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Article in English | WPRIM | ID: wpr-826301


BACKGROUND@#Various treatments for hepatocellular carcinoma (HCC) are utilized in clinical practice; however, the prognosis is still poor on account of high recurrence rates. DNA methylation levels of CpG islands around promoters (promoter CpGis) inversely regulate gene expression and closely involved in carcinogenesis. As a new strategy, several chemicals globally inhibiting DNA methylation have been developed aiming at reducing DNA methylation levels and maintaining the expression of tumor suppressor genes. On the other hand, since these drugs nonspecifically modify DNA methylation, they can cause serious adverse effects. In order to ameliorate the methods by targeting specific CpGs, information of cancer-related genes that are regulated by DNA methylation is required.@*METHODS@#We searched candidate genes whose expressions were regulated by DNA methylation of promoter CpGi and which are involved in HCC cases. To do so, we first identified genes whose expression were changed in HCC by comparing gene expressions of 371 HCC tissues and 41 non-tumor tissues using the Cancer Genome Atlas (TCGA) database. The genes were further selected for poor prognosis by log-rank test of Kaplan-Meier plot and for cancer relevance by Pubmed search. Expression profiles of upregulated genes in HCC tissues were assessed by Gene Ontology (GO) analysis. Finally, using DNA methylation data of TCGA database, we selected genes whose promoter DNA methylation levels were inversely correlated with gene expression.@*RESULTS@#We found 115 genes which were significantly up- or downregulated in HCC tissues and were associated with poor prognosis and cancer relevance. The upregulated genes were significantly enriched in cell division, cell cycle, and cell proliferation. Among the upregulated genes in HCC, we identified hypomethylation of CpGis around promoters of FANCB, KIF15, KIF4A, ERCC6L, and UBE2C. In addition, TCGA data showed that the tumor suppressor gene P16 is unexpectedly overexpressed in many types of cancers.@*CONCLUSIONS@#We identified five candidate genes whose expressions were regulated by DNA methylation of promoter CpGi and associate with cancer cases and poor prognosis in HCC. Modification of site-specific DNA methylation of these genes enables a different approach for HCC treatment with higher selectivity and lower adverse effects.

Carcinoma, Hepatocellular , Genetics , Metabolism , Cell Proliferation , CpG Islands , Genetics , DNA Methylation , Databases as Topic , Gene Expression Regulation, Neoplastic , Humans , Liver Neoplasms , Genetics , Metabolism , Promoter Regions, Genetic
Article in English | WPRIM | ID: wpr-766029


BACKGROUND: Although colorectal sessile serrated adenomas/polyps (SSA/Ps) with morphologic dysplasia are regarded as definite high-risk premalignant lesions, no reliable grading or risk-stratifying system exists for non-dysplastic SSA/Ps. The accumulation of CpG island methylation is a molecular hallmark of progression of SSA/Ps. Thus, we decided to classify non-dysplastic SSA/Ps into risk subgroups based on the extent of CpG island methylation. METHODS: The CpG island methylator phenotype (CIMP) status of 132 non-dysplastic SSA/Ps was determined using eight CIMP-specific promoter markers. SSA/Ps with CIMP-high and/or MLH1 promoter methylation were regarded as a high-risk subgroup. RESULTS: Based on the CIMP analysis results, methylation frequency of each CIMP marker suggested a sequential pattern of CpG island methylation during progression of SSA/P, indicating MLH1 as a late-methylated marker. Among the 132 non-dysplastic SSA/Ps, 34 (26%) were determined to be high-risk lesions (33 CIMP-high and 8 MLH1-methylated cases; seven cases overlapped). All 34 high-risk SSA/Ps were located exclusively in the proximal colon (100%, p = .001) and were significantly associated with older age (≥ 50 years, 100%; p = .003) and a larger histologically measured lesion size (> 5 mm, 100%; p = .004). In addition, the high-risk SSA/Ps were characterized by a relatively higher number of typical base-dilated serrated crypts. CONCLUSIONS: Both CIMP-high and MLH1 methylation are late-step molecular events during progression of SSA/Ps and rarely occur in SSA/Ps of young patients. Comprehensive consideration of age (≥ 50), location (proximal colon), and histologic size (> 5 mm) may be important for the prediction of high-risk lesions among non-dysplastic SSA/Ps.

Colon , Colorectal Neoplasms , CpG Islands , Diagnosis, Differential , DNA Methylation , Humans , Methylation , Phenotype
Clinical Endoscopy ; : 235-238, 2019.
Article in English | WPRIM | ID: wpr-763437


Conventional adenomas have historically been considered to be the only screening-relevant colorectal cancer (CRC) precursor lesion. The prevailing paradigm was that most CRCs arise along the chromosomal instability pathway, where adenomas accumulate incremental genetic alterations over time, leading eventually to malignancy. However, it is now recognized that this “conventional” pathway accounts for only about two-thirds of CRCs. The serrated pathway is responsible for most of the remainder, and is a disproportionate contributor to postcolonoscopy CRC. Hallmarks of the serrated pathway are mutations in the BRAF gene, high levels of methylation of promoter CpG islands, and the sessile serrated polyp (SSP). Accumulating evidence shows that SSPs can be considered adenoma-equivalent from the standpoint of CRC screening. SSPs have a higher prevalence than previously thought, and appear to have a relatively long dwell time similar to that of conventional adenomas. In addition, SSPs, whether sporadic or as part of the serrated polyposis syndrome, are associated with increased risk of synchronous and metachronous neoplasia. These features collectively support that SSPs are highly relevant to CRC prevention.

Adenoma , Chromosomal Instability , Colonoscopy , Colorectal Neoplasms , CpG Islands , Mass Screening , Methylation , Polyps , Prevalence
Article in Chinese | WPRIM | ID: wpr-776810


OBJECTIVE@#To explore the characteristics of differentially methylated genes and gene ontology associated with neural tube defects (NTDs).@*METHODS@#Twelve subjects from 3 NTDs pedigrees were enrolled. Patients with NTDs have served as the case group, while their family members with normal phenotypes have served as the control group. Genomic DNA was extracted from peripheral venous blood samples of the families and used for DNA methylation analysis. Pairwise comparison was carried out primarily for patient-offspring pairs, and co-segregation of methylation pattern with NTDs was analyzed. Pathway related to differentially methylated genes was predicted with DAVID software.@*RESULTS@#Pairwise comparison indicated that VTRNA2-1 was the only gene in which all CpG sites were methylated. Co-segregation of VTRNA2-1 gene methylation with NTDs was found in all pedigrees. Pathways of hypermethylated genes included plasma membrane component, regulation of cellular protein metabolic process, and regulation of actin cytoskeleton organization, while the pathways of hypomethylated genes have included transcription regulator activity, cell adhesion, and neuronal differentiation.@*CONCLUSION@#Methylation of the VTRNA2-1 gene has co-segregated with NTDs in the studied pedigrees. The pathways of differentially methylated genes has involved with mechanism of neural tube development.

CpG Islands , DNA Methylation , Gene Ontology , Humans , MicroRNAs , Genetics , Neural Tube Defects , Genetics , Pedigree
Journal of Experimental Hematology ; (6): 1540-1547, 2019.
Article in Chinese | WPRIM | ID: wpr-775688


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 β-MG concentration. 5-aza-dc could significantly inhibit the growth of U266 cell line, arrest the cell cycle in G 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.

Cell Line, Tumor , CpG Islands , DNA Methylation , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs , Genetics , Multiple Myeloma , Genetics
Article in English | WPRIM | ID: wpr-739551


PURPOSE: Emerging evidence indicates that runt-related transcription factor 3 (RUNX3) is an important tumor suppressor gene in several cancer types, including colorectal cancer (CRC). However, the clinical significance of RUNX3 inactivation in CRC remains unclear. The aim of this study was to examine the correlation between clinicopathologic factors and RUNX3 hypermethylation/expression in CRC. METHODS: Sixty-two CRC patients who were treated at the Soonchunhyang University College of Medicine were recruited in this study. The hypermethylation of CpG islands in the RUNX3 promoter and the expression of RUNX3 mRNA were identified by methylation-specific polymerase chain reaction (PCR) and reverse transcriptase-PCR, respectively. The expression of RUNX3 was determined by immunohistochemical staining. RESULTS: Of the 62 CRC tissue samples, 20 (32.3%) presented hypermethylated RUNX3 promoters. Aberrant RUNX3 hypermethylation was found to be associated with vascular (P = 0.006) and lymphatic (P = 0.002) invasion. Hypermethylation of RUNX3 was associated with poor survival outcomes (P = 0.038). However, expression of RUNX3 was not a prognostic factor (P = 0.363). CONCLUSION: Hypermethylation of RUNX3 may be a predictor of a poor prognosis in CRC.

Colorectal Neoplasms , Core Binding Factor Alpha 3 Subunit , CpG Islands , Epigenomics , Genes, Tumor Suppressor , Humans , Immunohistochemistry , Methylation , Polymerase Chain Reaction , Prognosis , RNA, Messenger , Transcription Factor 3
Annals of Coloproctology ; : 280-285, 2018.
Article in English | WPRIM | ID: wpr-718754


For many years, developmental and physiological differences have been known to exist between anatomic segments of the colorectum. Because of different outcomes, prognoses, and clinical responses to chemotherapy, the distinction between right colon cancer (RCC) and left colon cancer (LCC) has gained attention. Furthermore, variations in the molecular features and gut microbiota between right and LCCs have recently been a hot research topic. CpG island methylator phenotype-high, microsatellite instability-high colorectal cancers are more likely to occur on the right side whereas tumors with chromosomal instability have been detected in approximately 75% of LCC patients and 30% of RCC patients. The mutation rates of oncogenes and tumor suppressor genes also differ between RCC and LCC patients. Biofilm is more abundant in RCC patients than LLC patients, as are Prevotella, Selenomonas, and Peptostreptococcus. Conversely, Fusobacterium, Escherichia/Shigella, and Leptotrichia are more abundant in LCC patients compared to RCC patients. Distinctive characteristics are apparent in terms of molecular features and gut microbiota between right and LCC. However, how or to what extent these differences influence diverging oncologic outcomes remains unclear. Further clinical and translational studies are needed to elucidate the causative relationship between primary tumor location and prognosis.

Biofilms , Chromosomal Instability , Colon , Colonic Neoplasms , Colorectal Neoplasms , CpG Islands , Drug Therapy , Fusobacterium , Gastrointestinal Microbiome , Genes, Tumor Suppressor , Humans , Leptotrichia , Microsatellite Repeats , Mutation Rate , Oncogenes , Peptostreptococcus , Prevotella , Prognosis , Selenomonas , Treatment Outcome
Article in English | WPRIM | ID: wpr-741201


BACKGROUND: Previous studies on synchronous colorectal carcinoma (SCRC) have reported inconsistent results about its clinicopathologic and molecular features and prognostic significance. METHODS: Forty-six patients with multiple advanced tumors (T2 or higher category) who did not receive neoadjuvant chemotherapy and/or radiotherapy and who are not associated with familial adenomatous polyposis were selected and 99 tumors from them were subjected to clinicopathologic and molecular analysis. Ninety-two cases of solitary colorectal carcinoma (CRC) were selected as a control considering the distributions of types of surgeries performed on patients with SCRC and T categories of individual tumors from SCRC. RESULTS: SCRC with multiple advanced tumors was significantly associated with more frequent nodal metastasis (p = .003) and distant metastasis (p = .001) than solitary CRC. KRAS mutation, microsatellite instability, and CpG island methylator phenotype statuses were not different between SCRC and solitary CRC groups. In univariate survival analysis, overall and recurrence-free survival were significantly lower in patients with SCRC than in patients with solitary CRC, even after adjusting for the extensiveness of surgical procedure, adjuvant chemotherapy, or staging. Multivariate Cox regression analysis revealed that tumor multiplicity was an independent prognostic factor for overall survival (hazard ratio, 4.618; 95% confidence interval, 2.126 to 10.030; p < .001), but not for recurrence-free survival (p = .151). CONCLUSIONS: Findings suggested that multiplicity of advanced T category–tumors might be associated with an increased risk of nodal metastasis and a risk factor for poor survival, which raises a concern about the guideline of American Joint Committee on Cancer's tumor-node-metastasis staging that T staging of an index tumor determines T staging of SCRC.

Adenomatous Polyposis Coli , Chemotherapy, Adjuvant , Colorectal Neoplasms , CpG Islands , Drug Therapy , Humans , Joints , Microsatellite Instability , Neoplasm Metastasis , Phenotype , Radiotherapy , Risk Factors
Yonsei Medical Journal ; : 588-594, 2018.
Article in English | WPRIM | ID: wpr-715904


PURPOSE: Dysregulation of the Wnt pathway is a crucial step in the tumorigenesis of colorectal cancer (CRC). This study aimed to determine whether DNA methylation of Wnt pathway genes helps predict treatment response and survival in patients with metastatic or recurrent CRC. MATERIALS AND METHODS: We retrospectively collected primary tumor tissues from 194 patients with metastatic or recurrent CRC. Pyrosequencing was used to examine the methylation of 10 CpG island loci in DNA extracted from formalin-fixed paraffin-embedded specimens. To elucidate the predictive role of DNA methylation markers, Kaplan-Meier survival estimation and Cox regression were performed for progression-free survival and overall survival (OS). RESULTS: The methylation frequencies of the 10 genes analyzed (p16, p14, MINT1, MINT2, MINT31, hMLH1, DKK3, WNT5A, AXIN2, and TFAP2E) were 47.9%, 10.8%, 21.1%, 16.0%, 20.6%, 0.5%, 53.1%, 32.0%, 2.6%, and 2.1%, respectively. We divided patients into three groups based on the number of methylated genes (group 1, no methylation n=38; group 2, 1–2 methylations n=92; group 3, 3 or more methylations n=64). Among patients treated with palliative chemotherapy (n=167), median OSs of groups 1, 2, and 3 were 39.1, 39.7, and 29.1 months, respectively (log rank p=0.013). After adjustment, number of methylations was identified as an independent poor prognostic factor (0–2 methylated vs. ≥3 methylated: hazard ratio, 1.72; 95% confidence interval, 1.16–2.56, p=0.007). CONCLUSION: This study suggests that methylation of Wnt pathway genes, in addition to known CpG island methylator phenotype markers, may help predict treatment outcome and survival in patients with CRC.

Carcinogenesis , Colorectal Neoplasms , CpG Islands , Disease-Free Survival , DNA , DNA Methylation , Drug Therapy , Humans , Methylation , Phenotype , Retrospective Studies , Treatment Outcome , Wnt Signaling Pathway
Intestinal Research ; : 358-365, 2018.
Article in English | WPRIM | ID: wpr-715885


In the past two decades, besides conventional adenoma pathway, a subset of colonic lesions, including hyperplastic polyps, sessile serrated adenoma/polyps, and traditional serrated adenomas have been suggested as precancerous lesions via the alternative serrated neoplasia pathway. Major molecular alterations of sessile serrated neoplasia include BRAF mutation, high CpG island methylator phenotype, and escape of cellular senescence and progression via methylation of tumor suppressor genes or mismatch repair genes. With increasing information of the morphologic and molecular features of serrated lesions, one major challenge is how to reflect this knowledge in clinical practice, such as pathologic and endoscopic diagnosis, and guidelines for treatment and surveillance.

Adenoma , Carcinogenesis , Cellular Senescence , Colon , Colorectal Neoplasms , CpG Islands , Diagnosis , DNA Mismatch Repair , Genes, Tumor Suppressor , Methylation , Phenotype , Polyps , United Nations
Chinese Journal of Biotechnology ; (12): 1750-1759, 2018.
Article in Chinese | WPRIM | ID: wpr-776293


To explore the activity of the pmel core promoter of Bashang long-tail chickens, we constructed dual-luciferase expression vectors and transiently transfected into DF1 cells with Lipofectamine 2000. We measured the luciferase activity with the dual-luciferase detection kit. The 1 268 bp fragment in 5-flanking region of the pmel gene in Bashang long-tail chickens was cloned. The region from -1 200 bp to +68 bp included 2 CpG islands and multiple transcription factor binding sites. We constructed 9 expression vectors with different promoter regions and a mutant vector of the core promoter region of the pmel gene of Bashang long-tail chickens. The core promoter region from -840 bp to +68 bp was identified in the pmel gene. The region from -590 to -525 bp negatively regulated the pmel gene during the transcription process. The -840--590 bp and -525--266 bp regions were positive regulatory regions. The polymorphic sites (-456, -435, -410, -374 and -341) had a significant effect on the promoter activity of the pmel gene.

Animals , Chickens , Genetics , Cloning, Molecular , CpG Islands , Luciferases , Promoter Regions, Genetic , gp100 Melanoma Antigen , Genetics
Article in Chinese | WPRIM | ID: wpr-690977


<p><b>OBJECTIVE</b>To investigate the relationship of DNA methyltransferase 1 ( DNMT1 ) with hematopoietic cell phosphatase (SHP-1) gene expression and promoter 2 methylation status in cell line K562.</p><p><b>METHODS</b>The promoter sequence of SHP-1 gene promoter 2 in NCBI database was analyzed, the K562 cells were transfected with the lentiviral plasmids-the specified retroviral vector psiHIV-mU6-shDNMT1 and psiHIV-mU6-mcherryFP-control. The methylation status of SHP-1 gene promoter 2 in K562 cells was detected by methylation-specific polymerase chain reaction (MSP) and bisulfite-modified sequencing (BSP). Western blot was used to detect the protein expression level of SHP-1 and DNMT1, the SYBR Green fluorescence quantitative PCR was used to detect the expression of SHP-1 mRNA.</p><p><b>RESULTS</b>It was found that the promoter 2 of SHP-1 gene located between -577 bp to +300 bp, and 22 CpG sites contained between -353 bp-+182 bp were aberrantly hypermethylated and the SHP-1 could not be detected in K562 cells. In vitro, the detection demonstrated that the expression level of DNMT1 in K562 cells transfected with psiHIV-mU6-shDNMT1 was 0.48±0.06 significantly lower than that of psiHIV-mU6-control group (1.33±0.19)(t= 4.18, P<0.05). The expression of SHP-1 mRNA in K562 cells transfected with psiHIV-mU6-shDNMT1 was significantly higher than that in K562 cells transfected with psiHIV-mU6-shDNMT1 (14.23±3.83 vs 1.031±0.156)(P<0.01). DNMT1 silencing induced demethylation of the 22 CpG sites located in the SHP-1 promoter 2, and SHP-1 gene was re-expression in K562 cells.</p><p><b>CONCLUSION</b>The DNMT1 in K562 cells relates with the hypermethylation and silencing of SHP-1 promoter in K562 cells.</p>

CpG Islands , DNA (Cytosine-5-)-Methyltransferases , DNA Methylation , Humans , K562 Cells , Promoter Regions, Genetic , RNA, Messenger , Real-Time Polymerase Chain Reaction
IBJ-Iranian Biomedical Journal. 2017; 21 (1): 16-23
in English | IMEMR | ID: emr-185663


Backgrund: Imprinted genes are a unique subset of few genes, which have been differentially methylated region [DMR] in a parental origin-dependent manner during gametogenesis, and these genes are highly protected during pre-implantation epigenetic reprogramming. Several studies have shown that the particular vulnerability of imprinting genes during suboptimal pre- and peri-conception micro-environments often is occurred by assisted reproduction techniques [ART]. This study investigated the methylation status of H19/IGF2 DMR at high-quality expanding/expanded human blastocysts donated by healthy individuals to evaluate the risks linked to ART

Method: Methylation levels of H19/IGF2 DMR were analyzed by bisulfite conversion and sequencing at 18 CpG sites [CpGs] located in this region

Result: The overall percentage of methylated CpGs and the proportion of hyper-methylated clones of H19/IGF2 DMR in analyzed blastocysts were 37.85 +/- 4.87% and 43.75 +/- 5.1%, respectively. For validation of our technique, the corresponding methylation levels of peripheral human lymphocytes were defined [49.52 +/- 1.86% and 50%, respectively]

Conclusion: Considering the absence of in vivoproduced human embryos, it is not possible to conclude that the methylation found in H19/IGF2 DMR is actually normal or abnormal. Regarding the possible risks associated with ART, the procedures should be optimized in order to at least reduce some of the epigenetic risks

Animals, Laboratory , Female , Humans , Male , Blastocyst , Genomic Imprinting , In Vitro Techniques , CpG Islands , Epigenesis, Genetic , Reproductive Techniques, Assisted , Iran
Cell Journal [Yakhteh]. 2017; 18 (4): 565-581
in English | IMEMR | ID: emr-185782


Objective: Induced pluripotent stem cells are generated from somatic cells by direct reprogramming. These reprogrammed pluripotent cells have different applications in biomedical fields such as regenerative medicine. Although viral vectors are widely used for efficient reprogramming, they have limited applications in the clinic due to the risk for immunogenicity and insertional mutagenesis. Accordingly, we designed and developed a small, non-integrating plasmid named pLENSO/Zeo as a 2A-mediated polycistronic expression vector

Materials and Methods: In this experimental study, we developed a single plasmid which includes a single expression cassette containing open reading frames of human LIN28, NANOG, SOX2 and OCT4 along with an EGFP reporter gene. Each reprogramming factor is separated by an intervening sequence that encodes a 2A self-processing peptide. The reprogramming cassette is located downstream of a CMV promoter. The vector is easily propagated in the E. coli GT115 strain through a CpG-depleted vector backbone. We evaluated the stability of the constructed vector bioinformatically, and its ability to stoichiometric expression of the reprogramming factors using quantitative molecular methods analysis after transient transfection into HEK293 cells

Results: In the present study, we developed a nonviral episomal vector named pLENSO/Zeo. Our results demonstrated the general structural stability of the plasmid DNA. This relatively small vector showed concomitant, high-level expression of the four reprogramming factors with similar titers, which are considered as the critical parameters for efficient and consistent reprogramming

Conclusion: According to our experimental results, this stable extrachromosomal plasmid expresses reliable amounts of four reprogramming factors simultaneously. Consequently, these promising results encouraged us to evaluate the capability of pLENSO/Zeo as a simple and feasible tool for generation of induced pluripotent stem cells from primary cells in the future

Induced Pluripotent Stem Cells , CpG Islands , Plasmids/genetics , Bacteria/genetics
Genomics & Informatics ; : 170-177, 2017.
Article in English | WPRIM | ID: wpr-192014


HOTAIR is an lncRNA that has been known to have an oncogenic role in different cancers. There is limited knowledge of genetic and epigenetic elements and their interactions for the gene encoding HOTAIR. Therefore, understanding the molecular mechanism and its regulation remains to be challenging. We used different in silico analyses to find genetic and epigenetic elements of HOTAIR gene to gain insight into its regulation. We reported different regulatory elements including canonical promoters, transcription start sites, CpGIs as well as epigenetic marks that are potentially involved in the regulation of HOTAIR gene expression. We identified repeat sequences and single nucleotide polymorphisms that are located within or next to the CpGIs of HOTAIR. Our analyses may help to find potential interactions between genetic and epigenetic elements of HOTAIR gene in the human tissues and show opportunities and limitations for researches on HOTAIR gene in future studies.

Computational Biology , Computer Simulation , CpG Islands , Epigenomics , Gene Expression , Humans , Polymorphism, Single Nucleotide , RNA, Long Noncoding , Transcription Initiation Site
Gut and Liver ; : 38-46, 2017.
Article in English | WPRIM | ID: wpr-100546


The concept of a CpG island methylator phenotype (CIMP) was first introduced by Toyota and Issa to describe a subset of colorectal cancers (CRCs) with concurrent hypermethylation of multiple CpG island loci. The concept of CIMP as a molecular carcinogenesis mechanism was consolidated by the identification of the serrated neoplasia pathway, in which CIMP participates in the initiation and progression of serrated adenomas. Distinct clinicopathological and molecular features of CIMP-high (CIMP-H) CRCs have been characterized, including proximal colon location, older age of onset, female preponderance, and frequent associations of high-level microsatellite instability and BRAF mutations. CIMP-H CRCs arise in sessile or traditional serrated adenomas and thus tend to display the morphological characteristics of serrated adenomas, including epithelial serration, vesicular nuclei, and abundant cytoplasm. Both the frequent association of CIMP and poor prognosis and different responses of CRCs to adjuvant therapy depending on CIMP status indicate clinical implications. In this review, we present an overview of the literature documenting the relevant findings of CIMP-H CRCs and their relationships with the serrated neoplasia pathway.

Adenoma , Age of Onset , Carcinogenesis , Colon , Colonic Neoplasms , Colorectal Neoplasms , CpG Islands , Cytoplasm , Female , Humans , Microsatellite Instability , Phenotype , Prognosis
Article in English | WPRIM | ID: wpr-50093


Encystation mediating cyst specific cysteine proteinase (CSCP) of Acanthamoeba castellanii is expressed remarkably during encystation. However, the molecular mechanism involved in the regulation of CSCP gene expression remains unclear. In this study, we focused on epigenetic regulation of gene expression during encystation of Acanthamoeba. To evaluate methylation as a potential mechanism involved in the regulation of CSCP expression, we first investigated the correlation between promoter methylation status of CSCP gene and its expression. A 2,878 bp of promoter sequence of CSCP gene was amplified by PCR. Three CpG islands (island 1–3) were detected in this sequence using bioinformatics tools. Methylation of CpG island in trophozoites and cysts was measured by bisulfite sequence PCR. CSCP promoter methylation of CpG island 1 (1,633 bp) was found in 8.2% of trophozoites and 7.3% of cysts. Methylation of CpG island 2 (625 bp) was observed in 4.2% of trophozoites and 5.8% of cysts. Methylation of CpG island 3 (367 bp) in trophozoites and cysts was both 3.6%. These results suggest that DNA methylation system is present in CSCP gene expression of Acanthamoeba. In addition, the expression of encystation mediating CSCP is correlated with promoter CpG island 1 hypomethylation.

Acanthamoeba castellanii , Acanthamoeba , Computational Biology , CpG Islands , Cysteine Proteases , DNA Methylation , DNA , Epigenomics , Gene Expression Regulation , Gene Expression , Methylation , Negotiating , Polymerase Chain Reaction , Trophozoites
Genomics & Informatics ; : 28-37, 2017.
Article in English | WPRIM | ID: wpr-69981


Obesity is a highly prevalent, chronic disorder that has been increasing in incidence in young patients. Both epigenetic and genetic aberrations may play a role in the pathogenesis of obesity. Therefore, in-depth epigenomic and genomic analyses will advance our understanding of the detailed molecular mechanisms underlying obesity and aid in the selection of potential biomarkers for obesity in youth. Here, we performed microarray-based DNA methylation and gene expression profiling of peripheral white blood cells obtained from six young, obese individuals and six healthy controls. We observed that the hierarchical clustering of DNA methylation, but not gene expression, clearly segregates the obese individuals from the controls, suggesting that the metabolic disturbance that occurs as a result of obesity at a young age may affect the DNA methylation of peripheral blood cells without accompanying transcriptional changes. To examine the genome-wide differences in the DNA methylation profiles of young obese and control individuals, we identified differentially methylated CpG sites and investigated their genomic and epigenomic contexts. The aberrant DNA methylation patterns in obese individuals can be summarized as relative gains and losses of DNA methylation in gene promoters and gene bodies, respectively. We also observed that the CpG islands of obese individuals are more susceptible to DNA methylation compared to controls. Our pilot study suggests that the genome-wide aberrant DNA methylation patterns of obese individuals may advance not only our understanding of the epigenomic pathogenesis but also early screening of obesity in youth.

Adolescent , Biomarkers , Blood Cells , CpG Islands , DNA Methylation , DNA , Epigenomics , Gene Expression , Gene Expression Profiling , Humans , Incidence , Leukocytes , Mass Screening , Obesity , Pilot Projects
Yonsei Medical Journal ; : 749-755, 2017.
Article in English | WPRIM | ID: wpr-81898


PURPOSE: The molecular nature and the rate-limiting step of epigenetic field defects in the evolution of left-sided colorectal cancer (LCA) remain uncertain. MATERIALS AND METHODS: The methylation status of 27 candidate field defect markers, six classic CpG island methylator phenotype (CIMP) markers, and LINE-1 were determined in LCA and adjacent normal mucosas (ADJs) from 33 LCA patients and in left normal colorectal mucosa (LNM) from 33 age- and sex-matched controls. Hotspot mutation analyses in KRAS codons 12 and 13 and BRAF V600E were performed by genomic PCR and pyrosequencing using DNA extracted from endoscopically biopsied tissues. RESULTS: Among the 27 candidate genes tested, we confirmed 15 differentially methylated genes in cancer (15 DMGs; ER, SFRP1, MYOD1, MGMT, CD8a, SPOCK2, ABHD9, BNIP3, IGFBP3, WIF1, MAL, GDNF, ALX4, DOK5, and SLC16A12) in comparison to ADJ samples. We further compared the methylation status of 15 DMGs of ADJs to LNM and found only methylation levels of SLC16A12 in ADJs of LCA patients to be significantly higher than that in LNM (17.3% vs. 11.5%, p=0.002). Based on the CIMP, no significant differences in methylation levels of the 15 DMGs were found between ADJs in CIMP positive LCA cases and those without CIMP. In mutation analyses, no mutation was found in ADJs, while significant KRAS mutations (6/33, 18%) were noted in LCA samples. CONCLUSION: Epigenetic field defect marked by aberrant methylation is uncommon in normal-appearing ADJs of LCA, indicating the critical rate-limiting change of methylation is likely to occur with morphological alterations in the evolution of LCA.

Codon , Colorectal Neoplasms , CpG Islands , DNA , Epigenomics , Glial Cell Line-Derived Neurotrophic Factor , Humans , Methylation , Mucous Membrane , Phenotype , Polymerase Chain Reaction
Yonsei Medical Journal ; : 27-34, 2017.
Article in English | WPRIM | ID: wpr-65066


PURPOSE: Ovarian cancer (OC) is the most fatal of gynecological malignancies with a high rate of recurrence. We aimed to evaluate the expression of solute carrier family 6, member 12 (SLC6A12) and methylation of its promoter CpG sites in a xenograft mouse model of metastatic OC, and to investigate the regulatory mechanisms that promote aggressive properties during OC progression. MATERIALS AND METHODS: Expression of SLC6A12 mRNA was determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR), and DNA methylation status of its promoter CpGs was detected by quantitative methylation-specific PCR. The metastatic potential of SLC6A12 was evaluated by in vitro migration/invasion transwell assays. Gene expression and DNA methylation of SLC6A12 and clinical outcomes were further investigated from publicly available databases from curatedOvarianData and The Cancer Genome Atlas. RESULTS: SLC6A12 expression was 8.1–14.0-fold upregulated and its DNA methylation of promoter CpG sites was 41–62% decreased in tumor metastases. After treatment with DNA methyltransferase inhibitor and/or histone deacetylase inhibitor, the expression of SLC6A12 was profoundly enhanced (~8.0-fold), strongly supporting DNA methylation-dependent epigenetic regulation of SLC6A12. Overexpression of SLC6A12 led to increased migration and invasion of ovarian carcinoma cells in vitro, approximately 2.0-fold and 3.3-fold, respectively. The meta-analysis showed that high expression of SLC6A12 was significantly associated with poor overall survival [hazard ratio (HR)=1.07, p value=0.016] and that low DNA methylation levels of SLC6A12 at specific promoter CpG site negatively affected patient survival. CONCLUSION: Our findings provide novel evidence for the biological and clinical significance of SLC6A12 as a metastasis-promoting gene.

Animals , Carrier Proteins/genetics , Cell Line, Tumor , Cell Migration Assays , CpG Islands , DNA Methylation , Disease Progression , Epigenesis, Genetic , Female , Gene Expression Regulation, Neoplastic , Humans , Mice , Neoplasm Invasiveness , Neoplasm Transplantation , Ovarian Neoplasms/genetics , Polymerase Chain Reaction , Prognosis , Promoter Regions, Genetic , RNA, Messenger/metabolism , Up-Regulation