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1.
Nat Immunol ; 25(9): 1637-1649, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39060651

RESUMO

Approximately 25% of cancers are preceded by chronic inflammation that occurs at the site of tumor development. However, whether this multifactorial oncogenic process, which commonly occurs in the intestines, can be initiated by a specific immune cell population is unclear. Here, we show that an intestinal T cell subset, derived from interleukin-17 (IL-17)-producing helper T (TH17) cells, induces the spontaneous transformation of the intestinal epithelium. This subset produces inflammatory cytokines, and its tumorigenic potential is not dependent on IL-17 production but on the transcription factors KLF6 and T-BET and interferon-γ. The development of this cell type is inhibited by transforming growth factor-ß1 (TGFß1) produced by intestinal epithelial cells. TGFß signaling acts on the pretumorigenic TH17 cell subset, preventing its progression to the tumorigenic stage by inhibiting KLF6-dependent T-BET expression. This study therefore identifies an intestinal T cell subset initiating cancer.


Assuntos
Mucosa Intestinal , Fator 6 Semelhante a Kruppel , Proteínas com Domínio T , Células Th17 , Animais , Células Th17/imunologia , Camundongos , Proteínas com Domínio T/metabolismo , Proteínas com Domínio T/genética , Fator 6 Semelhante a Kruppel/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Transdução de Sinais/imunologia , Camundongos Endogâmicos C57BL , Transformação Celular Neoplásica/imunologia , Transformação Celular Neoplásica/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Camundongos Knockout , Interferon gama/metabolismo , Interferon gama/imunologia , Interleucina-17/metabolismo , Interleucina-17/imunologia , Camundongos Transgênicos , Proteínas Proto-Oncogênicas/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Neoplasias Intestinais/imunologia , Neoplasias Intestinais/patologia , Neoplasias Intestinais/metabolismo , Humanos
2.
Nature ; 620(7973): 409-416, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37532934

RESUMO

Netrin-1 is upregulated in cancers as a protumoural mechanism1. Here we describe netrin-1 upregulation in a majority of human endometrial carcinomas (ECs) and demonstrate that netrin-1 blockade, using an anti-netrin-1 antibody (NP137), is effective in reduction of tumour progression in an EC mouse model. We next examined the efficacy of NP137, as a first-in-class single agent, in a Phase I trial comprising 14 patients with advanced EC. As best response we observed 8 stable disease (8 out of 14, 57.1%) and 1 objective response as RECIST v.1.1 (partial response, 1 out of 14 (7.1%), 51.16% reduction in target lesions at 6 weeks and up to 54.65% reduction during the following 6 months). To evaluate the NP137 mechanism of action, mouse tumour gene profiling was performed, and we observed, in addition to cell death induction, that NP137 inhibited epithelial-to-mesenchymal transition (EMT). By performing bulk RNA sequencing (RNA-seq), spatial transcriptomics and single-cell RNA-seq on paired pre- and on-treatment biopsies from patients with EC from the NP137 trial, we noted a net reduction in tumour EMT. This was associated with changes in immune infiltrate and increased interactions between cancer cells and the tumour microenvironment. Given the importance of EMT in resistance to current standards of care2, we show in the EC mouse model that a combination of NP137 with carboplatin-paclitaxel outperformed carboplatin-paclitaxel alone. Our results identify netrin-1 blockade as a clinical strategy triggering both tumour debulking and EMT inhibition, thus potentially alleviating resistance to standard treatments.


Assuntos
Neoplasias do Endométrio , Transição Epitelial-Mesenquimal , Netrina-1 , Animais , Feminino , Humanos , Camundongos , Biópsia , Carboplatina/administração & dosagem , Carboplatina/farmacologia , Carboplatina/uso terapêutico , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/imunologia , Neoplasias do Endométrio/patologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Perfilação da Expressão Gênica , Netrina-1/antagonistas & inibidores , Paclitaxel/administração & dosagem , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , RNA-Seq , Análise da Expressão Gênica de Célula Única , Microambiente Tumoral/efeitos dos fármacos
3.
J Immunol ; 212(6): 1029-1039, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38284984

RESUMO

Both identity and plasticity of CD4 T helper (Th) cells are regulated in part by epigenetic mechanisms. However, a method that reliably and readily profiles DNA base modifications is still needed to finely study Th cell differentiation. Cytosine methylation in CpG context (5mCpG) and cytosine hydroxymethylation (5hmCpG) are DNA modifications that identify stable cell phenotypes, but their potential to characterize intermediate cell transitions has not yet been evaluated. To assess transition states in Th cells, we developed a method to profile Th cell identity using Cas9-targeted single-molecule nanopore sequencing. Targeting as few as 10 selected genomic loci, we were able to distinguish major in vitro polarized murine T cell subtypes, as well as intermediate phenotypes, by their native DNA 5mCpG patterns. Moreover, by using off-target sequences, we were able to infer transcription factor activities relevant to each cell subtype. Detection of 5mCpG and 5hmCpG was validated on intestinal Th17 cells escaping transforming growth factor ß control, using single-molecule adaptive sampling. A total of 21 differentially methylated regions mapping to the 10-gene panel were identified in pathogenic Th17 cells relative to their nonpathogenic counterpart. Hence, our data highlight the potential to exploit native DNA methylation profiling to study physiological and pathological transition states of Th cells.


Assuntos
Metilação de DNA , Epigênese Genética , Animais , Camundongos , Citosina , DNA/metabolismo , Células Th17/metabolismo
4.
EMBO Rep ; 24(4): e56524, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-36802267

RESUMO

We report the identification of a cell population that shares pericyte, stromal and stemness features, does not harbor the KrasG12D mutation and drives tumoral growth in vitro and in vivo. We term these cells pericyte stem cells (PeSCs) and define them as CD45- EPCAM- CD29+ CD106+ CD24+ CD44+ cells. We perform studies with p48-Cre;KrasG12D (KC), pdx1-Cre;KrasG12D ;Ink4a/Arffl/fl (KIC) and pdx1-Cre;KrasG12D ;p53R172H (KPC) and tumor tissues from PDAC and chronic pancreatitis patients. We also perform single-cell RNAseq analysis and reveal a unique signature of PeSC. Under steady-state conditions, PeSCs are barely detectable in the pancreas but present in the neoplastic microenvironment both in humans and mice. The coinjection of PeSCs and tumor epithelial cells leads to increased tumor growth, differentiation of Ly6G+ myeloid-derived suppressor cells, and a decreased amount of F4/80+ macrophages and CD11c+ dendritic cells. This population induces resistance to anti-PD-1 immunotherapy when coinjected with epithelial tumor cells. Our data reveal the existence of a cell population that instructs immunosuppressive myeloid cell responses to bypass PD-1 targeting and thus suggest potential new approaches for overcoming resistance to immunotherapy in clinical settings.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animais , Humanos , Camundongos , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/terapia , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/genética , Pericitos , Proteínas Proto-Oncogênicas p21(ras) , Células-Tronco , Microambiente Tumoral , Neoplasias Pancreáticas
5.
J Hepatol ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38782119

RESUMO

BACKGROUND & AIMS: Transcription termination fine-tunes gene expression and contributes to the specification of RNA function in eukaryotic cells. Transcription termination of HBV is subject to the recognition of the canonical polyadenylation signal (cPAS) common to all viral transcripts. However, the regulation of this cPAS and its impact on viral gene expression and replication is currently unknown. METHODS: To unravel the regulation of HBV transcript termination, we implemented a 3' RACE (rapid amplification of cDNA ends)-PCR assay coupled to single molecule sequencing both in in vitro-infected hepatocytes and in chronically infected patients. RESULTS: The detection of a previously unidentified transcriptional readthrough indicated that the cPAS was not systematically recognized during HBV replication in vitro and in vivo. Gene expression downregulation experiments demonstrated a role for the RNA helicases DDX5 and DDX17 in promoting viral transcriptional readthrough, which was, in turn, associated with HBV RNA destabilization and decreased HBx protein expression. RNA and chromatin immunoprecipitation, together with mutation of the cPAS sequence, suggested a direct role of DDX5 and DDX17 in functionally linking cPAS recognition to transcriptional readthrough, HBV RNA stability and replication. CONCLUSIONS: Our findings identify DDX5 and DDX17 as crucial determinants of HBV transcriptional fidelity and as host restriction factors for HBV replication. IMPACT AND IMPLICATIONS: HBV covalently closed circular (ccc)DNA degradation or functional inactivation remains the holy grail for the achievement of HBV cure. Transcriptional fidelity is a cornerstone in the regulation of gene expression. Here, we demonstrate that two helicases, DDX5 and DDX17, inhibit recognition of the HBV polyadenylation signal and thereby transcriptional termination, thus decreasing HBV RNA stability and acting as restriction factors for efficient cccDNA transcription and viral replication. The observation that DDX5 and DDX17 are downregulated in patients chronically infected with HBV suggests a role for these helicases in HBV persistence in vivo. These results open new perspectives for researchers aiming at identifying new targets to neutralise cccDNA transcription.

6.
Int J Cancer ; 151(1): 138-152, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35253899

RESUMO

Beyond their critical role in hemostasis, platelets physically interact with neutrophils to form neutrophil-platelet aggregates (NPAs), enhancing neutrophil effector functions during inflammation. NPAs may also promote disease worsening in various inflammatory diseases. However, characterization of NPAs in cancer remains totally unexplored. Using ImageStreamX (ISX) imaging flow cytometer, we were not only allowed able to detect CD15+ CD14- CD36+ ITGA2B+ NPAs in both healthy donors' (HDs) and cancer patients' bloods, but we also showed that NPAs result from the binding of platelets preferentially to low-density neutrophils (LDNs) as opposed to normal-density neutrophils (NDNs). By reanalyzing two independent public scRNAseq data of whole blood leukocytes from cancer patients and HDs, we could identify a subset of neutrophils with high platelet gene expression that may correspond to NPAs. Moreover, we showed that cancer patients' derived NPAs possessed a distinct molecular signature compared to the other neutrophil subsets, independently of platelet genes. Gene ontology (GO) term enrichment analysis of this NPAs-associated neutrophil transcriptomic signature revealed a significant enrichment of neutrophil degranulation, chemotaxis and trans-endothelial migration GO terms. Lastly, using The Cancer Genome Atlas (TCGA), we could show by multivariate Cox analysis that the NPAs-associated neutrophil transcriptomic signature was associated with a worse patient prognosis in several cancer types. These results suggest that neutrophils from NPAs are systemically primed by platelets empowering them with cancer progression capacities once at tumor site. NPAs may therefore hold clinical utility as novel noninvasive blood prognostic biomarker in cancer patients with solid tumors.


Assuntos
Neoplasias , Neutrófilos , Plaquetas , Citometria de Fluxo , Humanos , Neoplasias/patologia , Neutrófilos/patologia , Prognóstico
7.
J Virol ; 94(3)2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31694959

RESUMO

Merkel cell polyomavirus (MCPyV) is the first human polyomavirus etiologically associated with Merkel cell carcinoma (MCC), a rare and aggressive form of skin cancer. Similar to other polyomaviruses, MCPyV encodes early T antigen genes, viral oncogenes required for MCC tumor growth. To identify the unique oncogenic properties of MCPyV, we analyzed the gene expression profiles in human spontaneously immortalized keratinocytes (NIKs) expressing the early genes from six distinct human polyomaviruses (PyVs), including MCPyV. A comparison of the gene expression profiles revealed 28 genes specifically deregulated by MCPyV. In particular, the MCPyV early gene downregulated the expression of the tumor suppressor gene N-myc downstream-regulated gene 1 (NDRG1) in MCPyV gene-expressing NIKs and hTERT-MCPyV gene-expressing human keratinocytes (HK) compared to their expression in the controls. In MCPyV-positive MCC cells, the expression of NDRG1 was downregulated by the MCPyV early gene, as T antigen knockdown rescued the level of NDRG1. In addition, NDRG1 overexpression in hTERT-MCPyV gene-expressing HK or MCC cells resulted in a decrease in the number of cells in S phase and cell proliferation inhibition. Moreover, a decrease in wound healing capacity in hTERT-MCPyV gene-expressing HK was observed. Further analysis revealed that NDRG1 exerts its biological effect in Merkel cell lines by regulating the expression of the cyclin-dependent kinase 2 (CDK2) and cyclin D1 proteins. Overall, NDRG1 plays an important role in MCPyV-induced cellular proliferation.IMPORTANCE Merkel cell carcinoma was first described in 1972 as a neuroendocrine tumor of skin, most cases of which were reported in 2008 to be caused by a PyV named Merkel cell polyomavirus (MCPyV), the first PyV linked to human cancer. Thereafter, numerous studies have been conducted to understand the etiology of this virus-induced carcinogenesis. However, it is still a new field, and much work is needed to understand the molecular pathogenesis of MCC. In the current work, we sought to identify the host genes specifically deregulated by MCPyV, as opposed to other PyVs, in order to better understand the relevance of the genes analyzed on the biological impact and progression of the disease. These findings open newer avenues for targeted drug therapies, thereby providing hope for the management of patients suffering from this highly aggressive cancer.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Movimento Celular/genética , Proliferação de Células/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Poliomavírus das Células de Merkel/genética , Poliomavírus das Células de Merkel/fisiologia , Antígenos Virais de Tumores/genética , Antígenos Virais de Tumores/metabolismo , Carcinogênese/genética , Carcinoma de Célula de Merkel/virologia , Linhagem Celular , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Regulação Viral da Expressão Gênica , Humanos , Queratinócitos/virologia , Infecções por Polyomavirus/virologia , Pele/patologia , Neoplasias Cutâneas/genética , Transcriptoma , Infecções Tumorais por Vírus/virologia
8.
J Am Soc Nephrol ; 31(2): 324-336, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792155

RESUMO

BACKGROUND: Renal autoregulation maintains stable renal function despite BP fluctuations and protects glomerular capillaries from hypertensive injury. However, real-time dynamics of renal autoregulation in conscious animals have not been characterized. METHODS: To develop novel analytic methods for assessing renal autoregulation, we recorded concurrent BP and renal blood flow in conscious rats, comparing animals with renal autoregulation that was intact versus impaired (from 3/4 nephrectomy), before and after additional impairment (from the calcium channel blocker amlodipine). We calculated autoregulatory indices for adjacent short segments of increasing length (0.5, 1, 2.5, 5, 10, and 20 seconds) that exhibited a mean BP difference of at least 5 mm Hg. RESULTS: Autoregulatory restoration of renal blood flow to baseline after BP changes in conscious rats occurs rapidly, in 5-10 seconds. The response is significantly slower in states of impaired renal autoregulation, enhancing glomerular pressure exposure. However, in rats with severe renal autoregulation impairment (3/4 nephrectomy plus amlodipine), renal blood flow in conscious animals (but not anesthetized animals) was still restored to baseline, but took longer (15-20 seconds). Consequently, the ability to maintain overall renal blood flow stability is not compromised in conscious rats with impaired renal autoregulation. CONCLUSIONS: These novel findings show the feasibility of renal autoregulation assessment in conscious animals with spontaneous BP fluctuations and indicate that transient increases in glomerular pressure may play a greater role in the pathogenesis of hypertensive glomerulosclerosis than previously thought. These data also show that unidentified mechanosensitive mechanisms independent of known renal autoregulation mechanisms and voltage-gated calcium channels can maintain overall renal blood flow and GFR stability despite severely impaired renal autoregulation.


Assuntos
Pressão Sanguínea/fisiologia , Homeostase/fisiologia , Circulação Renal/fisiologia , Animais , Hipertensão/complicações , Hipertensão/fisiopatologia , Masculino , Ratos , Ratos Sprague-Dawley
9.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445674

RESUMO

Background: DNA methylation is an epigenetic control mechanism that may be altered by environmental exposures. We have previously reported that in utero exposure to the mycotoxin and liver carcinogen aflatoxin B1 from the maternal diet, as measured using biomarkers in the mothers' blood, was associated with differential DNA methylation in white blood cells of 6-month-old infants from The Gambia. Methods: Here we examined aflatoxin B1-associated differential DNA methylation in white blood cells of 24-month-old children from the same population (n = 244), in relation to the child's dietary exposure assessed using aflatoxin albumin biomarkers in blood samples collected at 6, 12 and 18 months of age. HM450 BeadChip arrays were used to assess DNA methylation, with data compared to aflatoxin albumin adduct levels using two approaches; a continuous model comparing aflatoxin adducts measured in samples collected at 18 months to DNA methylation at 24 months, and a categorical time-dose model that took into account aflatoxin adduct levels at 6, 12 and 18 months, for comparison to DNA methylation at 24 months. Results: Geometric mean (95% confidence intervals) for aflatoxin albumin levels were 3.78 (3.29, 4.34) at 6 months, 25.1 (21.67, 29.13) at 12 months and 49.48 (43.34, 56.49) at 18 months of age. A number of differentially methylated CpG positions and regions were associated with aflatoxin exposure, some of which affected gene expression. Pathway analysis highlighted effects on genes involved with with inflammatory, signalling and growth pathways. Conclusions: This study provides further evidence that exposure to aflatoxin in early childhood may impact on DNA methylation.


Assuntos
Aflatoxina B1/efeitos adversos , Metilação de DNA/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Experiências Adversas da Infância , Aflatoxinas/efeitos adversos , Aflatoxinas/análise , Aflatoxinas/sangue , Albuminas/análise , Pré-Escolar , DNA/metabolismo , Metilação de DNA/genética , Epigênese Genética/genética , Epigenômica/métodos , Feminino , Gâmbia/epidemiologia , Humanos , Lactente , Leucócitos/metabolismo , Masculino
10.
Am J Physiol Renal Physiol ; 318(5): F1086-F1099, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32174143

RESUMO

Unilateral ischemia-reperfusion (UIR) injury leads to progressive renal atrophy and tubulointerstitial fibrosis (TIF) and is commonly used to investigate the pathogenesis of the acute kidney injury-chronic kidney disease transition. Although it is well known that contralateral nephrectomy (CNX), even 2 wk post-UIR injury, can improve recovery, the physiological mechanisms and tubular signaling pathways mediating such improved recovery remain poorly defined. Here, we examined the renal hemodynamic and tubular signaling pathways associated with UIR injury and its reversal by CNX. Male Sprague-Dawley rats underwent left UIR or sham UIR and 2 wk later CNX or sham CNX. Blood pressure, left renal blood flow (RBF), and total glomerular filtration rate were assessed in conscious rats for 3 days before and over 2 wk after CNX or sham CNX. In the presence of a contralateral uninjured kidney, left RBF was lower (P < 0.05) from 2 to 4 wk following UIR (3.6 ± 0.3 mL/min) versus sham UIR (9.6 ± 0.3 mL/min). Without CNX, extensive renal atrophy, TIF, and tubule dedifferentiation, but minimal pimonidazole and hypoxia-inducible factor-1α positivity in tubules, were present at 4 wk post-UIR injury. Conversely, CNX led (P < 0.05) to sustained increases in left RBF (6.2 ± 0.6 mL/min) that preceded the increases in glomerular filtration rate. The CNX-induced improvement in renal function was associated with renal hypertrophy, more redifferentiated tubules, less TIF, and robust pimonidazole and hypoxia-inducible factor-1α staining in UIR injured kidneys. Thus, contrary to expectations, indexes of hypoxia are not observed with the extensive TIF at 4 wk post-UIR injury in the absence of CNX but are rather associated with the improved recovery of renal function and structure following CNX.


Assuntos
Injúria Renal Aguda/fisiopatologia , Rim/irrigação sanguínea , Circulação Renal , Insuficiência Renal Crônica/etiologia , Traumatismo por Reperfusão/fisiopatologia , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/metabolismo , Animais , Atrofia , Hipóxia Celular , Modelos Animais de Doenças , Progressão da Doença , Fibrose , Hemodinâmica , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Rim/metabolismo , Rim/patologia , Masculino , Nefrectomia , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/fisiopatologia , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/metabolismo
11.
J Virol ; 93(13)2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30996097

RESUMO

The histone modifier lysine (K)-specific demethylase 2B (KDM2B) plays a role in the differentiation of hematopoietic cells, and its expression appears to be deregulated in certain cancers of hematological and lymphoid origins. We have previously found that the KDM2B gene is differentially methylated in cell lines derived from Epstein-Barr virus (EBV)-associated endemic Burkitt lymphoma (eBL) compared with that in EBV-negative sporadic Burkitt lymphoma-derived cells. However, whether KDM2B plays a role in eBL development has not been previously investigated. Oncogenic viruses have been shown to hijack the host cell epigenome to complete their life cycle and to promote the transformation process by perturbing cell chromatin organization. Here, we investigated whether EBV alters KDM2B levels to enable its life cycle and promote B-cell transformation. We show that infection of B cells with EBV leads to downregulation of KDM2B levels. We also show that LMP1, one of the main EBV transforming proteins, induces increased DNMT1 recruitment to the KDM2B gene and augments its methylation. By altering KDM2B levels and performing chromatin immunoprecipitation in EBV-infected B cells, we show that KDM2B is recruited to the EBV gene promoters and inhibits their expression. Furthermore, forced KDM2B expression in immortalized B cells led to altered mRNA levels of some differentiation-related genes. Our data show that EBV deregulates KDM2B levels through an epigenetic mechanism and provide evidence for a role of KDM2B in regulating virus and host cell gene expression, warranting further investigations to assess the role of KDM2B in the process of EBV-mediated lymphomagenesis.IMPORTANCE In Africa, Epstein-Barr virus infection is associated with endemic Burkitt lymphoma, a pediatric cancer. The molecular events leading to its development are poorly understood compared with those leading to sporadic Burkitt lymphoma. In a previous study, by analyzing the DNA methylation changes in endemic compared with sporadic Burkitt lymphoma cell lines, we identified several differential methylated genomic positions in the proximity of genes with a potential role in cancer, and among them was the KDM2B gene. KDM2B encodes a histone H3 demethylase already shown to be involved in some hematological disorders. However, whether KDM2B plays a role in the development of Epstein-Barr virus-mediated lymphoma has not been investigated before. In this study, we show that Epstein-Barr virus deregulates KDM2B expression and describe the underlying mechanisms. We also reveal a role of the demethylase in controlling viral and B-cell gene expression, thus highlighting a novel interaction between the virus and the cellular epigenome.


Assuntos
Epigênese Genética , Infecções por Vírus Epstein-Barr/metabolismo , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Herpesvirus Humano 4/fisiologia , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Adolescente , Adulto , Linfócitos B/virologia , Linfoma de Burkitt/metabolismo , Linhagem Celular , Criança , Pré-Escolar , Cromatina/metabolismo , Imunoprecipitação da Cromatina , Metilação de DNA , Regulação para Baixo , Infecções por Vírus Epstein-Barr/genética , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
12.
Exp Dermatol ; 29(1): 39-50, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31602702

RESUMO

Tumor cell invasion is one of the key processes during cancer progression, leading to life-threatening metastatic lesions in melanoma. As methylation of cancer-related genes plays a fundamental role during tumorigenesis and may lead to cellular plasticity which promotes invasion, our aim was to identify novel epigenetic markers on selected invasive melanoma cells. Using Illumina BeadChip assays and Affymetrix Human Gene 1.0 microarrays, we explored the DNA methylation landscape of selected invasive melanoma cells and examined the impact of DNA methylation on gene expression patterns. Our data revealed predominantly hypermethylated genes in the invasive cells affecting the neural crest differentiation pathway and regulation of the actin cytoskeleton. Integrative analysis of the methylation and gene expression profiles resulted in a cohort of hypermethylated genes (IL12RB2, LYPD6B, CHL1, SLC9A3, BAALC, FAM213A, SORCS1, GPR158, FBN1 and ADORA2B) with decreased expression. On the other hand, hypermethylation in the gene body of the EGFR and RBP4 genes was positively correlated with overexpression of the genes. We identified several methylation changes that can have role during melanoma progression, including hypermethylation of the promoter regions of the ARHGAP22 and NAV2 genes that are commonly altered in locally invasive primary melanomas as well as during metastasis. Interestingly, the down-regulation of the methylcytosine dioxygenase TET2 gene, which regulates DNA methylation, was associated with hypermethylated promoter region of the gene. This can probably lead to the observed global hypermethylation pattern of invasive cells and might be one of the key changes during the development of malignant melanoma cells.


Assuntos
Metilação de DNA , Melanoma/genética , Melanoma/secundário , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Citoesqueleto de Actina/genética , Citoesqueleto de Actina/metabolismo , Diferenciação Celular/genética , Linhagem Celular Tumoral , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Dioxigenases , Epigênese Genética , Proteínas Ativadoras de GTPase/genética , Expressão Gênica/genética , Perfilação da Expressão Gênica , Humanos , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Fenótipo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas/genética
13.
Int J Cancer ; 142(5): 874-882, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28836271

RESUMO

The interaction between the (epi)genetic makeup of an individual and his/her environmental exposure record (exposome) is accepted as a determinant factor for a significant proportion of human malignancies. Recent evidence has highlighted the key role of epigenetic mechanisms in mediating gene-environment interactions and translating exposures into tumorigenesis. There is also growing evidence that epigenetic changes may be risk factor-specific ("fingerprints") that should prove instrumental in the discovery of new biomarkers in cancer. Here, we review the state of the science of epigenetics associated with environmental stimuli and cancer risk, highlighting key developments in the field. Critical knowledge gaps and research needs are discussed and advances in epigenomics that may help in understanding the functional relevance of epigenetic alterations. Key elements required for causality inferences linking epigenetic changes to exposure and cancer are discussed and how these alterations can be incorporated in carcinogen evaluation and in understanding mechanisms underlying epigenome deregulation by the environment.


Assuntos
Exposição Ambiental/efeitos adversos , Epigênese Genética , Epigenômica , Interação Gene-Ambiente , Neoplasias/etiologia , Animais , Metilação de DNA , Humanos , Neoplasias/patologia , Fatores de Risco
14.
Sensors (Basel) ; 18(3)2018 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-29495338

RESUMO

Proximity sensors are broadly used in mobile robots for obstacle detection. The traditional calibration process of this kind of sensor could be a time-consuming task because it is usually done by identification in a manual and repetitive way. The resulting obstacles detection models are usually nonlinear functions that can be different for each proximity sensor attached to the robot. In addition, the model is highly dependent on the type of sensor (e.g., ultrasonic or infrared), on changes in light intensity, and on the properties of the obstacle such as shape, colour, and surface texture, among others. That is why in some situations it could be useful to gather all the measurements provided by different kinds of sensor in order to build a unique model that estimates the distances to the obstacles around the robot. This paper presents a novel approach to get an obstacles detection model based on the fusion of sensors data and automatic calibration by using artificial neural networks.

15.
Int J Cancer ; 141(10): 2014-2029, 2017 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-28722770

RESUMO

Previous studies have revealed a robust association between exposure to asbestos and human lung cancer. Accumulating evidence has highlighted the role of epigenome deregulation in the mechanism of carcinogen-induced malignancies. We examined the impact of asbestos on DNA methylation. Our genome-wide studies (using Illumina HumanMethylation450K BeadChip) of lung cancer tissue and paired normal lung from 28 asbestos-exposed or non-exposed patients, mostly smokers, revealed distinctive DNA methylation changes. We identified a number of differentially methylated regions (DMR) and differentially variable, differentially methylated CpGs (DVMC), with individual CpGs further validated by pyrosequencing in an independent series of 91 non-small cell lung cancer and paired normal lung. We discovered and validated BEND4, ZSCAN31 and GPR135 as significantly hypermethylated in lung cancer. DMRs in genes such as RARB (FDR 1.1 × 10-19 , mean change in beta [Δ] -0.09), GPR135 (FDR 1.87 × 10-8 , mean Δ -0.09) and TPO (FDR 8.58 × 10-5 , mean Δ -0.11), and DVMCs in NPTN, NRG2, GLT25D2 and TRPC3 (all with p <0.05, t-test) were significantly associated with asbestos exposure status in exposed versus non-exposed lung tumors. Hypomethylation was characteristic to DVMCs in lung cancer tissue from asbestos-exposed subjects. When DVMCs related to asbestos or smoking were analyzed, 96% of the elements were unique to either of the exposures, consistent with the concept that the methylation changes in tumors may be specific for risk factors. In conclusion, we identified novel DNA methylation changes associated with lung tumors and asbestos exposure, suggesting that changes may be present in causal pathway from asbestos exposure to lung cancer.


Assuntos
Amianto/efeitos adversos , Biomarcadores Tumorais/genética , Metilação de DNA , Estudo de Associação Genômica Ampla , Neoplasias Pulmonares/etiologia , Estudos de Casos e Controles , Ilhas de CpG , Epigênese Genética , Seguimentos , Humanos , Neoplasias Pulmonares/patologia , Masculino , Prognóstico
16.
J Strength Cond Res ; 31(2): 313-322, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28129277

RESUMO

Signorile, JF, Rendos, NK, Heredia Vargas, HH, Alipio, TC, Regis, RC, Eltoukhy, MM, Nargund, RS, and Romero, MA. Differences in muscle activation and kinematics between cable-based and selectorized weight training. J Strength Cond Res 31(2): 313-322, 2017-Cable resistance training machines are showing resurgent popularity and allow greater number of degrees of freedom than typical selectorized equipment. Given that specific kinetic chains are used during distinct activities of daily living (ADL), cable machines may provide more effective interventions for some ADL, whereas others may be best addressed using selectorized equipment. This study examined differences in activity levels (root mean square of the EMG [rmsEMG]) of 6 major muscles (pectoralis major, PM; anterior deltoid, AD; biceps brachii, BB; rectus abdominis, RA; external obliques, EO; and triceps brachii, TB) and kinematics of multiple joints between a cable and standard selectorized machines during the biceps curl, the chest press, and the overhead press performed at 1.5 seconds per contractile stage. Fifteen individuals (9 men, 6 women; mean age ± SD, 24.33 ± 4.88 years) participated. Machine order was randomized. Significant differences favoring cable training were seen for PM and AD during biceps curl; BB, AD, and EO for chest press; and BB and EO during overhead press (p ≤ 0.05). Greater starting and ending angles were seen for the elbow and shoulder joints during selectorized biceps curl, whereas hip and knee starting and ending angles were greater for cable machine during chest and overhead presses (p < 0.0001). Greater range of motion (ROM) favoring the cable machine was also evident (p < 0.0001). These results indicate that utilization patterns of selected muscles, joint angles, and ROMs can be varied because of machine application even when similar exercises are used, and therefore, these machines can be used selectively in training programs requiring specific motor or biomechanical patterns.


Assuntos
Músculo Esquelético/fisiologia , Treinamento Resistido/métodos , Atividades Cotidianas , Adolescente , Adulto , Braço , Fenômenos Biomecânicos , Eletromiografia , Feminino , Humanos , Masculino , Contração Muscular/fisiologia , Força Muscular/fisiologia , Amplitude de Movimento Articular/fisiologia , Ombro , Tórax , Levantamento de Peso/fisiologia , Adulto Jovem
17.
J Transl Med ; 14: 13, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26762586

RESUMO

BACKGROUND: Naturally occurring polyphenolic compounds from fruits, particularly from blueberries, have been reported to be significantly involved in cancer chemoprevention and chemotherapy. Biotransformation of blueberry juice by Serratia vaccinii increases its polyphenolic content and endows it with anti-inflammatory properties. METHODS: This study evaluated the effect of a polyphenol-enriched blueberry preparation (PEBP) and its non-fermented counterpart (NBJ), on mammary cancer stem cell (CSC) development in in vitro, in vivo and ex vivo settings. Effects of PEBP on cell proliferation, mobility, invasion, and mammosphere formation were measured in vitro in three cell lines: murine 4T1 and human MCF7 and MDA-MB-231. Ex vivo mammosphere formation, tumor growth and metastasis observations were carried out in a BALB/c mouse model. RESULTS: Our research revealed that PEBP influence cellular signaling cascades of breast CSCs, regulating the activity of transcription factors and, consequently, inhibiting tumor growth in vivo by decreasing metastasis and controlling PI3K/AKT, MAPK/ERK, and STAT3 pathways, central nodes in CSC inflammatory signaling. PEBP significantly inhibited cell proliferation of 4T1, MCF-7 and MDA-MB-231. In all cell lines, PEBP reduced mammosphere formation, cell mobility and cell migration. In vivo, PEBP significantly reduced tumor development, inhibited the formation of ex vivo mammospheres, and significantly reduced lung metastasis. CONCLUSIONS: This study showed that polyphenol enrichment of a blueberry preparation by fermentation increases its chemopreventive potential by protecting mice against tumor development, inhibiting the formation of cancer stem cells and reducing lung metastasis. Thus, PEBP may represent a novel complementary alternative medicine therapy and a source for novel therapeutic agents against breast cancer.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Quimioprevenção , Inflamação/patologia , Células-Tronco Neoplásicas/patologia , Polifenóis/uso terapêutico , Animais , Mirtilos Azuis (Planta)/química , Neoplasias da Mama/complicações , Neoplasias da Mama/enzimologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Fermentação , Humanos , Inflamação/complicações , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Invasividade Neoplásica , Metástase Neoplásica , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/enzimologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Polifenóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/patologia
18.
J Strength Cond Res ; 30(7): 2001-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26694502

RESUMO

Rendos, NK, Heredia Vargas, HM, Alipio, TC, Regis, RC, Romero, MA, and Signorile, JF. Differences in muscle activity during cable resistance training are influenced by variations in handle types. J Strength Cond Res 30(7): 2001-2009, 2016-There has been a recent resurgence in the use of cable machines for resistance training allowing movements that more effectively simulate daily activities and sports-specific movements. By necessity, these devices require a machine/human interface through some type of handle. Considerable data from material handling, industrial engineering, and exercise training studies indicate that handle qualities, especially size and shape, can significantly influence force production and muscular activity, particularly of the forearm muscles, which affect the critical link in activities that require object manipulation. The purpose for this study was to examine the influence of three different handle conditions: standard handle (StandH), ball handle with the cable between the index and middle fingers (BallIM), and ball handle with the cable between the middle and ring fingers (BallMR), on activity levels (rmsEMG) of the triceps brachii lateral and long heads (TriHLat, TriHLong), brachioradialis (BR), flexor carpi radialis (FCR), extensor carpi ulnaris, and extensor digitorum (ED) during eight repetitions of standing triceps pushdown performed from 90° to 0° elbow flexion at 1.5 s per contractile stage. Handle order was randomized. No significant differences were seen for triceps or BR rmsEMG across handle conditions; however, relative patterns of activation did vary for the forearm muscles by handle condition, with more coordinated activation levels for the FCR and ED during the ball handle conditions. In addition, the rmsEMG for the ED was significantly higher during the BallIM than any other condition and during the BallMR than the StandH. These results indicate that the use of ball handles with the cable passing between different fingers can vary the utilization patterns of selected forearm muscles and may therefore be advantageous for coaches, personal trainers, therapists, or bodybuilders for targeted training or rehabilitation of these muscles.


Assuntos
Braço/fisiologia , Antebraço/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido/instrumentação , Adulto , Eletromiografia , Feminino , Humanos , Masculino , Treinamento Resistido/métodos
19.
Carcinogenesis ; 36(11): 1440-51, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26424750

RESUMO

Although Epstein-Barr virus (EBV) infection is widely distributed, certain EBV-driven malignancies are geographically restricted. EBV-associated Burkitt's lymphoma (eBL) is endemic in children living in sub-Saharan Africa. This population is heavily exposed to food contaminated with the mycotoxin aflatoxin B1 (AFB1). Here, we show that exposure to AFB1 in in vitro and in vivo models induces activation of the EBV lytic cycle and increases EBV load, two events that are associated with an increased risk of eBL in vivo. AFB1 treatment leads to the alteration of cellular gene expression, with consequent activations of signaling pathways, e.g. PI3K, that in turn mediate reactivation of the EBV life cycle. Finally, we show that AFB1 triggers EBV-driven cellular transformation both in primary human B cells and in a humanized animal model. In summary, our data provide evidence for a role of AFB1 as a cofactor in EBV-mediated carcinogenesis.


Assuntos
Aflatoxina B1/toxicidade , Linfócitos B/virologia , Linfoma de Burkitt/virologia , Exposição Ambiental , Infecções por Vírus Epstein-Barr/patologia , Herpesvirus Humano 4/efeitos dos fármacos , Animais , Linfócitos B/patologia , Linfoma de Burkitt/induzido quimicamente , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Transformação Celular Neoplásica/efeitos dos fármacos , Células Cultivadas , Feminino , Herpesvirus Humano 4/fisiologia , Humanos , Masculino , Camundongos Endogâmicos NOD , Camundongos SCID , Transdução de Sinais , Ativação Viral , Replicação Viral/efeitos dos fármacos
20.
Am J Physiol Renal Physiol ; 309(9): F791-9, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26109088

RESUMO

The diet-induced obesity (DIO) model is frequently used to examine the pathogenesis of obesity-related pathologies; however, only minimal glomerulosclerosis (GS) has been reported after 3 mo. We investigated if GS develops over longer periods of DIO and examined the potential role of hemodynamic mechanisms in its pathogenesis. Eight-week-old male obesity-prone (OP) and obesity-resistant (OR) rats (Charles River) were administered a moderately high-fat diet for 5 mo. Radiotelemetrically measured blood pressure, proteinuria, and GS were assessed. OP (n=10) rats developed modest hypertension (142±3 vs. 128±2 mmHg, P<0.05) and substantial levels of proteinuria (63±12 vs. 12±1 mg/day, P<0.05) and GS (7.7±1.4% vs. 0.4±0.2%) compared with OR rats (n=8). Potential hemodynamic mechanisms of renal injury were assessed in additional groups of OP and OR rats fed a moderately high-fat diet for 3 mo. Kidney weight (4.3±0.2 vs. 4.3±0.1 g), glomerular filtration rate (3.3±0.3 vs. 3.1±0.1 ml/min), and glomerular volume (1.9±0.1 vs. 2.0±0.1 µm3×10(-6)) were similar between OP (n=6) and OR (n=9) rats. Renal blood flow autoregulation was preserved in both OP (n=7) and OR (n=7) rats. In contrast, Nω-nitro-L-arginine methyl ester (L-NAME) administration in conscious, chronically instrumented OP (n=11) rats resulted in 15% and 39% increases in blood pressure and renal vascular resistance, respectively, and a 16% decrease in renal blood flow. Minimal effects of L-NAME were seen in OR (n=9) rats. In summary, DIO-associated GS is preceded by an increased hemodynamic sensitivity to L-NAME but not renal hypertrophy or hyperfiltration.


Assuntos
Dieta Hiperlipídica , Taxa de Filtração Glomerular/efeitos dos fármacos , Glomerulonefrite/etiologia , Hemodinâmica/efeitos dos fármacos , Glomérulos Renais/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico/metabolismo , Obesidade/etiologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Glomerulonefrite/metabolismo , Glomerulonefrite/patologia , Glomerulonefrite/fisiopatologia , Hipertensão/etiologia , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Hipertrofia , Glomérulos Renais/irrigação sanguínea , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Glomérulos Renais/fisiopatologia , Masculino , Óxido Nítrico Sintase/metabolismo , Obesidade/metabolismo , Proteinúria/etiologia , Proteinúria/metabolismo , Proteinúria/fisiopatologia , Ratos Sprague-Dawley , Circulação Renal/efeitos dos fármacos , Fatores de Tempo , Resistência Vascular/efeitos dos fármacos
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