急性髓性白血病降钙素基因甲基化定量研究

为探讨降钙素（ＣＴ）基因高甲基化能否作为急性髓性白血病（ＡＭＬ）微小残留病（ＭＲＤ）的检测指标。采用设有内、外参照的聚合酶链反应（ＰＣＲ），结合限制内切酶和激光扫描技术，检测了４０例ＡＭＬ患者骨髓细胞的ＣＴ基因５′端甲基化率（ＣＴＭＲ）。结果：初发ＡＭＬ患者ＣＴＭＲ为５２５％±１９３７％，显著高于对照组（８１％±３７３％；Ｐ＜００００５），部分缓解（ＰＲ）组显著高于对照组而显著低于初发组；完全缓解（ＣＲ）组显著高于对照组而与ＰＲ组差别无显著性；ＡＭＬ患者的ＣＴＭＲ与骨髓白血病细胞数呈显著正相关（ｒ＝０．７１５，Ｐ＜０００１），ＣＲ组１６例中４例ＣＴＭＲ在５０％以上，分别于２、４、４５和９个月后复发。结果提示：ＣＴＭＲ有可能成为检测ＡＭＬ微小残留病的有用指标     

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????Salivary gland tumor is one of the most common tumors in head and neck region with a great variety of morphology and biological behavior. Surgical operation is the major choice of salivary gland tumors. However?? except the benign and low-grade malignant tumors?? most salivary malignancies are in lack of specific treatment and the recurrent and metastic frequency is pretty high. Epigenetic study has become a hot spot of cancer research in recent years and one of widely studied field is the DNA promoter methylation. Our current article intends to discuss the possible application of DNA promoter methylation in the development??treatment and prognosis of salivary gland tumors.     

Epigenetics of oral infection and inflammatory diseases—DNA methylation changes in infections and inflammation diseases

BackgroundEpigenetics involves alterations in gene expression that do not involve modifications in the DNA sequence, the memory of which can be passed down to the next generation in somatic cells. DNA methylation is an example of a mechanism that produces epigenetic changes. The purpose of this review is to summarize recent publications on DNA methylation in oral infections and inflammatory diseases, and to discuss its potential as a cause of disease and as a therapeutic target.HighlightSeveral types of oral bacteria and viruses may lead to DNA hypermethylation in oral tissues. Aberrant DNA hypermethylation is observed in oral inflammatory diseases, including chronic periodontitis, lichen planus, and radicular cysts.ConclusionSince epigenetic modifications are reversible, aberrant DNA methylation is a possible therapeutic target for such diseases. However, little is known about the epigenetics in oral inflammatory diseases, and further investigation is needed to elucidate the underlying mechanisms before epigenetic therapy can be used to treat oral inflammatory diseases.     

表观遗传调控与青光眼发病机制研究进展

表观遗传学主要机制包括DNA甲基化、组蛋白修饰和miRNAs等。这些机制将环境与基因相联系，在基因的特异性表达过程中发挥重要作用，影响疾病的表型。青光眼是全球第一大不可逆致盲眼病，其发病机制复杂，受遗传和环境的共同影响。本文分别对DNA甲基化、组蛋白修饰和miRNAs参与青光眼发病的机制进行综述，以期为临床诊治提供参考。     

Prolonged exposure to particulate pollution, genes associated with glutathione pathways, and DNA methylation in a cohort of older men

Background: DNA methylation is a potential pathway linking environmental exposures to disease. Exposure to particulate air pollution has been associated with increased cardiovascular morbidity and mortality, and lower blood DNA methylation has been found in processes related to cardiovascular morbidity.Objective: We hypothesized that prolonged exposure to particulate pollution would be associated with hypomethylation of repetitive DNA elements and that this association would be modified by genes involved in glutathione metabolism and other host characteristics.Methods: DNA methylation of the long interspersed nucleotide element–1 (LINE-1) and the short interspersed nucleotide element Alu were measured by quantitative polymerase chain reaction pyrosequencing in 1,406 blood samples from 706 elderly participants in the Normative Aging Study. We estimated changes in repetitive element DNA methylation associated with ambient particles (particulate matter ≤ 2.5 µm in aerodynamic diameter), black carbon (BC), and sulfates (SO₄), with mixed models. We examined multiple exposure windows (1–6 months) before DNA methylation measurement. We investigated whether this association was modified by genotype and phenotype.Results: An interquartile range (IQR) increase in BC over a 90-day period was associated with a decrease of 0.31% 5-methylcytosine (5mC) (95% confidence interval, 0.12–0.50%) in Alu. An IQR increase in SO₄ over a 90-day period was associated with a decrease of 0.27% 5mC (0.02–0.52%) in LINE-1. The glutathione S-transferase mu-1–null genotype strengthened the association between BC and Alu hypomethylation.Conclusion: Prolonged exposure to BC and SO₄ particles was associated with hypomethylation of two types of repetitive elements.     

Hypermethylation of carcinogen metabolism genes,CYP1A1, CYP2A13 and GSTM1 genes in head and neck cancer

Oral Diseases (2010) 16 , 668–673 Objectives: To investigate the role of aberrant hypermethylation of carcinogen metabolism pathway genes, CYP1A1, CYP2A13 and GSTM1 in head and neck cancer independently as well as its relation to tobacco and alcohol consumption and CYP1A1 and CYP2A13 polymorphisms in Indian population. Methods: Seventy‐three histologically confirmed head and neck cancer patients undergoing treatment in Postgraduate Institute of Medical Education and Research, Chandigarh, India were recruited. Non‐cancerous tissues were obtained from 19 trauma subjects undergoing maxillofacial surgery. Methylation‐specific PCR was performed to determine the methylation status of selected genes. Results: The aberrant hypermethylation of CYP1A1, CYP2A13 and GSTM1 genes was found in cancer tissues with frequency of about 39.7%, 27.4%, and 58.1%, respectively, and in normal healthy tissues with a frequency of about 10.5%, 15.8%, and 20.0%, respectively. Hypermethylation of CYP1A1 (P 0.027) and GSTM1 (P 0.010) showed significant association with head and neck cancer. We also observed significant interaction between smoking and methylation status of CYP1A1 (P 0.029) and CYP2A13 (P ‐0.034) in head and neck cancer. No association was observed between methylation status and alcohol consumption, clinical features and genetic polymorphisms of CYP1A1 and CYP2A13. Conclusions: Hypermethylation of carcinogen metabolism pathway genes independently and in interaction with smoking is associated with increased risk of head and neck cancer.