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1.
Gene ; 723: 144142, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31589957

RESUMO

DNA methylation is an epigenetic alteration that may lead to carcinogenesis by silencing key tumor suppressor genes. Hypermethylation of the paired box gene 1 (PAX1) promoter is important in cervical cancer development. Here, PAX1 methylation levels were compared between Uyghur and Han patients with cervical lesions. Data on PAX1 methylation in different cervical lesions were obtained from the Gene Expression Omnibus (GEO) database, whereas data on survival and PAX1 mRNA expression in invasive cervical cancer (ICC) were retrieved from the Cancer Genome Atlas (TCGA) database. MassARRAY spectrometry was used to detect methylation of 19 CpG sites in the promoter region of PAX1, whereas gene mass spectrograms were drawn by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. Human papillomavirus (HPV) 16 infection was detected by polymerase chain reaction. PAX1 methylation in high-grade squamous intraepithelial lesion (HSIL) and ICC was significantly higher than in normal tissues. PAX1 hypermethylation was associated with poor prognosis and reduced transcription. ICC-specific PAX1 promoter methylation involved distinct CpG sites in Uyghur and Han patients HPV16 infection in HSIL and ICC patient was significantly higher than in normal women (p < 0.05). Our study revealed a strong association between PAX1 methylation and the development of cervical cancer. Moreover, hypermethylation of distinct CpG sites may induce HSIL transformation into ICC in both Uyghur and Han patients. Our results suggest the existence of ethnic differences in the genetic susceptibility to cervical cancer. Finally, PAX1 methylation and HPV infection exhibited synergistic effects on cervical carcinogenesis.


Assuntos
Carcinoma de Células Escamosas/virologia , Metilação de DNA , Papillomavirus Humano 16/patogenicidade , Fatores de Transcrição Box Pareados/genética , Infecções por Papillomavirus/diagnóstico , Lesões Intraepiteliais Escamosas Cervicais/virologia , Neoplasias do Colo do Útero/virologia , Carcinoma de Células Escamosas/genética , China/etnologia , DNA Viral/genética , Bases de Dados Factuais , Regulação para Baixo , Epigênese Genética , Feminino , Regulação Neoplásica da Expressão Gênica , Papillomavirus Humano 16/genética , Humanos , Infecções por Papillomavirus/genética , Prognóstico , Regiões Promotoras Genéticas , Lesões Intraepiteliais Escamosas Cervicais/genética , Análise de Sobrevida , Neoplasias do Colo do Útero/genética
2.
Adv Exp Med Biol ; 1164: 179-196, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31576549

RESUMO

DNA methylation is a chemically reversible epigenetic modification that regulates the chromatin structure and gene expression, and thereby takes part in various cellular processes like embryogenesis, genomic imprinting, X-chromosome inactivation, and genome stability. Alterations in the normal methylation levels of DNA may contribute to the development of pathological conditions like cancer. Even though both hypo- and hypermethylation-mediated abnormalities are prevalent in the cancer genome, the field of cancer epigenetics has been more focused on targeting hypermethylation. As a result, DNA hypomethylation-mediated abnormalities remained relatively less explored, and currently, there are no approved drugs that can be clinically used to target hypomethylation. Understanding the precise role of DNA hypomethylation is not only crucial from a mechanistic point of view but also for the development of pharmacological agents that can reverse the hypomethylated state of the DNA. This chapter focuses on the causes and impact of DNA hypomethylation in the development of cancer and describes the possible ways to pharmacologically target it, especially by using a naturally occurring physiologic agent S-adenosylmethionine (SAM).


Assuntos
Metilação de DNA , Epigênese Genética , Neoplasias , Epigenômica , Humanos , Neoplasias/genética , Neoplasias/terapia
3.
Medicine (Baltimore) ; 98(39): e17373, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31574886

RESUMO

Ionizing radiation can induce deoxyribonucleic acid (DNA) methylation pattern change, and ionizing radiation-induced oxidative damage may also affect DNA methylation status. However, the influence of low-dose ionizing radiation, such as occupational radiation exposure, on DNA methylation is still controversial.By investigating the relationship between occupational radiation exposure and DNA methylation changes, we evaluated whether radiation-induced oxidative damage was related to DNA methylation alterations and then determined the relationship among occupational radiation level, DNA methylation status, and oxidative damage in interventional physicians.The study population included 117 interventional physicians and 117 controls. We measured global methylation levels of peripheral blood leukocyte DNA and expression level of DNA methyltransferase (Dnmts) and homocysteine (Hcy) in serum to assess the DNA methylation status of the body. We measured 8-hydroxy-2'-deoxyguanosine (8-OHDG) and 4-hydroxynonenal (4-HNE) levels as indices of oxidative damage. Relevance analysis between multiple indices can reflect the relationship among occupational radiation exposure, DNA methylation changes, and oxidative damage in interventional physicians.The expression levels of Dnmts, 4-HNE, and 8-OHDG in interventional physicians were higher than those in controls, while there was no statistical difference in total DNA methylation rate and expression of Hcy between interventional physicians and controls. Total cumulative personal dose equivalent in interventional physicians was positively correlated with the expression levels of Dnmts, 8-OHDG, and 4-HNE. The expression levels of 8-OHDG in interventional physicians were negatively correlated with global DNA methylation levels and positively correlated with the expression levels of Hcy.Occupational radiation exposure of interventional physicians has a certain effect on the expression of related enzymes in the process of DNA methylation, while ionizing radiation-induced oxidative damage also has a certain effect on DNA methylation. However, there was no evidence that dose burden of occupational exposure was associated to changes of DNA methylation status of interventional physicians, since it is rather unclear which differences are observed among the effects produced by radiation exposure and oxidative damage.


Assuntos
Dano ao DNA/efeitos da radiação , Metilação de DNA/efeitos da radiação , Exposição Ocupacional/análise , Estresse Oxidativo/efeitos da radiação , Exposição à Radiação/análise , Radiologia Intervencionista/estatística & dados numéricos , Adulto , Aldeídos/sangue , Desoxiguanosina/análogos & derivados , Desoxiguanosina/sangue , Feminino , Homocisteína/sangue , Humanos , Leucócitos/metabolismo , Masculino , Metiltransferases/sangue , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Médicos/estatística & dados numéricos , Exposição à Radiação/efeitos adversos
4.
Anticancer Res ; 39(10): 5473-5481, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31570441

RESUMO

BACKGROUND/AIM: Aerial parts and seeds of the neem tree (Azadirachta indica) have long been used in traditional medicine such as Ayurveda for health-related purposes. Our interest in neem bioactives lies in their potential use as standalone anticancer agents, or as adjuvants to standard therapy. The aim of the present study was to explore a supercritical CO2 extract (SCNE) of neem leaf and a prominent liminoid in neem leaf, nimbolide, for epigenetic activity. MATERIALS AND METHODS: Human colorectal cancer cell lines (HCT116 and HT29) were cultured for 48 h in the presence of neem extract or nimbolide and evaluated for growth inhibition and evidence of suppression of histone deacetylation and DNA methylation. RESULTS: Both SCNE and nimbolide suppressed the proliferation of colon cancer cells by inducing epigenetic modifications. CONCLUSION: Neem leaf contains bioactive constituents which modify epigenetic activity.


Assuntos
Azadirachta/química , Neoplasias Colorretais/tratamento farmacológico , Epigênese Genética/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta/química , Dióxido de Carbono/química , Dióxido de Carbono/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Células HCT116 , Células HT29 , Humanos , Limoninas/farmacologia
5.
J Appl Oral Sci ; 27: e20180649, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31596367

RESUMO

OBJECTIVE: Cleft palate (CP) is a congenital birth defect caused by the failure of palatal fusion. Little is known about the potential role of DNA methylation in the pathogenesis of CP. This study aimed to explore the potential role of DNA methylation in the mechanism of CP. METHODOLOGY: We established an all-trans retinoic acid (ATRA)-induced CP model in C57BL/6J mice and used methylation-dependent restriction enzymes (MethylRAD, FspEI) combined with high-throughput sequencing (HiSeq X Ten) to compare genome-wide DNA methylation profiles of embryonic mouse palatal tissues, between embryos from ATRA-treated vs. untreated mice, at embryonic gestation day 14.5 (E14.5) (n=3 per group). To confirm differentially methylated levels of susceptible genes, real-time quantitative PCR (qPCR) was used to correlate expression of differentially methylated genes related to CP. RESULTS: We identified 196 differentially methylated genes, including 17,298 differentially methylated CCGG sites between ATRA-treated vs. untreated embryonic mouse palatal tissues (P<0.05, log2FC>1). The CP-related genes Fgf16 (P=0.008, log2FC=1.13) and Tbx22 (P=0.011, log2FC=1.64,) were hypermethylated. Analysis of Fgf16 and Tbx22, using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG), identified 3 GO terms and 1 KEGG pathway functionally related to palatal fusion. The qPCR showed that changes in expression level negatively correlated with methylation levels. CONCLUSIONS: Taken together, these results suggest that hypermethylation of Fgf16 and Tbx22 is associated with decreased gene expression, which might be responsible for developmental failure of palatal fusion, eventually resulting in the formation of CP.


Assuntos
Fissura Palatina/genética , Metilação de DNA , Fatores de Crescimento de Fibroblastos/genética , Expressão Gênica , Proteínas com Domínio T/genética , Animais , Fissura Palatina/embriologia , Fissura Palatina/patologia , Feminino , Fatores de Crescimento de Fibroblastos/análise , Masculino , Camundongos Endogâmicos C57BL , Domínios e Motivos de Interação entre Proteínas , Reação em Cadeia da Polimerase em Tempo Real , Valores de Referência , Análise de Sequência de DNA , Proteínas com Domínio T/análise
6.
Medicine (Baltimore) ; 98(43): e17651, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31651887

RESUMO

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is the leading histological type among head and neck cancers. Several studies have explored an association between aberrant methylation of MutL homolog-1 (MLH1) promoter and HNSCC risk. We aimed to explore the associations between MLH1 promoter methylation and HNSCC by using a meta-analysis. METHODS: Systematic literature search was conducted among PubMed, Google Scholar, Web of Science, and China National Knowledge Infrastructure, and Wanfang databases to retrieve relevant articles published up to June 30, 2018. A total of 12 studies were included in this meta-analysis (including 717 HNSCC and 609 controls). RESULTS: The results demonstrated that MLH1 promoter methylation was notably higher in patients with HNSCC than in controls (odds ratios [ORs] = 2.52, 95% confidence intervals [CIs] = 1.33-4.79). Besides, MLH1 promoter methylation was not associated with tumor stage, lymph node status, smoking behavior, age, clinical stage, gender, and differentiation grade (all P > .05). The pooled sensitivity and specificity rates of MLH1 methylation for HNSCC were 0.23 (95% CI = 0.12-0.38) and 0.95 (95% CI, 0.82-0.99), respectively. The area under the receiver operating characteristic (ROC) curve was presented as 0.64 (95% CI = 0.60-0.68). CONCLUSION: The results of this meta-analysis suggested that hypermethylation of MLH1 promoter was associated with HNSCC. Methylated MLH1 could be a potential diagnostic biomarker for diagnose of HNSCC.


Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias de Cabeça e Pescoço/genética , Proteína 1 Homóloga a MutL/genética , Biomarcadores Tumorais/genética , Metilação de DNA , Humanos , Regiões Promotoras Genéticas
7.
Ideggyogy Sz ; 72(9-10): 325-336, 2019 Sep 30.
Artigo em Húngaro | MEDLINE | ID: mdl-31625699

RESUMO

With the acceptance of "The developmental origins of health and disease" concept in the 1990s, it became clear that epigenetic inheritance, which do not involve changes in the DNA sequence has important role in the pathogenesis of diseases. Epigenetic regulation serves the adaptation to the changing environment and maintains the reproductive fitness even on the drawback of increased risk of diseases in later life. The role of epigenetic mechanisms in chronic non-communicable diseases has been well established. Recent studies have revealed that epigenetic changes have also causal role in certain pediatric diseases. The review evaluates the recent epigenetic findings in the pathomechanism of common pediatric diseases. The wide range and long-lasting duration of epigenetic regulations give importance to the subject. Methods are already available to evaluate a part of the epigenetic changes in the clinical practice, presently aiming primarily the estimation of the disease risk or definition of diagnosis. Furthermore, there are already available limited means to influence the epigenetic regulation.


Assuntos
Metilação de DNA/fisiologia , Epigênese Genética , Cardiopatias , Infecção , Transtornos Mentais , Doenças Metabólicas , Efeitos Tardios da Exposição Pré-Natal , Criança , Pré-Escolar , Metilação de DNA/genética , Feminino , Cardiopatias/genética , Humanos , Infecção/genética , Transtornos Mentais/genética , Doenças Metabólicas/genética , Pediatria , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética
8.
Anticancer Res ; 39(10): 5361-5367, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31570430

RESUMO

BACKGROUND/AIM: The mechanism responsible for B-cell translocation gene 1 (BTG1) down-regulation in breast carcinoma remains unknown. We examined the BTG1 expression status in breast carcinoma cells and investigated the mechanism underlying the observed alterations. MATERIALS AND METHODS: Four breast carcinoma cell lines (SK-BR-3, MDA-MB-231, T-47D, and MCF-7), and one normal mammary epithelial cell line (MCF-10A) were analyzed. BTG1 expression was examined using quantitative reverse transcription polymerase chain reaction (PCR) and western blot. Methylation status of the BTG1 promoter was analyzed using methylation-specific PCR (MSP). To investigate the effect of methylation on BTG1, the cells were treated with a demethylating agent. RESULTS: The carcinoma cells expressed significantly lower levels of BTG1 mRNA and protein than normal cells. The BTG1 promoter was highly methylated in the carcinoma cells. 5-aza-2-deoxycytidine significantly restored BTG1 expression. CONCLUSION: Down-regulation of BTG1 expression through epigenetic repression is involved in mammary carcinogenesis. BTG1 is a potential diagnostic marker and therapeutic target for breast carcinoma.


Assuntos
Neoplasias da Mama/genética , Metilação de DNA/genética , Regulação para Baixo/genética , Proteínas de Neoplasias/genética , Regiões Promotoras Genéticas/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Epigênese Genética/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Células MCF-7 , RNA Mensageiro/genética
9.
Anticancer Res ; 39(10): 5381-5391, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31570433

RESUMO

BACKGROUND/AIM: Long noncoding RNAs (lncRNAs) are noncoding transcripts that are >200 nucleotides in length. However, the biological functions and regulation mechanisms of lncRNAs in gastric carcinogenesis remain unknown. MATERIALS AND METHODS: The expression levels of Linc00472 were analyzed by real-time PCR. The DNA methylation status was assessed using Combined Bisulfite Restriction Analysis (COBRA). The biological role of Linc00472 was assessed in AGS cells with Linc00472 overexpression. RESULTS: Using the next-generation sequencing approach, we identified DNA methylation-associated lncRNAs in gastric cancer cells. Among them, the expression level of Linc00472 significantly decreased in gastric cancer tissues compared to adjacent normal tissues. Furthermore, we observed a more frequent hypermethylation of CpG islands upstream of Linc00472 in gastric cancer tissues. Ectopic Linc00472 expression could significantly inhibit gastric cancer cell growth and migration. CONCLUSION: Epigenetically regulated Linc00472 expression plays a crucial role in modulating gastric cancer cell growth and motility.


Assuntos
Metilação de DNA/genética , RNA Longo não Codificante/genética , Neoplasias Gástricas/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Ilhas de CpG/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos
10.
Anticancer Res ; 39(10): 5449-5459, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31570439

RESUMO

BACKGROUND/AIM: Epigenetic abnormalities in microRNAs (miRNAs) have not been analyzed in samples other than pancreaticobiliary tissues in patients with pancreaticobiliary cancer (PBC). To identify miRNAs specific for PBC, the present study analyzed the methylation of tumor-suppressive miRNAs in bile from patients with pancreaticobiliary diseases. MATERIALS AND METHODS: Bile was collected endoscopically or percutaneously from 52 patients with pancreatic cancer, 26 with biliary tract cancer, and 20 with benign pancreaticobiliary diseases. Sequences encoding 16 tumor-suppressive miRNAs were amplified by polymerase chain reaction and sequenced, and their methylation rates were determined. RESULTS: The methylation rates of miR-1247 and miR-200a were significantly higher in patients with pancreatic cancer, and biliary tract cancer than in those with benign diseases, and the methylation rate of miR-200b was significantly higher in patients with pancreatic cancer than in those with benign diseases. CONCLUSION: Methylation of miR-1247, miR-200a, and miR-200b in bile may be useful for distinguishing PBC from benign diseases.


Assuntos
Neoplasias do Sistema Biliar/genética , Metilação de DNA/genética , MicroRNAs/genética , Neoplasias Pancreáticas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Bile/metabolismo , Epigenômica/métodos , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Genes Supressores de Tumor/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade
11.
Medicine (Baltimore) ; 98(38): e17225, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31567982

RESUMO

The present study is to analyze the difference of gene methylation in early cervical adenocarcinoma and to find molecular markers for predicting the occurrence and development of cervical adenocarcinoma.A total of 15 cases of primary cervical adenocarcinoma and 10 cases of primary cervical squamous cell carcinoma at stages IB1 or IIA1 were included in the study. Infinium MethylationEPIC BeadChip (850K) was used to screen specifically expressed genes in cervical adenocarcinoma tissues. Bisulfite sequencing polymerase chain reaction (BSP) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to verify the methylation levels in cervical adenocarcinoma, cervical squamous cell carcinoma, and normal cervical tissues.Sex determining region Y-box 1 (SOX1) and cyclin D1 (CCND1) genes participated in multiple signaling pathways, being the central nodes of gene regulatory networks. SOX1 gene, but not CCND1 gene, was a specifically methylated gene in cervical adenocarcinoma according to BSP. According to qRT-PCR, methylation level of SOX1 in cervical adenocarcinoma tissues is significantly different from that in cervical squamous cell carcinoma tissues or normal cervical tissues, and the methylation level of CCND1 in cervical adenocarcinoma tissues or cervical squamous cell carcinoma tissues is significantly different from that in normal cervical tissues.The present study demonstrates that tumor-suppressor gene SOX1 is a methylation-specific expression gene of cervical adenocarcinoma and is expected to become a specific molecular marker for the diagnosis of cervical adenocarcinoma. However, CCND1 gene was not proven to be a specific methylation expression gene in cervical adenocarcinoma in the present study.


Assuntos
Adenocarcinoma/genética , Metilação de DNA/genética , Fatores de Transcrição SOXB1/genética , Neoplasias do Colo do Útero/genética , Adenocarcinoma/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Colo do Útero/metabolismo , Ciclina D1/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes/genética , Marcadores Genéticos/genética , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias do Colo do Útero/metabolismo
12.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1540-1547, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31607309

RESUMO

OBJECTIVE: To investigate the expression, mechanism and methylation level of miR-28-5p in multiple myeloma (MM), so as to provide the expirement basis for searching new targeted therapy. METHODS: RT-PCR was used to detect the expression levels of miR-28-5p and potential target CCND1 in CD138+ cells of the patients with MM and bone marrow mononuclear cells of patients with iron defficiency anemia(IDA) as control, Methylation-specific PCR(MSP) was used to detect methylation levels of CpG island in LPP/miR-28-5p promoter region and the correlation with other clinical indicators was analyzed. The 5-aza-2'-deoxycytidine (5-Aza-dC,DAC) was used to treat MM cell line U266; after drug treatment,MSP was used to analyze the methylation status of the CpG islands in LPP/miR-28-5p promoter; the qPCR was used to detect the expression levels of miR-28-5p,and the regulatory mechanism of miR-28-5p expression was explored furtherly. RESULTS: The methylation level of CpG island in LPP/miR-28-5p promoter region of MM patients was significantly higher than that of IDA patients. The relative expression level of miR-28-5p in MM patients was significantly lower than that of IDA patients. The relative expression level of miR-28-5p in newly diagnosed MM patients was higher than that in relapsed/progressive patients. The miR-28-5p target CCND1 was expressed at high levels in MM patients with LPP / miR-28-5p methylation, the expression level of miR-28-5p in MM patients correlated with ß2-MG concentration. 5-aza-dc could significantly inhibit the growth of U266 cell line, arrest the cell cycle in G1 phase, inhibit the biosynthesis of cellular RNA and protein and promote cell apoptosis. At the same time, up-regulation of miR-28-5p expression was found. CONCLUSION: The expression of miR-28-5p in MM patients is regulated by methylation of CpG islands in the promoter region of the genome.miR-28-5p may act as a tumor suppressor gene, and its low expression may be involved in the occurrence and development of MM, suggesting that miR-28-5p may become a new target for the treatment of MM.


Assuntos
MicroRNAs/genética , Mieloma Múltiplo , Linhagem Celular Tumoral , Ilhas de CpG , Metilação de DNA , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Humanos , Mieloma Múltiplo/genética
13.
Medicine (Baltimore) ; 98(43): e17578, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31651862

RESUMO

BACKGROUND: To evaluate the methylation levels of human telomerase reverse transcriptase (hTERT) promoter three CpG island (CGIs) regions and its prognostic impact in Chinese patients with acral and mucosal melanoma. METHODS: Bioinformatics software was used to analyze hTERT gene promoter. Fresh frozen tissues were taken from 14 patients with melanoma (6 acral melanoma and 8 mucosal melanoma) and 14 pigmented nevus as control subjects (14 acral pigmented nevus). Bisulfite sequencing PCR (BSP) combined TA clone sequencing was used to assess the methylation levels of hTERT promoter CGIs regions. The relative expression level of hTERT mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: CGIs-1 (-1392--1098 bp), CGIs-2 (-945--669 bp), and CGIs-3 (-445--48 bp) were selected for our study. Our results indicated that the methylation levels of hTERT promotor CGIs regions in melanoma were greater than pigmented nevus (CGIs-1: 69.3 ±â€Š18.7% vs 46.8 ±â€Š20.4%, t = 3.048 P = .005; CGIs-2: 73.8 ±â€Š14.7% vs 55.6 ±â€Š16.0%, t = 3.120 P = .004; CGIs-3: 5.8 ±â€Š2.2% vs 2.2 ±â€Š1.3%, t = 5.164 P < .001). The relative expression level of hTERT in melanoma was greater than in pigmented nevus (50.39 ±â€Š9.16 vs 26.10 ±â€Š7.25, t = 7.778, P < .001). Linear regression analysis showed that the methylation level of CGIs-2 in melanoma was positively correlated with the relative expression level of hTERT mRNA (R = .490, F = 13.478, P = .003). Combined with the analysis of clinicopathological features, the methylation level of CGIs-2 in melanoma with lymph node metastasis was greater than in melanoma without lymph node metastasis, and the methylation level of CGIs-2 increased with TNM staging. CONCLUSION: CGIs-2 methylation level was associated with the relative expression level of hTERT mRNA, lymph node metastasis and TNM staging, suggesting that CGIs-2 hypermethylation might be used to evaluate the prognosis in Chinese patients with acral and mucosal melanoma.


Assuntos
Ilhas de CpG/genética , Metilação de DNA/genética , Melanoma/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , Telomerase/metabolismo , Idoso , Grupo com Ancestrais do Continente Asiático/genética , China , Biologia Computacional , Feminino , Humanos , Modelos Lineares , Metástase Linfática , Masculino , Melanoma/mortalidade , Melanoma/patologia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase , Prognóstico , RNA Mensageiro/metabolismo
15.
Adv Exp Med Biol ; 1178: 175-206, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31493228

RESUMO

A global DNA hypomethylation and local changes in the methylation levels of specific DNA loci occur during aging in mammals. Global hypomethylation mainly affects highly methylated repeat sequences, such as transposable elements; it is an essentially stochastic process usually referred to as "epigenetic drift." Specific changes in DNA methylation affect various genome sequences and could be either hypomethylation or hypermethylation, but the prevailing tendencies are hypermethylation of promoter sequences associated with CpG islands and hypomethylation of CpG poor genes. Methylation levels of multiple CpG sites display a strong correlation to age common between individuals of the same species. Collectively, methylation of such CpG sites could be used as "epigenetic clocks" to predict biological age. Furthermore, the discrepancy between epigenetic and chronological ages could be predictive of all-cause mortality and multiple age-associated diseases. Random changes in DNA methylation (epigenetic drift) could also affect the aging phenotype, causing accidental changes in gene expression and increasing the transcriptional noise between cells of the same tissue. Both effects could become detrimental to tissue functioning and cause a gradual decline in organ function during aging. Strong evidence shows that epigenetic systems contribute to lifespan control in various organisms. Similar to other cell systems, the epigenome is prone to gradual degradation due to the genome damage, stressful agents and other aging factors. However, unlike mutations and many other hallmarks of aging, age-related epigenetic changes could be fully or partially reversed to a "young" state.


Assuntos
Envelhecimento , Epigênese Genética , Marcadores Genéticos , Envelhecimento/genética , Animais , Ilhas de CpG/genética , Metilação de DNA , Epigenômica , Marcadores Genéticos/genética , Longevidade
16.
BMC Infect Dis ; 19(1): 802, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31510934

RESUMO

BACKGROUND: Chronic infection with hepatitis B virus (HBV) is a serious global health problem. Persistence of the virus occurs as a result of stability of the replication intermediate comprising covalently closed circular DNA (cccDNA). Development of drugs that are capable of disabling this cccDNA is vital. METHODS: To investigate an epigenetic approach to inactivating viral DNA, we engineered transcriptional repressors that comprise an HBV DNA-binding domain of transcription activator like effectors (TALEs) and a fused Krüppel Associated Box (KRAB). These repressor TALEs (rTALEs) targeted the viral surface open reading frame and were placed under transcription control of constitutively active or liver-specific promoters. RESULTS: Evaluation in cultured cells and following hydrodynamic injection of mice revealed that the rTALEs significantly inhibited production of markers of HBV replication without evidence of hepatotoxicity. Increased methylation of HBV DNA at CpG island II showed that the rTALEs caused intended epigenetic modification. CONCLUSIONS: Epigenetic modification of HBV DNA is a new and effective means of inactivating the virus in vivo. The approach has therapeutic potential and avoids potentially problematic unintended mutagenesis of gene editing.


Assuntos
DNA Viral/genética , Vírus da Hepatite B/crescimento & desenvolvimento , Vírus da Hepatite B/genética , Hepatite B/terapia , Hepatite B/virologia , Proteínas Repressoras/metabolismo , Replicação Viral/genética , Animais , Linhagem Celular , Ilhas de CpG , Metilação de DNA , DNA Circular/genética , DNA Viral/biossíntese , Epigênese Genética , Feminino , Fígado/metabolismo , Fígado/virologia , Camundongos , Fases de Leitura Aberta/genética , Regiões Promotoras Genéticas/genética , Proteínas Repressoras/genética
17.
Cancer Invest ; 37(9): 417-426, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31483161

RESUMO

To investigate the molecular mechanisms of gastric carcinogenesis after Helicobacter pylori (H. pylori) eradication, expression of miR-124a, miR-34b, and miR-34c was examined in nonneoplastic gastric specimens after successful H. pylori eradication. The magnifying narrow-band imaging (NBI) endoscopic features of gastric mucosa were also examined. The atrophic type, an informative endoscopic feature for histological intestinal metaplasia, showed lower expression of miR-124a. Lower expression of miR-124a correlated with hypermethylation of the miR-124a3 locus. The atrophic type represents gastric microarchitectures associated with irreversibility with H. pylori eradication and downregulation of miR-124a.


Assuntos
Regulação para Baixo , Mucosa Gástrica/diagnóstico por imagem , Infecções por Helicobacter/prevenção & controle , MicroRNAs/genética , Imagem de Banda Estreita/métodos , Neoplasias Gástricas/genética , Idoso , Idoso de 80 Anos ou mais , Metilação de DNA , Erradicação de Doenças , Epigênese Genética , Feminino , Mucosa Gástrica/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/diagnóstico por imagem
18.
Cancer Invest ; 37(9): 432-439, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31516038

RESUMO

Eighty seven women with benign breast lesion, 120 patients with breast cancer (BC) and one hundred controls were included in the study. Quantification of mtDNA and nDNA was done by qPCR. Global DNA methylation was measured using ELISA. Circulating cell-free nDNA and mtDNA were significantly elevated in BC and benign breast lesions patients. Global methylation was significantly low in BC patients. Combining the studied parameters in one panel, nDNA/mtDNA/hypomethylation, improved their sensitivity in detecting BC to reach 92.5%. Circulating cell-free nDNA, mtDNA and global DNA hypomethylation can be used as diagnostic and prognostic markers for BC.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/diagnóstico , Ácidos Nucleicos Livres/genética , Metilação de DNA , Adulto , Neoplasias da Mama/genética , Estudos de Casos e Controles , Núcleo Celular/genética , DNA Mitocondrial/genética , Detecção Precoce de Câncer , Egito , Feminino , Humanos , Pessoa de Meia-Idade , Sensibilidade e Especificidade
19.
Gene ; 721: 144107, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31499127

RESUMO

BACKGROUND: Gene environment interactions leading to epigenetic alterations play pivotal role in the pathogenesis of Coronary Artery Disease (CAD). Altered DNA methylation is one such epigenetic factor that could lead to altered disease etiology. In this study, we comprehensively identified methylation sites in several genes that have been previously associated with young CAD patients. METHODS: The study population consisted of 42 healthy controls and 33 young CAD patients (age group <50 years). We performed targeted bisulfite sequencing of promoter as well as gene body regions of several genes in various pathways like cholesterol synthesis and metabolism, endothelial dysfunction, apoptosis, which are implicated in the development of CAD. RESULTS: We observed that the genes like GALNT2, HMGCR were hypermethylated in the promoter whereas LDLR gene promoter was hypomethylated indicating that intracellular LDL uptake was higher in CAD patients. Although APOA1 did not show significant change in methylation but APOC3 and APOA5 showed variation in methylation in promoter and exonic regions. Glucokinase (GCK) and endothelial nitric oxide synthase 3 (NOS3) were hyper methylated in the promoter. Genes involved in apoptosis (BAX/BCL2/AKT2) and inflammation (PHACTR1/LCK) also showed differential methylation between controls and CAD patients. A combined analysis of the methylated CpG sites using machine learning tool revealed 14 CpGs in 11 genes that could discriminate CAD cases from controls with over 93% accuracy. CONCLUSIONS: This study is unique because it highlights important gene methylation alterations which might predict the risk of young CAD in Indian population. Large scale studies in different populations would be important for validating our findings and understanding the epigenetic events associated with CAD.


Assuntos
Doença da Artéria Coronariana/metabolismo , Ilhas de CpG , Metilação de DNA , Análise de Sequência de DNA , Adulto , Apolipoproteínas/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/patologia , Feminino , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Masculino , Pessoa de Meia-Idade , Sulfitos/química
20.
BMC Bioinformatics ; 20(1): 462, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31500564

RESUMO

BACKGROUND: Determining the association between tumor sample and the gene is demanding because it requires a high cost for conducting genetic experiments. Thus, the discovered association between tumor sample and gene further requires clinical verification and validation. This entire mechanism is time-consuming and expensive. Due to this issue, predicting the association between tumor samples and genes remain a challenge in biomedicine. RESULTS: Here we present, a computational model based on a heat diffusion algorithm which can predict the association between tumor samples and genes. We proposed a 2-layered graph. In the first layer, we constructed a graph of tumor samples and genes where these two types of nodes are connected by "hasGene" relationship. In the second layer, the gene nodes are connected by "interaction" relationship. We applied the heat diffusion algorithms in nine different variants of genetic interaction networks extracted from STRING and BioGRID database. The heat diffusion algorithm predicted the links between tumor samples and genes with mean AUC-ROC score of 0.84. This score is obtained by using weighted genetic interactions of fusion or co-occurrence channels from the STRING database. For the unweighted genetic interaction from the BioGRID database, the algorithms predict the links with an AUC-ROC score of 0.74. CONCLUSIONS: We demonstrate that the gene-gene interaction scores could improve the predictive power of the heat diffusion model to predict the links between tumor samples and genes. We showed the efficient runtime of the heat diffusion algorithm in various genetic interaction network. We statistically validated our prediction quality of the links between tumor samples and genes.


Assuntos
Algoritmos , Genes Neoplásicos , Neoplasias/genética , Área Sob a Curva , Metilação de DNA/genética , Bases de Dados Factuais , Difusão , Epistasia Genética , Redes Reguladoras de Genes , Humanos , Curva ROC , Reprodutibilidade dos Testes
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