (iKO) models. APPROACH AND RESULTS: Eng or Alk1 were deleted from either vascular endothelial cells (ECs) or smooth muscle cells in adult stages using Scl-CreER and Myh11-CreER lines, respectively. Latex perfusion and intravital spectral imaging in a dorsal skinfold window chamber system were used to visualize remodeling vasculature during AVM formation. Global Eng deletion resulted in lethality with visceral AVMs and wound-induced skin AVMs. Deletion of Alk1 or Eng in ECs, but not in smooth muscle cells, resulted in wound-induced skin AVMs. Visceral AVMs were observed in EC-specific Alk1-iKO but not in Eng-iKO. Intravital spectral imaging revealed that Eng-iKO model exhibited more dynamic processes for AVM development when compared with Alk1-iKO model. CONCLUSIONS: Both Alk1- and Eng-deficient models require a secondary insult, such as wounding, and ECs are the primary cell type responsible for the pathogenesis. However, Alk1 but not Eng deletion in ECs results in visceral AVMs.
Assuntos
Malformações Arteriovenosas/patologia , Telangiectasia Hemorrágica Hereditária/patologia , Receptores de Ativinas Tipo I/deficiência , Receptores de Ativinas Tipo I/genética , Receptores de Activinas Tipo II , Animais , Malformações Arteriovenosas/genética , Malformações Arteriovenosas/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Endoglina , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Camundongos , Camundongos Knockout , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Telangiectasia Hemorrágica Hereditária/genética , Telangiectasia Hemorrágica Hereditária/metabolismo , Fatores de Tempo , CicatrizaçãoRESUMO
Testicular germ cell tumors (TGCTs) are highly responsive to and curable by cisplatin-based chemotherapy even in advanced stages. We have studied the molecular mechanisms involved in the induction of apoptosis in response to cisplatin, and found that proapoptotic Noxa is transcriptionally up-regulated following cisplatin exposure, even in the absence of p53, in NTERA2 cisplatin-sensitive cells but not in 1411HP-resistant cells. Blockade of Noxa reduced the apoptotic response of embryonal carcinoma (EC) NTERA2 cells to cisplatin. A detailed analysis of the Noxa promoter revealed that p73 and Sp1-like factors, Sp1 and KLF6, played key roles in the transcriptional control of this gene. Overexpression of TAp73 induced Noxa whereas the dominant negative isoform ΔNp73, reduced the levels of Noxa after cisplatin exposure in NTERA2 and 2102EP. Interestingly, down-regulation of Sp1 increased Noxa expression in response to cisplatin. However, blockade of KLF6 decreased cisplatin-induced up-regulation of Noxa in EC cell lines. In addition, tissue microarray analyses of TGCTs revealed that expression of Noxa correlates with good clinical prognosis in patients with embryonal carcinoma. Thus, our data show the transcriptional network that regulates Noxa in EC cells, which is key for their apoptotic response to cisplatin-based chemotherapy, and propose Noxa as a predictive factor of therapeutic response.
Assuntos
Apoptose/fisiologia , Carcinoma Embrionário/patologia , Cisplatino/farmacologia , Proteínas de Ligação a DNA/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Proteínas Nucleares/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Fator de Transcrição Sp1/fisiologia , Neoplasias Testiculares/patologia , Proteínas Supressoras de Tumor/fisiologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Sequência de Bases , Carcinoma Embrionário/tratamento farmacológico , Carcinoma Embrionário/genética , Linhagem Celular Tumoral , Cisplatino/uso terapêutico , Estudos de Coortes , Primers do DNA , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Prognóstico , Regiões Promotoras Genéticas , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias Testiculares/tratamento farmacológico , Neoplasias Testiculares/genética , Proteína Tumoral p73RESUMO
Lung cancer is the leading cause of cancer mortality worldwide, with non-small cell lung cancer (NSCLC) being the most prevalent histology. While immunotherapy with checkpoint inhibitors has shown outstanding results in NSCLC, the precise identification of responders remains a major challenge. Most studies attempting to overcome this handicap have focused on adenocarcinomas or squamous cell carcinomas. Among NSCLC subtypes, the molecular and immune characteristics of lung large cell carcinoma (LCC), which represents 10% of NSCLC cases, are not well defined. We hypothesized that specific molecular aberrations may impact the immune microenvironment in LCC and, consequently, the response to immunotherapy. To that end, it is particularly relevant to thoroughly describe the molecular genotype-immunophenotype association in LCC-to identify robust predictive biomarkers and improve potential benefits from immunotherapy. We established a cohort of 18 early-stage, clinically annotated, LCC cases. Their molecular and immune features were comprehensively characterized by genomic and immune-targeted sequencing panels along with immunohistochemistry of immune cell populations. Unbiased clustering defined two novel subgroups of LCC. Pro-immunogenic tumors accumulated certain molecular alterations, showed higher immune infiltration and upregulated genes involved in potentiating immune responses when compared to pro-tumorigenic samples, which favored tumoral progression. This classification identified a set of biomarkers that could potentially predict response to immunotherapy. These results could improve patient selection and expand potential benefits from immunotherapy.
RESUMO
INTRODUCTION: SCLC is an extremely aggressive subtype of lung cancer without approved targeted therapies. Here we identified YES1 as a novel targetable oncogene driving SCLC maintenance and metastasis. METHODS: Association between YES1 levels and prognosis was evaluated in SCLC clinical samples. In vitro functional experiments for proliferation, apoptosis, cell cycle, and cytotoxicity were performed. Genetic and pharmacologic inhibition of YES1 was evaluated in vivo in cell- and patient-derived xenografts and metastasis. YES1 levels were evaluated in mouse and patient plasma-derived exosomes. RESULTS: Overexpression or gain/amplification of YES1 was identified in 31% and 26% of cases, respectively, across molecular subgroups, and was found as an independent predictor of poor prognosis. Genetic depletion of YES1 dramatically reduced cell proliferation, three-dimensional organoid formation, tumor growth, and distant metastasis, leading to extensive apoptosis and tumor regressions. Mechanistically, YES1-inhibited cells revealed alterations in the replisome and DNA repair processes, that conferred sensitivity to irradiation. Pharmacologic blockade with the novel YES1 inhibitor CH6953755 or dasatinib induced marked antitumor activity in organoid models and cell- and patient-derived xenografts. YES1 protein was detected in plasma exosomes from patients and mouse models, with levels matching those of tumors, suggesting that circulating YES1 could represent a biomarker for patient selection/monitoring. CONCLUSIONS: Our results provide evidence that YES1 is a new druggable oncogenic target and biomarker to advance the clinical management of a subpopulation of patients with SCLC.
Assuntos
Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Camundongos , Animais , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Linhagem Celular Tumoral , Oncogenes , Proliferação de Células/genética , Apoptose , Carcinogênese/genética , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/genética , Carcinoma de Pequenas Células do Pulmão/patologia , Proteínas Proto-Oncogênicas c-yes/genéticaRESUMO
Whole-brain radiotherapy (WBRT) is the treatment backbone for many patients with brain metastasis; however, its efficacy in preventing disease progression and the associated toxicity have questioned the clinical impact of this approach and emphasized the need for alternative treatments. Given the limited therapeutic options available for these patients and the poor understanding of the molecular mechanisms underlying the resistance of metastatic lesions to WBRT, we sought to uncover actionable targets and biomarkers that could help to refine patient selection. Through an unbiased analysis of experimental in vivo models of brain metastasis resistant to WBRT, we identified activation of the S100A9-RAGE-NF-κB-JunB pathway in brain metastases as a potential mediator of resistance in this organ. Targeting this pathway genetically or pharmacologically was sufficient to revert the WBRT resistance and increase therapeutic benefits in vivo at lower doses of radiation. In patients with primary melanoma, lung or breast adenocarcinoma developing brain metastasis, endogenous S100A9 levels in brain lesions correlated with clinical response to WBRT and underscored the potential of S100A9 levels in the blood as a noninvasive biomarker. Collectively, we provide a molecular framework to personalize WBRT and improve its efficacy through combination with a radiosensitizer that balances therapeutic benefit and toxicity.
Assuntos
Neoplasias Encefálicas , Melanoma , Neoplasias Encefálicas/secundário , Irradiação Craniana , Humanos , Melanoma/radioterapiaRESUMO
BACKGROUND: Intestinal macrophages are key immune cells in the maintenance of intestinal immune homeostasis and have a role in the pathogenesis of inflammatory bowel disease (IBD). However, the mechanisms by which macrophages exert a pathological influence in both ulcerative colitis (UC) and Crohn disease (CD) are not yet well understood. METHODS: We purified intestinal macrophages from gastrointestinal mucosal biopsies (patients with UC, patients with CD, and healthy donors) and analyzed their transcriptome by RNA sequencing and bioinformatics, confirming results with quantitative polymerase chain reaction and immunohistochemistry. RESULTS: Compared with those of healthy donors, intestinal macrophages in patients with UC and with CD showed cellular reprograming of 1287 and 840 dysregulated genes, respectively (false discovery rateâ ≤â 0.1). The UC and CD intestinal macrophages showed an activated M1 inflammatory phenotype and the downregulation of genes engaged in drug/xenobiotic metabolism. Only macrophages from CD showed, concomitant to an M1 phenotype, a significant enrichment in the expression of M2 and fibrotic and granuloma-related genes. For the first time, we showed (and validated by quantitative polymerase chain reaction and immunohistochemistry) that intestinal macrophages in patients with IBD present both M1 and M2 features, as recently described for tumor-associated macrophages, that affect key pathways for IBD pathology, represented by key markers such as MMP12 (fibrosis), CXCL9 (T-cell attraction), and CD40 (T-cell activation). CONCLUSIONS: Our data support the therapeutic targeting of macrophages to maintain remission in IBD but also indicate that a shift toward an M2 program-as proposed by some reports-may not limit the recruitment and activation of T cells because M2 features do not preclude M1 activation in patients with UC or CD and could exacerbate M2-related CD-specific features such as fibrosis and the formation of granulomas.
Assuntos
Colite Ulcerativa , Colite , Doença de Crohn , Doenças Inflamatórias Intestinais , Fibrose , Humanos , Mucosa Intestinal , MacrófagosRESUMO
BACKGROUND: Tumor mutational burden (TMB) is a recently proposed predictive biomarker for immunotherapy in solid tumors, including non-small cell lung cancer (NSCLC). Available assays for TMB determination differ in horizontal coverage, gene content and algorithms, leading to discrepancies in results, impacting patient selection. A harmonization study of TMB assessment with available assays in a cohort of patients with NSCLC is urgently needed. METHODS: We evaluated the TMB assessment obtained with two marketed next generation sequencing panels: TruSight Oncology 500 (TSO500) and Oncomine Tumor Mutation Load (OTML) versus a reference assay (Foundation One, FO) in 96 NSCLC samples. Additionally, we studied the level of agreement among the three methods with respect to PD-L1 expression in tumors, checked the level of different immune infiltrates versus TMB, and performed an inter-laboratory reproducibility study. Finally, adjusted cut-off values were determined. RESULTS: Both panels showed strong agreement with FO, with concordance correlation coefficients (CCC) of 0.933 (95% CI 0.908 to 0.959) for TSO500 and 0.881 (95% CI 0.840 to 0.922) for OTML. The corresponding CCCs were 0.951 (TSO500-FO) and 0.919 (OTML-FO) in tumors with <1% of cells expressing PD-L1 (PD-L1<1%; N=55), and 0.861 (TSO500-FO) and 0.722 (OTML-FO) in tumors with PD-L1≥1% (N=41). Inter-laboratory reproducibility analyses showed higher reproducibility with TSO500. No significant differences were found in terms of immune infiltration versus TMB. Adjusted cut-off values corresponding to 10 muts/Mb with FO needed to be lowered to 7.847 muts/Mb (TSO500) and 8.380 muts/Mb (OTML) to ensure a sensitivity >88%. With these cut-offs, the positive predictive value was 78.57% (95% CI 67.82 to 89.32) and the negative predictive value was 87.50% (95% CI 77.25 to 97.75) for TSO500, while for OTML they were 73.33% (95% CI 62.14 to 84.52) and 86.11% (95% CI 74.81 to 97.41), respectively. CONCLUSIONS: Both panels exhibited robust analytical performances for TMB assessment, with stronger concordances in patients with negative PD-L1 expression. TSO500 showed a higher inter-laboratory reproducibility. The cut-offs for each assay were lowered to optimal overlap with FO.
Assuntos
Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Análise Mutacional de DNA , Sequenciamento de Nucleotídeos em Larga Escala , Neoplasias Pulmonares/genética , Mutação , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Predisposição Genética para Doença , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Variações Dependentes do Observador , Fenótipo , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos TestesRESUMO
PURPOSE: The induction of 4-1BB signaling by agonistic antibodies can drive the activation and proliferation of effector T cells and thereby enhance a T-cell-mediated antitumor response. Systemic administration of anti-4-1BB-agonistic IgGs, although effective preclinically, has not advanced in clinical development due to their severe hepatotoxicity. EXPERIMENTAL DESIGN: Here, we generated a humanized EGFR-specific 4-1BB-agonistic trimerbody, which replaces the IgG Fc region with a human collagen homotrimerization domain. It was characterized by structural analysis and in vitro functional studies. We also assessed pharmacokinetics, antitumor efficacy, and toxicity in vivo. RESULTS: In the presence of a T-cell receptor signal, the trimerbody provided potent T-cell costimulation that was strictly dependent on 4-1BB hyperclustering at the point of contact with a tumor antigen-displaying cell surface. It exhibits significant antitumor activity in vivo, without hepatotoxicity, in a wide range of human tumors including colorectal and breast cancer cell-derived xenografts, and non-small cell lung cancer patient-derived xenografts associated with increased tumor-infiltrating CD8+ T cells. The combination of the trimerbody with a PD-L1 blocker led to increased IFNγ secretion in vitro and resulted in tumor regression in humanized mice bearing aggressive triple-negative breast cancer. CONCLUSIONS: These results demonstrate the nontoxic broad antitumor activity of humanized Fc-free tumor-specific 4-1BB-agonistic trimerbodies and their synergy with checkpoint blockers, which may provide a way to elicit responses in most patients with cancer while avoiding Fc-mediated adverse reactions.
Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Receptores ErbB , Imunoterapia/métodos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/uso terapêutico , Animais , Neoplasias da Mama/imunologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Linhagem Celular , Modelos Animais de Doenças , Feminino , Neoplasias Pulmonares/imunologia , Ativação Linfocitária/genética , Ativação Linfocitária/fisiologia , Camundongos Transgênicos , Linfócitos T/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismoRESUMO
Endoglin is a coreceptor for transforming growth factor-ß (TGF-ß) that acts as a suppressor of malignancy during mouse skin carcinogenesis. Because in this model system H-Ras activation drives tumor initiation and progression, we have assessed the effects of endoglin on the expression of H-Ras in transformed keratinocytes. We found that TGF-ß1 increases the expression of H-Ras at both messenger RNA and protein levels. The TGF-ß1-induced H-Ras promoter transactivation was Smad4 independent but mediated by the activation of the TGF-ß type I receptor ALK5 and the Ras-mitogen-activated protein kinase (MAPK) pathway. Endoglin attenuated stimulation by TGF-ß1 of both MAPK signaling activity and H-Ras gene expression. Moreover, endoglin inhibited the Ras/MAPK pathway in transformed epidermal cells containing an H-Ras oncogene, as evidenced by the levels of Ras-guanosine triphosphate, phospho-MAPK kinase (MEK) and phospho-extracellular signal-regulated kinase (ERK) as well as the expression of c-fos, a MAPK downstream target gene. Interestingly, in spindle carcinoma cells, that have a hyperactivated Ras/MAPK pathway, endoglin inhibited ERK phosphorylation without affecting MEK or Ras activity. The mechanism for this effect is unknown but strongly depends on the endoglin extracellular domain. Because the MAPK pathway is a downstream mediator of the transforming potential of Ras, the effect of endoglin on the oncogenic function of H-Ras was assessed. Endoglin inhibited the transforming capacity of H-Ras(Q61K) and H-Ras(G12V) oncogenes in a NIH3T3 focus formation assay. The ability to interfere with the expression and oncogenic potential of H-Ras provides a new face of the suppressor role exhibited by endoglin in H-Ras-driven carcinogenesis.
Assuntos
Genes ras/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Animais , Linhagem Celular , Transformação Celular Neoplásica , Endoglina , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Regulação da Expressão Gênica/efeitos dos fármacos , Queratinócitos/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos , Células NIH 3T3 , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases/fisiologia , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/fisiologia , Proteínas Smad/fisiologia , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
BACKGROUND: Activin receptor-like kinase 1 (ALK1) is a Transforming Growth Factor-beta (TGF-beta) receptor type I, mainly expressed in endothelial cells that plays a pivotal role in vascular remodelling and angiogenesis. Mutations in the ALK1 gene (ACVRL1) give rise to Hereditary Haemorrhagic Telangiectasia, a dominant autosomal vascular dysplasia caused by a haploinsufficiency mechanism. In spite of its patho-physiological relevance, little is known about the transcriptional regulation of ACVRL1. Here, we have studied the different origins of ACVRL1 transcription, we have analyzed in silico its 5'-proximal promoter sequence and we have characterized the role of Sp1 in the transcriptional regulation of ACVRL1. RESULTS: We have performed a 5'Rapid Amplification of cDNA Ends (5'RACE) of ACVRL1 transcripts, finding two new transcriptional origins, upstream of the one previously described, that give rise to a new exon undiscovered to date. The 5'-proximal promoter region of ACVRL1 (-1,035/+210) was analyzed in silico, finding that it lacks TATA/CAAT boxes, but contains a remarkably high number of GC-rich Sp1 consensus sites. In cells lacking Sp1, ACVRL1 promoter reporters did not present any significant transcriptional activity, whereas increasing concentrations of Sp1 triggered a dose-dependent stimulation of its transcription. Moreover, silencing Sp1 in HEK293T cells resulted in a marked decrease of ACVRL1 transcriptional activity. Chromatin immunoprecipitation assays demonstrated multiple Sp1 binding sites along the proximal promoter region of ACVRL1 in endothelial cells. Furthermore, demethylation of CpG islands, led to an increase in ACVRL1 transcription, whereas in vitro hypermethylation resulted in the abolishment of Sp1-dependent transcriptional activation of ACVRL1. CONCLUSIONS: Our results describe two new transcriptional start sites in ACVRL1 gene, and indicate that Sp1 is a key regulator of ACVRL1 transcription, providing new insights into the molecular mechanisms that contribute to the expression of ACVRL1 gene. Moreover, our data show that the methylation status of CpG islands markedly modulates the Sp1 regulation of ACVRL1 gene transcriptional activity.
Assuntos
Receptores de Activinas Tipo II/genética , Regiões Promotoras Genéticas , Fator de Transcrição Sp1/metabolismo , Regiões 5' não Traduzidas , Receptores de Activinas Tipo II/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Bovinos , Imunoprecipitação da Cromatina , Ilhas de CpG , Metilação de DNA , Cães , Cavalos , Humanos , Macaca mulatta , Camundongos , Dados de Sequência Molecular , Pongo , Ligação Proteica , Ratos , Alinhamento de Sequência , Sítio de Iniciação de Transcrição , Ativação TranscricionalRESUMO
KLF6 (Krüppel-like factor 6) is a transcription factor and tumour suppressor with a growing range of biological activities and transcriptional targets. Among these, KLF6 suppresses growth through transactivation of TGF-beta1 (transforming growth factor-beta1). KLF6 can be alternatively spliced, generating lower-molecular-mass isoforms that antagonize the full-length WT (wild-type) protein and promote growth. A key target gene of full-length KLF6 is endoglin, which is induced in vascular injury. Endoglin, a homodimeric cell membrane glycoprotein and TGF-beta auxiliary receptor, has a pro-angiogenic role in endothelial cells and is also involved in malignant progression. The aim of the present work was to explore the effect of TGF-beta on KLF6 expression and splicing, and to define the contribution of TGF-beta on promoters regulated by co-operation between KLF6 and Sp1 (specificity protein 1). Using co-transfection, co-immunoprecipitation and fluorescence resonance energy transfer, our data demonstrate that KLF6 co-operates with Sp1 in transcriptionally regulating KLF6-responsive genes and that this co-operation is further enhanced by TGF-beta1 through at least two mechanisms. First, in specific cell types, TGF-beta1 may decrease KLF6 alternative splicing, resulting in a net increase in full-length, growth-suppressive KLF6 activity. Secondly, KLF6-Sp1 co-operation is further enhanced by the TGF-beta-Smad (similar to mothers against decapentaplegic) pathway via the likely formation of a tripartite KLF6-Sp1-Smad3 complex in which KLF6 interacts indirectly with Smad3 through Sp1, which may serve as a bridging molecule to co-ordinate this interaction. These findings unveil a finely tuned network of interactions between KLF6, Sp1 and TGF-beta to regulate target genes.
Assuntos
Processamento Alternativo/genética , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteína Smad3/metabolismo , Fator de Transcrição Sp1/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Animais , Células COS , Linhagem Celular , Chlorocebus aethiops , Colágeno/metabolismo , Citometria de Fluxo , Transferência Ressonante de Energia de Fluorescência , Células HeLa , Humanos , Imunoprecipitação , Fator 6 Semelhante a Kruppel , Reação em Cadeia da Polimerase , Ligação Proteica/genética , Ligação Proteica/fisiologia , Proteína Smad3/genética , Fator de Transcrição Sp1/genéticaRESUMO
BACKGROUND: The role of tumor-associated macrophages (TAMs) in determining the outcome between the antitumor effects of the adaptive immune system and the tumor's anti-immunity stratagems, is controversial. Macrophages modulate their activities and phenotypes by integration of signals in the tumor microenvironment. Depending on how macrophages are activated, they may adopt so-called M1-like, antitumor or M2-like, protumor profiles. In many solid tumors, a dominance of M2-like macrophages is associated with poor outcomes but in some tumor types, strong M1-like profiles are linked to better outcomes. We aimed to investigate the interrelationship of these TAM populations to establish how they modulate the efficacy of the adaptive immune system in early lung cancer. METHODS: Macrophages from matched lung (non-tumor-associated macrophages (NTAMs)) and tumor samples (TAMs) from resected lung cancers were assessed by bulk and single-cell transcriptomic analysis. Protein expression of genes characteristic of M1-like (chemokine (C-X-C motif) ligand 9) or M2-like (matrix metallopeptidase 12) functions was confirmed by confocal microscopy. Immunohistochemistry related the distribution of TAM transcriptomic signatures to density of CD8+ tissue-resident memory T cells (TRM) in tumors and survival data from an independent cohort of 393 patients with lung cancer. RESULTS: TAMs have significantly different transcriptomic profiles from NTAMs with >1000 differentially expressed genes. TAMs displayed a strong M2-like signature with no significant variation between patients. However, single-cell RNA-sequencing supported by immuno-stained cells revealed that additionally, in 25% of patients the M2-like TAMs also co-expressed a strong/hot M1-like signature (M1hot). Importantly, there was a strong association between the density of M1hot TAMs and TRM cells in tumors that was in turn linked to better survival. Our data suggest a mechanism by which M1hot TAMs may recruit TRM cells via CXCL9 expression and sustain them by making available more of the essential fatty acids on which TRM depend. CONCLUSIONS: We showed that in early lung cancer, expression of M1-like and M2-like gene signatures are not mutually exclusive since the same TAMs can simultaneously display both gene-expression profiles. The presence of M1hot TAMs was associated with a strong TRM tumor-infiltrate and better outcomes. Thus, therapeutic approaches to re-program TAMs to an M1hot phenotype are likely to augment the adaptive antitumor responses.
Assuntos
Neoplasias Pulmonares/genética , Linfócitos T/metabolismo , Macrófagos Associados a Tumor/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Masculino , Análise de SobrevidaRESUMO
Stratification of patients for targeted and immune-based therapies requires extensive genomic profiling that enables sensitive detection of clinically relevant variants and interrogation of biomarkers, such as tumor mutational burden (TMB) and microsatellite instability (MSI). Detection of single and multiple nucleotide variants, copy number variants, MSI, and TMB was evaluated using a commercially available next-generation sequencing panel containing 523 cancer-related genes (1.94 megabases). Analysis of formalin-fixed, paraffin-embedded tissue sections and cytologic material from 45 tumor samples showed that all previously known MSI-positive samples (n = 7), amplifications (n = 9), and pathogenic variants (n = 59) could be detected. TMB and MSI scores showed high intralaboratory and interlaboratory reproducibility (eight samples tested in 11 laboratories). For reliable TMB analysis, 20 ng DNA was shown to be sufficient, even for relatively poor-quality samples. A minimum of 20% neoplastic cells was required to minimize variations in TMB values induced by chromosomal instability or tumor heterogeneity. Subsequent analysis of 58 consecutive lung cancer samples in a diagnostic setting was successful and revealed sufficient somatic mutations to generate mutational signatures in 14 cases. In conclusion, the 523-gene assay can be applied for evaluation of multiple DNA-based biomarkers relevant for treatment selection.
Assuntos
Variações do Número de Cópias de DNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Instabilidade de Microssatélites , Neoplasias/genética , Oncogenes , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/patologia , Reprodutibilidade dos Testes , Análise de Sequência de DNA/métodosRESUMO
AIMS: Activin receptor-like kinase (ALK)1 is a transforming growth factor (TGF)-beta type I membrane receptor restricted almost entirely to endothelial cells (ECs) and involved in vascular remodelling and angiogenesis. Previous reports have shown that the ubiquitous TGF-beta type I receptor ALK5 and the type II receptor are located in cholesterol-rich membrane microdomains named caveolae. The aim of this work was to assess the location of ALK1 in endothelial caveolae as well as to study the role of caveolin-1 on the TGF-beta/ALK1 signalling pathway. METHODS AND RESULTS: The subcellular distribution of ALK1 was analysed by confocal microscopy and co-fractionation experiments in human ECs. The association between human ALK1 and caveolin-1 was studied in caveolin-1-deficient human epithelial cells by co-immunoprecipitation. The functional role of caveolin-1 on the ALK1-mediated TGF-beta signalling was elucidated using ALK1-specific luciferase reporters in human ECs, caveolin-1(-/-)mouse embryonic fibroblasts, and rat myoblasts. Confocal microscopy analyses, as well as cholesterol depletion experiments in the presence of cholesterol-depleting agents such as nystatin or methyl-beta-cyclodextrin, demonstrated that ALK1 is located in endothelial caveolae. Also, co-immunoprecipitation assays showed that ALK1 associates with the main caveolae component caveolin-1. Mapping of the ALK1/caveolin-1 interaction revealed that the caveolin-1 scaffolding domain and the caveolin-1 binding motif in ALK1 are responsible for this association. Moreover, this hitherto not reported interaction had a functional consequence for the ALK1-dependent signalling. In contrast with the previously published ALK5/caveolin-1 interaction, caveolin-1 enhances the TGF-beta/ALK1 signalling pathway, promoting the activity of the ALK1-specific reporters. Conversely, specific suppression of caveolin-1 abrogated the ALK1 signalling pathway. CONCLUSION: ALK1 is located in endothelial caveolae where it functionally interacts with caveolin-1 through its scaffolding domain, suggesting a joint contribution of ALK1 and caveolin-1 as key mediators of the TGF-beta pathway in angiogenesis.
Assuntos
Receptores de Activinas Tipo II/metabolismo , Cavéolas/metabolismo , Caveolina 1/metabolismo , Células Endoteliais/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta1/metabolismo , Motivos de Aminoácidos , Animais , Caveolina 1/química , Caveolina 1/genética , Linhagem Celular , Colesterol/deficiência , Humanos , Imunoprecipitação , Camundongos , Camundongos Knockout , Microscopia Confocal , Neovascularização Fisiológica , Ligação Proteica , Mapeamento de Interação de Proteínas , Estrutura Terciária de Proteína , Interferência de RNA , RatosRESUMO
The European Respiratory Society (ERS) International Congress is the largest respiratory congress and brings together leading experts in all fields of respiratory medicine and research. ERS Assembly 3 shapes the basic and translational science aspects of this congress, aiming to combine cutting-edge novel developments in basic research with novel clinical findings. In this article, we summarise a selection of the scientific highlights from the perspective of the three groups within Assembly 3. In particular, we discuss new insights into the pathophysiology of the human alveolus, novel tools in organoid development and (epi)genome editing, as well as insights from the presented abstracts on novel therapeutic targets being identified for idiopathic pulmonary fibrosis.
RESUMO
MicroRNAs are known to regulate important pathways in asthma pathology including the IL-6 and IFN pathways. MicroRNAs have been found not only within cells but also within extracellular vesicles such as exosomes. In this study, we particularly focused on microRNA cargo of nanovesicles in bronchoalveolar lavage of severe asthmatic patients. We extracted nanovesicle RNA using a serial filtration method. RNA content was analyzed with small RNA sequencing and mapped to pathways affected using WebGestalt 2017 Software. We report that severe asthma patients have deficient loading of microRNAs into their airway luminal nanovesicles and an altered profile of small RNA nanovesicle content (i.e., ribosomal RNA and broken transcripts, etc.). This decrease in microRNA cargo is predicted to increase the expression of genes by promoting inflammation and remodeling. Consistently, a network of microRNAs was associated with decreased FEV1 and increased eosinophilic and neutrophilic inflammation in severe asthma. MicroRNAs in airway nanovesicles may, thus, be valid biomarkers to define abnormal biological disease processes in severe asthma and monitor the impact of interventional therapies.
RESUMO
BACKGROUND: Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant and age-dependent vascular disorder characterised mainly by mutations in the Endoglin (ENG) or activin receptor-like kinase-1 (ALK1, ACVRL1) genes. METHODS: Here, we have identified 22 ALK1 mutations and 15 ENG mutations, many of which had not previously been reported, in independent Spanish families afflicted with HHT. RESULTS: We identified mutations in thirty-seven unrelated families. A detailed analysis of clinical symptoms was recorded for each patient analyzed, with a higher significant presence of pulmonary arteriovenous malformations (PAVM) in HHT1 patients over HHT2. Twenty-two mutations in ALK1 and fifteen in ENG genes were identified. Many of them, almost half, represented new mutations in ALK1 and in ENG. Missense mutations in ENG and ALK1 were localized in a tridimensional protein structure model. CONCLUSION: Overall, ALK1 mutations (HHT2) were predominant over ENG mutations (HHT1) in our Spanish population, in agreement with previous data from our country and other Mediterranean countries (France, Italy), but different to Northern Europe or North America. There was a significant increase of PAVM associated with HHT1 over HHT2 in these families.
Assuntos
Receptores de Activinas Tipo II/genética , Antígenos CD/genética , Mutação , Receptores de Superfície Celular/genética , Telangiectasia Hemorrágica Hereditária/genética , Endoglina , Éxons , Humanos , Mutação de Sentido Incorreto , Linhagem , EspanhaRESUMO
.@EarlyCareerERS looks back on #LSC2018 http://ow.ly/6hjS30jB6P9.