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1.
Hepatology ; 74(6): 3110-3126, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34322898

RESUMO

BACKGROUND AND AIMS: NASH is an advanced stage of liver disease accompanied by lipid accumulation, inflammation, and liver fibrosis. Guanine nucleotide-binding protein G(i) subunit alpha-2 (GNAI2) is a member of the "inhibitory" class of α-subunits, and recent studies showed that Gnai2 deficiency is known to cause reduced weight in mice. However, the role of GNAI2 in hepatocytes, particularly in the context of liver inflammation and lipid metabolism, remains to be elucidated. Herein, we aim to ascertain the function of GNAI2 in hepatocytes and its impact on the development of NASH. APPROACH AND RESULTS: Human liver tissues were obtained from NASH patients and healthy persons to evaluate the expression and clinical relevance of GNAI2. In addition, hepatocyte-specific Gnai2-deficient mice (Gnai2hep-/- ) were fed either a Western diet supplemented with fructose in drinking water (WDF) for 16 weeks or a methionine/choline-deficient diet (MCD) for 6 weeks to investigate the regulatory role and underlying mechanism of Gnai2 in NASH. GNAI2 was significantly up-regulated in liver tissues of patients with NASH. Following feeding with WDF or MCD diets, livers from Gnai2hep-/- mice had reduced steatohepatitis with suppression of markers of inflammation and an increase in lipophagy compared to Gnai2flox/flox mice. Toll-like receptor 4 signals through nuclear factor kappa B to trigger p65-dependent transcription of Gnai2. Intriguingly, immunoprecipitation, immunofluorescence, and mass spectrometry identified peroxiredoxin 1 (PRDX1) as a binding partner of GNAI2. Moreover, the function of PRDX1 in the suppression of TNF receptor-associated factor 6 ubiquitin-ligase activity and glycerophosphodiester phosphodiesterase domain-containing 5-related phosphatidylcholine metabolism was inhibited by GNAI2. Suppression of GNAI2 combined with overexpression of PRDX1 reversed the development of steatosis and fibrosis in vivo. CONCLUSIONS: GNAI2 is a major regulator that leads to the development of NASH. Thus, inhibition of GNAI2 could be an effective therapeutic target for the treatment of NASH.


Assuntos
Subunidade alfa Gi2 de Proteína de Ligação ao GTP/metabolismo , Hepatopatia Gordurosa não Alcoólica/imunologia , Peroxirredoxinas/metabolismo , Adulto , Animais , Autofagia/imunologia , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Subunidade alfa Gi2 de Proteína de Ligação ao GTP/genética , Hepatócitos , Humanos , Fígado/imunologia , Fígado/patologia , Masculino , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Ligação Proteica/imunologia , Transdução de Sinais/imunologia , Adulto Jovem
2.
Gastroenterology ; 156(8): 2297-2312, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30836096

RESUMO

BACKGROUND & AIMS: Interleukin 6 (IL6) and tumor necrosis factor contribute to the development of colitis-associated cancer (CAC). We investigated these signaling pathways and the involvement of G protein subunit alpha i1 (GNAI1), GNAI2, and GNAI3 in the development of CAC in mice and humans. METHODS: B6;129 wild-type (control) or mice with disruption of Gnai1, Gnai2, and/or Gnai3 or conditional disruption of Gnai2 in CD11c+ or epithelial cells were given dextran sulfate sodium (DSS) to induce colitis followed by azoxymethane (AOM) to induce carcinogenesis; some mice were given an antibody against IL6. Feces were collected from mice, and the compositions of microbiomes were analyzed by polymerase chain reactions. Dendritic cells (DCs) and myeloid-derived suppressor cells (MDSCs) isolated from spleen and colon tissues were analyzed by flow cytometry. We performed immunoprecipitation and immunoblot analyses of colon tumor tissues, MDSCs, and mouse embryonic fibroblasts to study the expression levels of GNAI1, GNAI2, and GNAI3 and the interactions of GNAI1 and GNAI3 with proteins in the IL6 signaling pathway. We analyzed the expression of Gnai2 messenger RNA by CD11c+ cells in the colonic lamina propria by PrimeFlow, expression of IL6 in DCs by flow cytometry, and secretion of cytokines in sera and colon tissues by enzyme-linked immunosorbent assay. We obtained colon tumor and matched nontumor tissues from 83 patients with colorectal cancer having surgery in China and 35 patients with CAC in the United States. Mouse and human colon tissues were analyzed by histology, immunoblot, immunohistochemistry, and/or RNA-sequencing analyses. RESULTS: GNAI1 and GNAI3 (GNAI1;3) double-knockout (DKO) mice developed more severe colitis after administration of DSS and significantly more colonic tumors than control mice after administration of AOM plus DSS. Development of increased tumors in DKO mice was not associated with changes in fecal microbiomes but was associated with activation of nuclear factor (NF) κB and signal transducer and activator of transcription (STAT) 3; increased levels of GNAI2, nitric oxide synthase 2, and IL6; increased numbers of CD4+ DCs and MDSCs; and decreased numbers of CD8+ DCs. IL6 was mainly produced by CD4+/CD11b+, but not CD8+, DCs in DKO mice. Injection of DKO mice with a blocking antibody against IL6 reduced the expansion of MDSCs and the number of tumors that developed after CAC induction. Incubation of MDSCs or mouse embryonic fibroblasts with IL6 induced activation of either NF-κB by a JAK2-TRAF6-TAK1-CHUK/IKKB signaling pathway or STAT3 by JAK2. This activation resulted in expression of GNAI2, IL6 signal transducer (IL6ST, also called GP130) and nitric oxide synthase 2, and expansion of MDSCs; the expression levels of these proteins and expansion of MDSCs were further increased by the absence of GNAI1;3 in cells and mice. Conditional disruption of Gnai2 in CD11c+ cells of DKO mice prevented activation of NF-κB and STAT3 and changes in numbers of DCs and MDSCs. Colon tumor tissues from patients with CAC had reduced levels of GNAI1 and GNAI3 and increased levels of GNAI2 compared with normal tissues. Further analysis of a public human colorectal tumor DNA microarray database (GSE39582) showed that low Gani1 and Gnai3 messenger RNA expression and high Gnai2 messenger RNA expression were significantly associated with decreased relapse-free survival. CONCLUSIONS: GNAI1;3 suppresses DSS-plus-AOM-induced colon tumor development in mice, whereas expression of GNAI2 in CD11c+ cells and IL6 in CD4+/CD11b+ DCs appears to promote these effects. Strategies to induce GNAI1;3, or block GNAI2 and IL6, might be developed for the prevention or therapy of CAC in patients.


Assuntos
Transformação Celular Neoplásica/genética , Colite/patologia , Neoplasias do Colo/patologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Animais , Biópsia por Agulha , Carcinogênese , Colite/genética , Neoplasias do Colo/genética , Modelos Animais de Doenças , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Imuno-Histoquímica , Interleucina-16/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Distribuição Aleatória , Valores de Referência , Sensibilidade e Especificidade , Transdução de Sinais/genética
3.
Breast Cancer Res Treat ; 175(2): 353-368, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30830488

RESUMO

PURPOSE: Low expression of long intergenic non-coding RNA LINC00472 in breast cancer is associated with aggressive tumors and unfavorable disease outcomes in multiple clinical datasets, but the reasons for these associations were unknown. METHODS: To study the mechanisms underlying the lncRNA's connection to breast cancer, we investigated the molecular targets and regulation of LINC00472 in breast cancer cells, and analyzed relevant molecular features in relation to patient survival. Gene expression profiles of breast cancer cells overexpressing LINC00472 were analyzed for its regulatory pathways and downstream targets. Effects of LINC00472 overexpression on cell behaviors were evaluated in vitro and in vivo. Meta-analysis was performed using online datasets and our own study. RESULTS: Analysis of LINC00472 transcriptome revealed ERα upregulation of LINC00472 expression, and an ERα-binding site in the LINC00472 promoter was identified. Evaluation of LINC00472 overexpression also indicated a possible link between LINC00472 and NF-κB. Cell experiments confirmed that LINC00472 suppressed the phosphorylation of p65 and IκBα through binding to IKKß, inhibiting its phosphorylation. High LINC00472 expression inhibited tumor growth both in vitro and in vivo and suppressed aggressive tumor cell behaviors in vitro. Suppressing LINC00472 expression in ER-positive tumor cells increased cell aggressive behaviors. Tamoxifen treatment of ER-positive cells inhibited ERα and LINC00472 expression and increased p65 and IκBα phosphorylation. Meta-analysis showed that LINC00472 expression were higher in ER-positive than ER-negative tumors and that high expression was associated with better disease outcomes in ER-positive patients. CONCLUSIONS: The study demonstrates that ERα upregulates LINC00472 which suppresses the phosphorylation of NF-κB, and suggests that endocrine treatment may lower LINC00472 and increase NF-κB activities, leading to tumor progression and disease recurrence.


Assuntos
Neoplasias da Mama/genética , Receptor alfa de Estrogênio/genética , Recidiva Local de Neoplasia/genética , RNA Longo não Codificante/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Neoplasias da Mama/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Xenoenxertos , Humanos , Células MCF-7 , Camundongos , Pessoa de Meia-Idade , NF-kappa B/genética , Recidiva Local de Neoplasia/patologia , Fosforilação/efeitos dos fármacos , Tamoxifeno/farmacologia , eIF-2 Quinase/genética
5.
Proc Natl Acad Sci U S A ; 112(15): 4731-6, 2015 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-25825741

RESUMO

Heterotrimeric G proteins have been implicated in Toll-like receptor 4 (TLR4) signaling in macrophages and endothelial cells. However, whether guanine nucleotide-binding protein G(i) subunit alpha-1 and alpha-3 (Gαi1/3) are required for LPS responses remains unclear, and if so, the underlying mechanisms need to be studied. In this study, we demonstrated that, in response to LPS, Gαi1/3 form complexes containing the pattern recognition receptor (PRR) CD14 and growth factor receptor binding 2 (Grb2)-associated binding protein (Gab1), which are required for activation of PI3K-Akt signaling. Gαi1/3 deficiency decreased LPS-induced TLR4 endocytosis, which was associated with decreased phosphorylation of IFN regulatory factor 3 (IRF3). Gαi1/3 knockdown in bone marrow-derived macrophage cells (Gαi1/3 KD BMDMs) exhibited an M2-like phenotype with significantly suppressed production of TNF-α, IL-6, IL-12, and NO in response to LPS. The altered polarization coincided with decreased Akt activation. Further, Gαi1/3 deficiency caused LPS tolerance in mice. In vitro studies revealed that, in LPS-tolerant macrophages, Gαi1/3 were down-regulated partially by the proteasome pathway. Collectively, the present findings demonstrated that Gαi1/3 can interact with CD14/Gab1, which modulates macrophage polarization in vitro and in vivo.


Assuntos
Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Macrófagos/metabolismo , Fosfoproteínas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Western Blotting , Linhagem Celular Tumoral , Células Cultivadas , Endocitose/efeitos dos fármacos , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Humanos , Interleucina-12/metabolismo , Interleucina-6/metabolismo , Receptores de Lipopolissacarídeos/genética , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Camundongos da Linhagem 129 , Camundongos Knockout , Microscopia Confocal , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfoproteínas/genética , Ligação Proteica/efeitos dos fármacos , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sobrevida , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
6.
Cell Commun Signal ; 12: 10, 2014 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-24521094

RESUMO

BACKGROUND: In a classic model, G(i)α proteins including G(i1)α, G(i2)α and G(i3)α are important for transducing signals from G(i)α protein-coupled receptors (G(i)αPCRs) to their downstream cascades in response to hormones and neurotransmitters. Our previous study has suggested that G(i1)α, G(i2)α and G(i3)α are also important for the activation of the PI3K/Akt/mTORC1 pathway by epidermal growth factor (EGF) and its family members. However, a genetic role of these G(i)α proteins in the activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) by EGF is largely unknown. Further, it is not clear whether these G(i)α proteins are also engaged in the activation of both the Akt/mTORC1 and ERK1/2 pathways by other growth factor family members. Additionally, a role of these G(i)α proteins in breast cancer remains to be elucidated. RESULTS: We found that Gi1/3 deficient MEFs with the low expression level of G(i2)α showed defective ERK1/2 activation by EGFs, IGF-1 and insulin, and Akt and mTORC1 activation by EGFs and FGFs. Gi1/2/3 knockdown breast cancer cells exhibited a similar defect in the activations and a defect in in vitro growth and invasion. The G(i)α proteins associated with RTKs, Gab1, FRS2 and Shp2 in breast cancer cells and their ablation impaired Gab1's interactions with Shp2 in response to EGF and IGF-1, or with FRS2 and Grb2 in response to bFGF. CONCLUSIONS: G(i)α proteins differentially regulate the activation of Akt, mTORC1 and ERK1/2 by different families of growth factors. G(i)α proteins are important for breast cancer cell growth and invasion.


Assuntos
Neoplasias da Mama/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Sistema de Sinalização das MAP Quinases , Complexos Multiproteicos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/farmacologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Humanos , Fator de Crescimento Insulin-Like I/farmacologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo
7.
J Exp Med ; 204(10): 2383-96, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17846149

RESUMO

The best-characterized type 1 interferon (IFN) signaling pathway depends on signal transducer and activator of transcription 1 (STAT1) and STAT2. The cytokines can, however, conditionally activate all STATs. Regulation of their access to particular signaling pathways is poorly understood. STAT4 is important for IFN-gamma induction, and NK cells are major producers of this cytokine. We report that NK cells have high basal STAT4 levels and sensitivity to type 1 IFN-mediated STAT4 activation for IFN-gamma production. Increases in STAT1, driven during viral infection by either type 1 IFN or IFN-gamma, are associated with decreased STAT4 access. Both STAT1 and STAT2 are important for antiviral defense, but STAT1 has a unique role in protecting against sustained NK cell IFN-gamma production and resulting disease. The regulation occurs with an NK cell type 1 IFN receptor switch from a STAT4 to a STAT1 association. Thus, a fundamental characteristic of NK cells is high STAT4 bound to the type 1 IFN receptor. The conditions of infection result in STAT1 induction with displacement of STAT4. These studies elucidate the critical role of STAT4 levels in predisposing selection of specific signaling pathways, define the biological importance of regulation within particular cell lineages, and provide mechanistic insights for how this is accomplished in vivo.


Assuntos
Interferon Tipo I/metabolismo , Células Matadoras Naturais/metabolismo , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT4/metabolismo , Animais , Regulação da Expressão Gênica , Interferon Tipo I/genética , Interferon gama/metabolismo , Células Matadoras Naturais/imunologia , Ativação Linfocitária , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/metabolismo , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos , Camundongos Transgênicos , Receptor de Interferon alfa e beta/metabolismo , Fator de Transcrição STAT1/deficiência , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT2/deficiência , Fator de Transcrição STAT2/genética , Fator de Transcrição STAT2/metabolismo , Fator de Transcrição STAT4/deficiência , Fator de Transcrição STAT4/genética
8.
J Biol Chem ; 285(19): 14842, 2010 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29874310

RESUMO

[This retracts the article on p. 28897 in vol. 283, PMID: 18715874.].

9.
Breast Cancer Res Treat ; 122(1): 193-8, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19949855

RESUMO

The SULT1A1 R213H polymorphism is suggested to be implicated in the development and progression of breast cancer. However, the published findings are inconsistent. We therefore performed a meta-analysis of 8,454 breast cancer cases and 11,800 controls from 14 published case-control studies. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association of the R213H polymorphism with breast cancer risk. Overall, our results suggested that there is no significant relationship between SULT1A1 R213H polymorphism and the risk of breast cancer. However, further ethnic population analysis revealed a significantly increased risk of breast cancer for HH allele carriers among Asians (for HH vs. RR: OR = 2.27, 95% CI = 1.11-4.63, P (heterogeneity) = 0.63; for the recessive model: OR = 2.03, 95% CI = 1.00-4.41, P (heterogeneity) = 0.62). Taken together, this meta-analysis suggests that the SULT1A1 R213H may be a low-penetrant risk factor for developing breast cancer in Asian population.


Assuntos
Arilsulfotransferase/genética , Neoplasias da Mama/epidemiologia , Proteínas de Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Alelos , Substituição de Aminoácidos , Ásia/epidemiologia , Povo Asiático/genética , Neoplasias da Mama/etnologia , Neoplasias da Mama/genética , Estudos de Casos e Controles , Códon/genética , Europa (Continente)/epidemiologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Razão de Chances , Penetrância , População Branca/genética
10.
Biochem J ; 421(2): 301-10, 2009 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-19426145

RESUMO

TLR7 (Toll-like receptor 7) mediates anti-viral immunity by recognizing ssRNA (single-stranded RNA) viruses. Small-molecular-mass TLR7 agonists have been approved, or are being evaluated, for treatment of cancers or infectious diseases. Although TLR7 is predominantly expressed in a restricted set of immune cell types, including pDCs (plasmacytoid dendritic cells), it is also expressed in non-native expressing cells (e.g. hepatocytes) under certain circumstances. To elucidate the molecular basis of TLR7 induction by pro-inflammatory stimulation and the subsequent cellular responses in these non-native TLR7-expressing cell types, we first cloned and characterized the 5'-promoter region of TLR7. The proximal region of this promoter drives the transcription of the TLR7 gene. Pro-inflammatory stimuli activated TLR 7 transcription via a NF-kappaB (nuclear factor kappaB)-binding motif in this region, and this activation could be blocked by mutation of the NF-kappaB binding site or addition of NF-kappaB inhibitors. Further studies showed that pretreatment of the Hep3B hepatocytes with TNF-alpha (tumour necrosis factor-alpha) or IL-1 (interleukin-1) rendered them responsive to TLR7 activation by a TLR7 agonist. However, distinct from TLR7 activation in pDCs, which respond to stimulation with Th1 polarized cytokine production, TLR7 induction by pro-inflammatory signals in hepatocytes reconstitutes the NF-kappaB-dependent cascade but not the IRF7 (interferon regulatory factor 7)-dependent cascade, resulting in a pro-inflammatory polarized response rather than a Th1 polarized response. These results indicate that inflammatory stimulation is capable of priming cells to respond to TLR7 agonist with an immune response that differs from that in native TLR7-expressing cells.


Assuntos
Mediadores da Inflamação/farmacologia , NF-kappa B/metabolismo , Receptor 7 Toll-Like/agonistas , Receptor 7 Toll-Like/genética , Ativação Transcricional , Sequência de Bases , Humanos , Interleucina-1/metabolismo , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Receptor 7 Toll-Like/biossíntese , Transfecção , Fator de Necrose Tumoral alfa/metabolismo
11.
J Cell Mol Med ; 13(9B): 3632-43, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18681908

RESUMO

SIRT1 is a member of a highly conserved gene family (sirtuins) encoding nicotinamide adenine dinucleotide (NAD)(+)-dependent deacetylases, originally found to deacetylate histones leading to increased DNA stability and prolonged survival in yeast and higher organisms, including mammals. SIRT1 has been found to function as a deacetylase for numerous protein targets involved in various cellular pathways, including stress responses, apoptosis and axonal degeneration. However, the role of SIRT1 in ultraviolet (UV) signalling pathways remains unknown. Using cell culture and Western blot analysis in this study we found that SIRT1 is expressed in cultured human skin keratinocytes. Both UV radiation and H(2)O(2), two major inducers of skin cell damage, down-regulate SIRT1 in a time- and dose-dependent manner. We observed that reactive oxygen species-mediated JNK activation is involved in this SIRT1 down-regulation. SIRT1 activator, resveratrol, which has been considered as an important antioxidant, protects against UV- and H(2)O(2)-induced cell death, whereas SIRT inhibitors such as sirtinol and nicotinamide enhance cell death. Activation of SIRT1 negatively regulates UV- and H(2)O(2)-induced p53 acetylation, because nicotinamide and sirtinol as well as SIRT1 siRNA enhance UV- and H(2)O(2)-induced p53 acetylation, whereas SIRT1 activator resveratrol inhibits it. We also found that SIRT1 is involved in UV-induced AMP-activated protein kinase (AMPK) and downstream acetyl-CoA carboxylase (ACC), phosphofructose kinase-2 (PFK-2) phosphorylation. Collectively, our data provide new insights into understanding of the molecular mechanisms of UV-induced skin aging, suggesting that SIRT1 activators such as resveratrol could serve as new anti-skin aging agents.


Assuntos
Células Cultivadas/metabolismo , Regulação da Expressão Gênica , Peróxido de Hidrogênio/farmacologia , MAP Quinase Quinase 4/metabolismo , Sirtuína 1/metabolismo , Pele/citologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Morte Celular , Proliferação de Células , Relação Dose-Resposta a Droga , Humanos , Camundongos , Espécies Reativas de Oxigênio
12.
Cell Signal ; 20(10): 1830-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18644433

RESUMO

Ultraviolet radiation (UV) induces apoptosis and functional maturation in skin dendritic cells (DCs). However, the molecular mechanisms through which UV activates DCs have not been thoroughly investigated. In this study, we examined the mechanisms of activation and apoptosis of DCs after UV irradiation by focusing on epidermal growth factor receptor (EGFR). Our previous studies have demonstrated that in addition to cognate ligands, EGFR is also activated by UVB irradiation in cultured human skin keratinocytes in vitro and in human skin in vivo. We found for the first time in this study that UV also induces EGFR activation in cultured mouse skin DCs (XS 106 cell line) as well as mouse monocyte-derived dendritic cells (MoDCs). Pharmacological inhibition of EGFR tyrosine kinase significantly inhibits UV-induced ERK, p38, and JNK MAP kinases, and their effectors, transcription factors c-Fos and c-Jun. Inhibition of EGFR also suppresses UV-induced activation of PI3K/AKT/mTOR/S6K and NF-kappaB signal transduction pathways. Our data demonstrated that UV induces LKB1/AMPK pathway, also dependent on EGFR trans-activation. We further observed that MAPK, LKB1/AMPK, PI3K/AKT/mTOR/S6K as well as NF-kappaB activation are impaired in EGFR-/- cells compared to wide type MEF cells after UV radiation. Taken together, we conclude that UV induces multiple signaling pathways mediated by EGFR trans-activation leading to possible maturation, apoptosis and survival, and EGFR activation protects against UV-induced apoptosis in cultured mouse dendritic cells.


Assuntos
Apoptose/efeitos da radiação , Células Dendríticas/citologia , Células Dendríticas/enzimologia , Receptores ErbB/metabolismo , Pele/citologia , Raios Ultravioleta , Proteínas Quinases Ativadas por AMP , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular , Células Cultivadas , Células Dendríticas/efeitos da radiação , Ativação Enzimática/efeitos da radiação , Receptores ErbB/genética , Fatores de Iniciação em Eucariotos , Humanos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Modelos Biológicos , Complexos Multienzimáticos/metabolismo , NF-kappa B/metabolismo , Fosfoproteínas/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases S6 Ribossômicas/metabolismo , Transdução de Sinais/efeitos da radiação , Pele/enzimologia , Serina-Treonina Quinases TOR , Ativação Transcricional/efeitos da radiação
13.
Brief Funct Genomics ; 18(2): 133-139, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30137232

RESUMO

Immune checkpoints have been the subject of a wave of new studies. Among these checkpoints are tytotoxic T-lymphocyte-associated antigen 4, checkpoints programmed death-1 and programmed death-ligand 1; their blockades have been approved by the Food and Drug Administration for therapy of melanoma and other types of cancers. Immunogenomics, which combines the latest nucleic acid sequencing strategy with immunotherapy, provides precise information about genomic alterations (e.g. mutations) and enables a paradigm shift of immune checkpoint therapy from tumor types to molecular signatures. Studying these critical checkpoints in relation to genomic mutations and neoantigens has produced groundbreaking results. This article examines these studies and delves into the relationships between immune checkpoint blockade and tumors harboring certain genomic mutations. Moreover, this article reviews recent studies on resistance to immune checkpoint therapy.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Genômica/métodos , Imunoterapia/métodos , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Animais , Humanos , Proteínas de Neoplasias/genética , Neoplasias/genética , Neoplasias/imunologia
14.
Ann N Y Acad Sci ; 1112: 339-50, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17567943

RESUMO

Thymosin alpha 1 (Talpha1) has therapeutic potential in the treatment of infectious diseases and cancer. However, the exact molecular pathways for Talpha1 action are not fully understood. We found that Talpha1 induces the production of interleukin-6 (IL-6), IL-10, and IL-12 in murine bone marrow-derived macrophages (BMDMs) through IKK and MAPK pathways. Talpha1 triggers the activation of AP-1 and the phosphorylation of JNK and p38. Inhibition of p38 impairs IL-6 production in response to Talpha1. Further, TRAF6 is involved in the activation of JNK and IRAK4 is involved for the activation of IKK and PKCzeta in a Talpha1-induced system. Loss of IRAK4 largely blocked induction of IL-6. Thus, our studies define early signal events that are critical for the Talpha1-induced immune responses.


Assuntos
Quinase I-kappa B/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Transdução de Sinais/fisiologia , Células Dendríticas/imunologia , Ativação Enzimática , Humanos , Interleucina-12/metabolismo , Proteína Quinase C/metabolismo , Timalfasina , Timosina/análogos & derivados , Timosina/fisiologia
15.
Nat Commun ; 8: 15129, 2017 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-28541302

RESUMO

Long noncoding RNAs play a pivotal role in T-helper cell development but little is known about their roles in Treg differentiation and functions during the progression of hepatocellular carcinoma (HCC). Here, we show that lnc-epidermal growth factor receptor (EGFR) upregulation in Tregs correlates positively with the tumour size and expression of EGFR/Foxp3, but negatively with IFN-γ expression in patients and xenografted mouse models. Lnc-EGFR stimulates Treg differentiation, suppresses CTL activity and promotes HCC growth in an EGFR-dependent manner. Mechanistically, lnc-EGFR specifically binds to EGFR and blocks its interaction with and ubiquitination by c-CBL, stabilizing it and augmenting activation of itself and its downstream AP-1/NF-AT1 axis, which in turn elicits EGFR expression. Lnc-EGFR links an immunosuppressive state to cancer by promoting Treg cell differentiation, thus offering a potential therapeutic target for HCC.


Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/imunologia , Diferenciação Celular/genética , Evasão da Resposta Imune , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/imunologia , RNA Longo não Codificante/genética , Linfócitos T Reguladores/citologia , Animais , Sequência de Bases , Carcinoma Hepatocelular/patologia , Proliferação de Células , Biologia Computacional , Receptores ErbB/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologia , Linfócitos do Interstício Tumoral/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Modelos Biológicos , Fatores de Transcrição NFATC/metabolismo , Proteínas Proto-Oncogênicas c-cbl/metabolismo , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/metabolismo , Fator de Transcrição AP-1/metabolismo , Transcriptoma/genética , Tirosina/metabolismo , Ubiquitinação
16.
Oncotarget ; 7(26): 39834-39845, 2016 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-27213581

RESUMO

ADP-ribosylation factor 1 (ARF1) is a crucial regulator in vesicle-mediated membrane trafficking and involved in the activation of signaling molecules. However, virtually nothing is known about its function in prostate cancer. Here we have demonstrated that ARF1 expression is significantly elevated in prostate cancer cells and human tissues and that the expression levels of ARF1 correlate with the activation of mitogen-activated protein kinases (MAPK) ERK1/2. Furthermore, we have shown that overexpression and knockdown of ARF1 produce opposing effects on prostate cancer cell proliferation, anchorage-independent growth and tumor growth in mouse xenograft models and that ARF1-mediated cell proliferation can be abolished by the Raf1 inhibitor GW5074 and the MEK inhibitors U0126 and PD98059. Moreover, inhibition of ARF1 activation achieved by mutating Thr48 abolishes ARF1's abilities to activate the ERK1/2 and to promote cell proliferation. These data demonstrate that the aberrant MAPK signaling in prostate cancer is, at least in part, under the control of ARF1 and that, similar to Ras, ARF1 is a critical regulator in prostate cancer progression. These data also suggest that ARF1 may represent a key molecular target for prostate cancer therapeutics and diagnosis.


Assuntos
Fator 1 de Ribosilação do ADP/metabolismo , Regulação Neoplásica da Expressão Gênica , Sistema de Sinalização das MAP Quinases , Neoplasias da Próstata/patologia , Animais , Butadienos/química , Carcinogênese , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Flavonoides/química , Humanos , MAP Quinase Quinase 4/metabolismo , Masculino , Camundongos , Camundongos SCID , Mutação , Nitrilas/química , Neoplasias da Próstata/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
17.
PLoS One ; 10(3): e0121371, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25812014

RESUMO

CpG-ODNs activate dendritic cells (DCs) to produce interferon alpha (IFNα) and beta (IFNß). Previous studies demonstrated that Toll-like receptor 9 (TLR9) deficient DCs exhibited a residual IFNα response to CpG-A, indicating that yet-unidentified molecules are also involved in induction of IFNα by CpG-A. Here, we report that the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) but not Ku70 deficient BMDCs showed defective IFNα and IFNß responses to CpG-A or CpG-B. Loss of both DNA-PKcs and TLR9 further reduced the IFNα response to CpG-A. These DNA-PKcs and TLR9 effects were mediated by their downstream Akt/mTORC1 pathway and downstream events IRAK1 and IKKα. Loss of DNA-PKcs, TLR9, MyD88 or IRAK4 impaired phosphorylation of Akt(S473), S6K, S6, IRAK1, or IKKα in BMDCs in response to CpG-ODNs. The residual IFNα and IFNß in DNA-PKcs-deficient BMDCs were partially responsible for the induction of IL-6 and IL-12 by CpG-ODNs and their stimulatory effect was blocked by IFNAR1 neutralizing antibodies. Further analysis indicated that CpG-ODN associated with DNA-PKcs and Ku70, and induced DNA-PKcs's interaction with TRAF3. Intriguingly, DNA-PKcs but not Ku70 expression level was reduced in TLR9-deficient BMDCs. Taken together, our data suggest that DNA-PKcs is an important mediator in the type I IFN response to CpG-ODNs in TLR9-dependent or -independent fashions.


Assuntos
Proteína Quinase Ativada por DNA/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Interferon Tipo I/farmacologia , Oligodesoxirribonucleotídeos/farmacologia , Receptor Toll-Like 9/metabolismo , Animais , Antígenos Nucleares/imunologia , Antígenos Nucleares/metabolismo , Proteína Quinase Ativada por DNA/genética , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/metabolismo , Células Dendríticas/imunologia , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Interleucina-12/metabolismo , Interleucina-12/farmacologia , Interleucina-6/metabolismo , Interleucina-6/farmacologia , Autoantígeno Ku , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Knockout , Complexos Multiproteicos/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator 3 Associado a Receptor de TNF/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Receptor Toll-Like 9/genética
18.
PLoS One ; 10(8): e0136246, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26287798

RESUMO

To investigate the biologic relevance and clinical implication of genes involved in multiple gene expression signatures for breast cancer prognosis, we identified 16 published gene expression signatures, and selected two genes, MAD2L1 and BUB1. These genes appeared in 5 signatures and were involved in cell-cycle regulation. We analyzed the expression of these genes in relation to tumor features and disease outcomes. In vitro experiments were also performed in two breast cancer cell lines, MDA-MB-231 and MDA-MB-468, to assess cell proliferation, migration and invasion after knocking down the expression of these genes. High expression of these genes was found to be associated with aggressive tumors and poor disease-free survival of 203 breast cancer patients in our study, and the association with survival was confirmed in an online database consisting of 914 patients. In vitro experiments demonstrated that lowering the expression of these genes by siRNAs reduced tumor cell growth and inhibited cell migration and invasion. Our investigation suggests that MAD2L1 and BUB1 may play important roles in breast cancer progression, and measuring the expression of these genes may assist the prediction of breast cancer prognosis.


Assuntos
Neoplasias da Mama/genética , Proteínas Mad2/genética , Proteínas Serina-Treonina Quinases/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Intervalo Livre de Doença , Feminino , Expressão Gênica , Marcadores Genéticos , Humanos , Estimativa de Kaplan-Meier , Prognóstico , RNA Interferente Pequeno/genética
19.
Oncotarget ; 6(11): 8579-92, 2015 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-25865225

RESUMO

LINC00472 is a novel long intergenic non-coding RNA. We evaluated LINC00472 expression in breast tumor samples using RT-qPCR, performed a meta-analysis of over 20 microarray datasets from the Gene Expression Omnibus (GEO) database, and investigated the effect of LINC00472 expression on cell proliferation and migration in breast cancer cells transfected with a LINC00472-expressing vector. Our qPCR results showed that high LINC00472 expression was associated with less aggressive breast tumors and more favorable disease outcomes. Patients with high expression of LINC00472 had significantly reduced risk of relapse and death compared to those with low expression. Patients with high LINC00472 expression also had better responses to adjuvant chemo- or hormonal therapy than did patients with low expression. Results of meta-analysis on multiple studies from the GEO database were in agreement with the findings of our study. High LINC00472 was also associated with favorable molecular subtypes, Luminal A or normal-like tumors. Cell culture experiments showed that up-regulation of LINC00472 expression could suppress breast cancer cell proliferation and migration. Collectively, our clinical and in vitro studies suggest that LINC00472 is a tumor suppressor in breast cancer. Evaluating this long non-coding RNA in breast tumors may have prognostic and predictive value in the clinical management of breast cancer.


Assuntos
Neoplasias da Mama/genética , Carcinoma/genética , Genes Supressores de Tumor , RNA Longo não Codificante/genética , RNA Neoplásico/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Carcinoma/química , Carcinoma/tratamento farmacológico , Carcinoma/mortalidade , Carcinoma/patologia , Divisão Celular , Linhagem Celular Tumoral , Movimento Celular , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Expressão Gênica , Vetores Genéticos , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , RNA/biossíntese , RNA Longo não Codificante/análise , RNA Longo não Codificante/biossíntese , RNA Neoplásico/análise , RNA Neoplásico/biossíntese , Recidiva , Risco , Análise Serial de Tecidos , Resultado do Tratamento , Adulto Jovem
20.
Cancer Lett ; 328(2): 222-5, 2013 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-23085193

RESUMO

Tumor necrosis factor (TNF) is a critical cytokine, which contributes to both physiological and pathological processes. This mini-review will briefly touch the history of TNF discovery, its family members and its biological and pathological functions. Then, it will focus on new findings on the molecular mechanisms of how TNF triggers activation of the NF-κB and AP-1 pathways, which are critical for expression of pro-inflammatory cytokines, as well as the MLKL cascade, which is critical for the generation of ROS in response to TNF. Finally, this review will briefly summarize recent advances in understanding TNF-induced cell survival, apoptosis and necrosis (also called necroptosis). Understanding new findings and emerging concepts will impact future research on the molecular mechanisms of TNF signaling in immune disorders and cancer-related inflammation.


Assuntos
Fatores de Necrose Tumoral/genética , Fatores de Necrose Tumoral/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/genética , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/genética , Doenças Autoimunes/metabolismo , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Inibidores do Fator de Necrose Tumoral
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