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1.
J Nanobiotechnology ; 22(1): 27, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38212782

RESUMO

BACKGROUND: The pro-inflammatory ATP-gated P2X7 receptor is widely expressed by immune and non-immune cells. Nanobodies targeting P2X7, with potentiating or antagonistic effects, have been developed. Adeno-associated virus (AAV)-mediated gene transfer represents an efficient approach to achieve long-term in vivo expression of selected nanobody-based biologics. This approach (AAVnano) was used to validate the relevance of P2X7 as a target in dextran sodium sulfate (DSS)-induced colitis in mice. RESULTS: Mice received an intramuscular injection of AAV vectors coding for potentiating (14D5-dimHLE) or antagonistic (13A7-Fc) nanobody-based biologics targeting P2X7. Long-term modulation of P2X7 activity was evaluated ex vivo from blood samples. Colitis was induced with DSS in mice injected with AAV vectors coding for nanobody-based biologics. Severity of colitis, colon histopathology and expression of chemokines and cytokines were determined to evaluate the impact of P2X7 modulation. A single injection of an AAV vector coding for 13A7-Fc or 14D5-dimHLE efficiently modulated P2X7 function in vivo from day 15 up to day 120 post-injection in a dose-dependent manner. An AAV vector coding for 13A7-Fc significantly ameliorated DSS-induced colitis and significantly reduced immune cell infiltration and expression of chemokines and proinflammatory cytokines in colonic tissue. CONCLUSIONS: We have demonstrated the validity of AAVnano methodology to modulate P2X7 functions in vivo. Applying this methodological approach to a DSS-induced colitis model, we have shown that P2X7 blockade reduces inflammation and disease severity. Hence, this study confirms the importance of P2X7 as a pharmacological target and suggests the use of nanobody-based biologics as potential therapeutics in inflammatory bowel disease.


Assuntos
Produtos Biológicos , Colite , Camundongos , Animais , Colo/metabolismo , Colite/induzido quimicamente , Colite/tratamento farmacológico , Citocinas/metabolismo , Quimiocinas/metabolismo , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças
2.
Biol Proced Online ; 25(1): 1, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36600200

RESUMO

BACKGROUND: P2RX7 is a purinergic receptor with pleiotropic activities that is activated by high levels of extracellular ATP that are found in inflamed tissues. P2RX7 has immunomodulatory and anti-tumor proprieties and is therefore a therapeutic target for various diseases. Several compounds are developed to either inhibit or enhance its activation. However, studying their effect on P2RX7's activities is limited to in vitro and ex vivo studies that require the use of unphysiological media that could affect its activation. Up to now, the only way to assess the activity of P2RX7 modulators on the receptor in vivo was in an indirect manner. RESULTS: We successfully developed a protocol allowing the detection of P2RX7 activation in vivo in lungs of mice, by taking advantage of its unique macropore formation ability. The protocol is based on intranasal delivery of TO-PRO™-3, a non-permeant DNA intercalating dye, and fluorescence measurement by flow cytometry. We show that ATP enhances TO-PRO™-3 fluorescence mainly in lung immune cells of mice in a P2RX7-dependant manner. CONCLUSIONS: The described approach has allowed the successful analysis of P2RX7 activity directly in the lungs of WT and transgenic C57BL6 mice. The provided detailed guidelines and recommendations will support the use of this protocol to study the potency of pharmacologic or biologic compounds targeting P2RX7.

3.
Int J Mol Sci ; 24(11)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37298187

RESUMO

Cancer is the leading cause of death worldwide despite the variety of treatments that are currently used. This is due to an innate or acquired resistance to therapy that encourages the discovery of novel therapeutic strategies to overcome the resistance. This review will focus on the role of the purinergic receptor P2RX7 in the control of tumor growth, through its ability to modulate antitumor immunity by releasing IL-18. In particular, we describe how the ATP-induced receptor activities (cationic exchange, large pore opening and NLRP3 inflammasome activation) modulate immune cell functions. Furthermore, we recapitulate our current knowledge of the production of IL-18 downstream of P2RX7 activation and how IL-18 controls the fate of tumor growth. Finally, the potential of targeting the P2RX7/IL-18 pathway in combination with classical immunotherapies to fight cancer is discussed.


Assuntos
Interleucina-18 , Receptores Purinérgicos P2X7 , Receptores Purinérgicos P2X7/genética
4.
Purinergic Signal ; 17(4): 619-631, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34347213

RESUMO

Despite new biological insights and recent therapeutic advances, many tumors remain at baseline during treatments. Therefore, there is an urgent need to find new therapeutic strategies to improve the care of patients with solid tumors. P2RX7 receptor (P2XR7), an ATP-gated ion channel characterized by its ability to form large pore within the cell membrane, is described by most of the investigators as a "chef d'orchestre" of the antitumor immune response. The purpose of this review is to detail the recent information concerning different cellular mechanisms linking P2RX7 to hallmarks of cancer and to discuss different progresses in elucidating how activation of the ATP/P2RX7/NLRP3/IL-18 pathway is a very promising approach to fight cancer progression by increasing antitumor immune responses.


Assuntos
Trifosfato de Adenosina/metabolismo , Imunoterapia , Neoplasias/terapia , Receptores Purinérgicos P2X7/metabolismo , Transdução de Sinais/fisiologia , Animais , Proliferação de Células/fisiologia , Humanos , Neoplasias/metabolismo
5.
Gut ; 64(3): 428-37, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24898815

RESUMO

OBJECTIVE: Adherent-invasive Escherichia coli (AIEC) are abnormally predominant on Crohn's disease (CD) ileal mucosa. AIEC strains adhere to enterocytes via interaction between type 1 pili and CEACAM6 receptors abnormally expressed on CD ileal mucosa, leading to gut inflammation. We analysed whether epigenetic mechanisms are involved in the upregulation of CEACAM6 expression in intestinal epithelial cells (IECs). DESIGN: Methylation of CEACAM6 promoter was analysed using bisulfite sequencing and site-specific methylation by SnapShot. pCpGfree reporter system was used to analyse CEACAM6 promoter activity. Transgenic mice expressing human CEACAM6 fed either standard food or a low-methyl diet (LMD) were orally challenged with 10(9) AIEC LF82. After 3 days, gut-associated AIEC and proinflammatory cytokines were quantified. RESULTS: Analysis of CEACAM6 gene promoter revealed potentially methylated dinucleotide CpGs within HIF-1-responsive elements (HREs). Methylation levels of CpG within CEACAM6 promoter were inversely correlated with CEACAM6 expression in IEC expressing various levels of CEACAM6. We show the critical role of HRE methylation and transcription factor HIF-1 in the regulation of CEACAM6 gene in IEC. This was confirmed in transgenic mice expressing human CEACAM6 fed a LMD. LMD-dependent HRE demethylation led to abnormal gut expression of CEACAM6, favouring AIEC colonisation and subsequent inflammation. CONCLUSIONS: HRE hypomethylation in CEACAM6 promoter correlates with high expression in IEC. Our findings suggest that abnormal DNA methylation leading to CEACAM6 increased expression and AIEC-mediated gut inflammation can be related to changes in nutritional habits, such as low intake in methyl donor molecules, leading to abnormal epigenetic marks in mouse model mimicking CD susceptibility.


Assuntos
Antígenos CD/metabolismo , Moléculas de Adesão Celular/metabolismo , Doença de Crohn/etiologia , Dieta/efeitos adversos , Infecções por Escherichia coli/complicações , Proteínas Ligadas por GPI/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Animais , Antígenos CD/fisiologia , Células CACO-2 , Moléculas de Adesão Celular/fisiologia , Doença de Crohn/metabolismo , Doença de Crohn/microbiologia , Metilação de DNA , Epigênese Genética , Infecções por Escherichia coli/metabolismo , Proteínas Ligadas por GPI/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Camundongos , Camundongos Transgênicos
6.
Elife ; 122024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38300690

RESUMO

Idiopathic pulmonary fibrosis (IPF) is an aggressive interstitial lung disease associated with progressive and irreversible deterioration of respiratory functions that lacks curative therapies. Despite IPF being associated with a dysregulated immune response, current antifibrotics aim only at limiting fibroproliferation. Transcriptomic analyses show that the P2RX7/IL18/IFNG axis is downregulated in IPF patients and that P2RX7 has immunoregulatory functions. Using our positive modulator of P2RX7, we show that activation of the P2RX7/IL-18 axis in immune cells limits lung fibrosis progression in a mouse model by favoring an antifibrotic immune environment, with notably an enhanced IL-18-dependent IFN-γ production by lung T cells leading to a decreased production of IL-17 and TGFß. Overall, we show the ability of the immune system to limit lung fibrosis progression by targeting the immunomodulator P2RX7. Hence, treatment with a small activator of P2RX7 may represent a promising strategy to help patients with lung fibrosis.


Assuntos
Fibrose Pulmonar , Animais , Camundongos , Humanos , Interleucina-18 , Adjuvantes Imunológicos , Agressão , Modelos Animais de Doenças , Receptores Purinérgicos P2X7/genética
7.
Cancers (Basel) ; 16(12)2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38927931

RESUMO

The aim of this study was to assess the potential value of circulating active and inactive IL-18 levels in distinguishing pseudo and true tumor progression among NSCLC patients receiving immune checkpoint inhibitor treatments (ICIs). METHODS: This ancillary study includes 195 patients with metastatic non-small-cell lung cancer (NSCLC) treated with ICI in monotherapy, either pembrolizumab or nivolumab. Plasmatic levels of IL-18-related compounds, comprising the inhibitor IL-18 binding protein (IL-18BP), the inactive IL-18 (corresponding to IL-18/IL-18BP complex), and the active free IL-18, were assayed by ELISA. Objective tumoral response was analyzed by 18FDG PET-CT at baseline, 7 weeks, and 3 months post treatment induction, using PERCIST criteria. RESULTS: Plasmatic IL-18BP and total IL-18 levels are increased at baseline in NSCLC patients compared with healthy controls, whereas IL-18/IL-18BP complexes are decreased, and free IL-18 levels remain unchanged. Neither of the IL-18-related compounds allowed to discriminate ICI responding to nonresponding patients. However, inactive IL-18 levels allowed to discriminate patients with a first tumor progression, assessed after 7 weeks of treatment, with worse overall survival. In addition, we showed that neutrophil concentration is also a predictive indicator of patients' outcomes with OS (HR = 2.6, p = 0.0001) and PFS (HR = 2.2, p = 0.001). CONCLUSIONS: Plasmatic levels of inactive IL-18, combined with circulating neutrophil concentrations, can effectively distinguish ICI nonresponding patients with better overall survival (OS), potentially guiding rapid decisions for therapeutic intensification.

8.
Cancers (Basel) ; 16(19)2024 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-39409962

RESUMO

The past several years have provided a more profound understanding of the role of microbial species in the lung. The respiratory tract is a delicate ecosystem of bacteria, fungi, parasites, and viruses. Detecting microbial DNA, pathogen-associated molecular patterns (PAMPs), and metabolites in sputum is poised to revolutionize the early diagnosis of lung cancer. The longitudinal monitoring of the lung microbiome holds the potential to predict treatment response and side effects, enabling more personalized and effective treatment options. However, most studies into the lung microbiota have been observational and have not adequately considered the impact of dietary intake and air pollutants. This gap makes it challenging to establish a direct causal relationship between environmental exposure, changes in the composition of the microbiota, lung carcinogenesis, and tumor progression. A holistic understanding of the lung microbiota that considers both diet and air pollutants may pave the way to improved prevention and management strategies for lung cancer.

9.
Cancers (Basel) ; 14(8)2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35454832

RESUMO

Lung cancer is the most common cancer worldwide. Despite recent therapeutic advances, including targeted therapies and immune checkpoint inhibitors, the disease progresses in almost all advanced lung cancers and in up to 50% of early-stage cancers. The purpose of this review is to discuss whether purinergic checkpoints (CD39, CD73, P2RX7, and ADORs), which shape the immune response in the tumor microenvironment, may represent novel therapeutic targets to combat progression of non-small cell lung cancer by enhancing the antitumor immune response.

10.
Cell Microbiol ; 12(5): 640-53, 2010 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-20039880

RESUMO

Microbes regulate a large panel of intracellular signalling events that can promote inflammation and/or enhance tumour progression. Indeed, it has been shown that infection of human intestinal cells with the Afa/Dr diffusely adhering E. coli C1845 strain induces expression of pro-angiogenic and pro-inflammatory genes. Here, we demonstrate that exposure of cryptic-like intestinal epithelial cells to C1845 bacteria induces HIF-1alpha protein levels. This effect depends on the binding of F1845 adhesin to the membrane-associated DAF receptor that initiates signalling cascades promoting translational mechanisms. Indeed, inhibition of MAPK and PI-3K decreases HIF-1alpha protein levels and blocks C1845-induced phosphorylation of the ribosomal S6 protein. Using RNA interference we show that bacteria-induced HIF-1alpha regulates the expression of IL-8, VEGF and Twist1, thereby pointing to a role for HIF-1 in angiogenesis and inflammation. In addition, infection correlates with a loss of E-cadherin and cytokeratin 18 and a rise in fibronectin, suggesting that bacteria may induce an epithelial to mesenchymal transition-like phenotype. Since HIF-1alpha silencing results in reversion of bacteria-induced EMT markers, we speculate that HIF-1alpha plays a key role linking bacterial infection to angiogenesis, inflammation and some aspects of cancer initiation.


Assuntos
Células Epiteliais/microbiologia , Escherichia coli/imunologia , Regulação da Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Interleucina-8/biossíntese , Fator A de Crescimento do Endotélio Vascular/biossíntese , Adesinas Bacterianas/metabolismo , Aderência Bacteriana , Caderinas/metabolismo , Linhagem Celular , Inativação Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Queratina-18/metabolismo , Proteínas Nucleares/biossíntese , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Proteína 1 Relacionada a Twist/biossíntese
11.
Nat Commun ; 12(1): 653, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33510147

RESUMO

Only a subpopulation of non-small cell lung cancer (NSCLC) patients responds to immunotherapies, highlighting the urgent need to develop therapeutic strategies to improve patient outcome. We develop a chemical positive modulator (HEI3090) of the purinergic P2RX7 receptor that potentiates αPD-1 treatment to effectively control the growth of lung tumors in transplantable and oncogene-induced mouse models and triggers long lasting antitumor immune responses. Mechanistically, the molecule stimulates dendritic P2RX7-expressing cells to generate IL-18 which leads to the production of IFN-γ by Natural Killer and CD4+ T cells within tumors. Combined with immune checkpoint inhibitor, the molecule induces a complete tumor regression in 80% of LLC tumor-bearing mice. Cured mice are also protected against tumor re-challenge due to a CD8-dependent protective response. Hence, combination treatment of small-molecule P2RX7 activator followed by immune checkpoint inhibitor represents a strategy that may be active against NSCLC.


Assuntos
Carcinoma Pulmonar de Lewis/terapia , Inibidores de Checkpoint Imunológico/farmacologia , Imunoterapia/métodos , Receptores Purinérgicos P2X7/imunologia , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/imunologia , Linhagem Celular Tumoral , Terapia Combinada , Feminino , Células HEK293 , Humanos , Inibidores de Checkpoint Imunológico/imunologia , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-18/genética , Interleucina-18/imunologia , Interleucina-18/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Estrutura Molecular , Receptores Purinérgicos P2X7/genética , Receptores Purinérgicos P2X7/metabolismo , Bibliotecas de Moléculas Pequenas/química , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/imunologia
12.
Am J Physiol Gastrointest Liver Physiol ; 299(1): G32-42, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20185692

RESUMO

Inflammatory bowel diseases (IBD) are characterized during their active phase by polymorphonuclear leukocyte (PMNL) transepithelial migration. The efflux of PMNL into the mucosa is associated with the production of proinflammatory cytokines and the release of ATP from damaged and necrotic cells. The expression and function of purinergic P2X(7) receptor (P2X(7)R) in intestinal epithelial cells (IEC) and its potential role in the "cross talk" between IEC and PMNL have not been explored. The aims of the present study were 1) to examine P2X(7)R expression in IEC (T84 cells) and in human intestinal biopsies; 2) to detect any changes in P2X(7)R expression in T84 cells during PMNL transepithelial migration, and during the active and quiescent phases of IBD; and 3) to test whether P2X(7)R stimulation in T84 monolayers can induce caspase-1 activation and IL-1beta release by IEC. We found that a functional ATP-sensitive P2X(7)R is constitutively expressed at the apical surface of IEC T84 cells. PMNL transmigration regulates dynamically P2X(7)R expression and alters its distribution from the apical to basolateral surface of IEC during the early phase of PMNL transepithelial migration in vitro. P2X(7)R expression was weak in intestinal biopsies obtained during the active phase of IBD. We show that activation of epithelial P2X(7)R is mandatory for PMNL-induced caspase-1 activation and IL-1beta release by IEC. Overall, these changes in P2X(7)R function may serve to tailor the intensity of the inflammatory response and to prevent IL-1beta overproduction and inflammatory disease.


Assuntos
Trifosfato de Adenosina/metabolismo , Quimiotaxia de Leucócito , Células Epiteliais/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Receptores Purinérgicos P2/metabolismo , Biópsia , Caspase 1/metabolismo , Linhagem Celular Tumoral , Ativação Enzimática , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Células Epiteliais/patologia , Humanos , Imuno-Histoquímica , Mediadores da Inflamação/metabolismo , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Interleucina-1beta/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Neutrófilos/patologia , Interferência de RNA , RNA Mensageiro/metabolismo , Receptores Purinérgicos P2/efeitos dos fármacos , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2X7 , Índice de Gravidade de Doença , Fatores de Tempo , Análise Serial de Tecidos
13.
Theranostics ; 10(24): 10849-10860, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042257

RESUMO

Rationale: The characterization of new theranostic biomarkers is crucial to improving the clinical outcome of patients with advanced lung cancer. Here, we aimed at characterizing the P2RX7 receptor, a positive modulator of the anti-tumor immune response, in patients with lung adenocarcinoma. Methods: The expression of P2RX7 and its splice variants was analyzed by RT-qPCR using areas of tumor and non-tumor lung adenocarcinoma (LUAD) tissues on both immune and non-immune cells. The biological activity of P2RX7 was studied by flow cytometry using fluorescent dyes. Bi-molecular fluorescence complementation and confocal microscopy were used to assess the oligomerization of P2RX7. Tumor immune infiltrates were characterized by immunohistochemistry. Results: Fifty-three patients with LUAD were evaluated. P2RX7A, and 3 alternative splice variants were expressed in LUAD tissues and expression was down regulated in tumor versus adjacent non-tumor tissues. The protein retained biological activity only in immune cells. The P2RX7B splice variant was differentially upregulated in immune cells (P < 0.001) of the tumor and strong evidence of oligomerization of P2RX7A and B was observed in the HEK expression model, which correlated with a default in the activity of P2RX7. Finally, LUAD patients with a high level of P2RX7B had non-inflamed tumors (P = 0.001). Conclusion: Our findings identified P2RX7B as a new theranostic tool to restore functional P2RX7 activity and open alternative therapeutic opportunities to improve LUAD patient outcome.


Assuntos
Adenocarcinoma de Pulmão/genética , Biomarcadores Tumorais/genética , Neoplasias Pulmonares/genética , Recidiva Local de Neoplasia/etnologia , Receptores Purinérgicos P2X7/genética , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Processamento Alternativo , Biomarcadores Tumorais/metabolismo , Quimioterapia Adjuvante , Feminino , Regulação Neoplásica da Expressão Gênica/imunologia , Células HEK293 , Humanos , Pulmão/imunologia , Pulmão/patologia , Pulmão/cirurgia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/imunologia , Pneumonectomia , Estudos Prospectivos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Multimerização Proteica/genética , Multimerização Proteica/imunologia , Receptores Purinérgicos P2X7/metabolismo , Estudos Retrospectivos , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Regulação para Cima
14.
J Med Chem ; 63(5): 2074-2094, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-31525963

RESUMO

This report deals with the design, the synthesis, and the pharmacological evaluation of pyroglutamide-based P2X7 antagonists. A dozen were shown to possess improved properties, among which inhibition of YO-PRO-1/TO-PRO-3 uptake and IL1ß release upon BzATP activation of the receptor and dampening signs of DSS-induced colitis on mice, in comparison with reference antagonist GSK1370319A. Docking study and biological evaluation of synthesized compounds has highlighted new SAR, and low toxicity profiles of pyroglutamides herein described are clues for the finding of a usable h-P2X7 antagonist drug. Such a drug would raise the hope for a cure to many P2X7-dependent pathologies, including inflammatory, neurological, and immune diseases.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Sulfato de Dextrana/toxicidade , Feminino , Células HEK293 , Humanos , Doenças Inflamatórias Intestinais/induzido quimicamente , Camundongos , Camundongos Endogâmicos C57BL
15.
Biomed J ; 42(3): 141-154, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31466708

RESUMO

Alternative splicing (AS) tremendously increases the use of genetic information by generating protein isoforms that differ in protein-protein interactions, catalytic activity and/or subcellular localization. This review is not dedicated to AS in general, but rather we focus our attention on AS of P2RX7 pre-mRNA. Whereas P2RX7 mRNA is expressed by virtually all eukaryotic mammalian cells, the expression of this channel receptor is restrained to certain cells. When expressed at the cell membrane, P2RX7 controls downstream events including release of inflammatory molecules, phagocytosis, cell proliferation and death and metabolic events. Therefore, P2RX7 is an important actor of health and diseases. In this review, we summarize the general mechanisms leading to AS. Further, we recapitulate our current knowledge concerning the functional regions in P2RX7, identified at the genetic or exonic levels, and how AS may affect the expression of these regions. Finally, the potential of P2RX7 splice variants to control the fate of cancer cells is discussed.


Assuntos
Processamento Alternativo/genética , RNA Mensageiro/genética , Receptores Purinérgicos P2X7/genética , Trifosfato de Adenosina/metabolismo , Animais , Proliferação de Células/fisiologia , Humanos , Receptores Purinérgicos P2X7/metabolismo
16.
Theranostics ; 9(3): 661-675, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30809300

RESUMO

Hypoxic zones are common features of metastatic tumors. Due to inactivation of the von Hippel-Lindau gene (VHL), renal cell carcinomas (RCC) show constitutive stabilization of the alpha subunit of the hypoxia-inducible factor (HIF). Thus, RCC represents a model of chronic hypoxia. Development of the lymphatic network is dependent on vascular endothelial growth factor C (VEGFC) and lies at the front line of metastatic spreading. Here, we addressed the role of VEGFC in RCC aggressiveness and the regulation of its expression in hypoxia. Methods: Transcriptional and post transcriptional regulation of VEGFC expression was evaluated by qPCR and with reporter genes. The involvement of HIF was evaluated using a siRNA approach. Experimental RCC were performed with immuno-competent/deficient mice using human and mouse cells knocked-out for the VEGFC gene by a CRISPR/Cas9 method. The VEGFC axis was analyzed with an online available data base (TCGA) and using an independent cohort of patients. Results: Hypoxia induced VEGFC protein expression but down-regulated VEGFC gene transcription and mRNA stability. Increased proliferation, migration, over-activation of the AKT signaling pathway and enhanced expression of mesenchymal markers characterized VEGFC-/- cells. VEGFC-/- cells did not form tumors in immuno-deficient mice but developed aggressive tumors in immuno-competent mice. These tumors showed down-regulation of markers of activated lymphocytes and M1 macrophages, and up-regulation of M2 macrophages markers and programmed death ligand 1 (PDL1). Over-expression of lymphangiogenic genes including VEGFC was linked to increased disease-free and overall survival in patients with non-metastatic tumors, whereas its over-expression correlated with decreased progression-free and overall survival of metastatic patients. Conclusion: Our study revisited the admitted dogma linking VEGFC to tumor aggressiveness. We conclude that targeting VEGFC for therapy must be considered with caution.


Assuntos
Carcinoma de Células Renais/patologia , Fator C de Crescimento do Endotélio Vascular/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Camundongos , Transplante de Neoplasias , Transplante Heterólogo
17.
Oncotarget ; 8(34): 57174-57186, 2017 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-28915663

RESUMO

MicroRNAs (miRs) participate in tumor growth and dissemination by regulating expression of various target genes. MiR-223-3p is suspected of being involved in head and neck squamous cell carcinoma (HNSCC) growth although its precise role has not been elucidated. In this study, we showed that miR-223-3p is present in biopsies of HNSCC patients and that its presence is correlated with high neutrophil infiltrate. We found that overexpression of miR-223-3p slightly increased proliferation of the CAL27 squamous carcinoma cell line both in vitro and in vivo. Moreover, miR-223-3p induced CAL27 apoptosis in an orthotopic xenograft mouse model, counteracting the proliferative effect and resulting in no impact on overall tumor growth. We analyzed the effect of miR-223-3p overexpression on signaling pathways and showed that it induced pERK2, pAKT and AKT, consistent with an increase in cell proliferation. In addition, we found that miR-223-3p reduced the STAT3 level correlating with increased cell apoptosis and inhibited vasculature formation. In HNSCC tissues, miR-223-3p expression was inversely correlated to CD31, highlighting the relationship between miR-223 and vessel formation. Finally, we studied the effect of miR-223-3p on response to selected anticancer agents and showed that cells expressing miR-223-3p are more resistant to drugs, notably cetuximab. In conclusion, our study is the first to show the antiangiogenic properties of miR-223-3p in HNSCC patients and to question whether expression levels of miR-223-3p can be evaluated as an indicator of eligibility for non-treatment of HNSCC patients with cetuximab.

18.
Cancer Res ; 75(5): 835-45, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25564520

RESUMO

Colitis-associated cancer (CAC) is a complication of inflammatory bowel disease (IBD). Binding of extracellular ATP to the purinergic receptor P2RX7 has emerged as a critical event in controlling intestinal inflammation, acting to limit elevation of proinflammatory mast cells and cytokines and promote survival of regulatory T cells (Treg) and enteric neurons. In this study, we investigated the effect of P2RX7 blockade in an established mouse model of CAC. Using genetic and pharmacologic tools, we found unexpectedly that while P2RX7 mediated inflammatory responses, it also acted at an early time to suppress CAC development. P2RX7 blockade enhanced proliferation of intestinal epithelial cells and protected them from apoptosis. The proliferative effects of P2RX7 blockade were associated with an increased production of TGFß1 that was sufficient to stimulate the proliferation of intestinal epithelial cells. Finally, P2RX7 blockade also altered immune cell infiltration and promoted Treg accumulation within lesions of the digestive system. Taken together, our findings reveal an unexpected role for P2RX7 in preventing CAC, suggesting cautions in the use of P2RX7 inhibitors to treat IBD given the possibility of increasing risks CAC as a result.


Assuntos
Colite/metabolismo , Colite/patologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos P2X7/metabolismo , Animais , Colite/imunologia , Neoplasias do Colo/imunologia , Modelos Animais de Doenças , Imuno-Histoquímica , Incidência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores Purinérgicos P2X7/genética , Transdução de Sinais , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta1/biossíntese
19.
Autophagy ; 10(12): 2333-45, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25484075

RESUMO

The hypoxia inducible transcription factor HIF1 activates autophagy, a general catabolic pathway involved in the maintenance of cellular homeostasis. Dysfunction in both autophagy and HIF1 has been implicated in an increasing number of human diseases, including inflammatory bowel disease (IBD), such as Crohn disease (CD). Adherent invasive E. coli (AIEC) colonize ileal mucosa of CD patients and strongly promote gastrointestinal inflammatory disorders by activation of HIF-dependent responses. Here, we aim to characterize the contribution of HIF1 in xenophagy, a specialized form of autophagy involved in the degradation of intracellular bacteria. Our results showed that endogenous HIF1A knockdown increased AIEC survival in intestinal epithelial cells. We demonstrate that the increase in survival rate correlates with a dramatic impairment of the autophagic flux at the autolysosomal maturation step. Furthermore, we show that AIEC remained within single-membrane LC3-II-positive vesicles and that they were unable to induce the phosphorylation of ULK1. These results suggested that, in the absence of HIF1A, AIEC were found within LC3-associated phagosomes. Using blocking antibodies against TLR5 and CEACAM6, the 2 well-known AIEC-bound receptors, we showed that downstream receptor signaling was necessary to mediate ULK1 phosphorylation. Finally, we provide evidence that HIF1 mediates CEACAM6 expression and that CEACAM6 is necessary to recruit ULK1 in a bacteria-containing signaling hub. Collectively, these results identify a new function for HIF1 in AIEC-dedicated xenophagy, and suggest that coactivation of autophagy and HIF1A expression may be a potential new therapy to resolve AIEC infection in CD patients.


Assuntos
Autofagia/fisiologia , Células Epiteliais/microbiologia , Infecções por Escherichia coli/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Linhagem Celular , Doença de Crohn/imunologia , Doença de Crohn/metabolismo , Células Epiteliais/metabolismo , Humanos , Mucosa Intestinal/metabolismo
20.
Cancer Res ; 73(14): 4311-22, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23704209

RESUMO

Degradation of signaling proteins is one of the most powerful tumor-suppressive mechanisms by which a cell can control its own growth. Here, we identify RHOA as the molecular target by which autophagy maintains genomic stability. Specifically, inhibition of autophagosome degradation by the loss of the v-ATPase a3 (TCIRG1) subunit is sufficient to induce aneuploidy. Underlying this phenotype, active RHOA is sequestered via p62 (SQSTM1) within autolysosomes and fails to localize to the plasma membrane or to the spindle midbody. Conversely, inhibition of autophagosome formation by ATG5 shRNA dramatically increases localization of active RHOA at the midbody, followed by diffusion to the flanking zones. As a result, all of the approaches we examined that compromise autophagy (irrespective of the defect: autophagosome formation, sequestration, or degradation) drive cytokinesis failure, multinucleation, and aneuploidy, processes that directly have an impact upon cancer progression. Consistently, we report a positive correlation between autophagy defects and the higher expression of RHOA in human lung carcinoma. We therefore propose that autophagy may act, in part, as a safeguard mechanism that degrades and thereby maintains the appropriate level of active RHOA at the midbody for faithful completion of cytokinesis and genome inheritance.


Assuntos
Autofagia/fisiologia , Citocinese/fisiologia , Instabilidade Genômica , Proteína rhoA de Ligação ao GTP/metabolismo , Animais , Autofagia/genética , Carcinoma/genética , Carcinoma/metabolismo , Carcinoma/patologia , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/genética , Membrana Celular/metabolismo , Membrana Celular/fisiologia , Citocinese/genética , Células Gigantes/metabolismo , Células Gigantes/fisiologia , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Lisossomos/genética , Lisossomos/metabolismo , Lisossomos/fisiologia , Camundongos , Fagossomos/genética , Fagossomos/metabolismo , Fagossomos/fisiologia , Proteólise , ATPases Vacuolares Próton-Translocadoras/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo , Proteína rhoA de Ligação ao GTP/genética
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