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1.
Int J Pharm ; 656: 124045, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38561134

RESUMO

The field of cancer therapy is witnessing the emergence of immunotherapy, an innovative approach that activates the body own immune system to combat cancer. Immunogenic cell death (ICD) has emerged as a prominent research focus in the field of cancer immunotherapy, attracting significant attention in recent years. The activation of ICD can induce the release of damage-associated molecular patterns (DAMPs), such as calreticulin (CRT), adenosine triphosphate (ATP), high mobility group box protein 1 (HMGB1), and heat shock proteins (HSP). Subsequently, this process promotes the maturation of innate immune cells, including dendritic cells (DCs), thereby triggering a T cell-mediated anti-tumor immune response. The activation of the ICD ultimately leads to the development of long-lasting immune responses against tumors. Studies have demonstrated that partial therapeutic approaches, such as chemotherapy with doxorubicin, specific forms of radiotherapy, and phototherapy, can induce the generation of ICD. The main focus of this article is to discuss and review the therapeutic methods triggered by nanoparticles for ICD, while briefly outlining their anti-tumor mechanism. The objective is to provide a comprehensive reference for the widespread application of ICD.

2.
Oncol Lett ; 27(5): 199, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38516689

RESUMO

The novel long non-coding RNA, EGFR-AS1, is expressed in various types of solid tumour, and its oncogenic role has been fully identified. In the present study, several articles were screened following an electronic search of the PubMed database. In total, 8 studies were included in the present systematic review. For each analysis indicator risk ratios (RRs) with 95% confidence intervals (CIs) or hazard ratios (HRs) with standard errors and 95% CIs were estimated using Review Manager 5.3. The pooled RR of high EGFR-AS1 expression among patients with or without vascular invasion was 1.81 with a 95% CI of 1.22-2.69; the pooled HR of high EGFR-AS1 expression for patient overall survival rate was 1.74 with a 95% CI of 1.39-2.18. Therefore, EGFR-AS1 was identified as an oncogene and the upregulated EGFR-AS1 expression was significantly associated with advanced tumour progression and poor prognosis.

3.
Front Endocrinol (Lausanne) ; 15: 1323990, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38505748

RESUMO

Background: The associations of serum calcium and phosphorus with nonalcoholic fatty liver disease (NAFLD) remain unclear. In addition, there may be an effect of albumin correction on the association between serum calcium and NAFLD. We aimed to explore these relationships in the National Health and Nutrition Examination Survey (NHANES). Methods: Eligible adult individuals from NHANES 1999-2018 were recruited for the study. We explored the associations of serum calcium, albumin-adjusted serum calcium, and serum phosphorus with NAFLD in multivariable-adjusted regression models. In addition, restricted cubic spline (RCS), stratified analysis, and multiple sensitivity analyses were used for further elaboration. Results: The study sample consisted of 20,900 participants, with an observed NAFLD prevalence of 44.65%. Fully adjusted models indicated that serum calcium was inversely associated with NAFLD (odds ratio [OR] and 95% confidence interval [CI] = 0.70 (0.62, 0.78), p<0.0001), whereas albumin-adjusted serum calcium was positively associated with NAFLD (OR and 95% CI=1.59 (1.41, 1.79), p<0.0001). RCS modeling indicated that serum calcium without and with albumin adjustment was linearly(p nonlinear = 0.083) and nonlinearly (p nonlinear < 0.0001) associated with NAFLD, respectively, whereas serum phosphorus showed a U-shaped relationship with NAFLD(p nonlinear < 0.0001). Gender is a significant influence in all associations, and other variables may also have an effect. Sensitivity analyses indicated that these associations were independent of additional significant confounders. Conclusion: Serum calcium and phosphorus were significantly associated with the development of NAFLD. These findings suggest the potential clinical significance of serum calcium/phosphorus and albumin levels in individuals at high risk for NAFLD. Our study supports the potential role of serum calcium/phosphorus homeostasis in the pathophysiology of NAFLD and could serve as NAFLD-related biomarkers.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Adulto , Humanos , Inquéritos Nutricionais , Cálcio , Fósforo , Albumina Sérica , Cálcio da Dieta
4.
Colloids Surf B Biointerfaces ; 234: 113743, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38215604

RESUMO

Cancer is currently one of the leading causes of mortality worldwide. Due to the inevitable shortcomings of conventional treatments, photothermal therapy (PTT) has attracted great attention as an emerging and non-invasive cancer treatment method. Photothermal agents (PTAs) is a necessary component of PTT to play its role. It accumulates at the tumor site through appropriate methods and converts the absorbed light energy into heat energy effectively under near-infrared light irradiation, thus increasing the temperature of the tumor area and facilitating ablation of the tumor cells. Compared to inorganic photothermal agents, which have limitations such as non-degradability and potential long-term toxicity in vivo, organic photothermal agents exhibit excellent biocompatibility and biodegradability, thus showing promising prospects for the application of PTT in cancer treatment. And these organic photothermal agents can also be engineered into nanoparticles to improve their water solubility, extend their circulation time in vivo, and specifically target tumors. Moreover, further combination of PTT with other treatment methods can effectively enhance the efficacy of cancer treatment and alleviate the side effects associated with single treatments. This article briefly introduces several common types of organic photothermal agents and their nanoparticles, and reviews the applications of PTT based on organic photothermal agents in combination with chemotherapy, photodynamic therapy, chemodynamic therapy, immunotherapy, and multimodal combination therapy for tumor treatment, which expands the ideas and methods in the field of tumor treatment.


Assuntos
Nanopartículas , Neoplasias , Fotoquimioterapia , Humanos , Fototerapia/métodos , Neoplasias/patologia , Terapia Combinada , Linhagem Celular Tumoral
6.
Am J Transl Res ; 12(5): 1839-1850, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32509180

RESUMO

Glioma-associated oncogene homolog 1 (GLI1), an oncogenic molecule in non-small cell lung cancer (NSCLC), promotes the growth of NSCLC by enhancing lung cancer stem cells (LCSCs). However, the mechanism responsible remains unknown. FOXP3 is known to maintain LCSCs. The aim of this study was to explore whether GLI1 enhanced LCSCs via stimulating FOXP3. Experiments were performed in NSCLC tissue samples, cell lines and the animal tumor model. The expression of GLI1- and LCSC-related molecules was assessed at protein and mRNA levels. Relevant cell functions were also determined. A tumor xenograft mouse model was established to confirm the oncogenic role of GLI1. We confirmed that the expression of GLI1 was up-regulated in the tumor tissues of NSCLC compared with adjacent non-tumor tissues. But no significant association between GLI1 and clinicopathological characteristics was found. GLI1 expression was positively correlated with FOXP3 and it could promote FOXP3 expression likely via acting on the promoter of FOXP3. Along with the upregulation of FOXP3, GLI1 increased the expression of LCSC markers, ALDH1A1 and OCT4A, and the formation of tumor spheres, whereas the inhibition of GLI1 decreased the above features. We also found the involvement of Notch1 activation in GLI1-mediated FOXP3 pathway. The In vivo mouse tumor model verified the positive role of GLI1 in the growth of the tumor. Collectively, this study has demonstrated that GLI1 stimulates FOXP3 to promote LCSCs.

7.
J Exp Clin Cancer Res ; 38(1): 359, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31420013

RESUMO

BACKGROUND: Epidemiological observations have demonstrated that ambient fine particulate matter with dp < 2.5 µm (PM2.5) as the major factor responsible for the increasing incidence of lung cancer in never-smokers. However, there are very limited experimental data to support the association of PM2.5 with lung carcinogenesis and to compare PM2.5 with smoking carcinogens. METHODS: To study whether PM2.5 can contribute to lung tumorigenesis in a way similar to smoking carcinogen 4-methylnitrosamino-l-3-pyridyl-butanone (NNK) via 15-lipoxygenases (15-LOXs) reduction, normal lung epithelial cells and cancer cells were treated with NNK or PM2.5 and then epigenetically and post-translationally examined the cellular and molecular profiles of the cells. The data were verified in lung cancer samples and a mouse lung tumor model. RESULTS: We found that similar to smoking carcinogen NNK, PM2.5 significantly enhanced cell proliferation, migration and invasion, but reduced the levels of 15-lipoxygenases-1 (15-LOX1) and 15-lipoxygenases-2 (15-LOX2), both of which were also obviously decreased in lung cancer tissues. 15-LOX1/15-LOX2 overexpression inhibited the oncogenic cell functions induced by PM2.5/NNK. The tumor formation and growth were significantly higher/faster in mice implanted with PM2.5- or NNK-treated NCI-H23 cells, accompanied with a reduction of 15-LOX1/15-LOX2. Moreover, 15-LOX1 expression was epigenetically regulated at methylation level by PM2.5/NNK, while both 15-LOX1 and 15-LOX2 could be significantly inhibited by a set of PM2.5/NNK-mediated microRNAs. CONCLUSION: Collectively, PM2.5 can function as the smoking carcinogen NNK to induce lung tumorigenesis by inhibiting 15-LOX1/15-LOX2.


Assuntos
Araquidonato 15-Lipoxigenase/química , Carcinogênese/patologia , Neoplasias Pulmonares/patologia , Material Particulado/efeitos adversos , Animais , Apoptose , Biomarcadores Tumorais/metabolismo , Carcinogênese/induzido quimicamente , Carcinogênese/metabolismo , Estudos de Casos e Controles , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Inibidores de Lipoxigenase/efeitos adversos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/etiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nitrosaminas/toxicidade , Prognóstico , Fumar/efeitos adversos , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Ther Adv Med Oncol ; 11: 1758835919855228, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31275431

RESUMO

BACKGROUND: Early data showed that FOXP3 could induce epithelial-mesenchymal transition by stimulating the Wnt/ß-catenin signaling pathway in non-small cell lung cancer (NSCLC). However, how the expression of FOXP3 is regulated in NSCLC remains unknown. We thus explored the impacts of the long noncoding RNA EGFR antisense RNA 1 (EGFR-AS1) and hypoxia-inducible factor-2A (HIF2A) on FOXP3 expression and the cancer stemness of NSCLC. METHODS: Lung tissues samples from 87 patients with NSCLC and two NSCLC cell lines were used in this study. The regulation of FOXP3 and lung cancer cell stemness by EGFR-AS1 and HIF2A was determined at molecular levels in NSCLC tissue samples and cultured cells in the presence/absence of the smoking carcinogen, 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (also known as nicotine-derived nitrosamine ketone). The results were confirmed in tumor xenograft models. RESULTS: We found that NNK decreased the expression of EGFR-AS1 in the long term, but increased the expression of HIF2A and FOXP3 to stimulate lung cancer cell stemness. EGFR-AS1 significantly inhibited FOXP3 expression and NSCLC cell stemness, whereas HIF2A obviously promoted both. The enhancement of lung cancer stemness by FOXP3 was, at least partially, via stimulating Notch1, as the inhibition of Notch1 could markedly diminish the effect of FOXP3. CONCLUSIONS: FOXP3, the expression of which is under the fine control of EGFR-AS1, is a critical molecule that promotes NSCLC cancer cell stemness through stimulating the Notch1 pathway.

9.
Biochim Biophys Acta Rev Cancer ; 1871(1): 170-178, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30630091

RESUMO

FOXP3 is a transcription factor, which belongs to the family of FOX protein. FOXP3 was initially discovered in regulatory T cells and supposed to play a significant role in the process of regulatory T cell differentiation. Increasing evidence has shown that FOXP3 is also expressed in tumor cells. However, the results of tumor FOXP3 is inconsistent and even the opposite. In some types of human cancers, the expression of FOXP3 is upregulated, and it can promote the development of cancers, leading to a poor prognosis. While in some other types of cancers, it is a different story. The reason for the contradictory data is unknown. The discovery of FOXP3 isoforms, interaction between tumor cells and lymphocytes in the tumor microenvironment, subcellular location, and mutation of FOXP3 may provide some clues. In this review, we first summarize and analyze the recent development. The final section focuses on the regulation of FOXP3 expression.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Neoplasias/metabolismo , Humanos , Linfócitos do Interstício Tumoral/metabolismo , Isoformas de Proteínas , Linfócitos T Reguladores/metabolismo , Microambiente Tumoral/fisiologia
10.
Cancer Lett ; 383(2): 183-194, 2016 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-27702662

RESUMO

Emerging evidence suggests that small nucleolar RNAs (snoRNAs) and their host genes (SNHGs) have malfunctioning roles in the development of human cancers. We globally investigated the molecular mechanisms by which snoRNA host gene 6 (SNHG6) promotes hepatocellular carcinoma (HCC) progression using human tissues and cell lines. We found that SNHG6 is overexpressed in HCC tissues and in hepatoma cell lines and is closely associated with histologic grade, hepatitis B virus DNA, Barcelona Clinic Liver Cancer stage and portal vein tumor thrombus in patients with HCC. Knockdown of SNHG6 induced apoptosis and repressed cell cycle progression in hepatoma cell lines, whereas transgenic expression of SNHG6 in the immortalized human hepatic cell line L02 had opposite effects. Xenograft tumors grown from SNHG6-knockdown cells had smaller mean volumes than did tumors grown from control cells. SNHG6 may act as a competing endogenous RNA, effectively becoming a sink for miR-101-3p and thereby modulating the derepression of zinc finger E-box binding homeobox 1, imposing an additional level of post-transcriptional regulation. Functionally, SNHG6 promotes tumor growth and metastasis by inducing epithelial to mesenchymal transition. Further investigations showed that SNHG6 could affect HCC tumorigenesis by binding to up-frameshift protein 1 and regulating Smad7 expression.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , MicroRNAs/metabolismo , RNA Nucleolar Pequeno/metabolismo , Transativadores/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Idoso , Animais , Apoptose , Ligação Competitiva , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Ciclo Celular , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal , Feminino , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica , RNA Helicases , Interferência de RNA , RNA Nucleolar Pequeno/genética , Transdução de Sinais , Proteína Smad7/metabolismo , Fatores de Tempo , Transativadores/genética , Transfecção , Fator de Crescimento Transformador beta/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética
11.
Growth Horm IGF Res ; 29: 11-20, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27064376

RESUMO

Accumulating evidence has indicated that noncoding RNAs (ncRNAs) have important regulatory potential in various biological processes. The molecular mechanisms by which growth hormone receptor (GHR) deficiency protects against age-related pathologies, reduces the incidence and delays the occurrence of fatal neoplasms are unclear. The aim of this study was to investigate miRNA, lncRNA and mRNA expression profiles and the potential functional roles of these RNA molecules in GHR knockout (GHR-KO) mice. Microarray expression profiles of miRNAs, lncRNAs and mRNAs were determined in wild type control mice and in GHR-KO mice. Differential expression, pathway and gene network analyses were developed to identify the possible biological roles of functional RNA molecules. Compared to wild type control mice, 1695 lncRNAs, 914 mRNAs and 9 miRNAs were upregulated and 1747 lncRNAs, 786 mRNAs and 21 miRNAs were downregulated in female GHR-KO mice. Moreover, 1265 lncRNAs, 724 mRNAs and 41 miRNAs were upregulated and 1377 lncRNAs, 765 mRNAs and 16 miRNAs were downregulated in male GHR-KO mice compared to wild type mice. Co-expression analysis of mRNAs, lncRNAs, and miRNAs showed that mRNAs including Hemxi2, Ero1Ib, 4933434i20RIK, Pde7a and Lgals1, lncRNAs including ASMM9PARTA014848, EL605414-P1, ASMM9PARTA051724, ASMM9PARTA045378 and ASMM9PARTA049185, and miRNAs including miR-188-3p, miR-690, miR-709 and miR-710 are situated at the core position of a three-dimensional lncRNA-mRNA-miRNA regulatory network. KEGG analysis showed that the most significantly regulated pathway was steroid hormone biosynthesis. We identified a set of lncRNAs, miRNAs and mRNAs that were aberrantly expressed in GHR-KO mice. Our results provide a foundation and an expansive view of the biological activities of the GHR.


Assuntos
Proteínas de Transporte/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Animais , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Masculino , Camundongos , Camundongos Knockout , Neoplasias/genética , Transcriptoma , Regulação para Cima
12.
Tumour Biol ; 37(1): 1079-89, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26271667

RESUMO

LncRNA has provided an important new perspective regarding gene regulation. Both the expression and activation of EGFR have been proven to be under the tight control of the GHR pathway. EGFR-AS1 has been found to inhibit the expression of EGFR. GHR-siRNA and EGFR-AS1-siRNA were transfected into HCC cell lines, and a series of WB, q-PCR, and IF experiments was conducted to evaluate whether EGFR-AS1 participated in the regulation of GHR and EGFR. We found that impeded expression of GHR decreased the expression of EGFR and EGFR-AS1 in vivo and in vitro. Then, it was verified that EGFR and EGFR-AS1 were relatively upregulated in HCC tissue, and they were significantly related to some clinical characteristics and patient prognosis. Furthermore, EGFR-AS1 was determined to promote HCC development by improving the ability of invasion and proliferation of HCC cells in vitro, and it was also found to affect the cell cycle. Our study identified that EGFR-AS1 may promote HCC genesis and development. EGFR-AS1 may act as a prognostic factor in HCC. More importantly, we observed that the inhibition of EGFR-AS1 in HCC cells significantly impeded cell proliferation and invasion in vivo, which might provide a potential possibility for targeted therapy of HCC.


Assuntos
Carcinoma Hepatocelular/genética , Proteínas de Transporte/genética , Receptores ErbB/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , RNA Longo não Codificante/genética , Animais , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal , Feminino , Perfilação da Expressão Gênica , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Knockout , Metástase Neoplásica , Prognóstico , Carga Tumoral , Regulação para Cima
13.
World J Gastroenterol ; 21(5): 1636-40, 2015 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-25663784

RESUMO

AIM: To evaluate whether the application of sorafenib during the peri-operative period of liver transplantation improves prognosis in liver cancer patients. METHODS: We searched PubMed, EMBASE and MEDLINE for eligible articles. A total of 4 studies were found that fulfilled the previously agreed-upon standards. We then performed a systematic review and meta-analysis on the enrolled trials that met the inclusion criteria. RESULTS: Out of the 104 studies identified in the database, 82 were not clinical experiments, and 18 did not fit the inclusion standards. Among the remaining 4 articles, only 1 was related to the preoperative use of sorafenib, whereas the other 3 were related to its postoperative use. As the heterogeneity among the 4 studies was high, with an I(2) of 86%, a randomized effect model was applied to pool the data. The application of sorafenib before liver transplantation had a hazard ratio (HR) of 3.29 with a 95% confidence interval (CI) of 0.33-32.56. The use of sorafenib after liver transplantation had an HR of 1.44 (95%CI: 0.27-7.71). The overall pooled HR was 1.68 (95%CI: 0.41-6.91). CONCLUSION: The results showed that the use of sorafenib during the peri-operative period of liver transplantation did not improve patient survival significantly. In fact, sorafenib could even lead to a worse prognosis, as its use may increase the hazard of poor survival.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/cirurgia , Transplante de Fígado , Terapia Neoadjuvante , Niacinamida/análogos & derivados , Compostos de Fenilureia/administração & dosagem , Inibidores de Proteínas Quinases/administração & dosagem , Antineoplásicos/efeitos adversos , Quimioterapia Adjuvante , Distribuição de Qui-Quadrado , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Transplante de Fígado/efeitos adversos , Transplante de Fígado/mortalidade , Terapia Neoadjuvante/efeitos adversos , Terapia Neoadjuvante/mortalidade , Niacinamida/administração & dosagem , Niacinamida/efeitos adversos , Razão de Chances , Compostos de Fenilureia/efeitos adversos , Inibidores de Proteínas Quinases/efeitos adversos , Fatores de Risco , Sorafenibe , Fatores de Tempo , Resultado do Tratamento
14.
Medicine (Baltimore) ; 94(4): e489, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25634198

RESUMO

Alterations in methionine metabolism that involve changes in the plasma S-adenosylmethionine (SAMe) level occur in chronic liver diseases. However, no evidence is available on whether circulating SAMe is involved in the development of liver cirrhosis and liver cancer. Cross-sectional data on clinical characteristics and plasma SAMe were collected for 130 cases of chronic hepatitis B (CHB) and HCC as well as for normal volunteers. Univariate and multivariate linear regression and receiver operating characteristic curves were introduced to determine their correlations. Serum ALB and PT levels were independent clinical factors that were correlated with the plasma SAMe levels in CHB and HCC patients. A higher SAMe concentration was observed in the HCC than in the normal and CHB. By exploring the association of the Child-Pugh score with the plasma SAMe level, we found a higher SAMe level at advanced Stage C than at stage A in CHB and HCC patients. We further assessed the diagnostic performance of SAMe with respect to the stages of liver fibrosis and Child-Pugh stage. The AUROC of SAMe for the prediction of cirrhosis was 0.721, and the sensitivity and specificity was 0.707 and 0.769, respectively. The AUROC of plasma SAMe to predict Child-Pugh stage C was 0.706 in patients with CHB and 0.825 in HCC patients. The sensitivity was 0.467 and 0.800, respectively; the specificity was 0.904 and 0.781, respectively. The plasma SAMe level was positively correlated with the severity of liver disease and might be a potential noninvasive biomarker.


Assuntos
Hepatite B Crônica/sangue , Hepatopatias/sangue , S-Adenosilmetionina/sangue , Índice de Gravidade de Doença , Estudos de Casos e Controles , Feminino , Humanos , Hepatopatias/virologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Prospectivos , Tempo de Protrombina , Curva ROC , Sensibilidade e Especificidade , Albumina Sérica
15.
J Biol Chem ; 289(47): 32639-55, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25271158

RESUMO

Patients with chronic hepatitis B usually exhibit a low response to treatment with interferon α (IFN-α). An alternative approach to increase the response rate of IFN-α might be to immunologically stimulate the host with glucocorticoids (GCs) before treatment with IFN-α, but the underlying mechanism remains unclear. We hypothesized that the GCs enhance IFN signaling by inducing S-adenosylmethionine (AdoMet) when hepatitis B virus (HBV) replication was effectively suppressed by IFN-α. Here, we investigated the effect of GCs and IFN-α on AdoMet production and methionine adenosyltransferase 1A (MAT1A) expression in vitro. Furthermore, we determined whether post-transcriptional regulation is involved in HBV-repressed MAT1A expression and AdoMet production induced by dexamethasone (Dex). We found that AdoMet homeostasis was disrupted by Dex and that Dex directly regulated MAT1A expression by enhancing the binding of the glucocorticoid receptor (GR) to the glucocorticoid-response element (GRE) of the MAT1A promoter. HBV reduced AdoMet production by increasing methylation at GRE sites within the MAT1A promoter. The X protein of hepatitis B virus led to hypermethylation in the MAT1A promoter by recruiting DNA methyltransferase 1, and it inhibited GR binding to the GRE in the MAT1A promoter. Dex could increase an antiviral effect by inducing AdoMet production via a positive feedback loop when HBV is effectively suppressed by IFN-α, and the mechanism that involves Dex-induced AdoMet could increase STAT1 methylation rather than STAT1 phosphorylation. These findings provide a possible mechanism by which GC-induced AdoMet enhances the antiviral activity of IFN-α by restoring STAT1 methylation in HBV-infected cells.


Assuntos
Glucocorticoides/farmacologia , Vírus da Hepatite B/efeitos dos fármacos , Interferon-alfa/farmacologia , S-Adenosilmetionina/metabolismo , Fator de Transcrição STAT1/metabolismo , Antivirais/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA/efeitos dos fármacos , Dexametasona/farmacologia , Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Vírus da Hepatite B/fisiologia , Humanos , Immunoblotting , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/metabolismo , Metilação/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Receptores de Glucocorticoides/metabolismo , Elementos de Resposta/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos
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