• 약학회지
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• 제49권6호
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• pp.511-517
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• 2005

Low sensitivity to anticancer drugs such as 5-fluorouracil (5-FU) has been associated with decreased expression of genes involved in cell proliferation, apoptosis and metastasis. Recently, it has been shown that the expression levels of some of these genes are reduced by transcription inhibition due to epigenetic silencing on CpG islands. Therefore, epigenetic therapy has been proposed, where epigenetic silencing is repressed with DNA methyltransferase (DNMT) inhibitors and histone deacetylase (HDAC) inhibitors alone or in combination with other chemotherapeutic agents. The aim of our study was to evaluate the combination effect of 5-FU and its association with the status of epigenetic silencing using methylation-specific PCR of $p14^{ARF}$ when given with S-aza-2'-deoxycytidine (5-aza-dC), a DNMT inhibitor and depsipeptide, an HDAC inhibitor in DLD-1 human colorectal cancer cells. The combination of 5-aza-dC with depsipeptide showed a synergism and induced unmethylation of $p14^{ARF}$. However, triplet combination of 5-aza-dc/depsipeptide and 5-FU resulted in antagonistic effects and abrogated unmethylation of $p14^{ARF}$. These results suggest that unfavorable interaction of 5-aza-dC/depsipeptide with 5-FU in DLD-1 cells may be related with the failure in repression of epigenetic silencing, which warrants further investigation.

• Molecules and Cells
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• 제38권3호
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• pp.210-220
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• 2015

Athletic performance is an important criteria used for the selection of superior horses. However, little is known about exercise-related epigenetic processes in the horse. DNA methylation is a key mechanism for regulating gene expression in response to environmental changes. We carried out comparative genomic analysis of genome-wide DNA methylation profiles in the blood samples of two different thoroughbred horses before and after exercise by methylated-DNA immunoprecipitation sequencing (MeDIP-Seq). Differentially methylated regions (DMRs) in the pre-and post-exercise blood samples of superior and inferior horses were identified. Exercise altered the methylation patterns. After 30 min of exercise, 596 genes were hypomethy-lated and 715 genes were hypermethylated in the superior horse, whereas in the inferior horse, 868 genes were hypomethylated and 794 genes were hypermethylated. These genes were analyzed based on gene ontology (GO) annotations and the exercise-related pathway patterns in the two horses were compared. After exercise, gene regions related to cell division and adhesion were hypermethylated in the superior horse, whereas regions related to cell signaling and transport were hypermethylated in the inferior horse. Analysis of the distribution of methylated CpG islands confirmed the hypomethylation in the gene-body methylation regions after exercise. The methylation patterns of transposable elements also changed after exercise. Long interspersed nuclear elements (LINEs) showed abundance of DMRs. Collectively, our results serve as a basis to study exercise-based reprogramming of epigenetic traits.

• 생명과학회지
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• 제18권4호
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• pp.580-584
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• 2008

본 연구에서는 손상된 DNA를 수복하는 중요한 효소로 알려진 $O^6-methylguanine-DNA$ methyltransferase (MGMT)발현의 의미를 비소세포폐암종에서 면역조직화학 염색법으로 알아보고자 하였다. 동아대학교 의료원에서 2001년부터 2004년까지 외과적으로 적출한 폐암종 조직 중 비소세포암종으로 진단된 74예를 연구대상으로 하였다. 면역염색 결과, MGMT 발현은 총 74예 중 49예(66.2%)에서 양성을 보였으며, 25예(33.8%)에서 단백 소실을 보였다. 조직학적 유형에 따른 결과를 살펴보면, 편평세포암종은 8/39예(20.5%)에서 단백 소실이 보였고, 샘암종은 17/35예(48.6%)에서 단백 소실이 관찰되어 통계적으로 유의한 차이가 관찰되었다(p=0.021). 하지만 나이, 성별, 흡연유무, 종양 크기, T 병기 및 림프절 전이에 따른 유의한 차이는 관찰되지 않았다(p>0.05). MGMT 단백 발현 소실은 특히 promoter 메틸화와 연관되어 종양에서 관찰된다고 알려져 있으므로, 향후 연구에서는 비소세포폐암종의 MGMT 단백 소실에 대한 임상적 의의를 밝히기 위하여 promoter 메틸화 연구가 추가적으로 수행되어져야 될 것으로 사료된다.