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1.
J. physiol. biochem ; 79(4): 685-693, nov. 2023.
Artigo em Inglês | IBECS | ID: ibc-227545

RESUMO

Neuronal death occurs in various physiological and pathological processes, and apoptosis, necrosis, and ferroptosis are three major forms of neuronal death. Neuronal apoptosis, necrosis, and ferroptosis are widely identified to involve the progress of stroke, Parkinson’s disease, and Alzheimer’s disease. A growing body of evidence has pointed out that neuronal death is tightly associated with expression of related genes and alteration of signaling molecules. In addition, recently, epigenetics has been increasingly focused on as a vital regulatory mechanism for neuronal apoptosis, necrosis, and ferroptosis, providing a new direction for treating nervous system diseases. Moreover, growing researches suggest that histone methylation or demethylation is involved in the processes of neuronal apoptosis, necrosis, and ferroptosis. These researches may imply that studying the potential roles of histone methylation is essential for treating the nervous system diseases. Here, we review potential roles of histone methylation and demethylation in neuronal death, which may give us a new direction in treating the nervous system diseases. (AU)


Assuntos
Humanos , Histonas , Doenças do Sistema Nervoso/patologia , Morte Celular/fisiologia , Metilação , Necrose
2.
Clin. transl. oncol. (Print) ; 25(6): 1594-1605, jun. 2023. ilus
Artigo em Inglês | IBECS | ID: ibc-221192

RESUMO

Hepatocellular carcinoma (HCC) is the prevalent form of liver cancer in adults and the fourth most common cause of cancer-related death worldwide. HCC predominantly arises in the context of cirrhosis as a result of chronic liver disease, injury and inflammation. Full-blown HCC has poor prognosis because it is highly aggressive and resistant to therapy. Consequently, interventions that can prevent or restrain HCC emergence from pre-cancerous diseased liver are a desirable strategy. Histone methylation is a dynamic, reversible epigenetic modification involving the addition or removal of methyl groups from lysine, arginine or glutamine residues. Aberrant activity of histone methylation writers, erases and readers has been implicated in several cancer types, including HCC. In this review, we provide an overview of research on the role of histone methylation in pre-cancerous and cancerous HCC published over the last 5 years. In particular, we present the evidence linking environmental factors such as diet, viral infections and carcinogenic agents with dysregulation of histone methylation during liver cancer progression with the aim to highlight future therapeutic possibilities (AU)


Assuntos
Humanos , Adulto , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Histonas/metabolismo , Lesões Pré-Cancerosas , Metilação
3.
Clin. transl. oncol. (Print) ; 25(6): 1719-1728, jun. 2023. graf
Artigo em Inglês | IBECS | ID: ibc-221204

RESUMO

Background There is growing evidence that methylation-associated genes (MAGs) play an important role in the prognosis of acute myeloid leukemia (AML) patients. Thus, the aim of this research was to investigate the impact of MAGs in predicting the outcomes of AML patients. Methods The expression profile and clinical information of patients were downloaded from public databases. A novel prognostic model based on 7 MAGs was established in the TCGA training cohort and validated in the GSE71014 dataset. To validate the clinical implications, the correlation between MAGs signature and drug sensitivity was further investigated. Results 76 genes were screened out by the univariate Cox regression and significantly enriched in multiple methylation-related pathways. After filtering variables using LASSO regression analysis, 7 MAGs were introduced to construct the predictive model. The survival analysis showed overall survival of patients with the high-risk score was considerably poorer than that with the low-risk score in both the training and validating cohorts (p < 0.01). Furthermore, the risk score system as a prognostic factor also worked in the intermediate-risk patients based on ELN-2017 classification. Importantly, the risk score was demonstrated to be an independent prognostic factor for AML in the univariate and multivariate Cox regression analysis. Interestingly, GSEA analysis revealed that multiple metabolism-related pathways were significantly enriched in the high-risk group. Drug sensitivity analysis showed there was a significant difference in sensitivity of some drugs between the two groups. Conclusion We developed a robust and accurate prognostic model with 7 MAGs. Our findings might provide a reference for the clinical prognosis and management of AML (AU)


Assuntos
Humanos , Leucemia Mieloide Aguda/genética , Bases de Dados Factuais , Análise Multivariada , Metilação , Prognóstico
4.
Clin. transl. oncol. (Print) ; 25(3): 673-684, mar. 2023.
Artigo em Inglês | IBECS | ID: ibc-216426

RESUMO

Aims This study set out to examine the expression and methylation levels of miR-486-5p/miR-34c-5p and its mechanism of action based on the microRNA methylation level of circulating tumor cells (CTCs) in colorectal cancer (CRC) through clinical data and tissue detection. Methods EGFR and EpCAM immunophospholipid magnetic spheres (EpCAM-IML/EGFR-IML) were synthesized by the thin film method to capture CTCs in peripheral blood. The expression of miR-486-5p/miR-34c-5p was detected via real-time fluorescent quantitative PCR (RT-PCR). Methylation-specific PCR was implemented to detect the methylation level of miR-486-5p/miR-34c-5p, and 5-Aza-dC was used for demethylation treatment to detect the effect of changes in methylation levels on the tumor cells development. Cell Counting Kit-8 (CCK-8) analysis, transwell assay, and flow cytometry were used to determine the effects of demethylation and overexpression on the proliferation, invasion, migration, and apoptosis of CRC cells. Results The results showed that the expression and methylation levels of the miR-486-5p/miR-34c-5p isolated from CTCs were low and the methylation level was high in tumor cells and tissues. In CRC cell lines, demethylation and overexpression of miR-486-5p/miR-34c-5p could effectively inhibit the proliferation, invasion and migration of tumor cells, and facilitate tumor apoptosis (p < 0.05). Conclusion The constructed CTCs sorting system has characteristics of high specificity and high sensitivity, is a supplement to tissue samples, and has guiding significance for the clinical rational use of drugs and personalized therapy (AU)


Assuntos
Humanos , Neoplasias Colorretais/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Células Neoplásicas Circulantes , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Células Epiteliais , Receptores ErbB/genética , Metilação , Reação em Cadeia da Polimerase em Tempo Real
5.
Clin. transl. oncol. (Print) ; 25(1): 269-282, ene. 2023.
Artigo em Inglês | IBECS | ID: ibc-215840

RESUMO

Background Thyroid cancer (TC) is the most common endocrine malignancy worldwide, and immunotherapy is a new cancer treatment that stimulates and enhances the natural ability of the immune system to fight cancer cells. The role of RNA N6-methyladenosine (m6A) related genes in these challenges has recently become a research hotspot, but he potential role of m6A modifications in tumor microenvironment (TME) cell infiltration remains unknown. Purpose There is growing evidence that m6A plays a critical role in the regulation of gene expression by participating in important biological processes. A comprehensive analysis of the m6A regulator-mediated infiltration characteristics of the TME will help advance the understanding of immune regulation in thyroid tumors. Methods This study assessed m6A modification modes in 510 thyroid cancer samples from the Cancer Genome Atlas (TCGA) databases according to a comprehensive set of 24 m6A regulators. In this study, we analyzed the biological characteristics and m6A methylation modification patterns. Based on this, we constructed m6A signatures and analyzed m6A modification features in tumor somatic mutations and TCGA molecular subtypes. Results These modification modes were systematically linked to TME cell infiltration signatures. m6A modification patterns were comprehensively assessed and correlated with immune cell infiltration features in the TME. An unsupervised clustering approach was applied and three distinct m6A modification subtypes and three m6A-associated gene subtypes were identified. Additionally, three distinct m6A methylation modification modes were identified in the thyroid cancer samples. The TME profiles of the identified genetic subtypes were strongly congruent with the immuno-heat and immuno-cold phenotypes... (AU)


Assuntos
Humanos , Neoplasias da Glândula Tireoide/genética , Microambiente Tumoral/genética , RNA/genética , Metilação
6.
Clin. transl. oncol. (Print) ; 24(10): 1940–1953, octubre 2022. tab, graf
Artigo em Inglês | IBECS | ID: ibc-207950

RESUMO

Purpose: Distal metastases are a major cause of poor prognosis in colorectal cancer patients. Approximately 95% of metastatic colorectal cancers are defined as DNA mismatch repair proficient (pMMR). Our previous study found that miR-6511b-5p was downregulated in pMMR colorectal cancer. However, the mechanism of miR-6511b-5p in pMMR colorectal cancer metastases remain unclear.MethodsWe first used quantitative real-time PCR to evaluate the role of miR-6511b-5p in colorectal cancer. Second, we conducted invasion assays and wound healing assays to investigate the role of miR-6511b-5p and CD44 in colorectal cancer cells metastases. Third, luciferase reporter assay, in situ hybridization (ISH), and immunohistochemistry assays were performed to study the relationship between miR-6511b-5p and BRG1. Finally, real-time quantitative PCR, immunohistochemistry, and chromatin immunoprecipitation (ChIP) assays were performed to analyze the relationship between BRG1 and CD44 in colorectal cancer.ResultsWe found that lower expression of miR-6511b-5p appeared more often in pMMR colorectal cancer patients compared with dMMR (mismatch repair deficient) cases, and was positively correlated with metastases. In vitro, overexpression of miR-6511b-5p inhibited metastasis by decreasing CD44 expression via directly targeting BRG1 in colorectal cancer. Furthermore, BRG1 knockdown decreased the expression of CD44 by promoting CD44 methylation in colorectal cancer cells.ConclusionOur data suggest that miR-6511b-5p may act as a promising biomarker and treatment target for pMMR colorectal cancer, particularly in metastatic patients. Mechanistically, miR-6511b-5p suppresses invasion and migration of colorectal cancer cells through methylation of CD44 via directly targeting BRG1. (AU)


Assuntos
Humanos , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Colorretais , Regulação Neoplásica da Expressão Gênica , Metilação , MicroRNAs
7.
Clin. transl. oncol. (Print) ; 24(10): 2044-2044, octubre 2022.
Artigo em Inglês | IBECS | ID: ibc-207960

RESUMO

Histone lysine methylation plays a key role in gene activation and repression. The trimethylation of histone H3 on lysine-27 (H3K27me3) is a critical epigenetic event that is controlled by Jumonji domain-containing protein-3 (JMJD3). JMJD3 is a histone demethylase that specifically removes methyl groups. Previous studies have suggested that JMJD3 has a dual role in cancer cells. JMJD3 stimulates the expression of proliferative-related genes and increases tumor cell growth, propagation, and migration in various cancers, including neural, prostate, ovary, skin, esophagus, leukemia, hepatic, head and neck, renal, lymphoma, and lung. In contrast, JMJD3 can suppress the propagation of tumor cells, and enhance their apoptosis in colorectal, breast, and pancreatic cancers. In this review, we summarized the recent advances of JMJD3 function in cancer cells. (AU)


Assuntos
Humanos , Metilação , Neoplasias , Apoptose
8.
J. physiol. biochem ; 78(1): 1-8, feb. 2022.
Artigo em Inglês | IBECS | ID: ibc-215868

RESUMO

Stroke, also known as cerebral stroke or cerebrovascular accident, refers to acute ischemic or hemorrhagic encephalopathy caused by a disturbance to cerebral blood flow. Ischemic stroke is the most common type of cerebral stroke, accounting for approximately 80% of the total incidence of clinical stroke. High morbidity, disability, and mortality rates place heavy burdens on the families of patients and society. An increasing number of studies have shown that histone modification plays an important role in the pathogenesis of ischemic stroke, but most studies on histone modification focus on acetylation, and studies on the role of histone methylation in the pathogenesis of ischemic stroke are limited. Here, we review the role of histone methylation and related histone methyltransferase (HMT) inhibitors in the pathogenesis of ischemic stroke and related HMT inhibitors in the treatment of ischemic stroke, which may open up a new avenue to the study of ischemic stroke. (AU)


Assuntos
Humanos , Isquemia Encefálica/patologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/genética , Histonas/metabolismo , Metilação , Modificação Traducional de Proteínas
9.
Clin. transl. oncol. (Print) ; 23(11): 2269-2279, nov. 2021. ilus
Artigo em Inglês | IBECS | ID: ibc-223421

RESUMO

Methylation of N6-adenosine (m6A) is the most prevalent internal RNA modification and is especially common among the messenger RNAs. These m6A modifications regulate splicing, translocation, stability and translation of RNA through dynamic and reversible interactions with m6A-binding proteins, namely the writers, erasers and readers. RNA methyltransferases catalyze the m6A modifications, while demethylases reverse this methylation. Deregulation of the m6A modification process has been implicated in human carcinogenesis, including melanoma—which carries one of the highest mutant rates. In this review, we provide an up-to-date summary of m6A regulation and its biological impacts on normal and cancer cells, with emphasis on the deregulation of m6A modification and m6A regulators in melanoma. In addition, we highlight the prospective potential of exploiting m6A modification in the treatment of melanoma and non-cancer diseases. (AU)


Assuntos
Humanos , Adenosina/análogos & derivados , Melanoma/metabolismo , Metiltransferases/metabolismo , Processamento Pós-Transcricional do RNA , RNA Mensageiro/metabolismo , Neoplasias Cutâneas/metabolismo , Adenosina/metabolismo , Adenosina/fisiologia , Expressão Gênica , Melanoma/genética , Metilação , Metiltransferases/genética , Mutação , Oxirredutases N-Desmetilantes/metabolismo , Neoplasias Cutâneas/genética
10.
Nutr. hosp ; 38(5)sep.-oct. 2021. tab
Artigo em Inglês | IBECS | ID: ibc-224647

RESUMO

Background: the biological activity of vitamin D depends on the activity of its receptor or VDR. On the other hand, the activity of this receptor is influenced by its state of methylation. The objective of this study was to verify if the BsmI polymorphism of the VDR gene influences its methylation profile in adolescents. Secondly, it was to verify if the status of some metabolic factors (oxidative stress, inflammation, lipid profile, and glycemia) in the serum, and gender-adjusted vitamin D levels are independent factors with an influence on the VDR methylation profile. Methods and results: the study included 198 adolescents of both sexes, aged 15-19 years, who underwent testing for VDR gene methylation polymorphisms, serum vitamin D levels, and metabolic, oxidative stress, and systemic inflammation markers. It was observed that the BB genotype was less methylated than the other groups (26.1 % versus 30.3 %, and 29.3 % for Bb and bb, respectively), although without statistical differences between them. The odds ratio indicated a protection of 13 % (partially methylated) for vitamin D status, while alpha glycols increased the risk ratio (of being partially methylated) by 3 %. MDA was protective at a 28 % chance of risk that adolescents with higher levels of lipid peroxidation would be hypomethylated. Conclusion: we conclude that the methylation profile of the VDR gene is not influenced by the different BsmI polymorphism genotypes, and that serum vitamin D and serum markers of oxidative stress and inflammation can modulate this profile. (AU)


Antecedentes: la actividad biológica de la vitamina D depende de la actividad de su receptor, el VDR. Por otro lado, la actividad de este receptor está influenciada por su estado de metilación. El objetivo de este estudio es verificar si el polimorfismo BsmI del gen VDR influye en el perfil de metilación del mismo en los adolescentes. En segundo lugar, verificar si los factores metabólicos (estrés oxidativo, inflamación, perfil lipídico y glucemia) del suero y la vitamina D ajustada por sexo actúan independientemente de los polimorfismos sobre el perfil de metilación del VDR. Métodos y resultados: el estudio incluyó a 198 adolescentes de ambos sexos, de 15 a 19 años de edad, que se sometieron a análisis de polimorfismos de metilación del gen VDR, niveles de vitamina D, marcadores metabólicos, estrés oxidativo e inflamación sistémica. Se observó que el genotipo BB estaba menos metilado que los otros grupos (26,1 % contra 30,3 % y 29,3 % para Bb y bb respectivamente), aunque sin diferencias estadísticas entre ellos. El odds ratio indicó una protección del 13 % (parcialmente metilado) para el estado de la vitamina D, mientras que los alfa glicoles aumentaron el índice de riesgo (de estar parcialmente metilado) en un 3 %. La MDA fue protectora con un 28 % de probabilidad de riesgo de que los adolescentes con niveles más altos de peroxidación lipídica fueran hipometilados. Conclusión: concluimos que el perfil de metilación del gen VDR no está influenciado por los diferentes genotipos del polimorfismo BsmI y que la vitamina D y los marcadores de estrés oxidativo e inflamación en el suero pueden modular este perfil. (AU)


Assuntos
Humanos , Masculino , Feminino , Adolescente , Inflamação/genética , Metilação , Fatores Sexuais , Receptores de Calcitriol/genética , Receptores de Calcitriol/efeitos dos fármacos , Inflamação/prevenção & controle , Metaboloma/genética , Estresse Oxidativo/genética , Polimorfismo Genético/genética
11.
Clin. transl. oncol. (Print) ; 23(7): 1440-1451, jul. 2021. ilus
Artigo em Inglês | IBECS | ID: ibc-221984

RESUMO

Purpose Altered miRNAs play a crucial role in the emergence of the breast cancer stem cell (BCSC) phenotype. The interplay between miRNAs and methylation enzymes has been documented. One of the most aggressive breast cancer cell lines, MDA-MB-231, has expressed much more DNMT3B than DNMT3A. This study aims to evaluate the ability of miR-203 restoration and miR-150 inhibition to regulate DNMT3B and DNMT3A to modify the methylation level of BCSC-associated genes. Methods MDA-MB-231 cells were transfected with miR-203 mimic or miR-150 inhibitor or DNMT3B siRNA, and downstream analysis was performed by flow cytometry, real-time PCR and Western blotting. Results DNMT3A and DNMT3B are regulated both by miR-203a-3p and miR-150-5p. Transfection with miR-203 mimic and miR-150 inhibitor significantly reduced the CD44+CD24− subpopulation and down-regulated the expression of CD44 mRNA by increasing promoter methylation levels. SiRNA knockdown of DNMT3B increased the CD44+CD24− subpopulation and the expression of CD44 and ALDH1A3 by decreasing methylation density. The inhibition of miR-150 down-regulated OCT3/4 and SOX2 expression without affecting methylation levels, while miR-203 restoration and miR-150 inhibition down-regulated NANOG expression by elevating the methylation level. A positive-feedback loop was found between miR-203 and its target DNMT3B, as restoring miR-203 suppressed DNMT3B, while knocking down DNMT3B up-regulated miR-203. The restoration of miR-203 and knockdown of DNMT3B decreased methylation levels and increased the expression of miR-141 and miR-200c. Conclusions The study concluded that miR-203 and miR-150 play a role in the regulation of genes involved in BCSC methylation, including other miRNAs, by targeting DNMT3B and DNMT3A (AU)


Assuntos
Humanos , Feminino , Neoplasias da Mama/genética , DNA (Citosina-5-)-Metiltransferase 1/fisiologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Metilação , Células Tumorais Cultivadas
12.
Arch. bronconeumol. (Ed. impr.) ; 56(8): 506-513, ago. 2020. tab, graf
Artigo em Inglês | IBECS | ID: ibc-198191

RESUMO

INTRODUCTION: MicroRNA-7 (miR-7) has a suppressive role in lung cancer and alterations in its DNA methylation may contribute to tumorigenesis. As COPD patients with emphysema have a higher risk of lung cancer than other COPD phenotypes, we compared the miR-7 methylation status among smoker subjects and patients with various COPD phenotypes to identify its main determinants. METHODS: 30 smoker subjects without airflow limitation and 136 COPD patients without evidence of cancer were recruited in a prospective study. Clinical and functional characteristics were assessed and patients were classified into: frequent exacerbator, emphysema, chronic bronchitis and asthma COPD overlap (ACO). DNA collected from buccal epithelial samples was isolated and bisulfite modified. miR-7 methylation status was evaluated by quantitative methylation-specific polymerase chain reaction (qMSP). RESULTS: miR-7 Methylated levels were higher in COPD patients than in smokers without airflow limitation (23.7 ± 12.4 vs. 18.5 ± 8.8 %, p = 0.018). Among COPD patients, those with emphysema had higher values of methylated miR-7 (27.1 ± 10.2 %) than those with exacerbator (19.4 ± 9.9 %, p = 0.004), chronic bronchitis (17.3 ± 9.0 %, p = 0.002) or ACO phenotypes (16.0 ± 7.2 %, p = 0.010). After adjusting for clinical parameters, differences between emphysematous patients and those with other phenotypes were retained. In COPD patients, advanced age, mild-moderate airflow limitation, reduced diffusing capacity and increased functional residual capacity were identified as independent predictors of methylated miR-7 levels. CONCLUSION: The increase of miR-7 methylation levels experienced by COPD patients occurs mainly at the expense of the emphysema phenotype, which might contribute to explain the higher incidence of lung cancer in these patients


INTRODUCCIÓN: El microRNA-7 (miR-7) tiene un papel supresor en el cáncer de pulmón, y las alteraciones en la metilación de su DNA podrían contribuir a la tumorogénesis. Como los pacientes con EPOC y enfisema presentan un mayor riesgo de sufrir cáncer de pulmón frente a otros fenotipos de EPOC, comparamos la metilación de miR-7 entre los pacientes fumadores y los pacientes con varios fenotipos de EPOC para identificar sus factores determinantes principales. MÉTODOS: Se reclutaron para un estudio prospectivo 30 sujetos fumadores sin restricciones en el flujo aéreo y 136 pacientes con EPOC sin evidencia de cáncer. Se valoraron las características clínicas y funcionales y se clasificaron a los pacientes en: exacerbaciones frecuentes, enfisema, bronquitis crónica y solapamiento de asma y EPOC (ACO, por sus siglas en inglés). Se recogió ADN a partir de muestras de epitelio bucal, se aisló y se modificó con bisulfito. El estado de metilación del miR-7 se evaluó mediante la reacción cuantitativa en cadena de la polimerasa específica de la metilación (qMPS por sus siglas en inglés). RESULTADOS: Los niveles de metilación del miR-7 fueron más altos en los pacientes con EPOC que en los fumadores sin restricciones en el flujo aéreo (23,7 ± 12,4 frente a 18,5 ± 8,8%, p = 0,018). Entre los pacientes con EPOC, aquellos con enfisema presentaban valores más altos de miR-7 metilado (27,1 ± 10,2%) que aquellos con exacerbaciones (19,4 ± 9,9%, p = 0,004), bronquitis crónica (17,3 ± 9,0%, p = 0,002) o los fenotipos ACO (16,0 ± 7,2%, p = 0,010). Tras ajustar los resultados a los parámetros clínicos, las diferencias entre los pacientes enfisematosos y aquellos con otros fenotipos permanecieron. En los pacientes con EPOC, se identificaron como predictores independientes de los niveles de metilación del miR-7 a: la edad avanzada, limitación al flujo aéreo leve-moderada, capacidad de difusión reducida y capacidad residual funcional aumentada. CONCLUSIÓN: El aumento de los niveles de metilación del miR-7 que experimentan los pacientes con EPOC ocurre principalmente a expensas del fenotipo con enfisema, lo que podría contribuir a explicar la mayor incidencia de cáncer de pulmón en estos pacientes


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Metilação , MicroRNAs/metabolismo , Enfisema Pulmonar/metabolismo , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/metabolismo , Estudos Prospectivos , Fenótipo
13.
Med. oral patol. oral cir. bucal (Internet) ; 25(4): e481-e487, jul. 2020. tab, ilus
Artigo em Inglês | IBECS | ID: ibc-196500

RESUMO

BACKGROUND: Phosphatase and tensin homolog (PTEN) acts as a tumor suppressor gene. Inactivation of PTEN has been reported in various types of cancers. PTEN promoter methylation possibly underlies PTEN inactivation, which results in tumorigenesis. The aim of this study was to investigate whether PTEN promoter methylation contributes to PTEN inactivation in ameloblastoma and its associated protein expression. MATERIAL AND METHODS: In total, 20 fresh-frozen ameloblastoma samples were evaluated for PTEN promoter methylation using methylation-specific polymerase chain reaction (MS-PCR). A subset of 10 paraffin-embedded ameloblastoma samples was examined for PTEN expression through immunohistochemistry. Four primary cultured ameloblastoma cells were investigated for PTEN promoter methylation and PTEN transcriptional expression via reverse transcription PCR. RESULTS: PTEN promoter methylation was detected in 65% (13/20) of the ameloblastoma samples. Of 10 ameloblastoma samples, 4 exhibited reduced PTEN expression. Of 5 samples with methylated PTEN, 3 (60%) were associated with loss of PTEN expression. However, PTEN expression was detected in 4 (80%) of 5 samples with unmethylated PTEN. In addition, 3 (75%) of 4 primary ameloblastoma cell cultures exhibited an inverse correlation between PTEN promoter methylation and PTEN transcription level. CONCLUSIONS: PTEN promoter methylation is found in a number of ameloblastomas but not significantly correlated with loss of PTEN expression. Genetic or epigenetic mechanisms other than PTEN promoter methylation may contribute to PTEN inactivation in ameloblastoma tumor cells


No disponible


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , PTEN Fosfo-Hidrolase/análise , Metilação , Ameloblastoma/metabolismo , Neoplasias Maxilomandibulares/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Inclusão em Parafina , Imuno-Histoquímica , Neoplasias Maxilomandibulares/genética , Ameloblastoma/genética , Epigênese Genética
14.
Reumatol. clín. (Barc.) ; 16(3): 229-234, mayo-jun. 2020. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-194356

RESUMO

BACKGROUND: IL-6 mRNA expression is significantly high in many autoimmune diseases such as Behçet's disease; this is often related with more aggressive phenotypes. Nevertheless, the essential molecular process for its high expression has not been completely realized. The aim of this study was undertaken to estimate the gene copy number variation and promoter methylation to IL-6's high expression. METHODS: This study was performed on 51 patients and 61 healthy controls. Initially, DNA and RNA were extracted from all specimens. Promoter methylation levels of IL-6 were evaluated by MeDIP-qPCR technique. Also, IL-6 gene expression was measured by Real-time PCR. After that, we evaluated the relationship between gene expression and methylation, as well as their relationship with clinical specification. RESULTS: As we expected, the expression level of IL-6 gene increased significantly in the patient group compared to the healthy subjects. Also, the relative promoter methylation level of the IL-6 mRNA was significantly lower in patient group compared to healthy group (p < 0.001). DISCUSSION: We disclosed that the promoter hypomethylation may be considered as one of the main defects for IL-6 mRNA high expression in patients with Behçet's disease


ANTECEDENTES: La expresión de ARNm de IL-6 es significativamente elevada en muchas enfermedades autoinmunes, tales como el síndrome de Behçet, y ello se relaciona a menudo con fenotipos más agresivos. Sin embargo, no se ha comprendido plenamente el proceso molecular esencial para esta expresión elevada. El objetivo de este estudio fue la estimación de la variación del número de copias del gen, y la metilación del promotor de la expresión elevada de IL-6. MÉTODOS: Este estudio se realizó en 51 pacientes y 61 controles sanos. Al inicio, se extrajo ADN y ARN de todas las muestras. Se evaluaron los niveles de metilación del promotor de IL-6 mediante la técnica MeDIP-qPCR. También se midió la expresión del gen IL-6 mediante PCR a tiempo real. Tras ello, evaluamos la relación entre la expresión del gen y la metilación, así como su relación con la especificación clínica. RESULTADOS: Según lo previsto, el nivel de expresión del gen IL-6 se incrementó significativamente en el grupo de pacientes, con respecto a los sujetos sanos. También encontramos que el nivel relativo de metilación del promotor de ARNm de IL-6 fue considerablemente menor en el grupo de pacientes, con respecto al grupo sano (p < 0,001). DISCUSIÓN: Concluimos que la hipometilación del promotor puede considerarse uno de los defectos principales de la expresión elevada de ARNm de IL-6, en los pacientes con síndrome de Behçet


Assuntos
Humanos , Metilação/efeitos dos fármacos , Interleucina-6/sangue , Interleucina-6/imunologia , Síndrome de Behçet/sangue , Síndrome de Behçet/genética , Interleucina-6/genética , Anti-Inflamatórios/uso terapêutico , RNA/isolamento & purificação , DNA/isolamento & purificação , Reação em Cadeia da Polimerase
15.
Rev. osteoporos. metab. miner. (Internet) ; 9(4): 114-120, nov.-dic. 2017. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-169411

RESUMO

Introducción: En pacientes con enfermedad renal crónica (ERC), la hiperfosfatemia agrava tanto la hiperplasia paratiroidea como la síntesis y secreción de PTH. La mayor hiperplasia se asocia a descensos en la expresión génica de los receptores de calcio (CaSR), vitamina D (VDR) y también de α-Klotho, induciendo resistencia de la glándula paratiroides para responder tanto al tratamiento como a los aumentos de FGF23. Este estudio examinó la posible contribución epigenética del fósforo elevado en agravar el hiperparatiroidismo secundario (HPTS). Material y métodos: Se comparó el grado de metilación mediante pirosecuenciación de bisulfito en secuencias ricas en CpG de los promotores en los genes del CaSR, VDR, PTH y α-Klotho en ADN de glándulas paratiroides de ratas urémicas alimentadas con dieta con contenido normal y elevado en fósforo. Resultados: La dieta rica en fósforo incrementó la expresión de PTH y causó una marcada reducción del grado de metilación en el promotor del gen de PTH. En cambio, las regiones promotoras de los genes de CaSR, VDR y α-Klotho no mostraron diferencias significativas en el porcentaje de metilación entre ambos grupos de ratas, no siendo, por tanto, éste el mecanismo determinante de la disminución de la expresión de estos genes observada en el HPTS. Conclusiones: Las alteraciones epigenéticas inducidas por la dieta rica en fósforo en el HPTS, en particular la hipometilación del gen de la PTH, podrían contribuir a los aumentos que se producen en la síntesis y secreción de esta hormona. La identificación de los mecanismos implicados permitiría diseñar mejores tratamientos para el HPTS en fases tempranas de la ERC (AU)


Introduction: Hyperphosphataemia aggravates both parathyroid hyperplasia and PTH secretion in patients with chronic kidney disease (CKD). Hyperplasia is associated with decreases in calcium receptor expression (CaSR), vitamin D (VDR) and α-Klotho, inducing resistance of the parathyroid gland to respond both to treatment and to increases in FGF23. This study examined the possible epigenetic contributions of raised phosphorus to aggravate secondary hyperparathyroidism (SHPT) in patients with (CRD). Material and methods: The degree of methylation was compared by pyrosequencing of bisulfite in CpGrich sequences of the promoters in the CaSR, VDR, PTH and α-Klotho genes in parathyroid gland DNA from uremic rats fed a normal and high phosphorus diet. Results: The diet rich in phosphorus increased PTH expression and caused a marked reduction in the degree of methylation in the promoter of the PTH gene. In contrast, the promoter regions of the CaSR, VDR and α-Klotho genes did not show significant differences in the percentage of methylation between the two groups of rats. Thus, it was not the determining mechanism for the decrease of the expression of these genes observed in the SHPT. Conclusions: The epigenetic alterations induced by the phosphorus rich diet in SHPT, particularly the PTH gene hypomethylation, could contribute to the increases that occur in the synthesis and secretion of this hormone. The identification of the mechanisms involved would allow better treatments for SHPT to be designed in the early stages of CKD (AU)


Assuntos
Animais , Ratos , Fósforo/uso terapêutico , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/genética , Hiperfosfatemia/complicações , Metilação , Modelos Animais , Fósforo/efeitos adversos , Hiperparatireoidismo Secundário/diagnóstico , Hiperparatireoidismo Secundário/genética , Neoplasias das Paratireoides/complicações , Metilação de DNA , Metilação de DNA/genética , Glândulas Paratireoides/patologia , Ratos Wistar , 28599
16.
Rev. senol. patol. mamar. (Ed. impr.) ; 30(4): 162-169, oct.-dic. 2017. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-169442

RESUMO

Introducción. El cáncer de mama es una enfermedad muy heterogénea a nivel clínico, morfológico y biológico, que se clasifica en diferentes subgrupos. El tipo «triple negativo» representa el 10-20% de todos los cánceres de mama, frecuentemente muestra expresión de marcadores basales, afecta a mujeres jóvenes y tiene mal pronóstico, sin una terapia dirigida. Material y método. Estudio retrospectivo de análisis de tres alteraciones moleculares (mutación de EGFR y PIK3CA e hipermetilación del promotor del gen BRCA1), mediante la técnica de pirosecuenciación, en 60 casos de cáncer de mama «triple negativo». Resultados. Un 28,33% de las pacientes fueron diagnosticadas con 50 o menos años, y el 16,67% progresaron por diseminación vía hematógena con metástasis viscerales y murieron (menos una) en un intervalo de entre 1-5 años desde el diagnóstico. En 5 de los 16 casos estudiados se encontró una mutación patogénica de BRCA. Inmunohistoquímicamente la mayoría eran tumores con alto índice proliferativo de Ki67 y un 73,33% eran «basal-like» por expresión de CK5/6 y/o EGFR. A nivel molecular, no se encontraron mutaciones activadoras de EGFR, aunque el 53,33% de los casos mostraron sobreexpresión inmunohistoquímica de EGFR. La mutación de PIK3CA se detectó en un 10% de casos, con predominio en exón20 y con coexpresión de receptores de andrógenos en la mitad de los casos. La hipermetilación de la región promotora del gen BRCA1 estaba presente en un 25% de los casos, coexistiendo en un caso con hipermetilación del estroma no tumoral y en dos con mutación patogénica del gen BRCA1. Conclusiones. El hallazgo de alguna alteración molecular específica, aunque sea infrecuente, puede plantear una posible diana terapéutica dirigida (AU)


Introduction. Breast cancer is a clinically, morphologically and biologically heterogeneous disease. It is classified in distinct subtypes. Triple-negative breast cancers represent approximately 10-20% of all breast cancers and often express basal markers. This type preferentially affects young women and has no specific therapy. Material and method. We conducted a retrospective study of three molecular alterations (the EGFR and PIK3CA mutations and BRCA1 promoter hypermethylation) by pyrosequencing in a series of 60 patients with a diagnosis of triple-negative breast cancer. Results. A total of 28.33% of patients were diagnosed at age 50 years or younger. Only 16.67% of patients had clinical progression due to haematological dissemination with visceral metastasis and all of them, except one, died from breast cancer between 1 and 5 years after diagnosis. The BRCA1 mutation was studied in 16 patients and a known pathogenic mutation was found in 5. Immunohistochemical study showed a high Ki67 proliferative index and 73.33% of carcinomas were basal-like due to CK5/6 and/or EGFR expression. Although we found no EGFR-activating mutations, EGFR overexpression was present in 53.33% of patients. The PIK3CA mutation was identified in 10% of patients, predominantly in exon 20 and with androgen receptor expression in half of these patients. BRCA1 promoter hypermethylation was observed in 25% of the patients. Only one of these patients exhibited BRCA1 hypermethylation of non-tumoural stroma and two showed a pathogenic mutation of the BRCA1 gene. Conclusion. The finding of specific molecular alterations, although infrequent, could suggest a possible directed therapeutic target (AU)


Assuntos
Humanos , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Genes BRCA1 , Receptores ErbB/genética , Proteínas Quinases Dependentes de 3-Fosfoinositídeo/genética , Neoplasias da Mama/genética , Mutação/genética , Metilação , Estudos Retrospectivos , Marcadores Genéticos/genética , Imuno-Histoquímica/métodos
17.
Prev. tab ; 18(3): 155-164, jul.-sept. 2016. ilus
Artigo em Espanhol | IBECS | ID: ibc-157844

RESUMO

Se sabe que el tabaco produce alteraciones en distintas partes del organismo que conllevan la aparición del cáncer. Los retrotransposones parecen estar implicados tanto en el inicio como en la evolución de esta enfermedad. Se ha visto que también contribuyen a que determinados tratamientos contra el cáncer, como la inmunoterapia, dejen de ser eficaces. En este trabajo analizamos cómo se ven afectados los elementos genéticos móviles por los distintos compuestos presentes en el tabaco (AU)


It is known that smoking causes alterations in different parts of the body that entail appearance of cancer. The retrotransposons seem to be involved both at the onset and in the evolution of this disease. It has also been seen that they contribute to the fact that certain treatments against cancer, such as immunotherapy, stop being effective. In this work, we analyze how the mobile genetic elements are affected by the different compounds present in tobacco (AU)


Assuntos
Humanos , Masculino , Feminino , Fumar/genética , Retroelementos/genética , Retroelementos/imunologia , Imunoterapia/métodos , Neoplasias/complicações , Neoplasias/genética , Metilação , DNA/genética , Elementos Nucleotídeos Curtos e Dispersos/genética , DNA Polimerase Dirigida por RNA/genética , Poluição por Fumaça de Tabaco/efeitos adversos , Compostos Orgânicos/síntese química , Metais/análise
18.
Arch. bronconeumol. (Ed. impr.) ; 52(6): 293-298, jun. 2016. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-152390

RESUMO

Introducción: La hipertensión arterial pulmonar es una enfermedad infrecuente caracterizada por una obstrucción progresiva de las arterias pulmonares. El receptor tipo II de la proteína ósea morfogenética (BMPR2) es el principal gen relacionado con esta enfermedad. EL objetivo de este trabajo fue analizar el patrón de metilación de la región promotora del gen BMPR2 en individuos con hipertensión arterial pulmonar y controles. Métodos: Se analizó la región a estudio con los softwares Methyl Primer Express® v.1.0 y MatInspector. El ADN genómico, obtenido a partir de sangre periférica, fue modificado con bisulfito de sodio. La metilación se analizó utilizando PCR específica de metilación. Como control positivo de metilación se utilizó ADN tratado con CpG metiltransferasa y como control positivo de expresión se utilizó ADN del cultivo celular H1299. Resultados: Se ha identificado una isla CpG susceptible de presentar metilación en la región promotora del gen que contiene secuencias específicas como sitios de unión a factores de trascripción NIT-2 (global-acting regulatory protein), sex-determining region Y y heat shock factor. No se han encontrado indicios de metilación en los pacientes ni en los controles. En las células H1299, que expresan el gen BMPR2, no se ha identificado metilación en la isla CpG analizada. Conclusiones: No se detectaron indicios de metilación en la región promotora a estudio en pacientes y controles, siendo esta la región más adecuada para realizar el estudio debido al alto número de sitios de unión a factores de transcripción que podrían estar involucrados en la correcta funcionalidad del gen


Introduction: Pulmonary arterial hypertension is characterizated by obstruction of the pulmonary arteries. The gene mainly related to pathology is the bone morphogenetic protein receptor type II(BMPR2). The aim of this study was to analyze the methylation pattern of the BMPR2promoter region in patients and controls. Methods: We used Methyl Primer Express® v.1.0 and MatInspector softwares to analyze this region. Genomic DNA obtained from the peripheral blood of patients and controls was modified with sodium bisulphite. Methylation was analyzed using methylation-specific PCR. DNA treated with CpG methyltransferase was used as a positive control for methylation and H1299 cell culture DNA was used as positive control for gene expression. Results: We identified a CpG island, which may have been methylated, in the BMPR2 promoter region, in addition to NIT-2 (global-acting regulatory protein), sex-determining region Y) and heat shock factor transcription factor binding sites. We found no evidence of methylation in patients and controls. No methylated CpG sites were identified in H1299 cells expressing theBMPR2 gene. Conclusions: The BMPR2 promoter region is the most suitable for study because of the high number of transcription factor binding sites that could alter gene function. No evidence of methylation was detected in this region in patients and controls


Assuntos
Humanos , Masculino , Feminino , Adulto , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/imunologia , Metilação , Metilação de DNA/genética , Metilação de DNA/imunologia , Metilação de DNA/fisiologia , Hipertensão Pulmonar/classificação , Hipertensão Pulmonar/epidemiologia , Fatores de Transcrição/administração & dosagem , Fatores de Transcrição/análise
19.
Clin. transl. oncol. (Print) ; 18(4): 391-397, abr. 2016. tab, ilus, graf
Artigo em Inglês | IBECS | ID: ibc-150454

RESUMO

Purpose: The MGMT gene encodes a DNA repair enzyme that counteracts with chemotherapy efficiency, specifically with alkylating agents such as temozolomide (TMZ). It is well established that MGMT methylation should be screened as a predictive marker for TMZ in glioblastoma, and we thus aimed to determine a reliable and practical diagnostic method of MGMT methylation detection. Patients and methods: 55 glioblastomas were investigated for MGMT methylation status using methylation-specific multiplexed ligation probe amplification (MS-MLPA), illumina human methylation 450K BeadChip array (HM450 K) analysis, and compared to MGMT protein expression by immunohistochemistry (IHC) staining. The methylation status of promoter, intron and all MGMT CpG targeted sites were separately correlated to patient’s survival. Results: In addition to MS-MLPA and 450 K concordance, our results showed significantly higher overall survival (OS) of patients receiving TMZ and presenting MGMT methylated promoter (mean OS = 21.5 months, p = 0.046). Including all glioblastoma cases and regardless of chemotherapy, MS-MLPA showed significant survival difference between MGMT methylated and unmethylated cases (mean OS = 13, p = 0.021). Conclusion: We concluded that in glioblastoma, MGMT promoter methylation predicts TMZ sensitivity. This current comparative analysis leads to consider that MS-MLPA is a valuable as HM450 K array for MGMT methylation status screening (AU)


No disponible


Assuntos
Humanos , Masculino , Feminino , Adulto , Metilação , Metilação/efeitos da radiação , Retinoblastoma/diagnóstico , Retinoblastoma/genética , O(6)-Metilguanina-DNA Metiltransferase , Imuno-Histoquímica/métodos , Imuno-Histoquímica/normas , Imuno-Histoquímica , Sensibilidade e Especificidade , Estimativa de Kaplan-Meier
20.
Clin. transl. oncol. (Print) ; 18(4): 398-404, abr. 2016. tab, graf
Artigo em Inglês | IBECS | ID: ibc-150455

RESUMO

Introduction: The possibility of detection of suppressor genes methylation in circulating free DNA (cf-DNA) of cancer patients and the lack of methylation in healthy individuals makes this epigenetic alternation an ideal diagnostic marker of neoplastic processes. Moreover, hypermethylation in several genes promoter was described as a biomarker of lung cancer. Methylation in the gene encoding doublecortin-like kinase 1 (DCLK1) is observed in patients with colorectal cancer and cholangiocarcinoma. However, there are no studies concerning DCLK1 methylation in lung cancer patients. The aims of the study was to evaluate the frequency of DCLK1 promoter methylation in cf-DNA of lung cancer patients and of healthy persons as well as the usefulness of this test for predicting the lung cancer course. Materials and methods: DCLK1 methylation status was evaluated in DNA isolated from peripheral blood plasma from 65 lung cancer patients and 95 healthy individuals. After DNA bisulfitation, DCLK1 methylation was determined using the qMSP-PCR technique. Moreover, the presence of DCLK1 methylation was correlated with the overall survival (OS) probability of lung cancer patients. Results: DCLK1 promoter methylation was detected in 32 lung cancer patients (49.2 %) and 8 healthy individuals (8.4 %). The methylation of the region before transcription start site (TSS) and the region after TSS of DCLK1 gene was detected in 28 and 11 patients, respectively. In seven cases (10.8 %), the DCLK1 promoter methylation in both regions was reported simultaneously. The methylation was observed slightly frequently in patients with small cell lung cancer (75 % of SCLC patients). The median overall survival of patients with DCLK1 promoter methylation was lower than that of patients without DCLK1 gene modification (p = < 0.001, HR = 4.235). Conclusions: The evaluation of DCLK1 promoter region methylation may be useful in both early diagnosis and prediction of the course of lung cancer (AU)


No disponible


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Metilação , Metilação/efeitos da radiação , Metilação de DNA/genética , Metilação de DNA/efeitos da radiação , Proteínas Serina-Treonina Quinases/análise , Proteínas Serina-Treonina Quinases/genética , Poluição por Fumaça de Tabaco/efeitos adversos , Fumar/efeitos adversos , Fumar/patologia , MicroRNAs/genética
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