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Objective To evaluate whether mono (2-ethylhexyl) phthalate (MEHP) affects genomic DNA methylation and the methylation status of some specific genes such as patched gene ( PTCH ) and smoothened gene ( SMO ) in LNCaP cells. Methods LNCaP cells were treated with MEHP (0, 1, 5, 10, and 25 μmol/L) for 3 days. An ELISA assay was preformed to detect genomic methylation, including 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) content. A pyrosequencing assay was applied to assess DNA methylation in PTCH and SMO gene promoters. The correlation between DNA methylation and gene expression was assessed. Results The proportion of cytosines with 5-mC methylation in LNCaP cells was significantly decreased by MEHP (1, 5, 10, and 25 μmol/L) in a dose-dependent manner ( P < 0.01). For genes in the Hedgehog pathway, there was no significant MEHP concentration-dependent difference in the DNA methylation of PTCH and SMO . Conclusion MEHP might affect the progression of prostate cancer through its effect on global DNA methylation. [ABSTRACT FROM AUTHOR]

Background: This study was conducted to determine the antineoplastic activities of 5-aza-2′-deoxycytidine (decitabine; DAC) and all-trans retinoic acid (ATRA), administered either alone or in combination, on in vitro cultured SHI-1 cells as well as their effects on the expression of the tumor suppressor gene p16INK4a (p16) and the retinoic acid receptor (RAR)-β. Methods: Cellgrowth inhibition, differentiation and apoptosis were determined in SHI-1 cells treated with DAC and/or ATRA, and the combination index of the two compounds was calculated. Methylation of the p16 and RAR-β genes in SHI-1 cells was detected by methylation-specific polymerase chain reaction (PCR). Real-time quantitative reverse transcriptase PCR was used to detect mRNA expression of the p16 and RAR-β genes, and Western blot analysis was performed for protein expression. Results: The drug combination had a synergistic effect on growth inhibition, differentiation and apoptosis of SHI-1 cells, and the effects of DAC and ATRA weredependent on time. DAC, either alone or in combination with ATRA, induced demethylation of the genes p16 and RAR-β, whereas ATRA alone had no effect on methylation. The RAR-β gene was reexpressed following DAC-ATRA combination treatment, and both agents had no effect on p16 expression. Conclusion: The results revealed that DAC used in combination with ATRA has significant clinical potential in the treatment of acute monocytic leukemia. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background Different gene expression profiles are observed in intracranial aneurysm tissues. Understanding these genes and what regulates their expression will provide insight into the pathogenesis of intracranial aneurysms. We investigated whether differences in DNA methylation regulate gene expression in intracranial aneurysms. Methods We compared 20 intracranial aneurysm tissue specimens with 20 matched specimens from the superficial temporal artery as controls. We identified the gene expression profiles in these samples using the GeneChip Human U133 Plus 2.0 array and evaluated DNA methylation modifications using the Infinium HumanMethylation450 BeadChip Kit. Results A total of 11,022 differentially methylated sites between aneurysm tissues and matched control tissues were identified, and 2142 differentially expressed gene transcripts were detected based on the 2 gene expression profiles. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses and verification analysis showed that the MYH11 , LIFR , and TLR4 genes were associated with the occurrence and development of intracranial aneurysms. These genes mainly encode cell adhesion molecules or are involved in the NF-κB, JAK-STAT, and ERK/JNK signaling pathways. Conclusions In the development of intracranial aneurysms, DNA methylation plays an important role in the regulation of genetic expression involved in immune and inflammatory reactions, cell function, cell maintenance, and cell signal transduction. [ABSTRACT FROM AUTHOR]

Gene expression is epigenetically regulated through DNA methylation and covalent chromatin modifications, such as acetylation, phosphorylation, ubiquitination, sumoylation, and methylation of histones. Histone methylation state is dynamically regulated by different groups of histone methyltransferases and demethylases. The trimethylation of histone 3 (H3K4) at lysine 4 is usually associated with the activation of gene expression, whereas trimethylation of histone 3 at lysine 27 (H3K27) is associated with the repression of gene expression. The polycomb repressive complex contains the H3K27 methyltransferase Ezh2 and controls dimethylation and trimethylation of H3K27 (H3K27me2/3). The Jumonji domain containing-3 (Jmjd3, KDM6B) and ubiquitously transcribed X-chromosome tetratricopeptide repeat protein (UTX, KDM6A) have been identified as H3K27 demethylases that catalyze the demethylation of H3K27me2/3. The role and mechanisms of both JMJD3 and UTX have been extensively studied for their involvement in development, cell plasticity, immune system, neurodegenerative disease, and cancer. In this review, we will focus on recent progresses made on understanding JMJD3 in the regulation of gene expression in development and diseases. This article is part of a Directed Issue entitled: Epigenetics dynamics in development and disease. [ABSTRACT FROM AUTHOR]