• BMB Reports
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• v.57 no.4
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• pp.182-187
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• 2024

Neural stem cells (NSCs) in the adult hippocampus divide infrequently; the endogenous molecules modulating adult hippocampal neurogenesis (AHN) remain largely unknown. Here, we show that ErbB3 binding protein 1 (Ebp1), which plays important roles in embryonic neurodevelopment, acts as an essential modulator of adult neurogenic factors. In vivo analysis of Ebp1 neuron depletion mice showed impaired AHN with a low number of hippocampal NSCs and neuroblasts. Ebp1 leads to transcriptional repression of Bmp4 and suppression of Ascl1 promoter methylation in the dentate gyrus of the adult hippocampus reflecting an unusually high level of Bmp4 and low Ascl1 level in neurons of Ebp1-deficient mice. Therefore, our findings suggests that Ebp1 could act as an endogenous modulator of the interplay between Bmp4 and Ascl1/Notch signaling, contributing to AHN.

• BMB Reports
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• v.57 no.2
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• pp.110-115
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• 2024

Alterations in DNA methylation play an important pathophysiological role in the development and progression of colorectal cancer. We comprehensively profiled DNA methylation alterations in 165 Korean patients with colorectal cancer (CRC), and conducted an in-depth investigation of cancer-specific methylation patterns. Our analysis of the tumor samples revealed a significant presence of hypomethylated probes, primarily within the gene body regions; few hypermethylated sites were observed, which were mostly enriched in promoter-like and CpG island regions. The CpG Island Methylator Phenotype-High (CIMP-H) exhibited notable enrichment of microsatellite instability-high (MSI-H). Additionally, our findings indicated a significant correlation between methylation of the MLH1 gene and MSI-H status. Furthermore, we found that the CIMP-H had a higher tendency to affect the right-side of the colon tissues and was slightly more prevalent among older patients. Through our methylome profile analysis, we successfully verified the methylation patterns and clinical characteristics of Korean patients with CRC. This valuable dataset lays a strong foundation for exploring novel molecular insights and potential therapeutic targets for the treatment of CRC.

• Genomics & Informatics
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• v.4 no.1
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• pp.1-10
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• 2006

Epigenetic alterations are common features of human solid tumors, though global DNA methylation has been difficult to assess. Restriction Landmark Genomic Scanning (RLGS) is one of technology to examine epigenetic alterations at several thousand Notl sites of promoter regions in tumor genome. To assess sequence information for Notl sequences in RLGS gel, we cloned 1,161 unique Notl-linked clones, compromising about 60% of the spots in the soluble region of RLGS profile, and performed BLAT searches on the UCSC genome server, May 2004 Freeze. 1,023 (88%) unique sequences were matched to the CpG islands of human genome showing a large bias of RLGS toward identifying potential genes or CpG islands. The cloned Notl-loci had a high frequency (71%) of occurrence within CpG islands near the 5' ends of known genes rather than within CpG islands near the 3' ends or intragenic regions, making RLGS a potent tool for the identification of gene-associated methylation events. By mixing RLGS gels with all Notl-linked clones, we addressed 151 Notl sequences onto a standard RLGS gel and compared them with previous reports from several types of tumors. We hope our sequence information will be useful to identify novel epigenetic targets in any types of tumor genome.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.505.1-505
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• 1986

The gene for iso-1-cytochrome c for Saccharomyces cerevisiae was recloned into a pSP65 vector containing an active bacteriophage SP6 promoter. The iso-1-cytochrome c gene was cloned as an 856 bp Xho 1-Hind III fragment. When the resulting plasmid was digested at the Hind 111 site 279 bases downstream from the termination codon of the gene and transcribed in vitro using SP6 RNA polymerase, full length transcripts were produced. The SP6 iso-1-cytochrome c mRNA was translated using a rabbit reticulocyte lysate system and the protein products analyzed on SDS polyacrylamide gels. One major band was detected by autofluorography. This band was found to have a molecular weight of 12,000 Da and coincided with the Coomassie staining band of apocytochrome c from S. cerebisiae. The product was also shown to be identical with that of standard yeast apocytochrome c on an isoelectric focusing gel. The in vitro synthesized iso-a-cytochrome c was methylated by adding partially purified S-adenosyl-L-methionine . protein-lysine N-methyltransferase (Protein methylase III; EC 2.1.1.43) from S. cerevisiae along with S-adenosyl-L-methionine to the in vitro translation mixtures. The methylation was shown to be inhibited by the addition of the methylase inhibitor S-adenosyl-L-homocysteine or the protein synthesis inhibitor pu omycin. The methyl derivatives in the protein were identified as $\varepsilon$-N-mono, di and trimethyllysine by amino acid analysis. The molar ratio of methyl groups incorporated to that of cytochrome c molecules synthesized showed that 23% of the translated cytochrome c molecules were methylated by protein methylase III.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8287-8292
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• 2016

Background: Thymidylate synthase (TS) catalyzes the methylation of deoxyuridylate to deoxythymidylate and is involved in DNA methylation, synthesis and repair. Two common polymorphisms have been reported, tandem repeats in the promoter-enhancer region (TSER), and 6bp ins/del in the 5'UTR, that are implicated in a number of human diseases, including cancer. The association between the two polymorphisms in risk for lung cancer (LC) was here investigated in the Jordanian population. Materials and Methods: An age, gender, and smoking-matched case-control study involving 84 lung cancer cases and 71 controls was conducted. The polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) technique was used to detect the polymorphism of interest. Results: Individuals bearing the ins/ins genotype were 2.5 times more likely to have lung cancer [(95%CI: 0.98-6.37), p=0.051]. Individuals who were less than or equal to 57 years and carrying ins/ins genotype were 4.6 times more susceptible to lung cancer [OR<57 vs >57years: 4.6 (95%CI: 0.93-22.5), p=0.059)]. Genotypes and alleles of TSER were distributed similarly between cases and controls. Weak linkage disequilibrium existed between the two loci of interest (Lewontin's coefficient [D']) (LC: D' =0.03, r2: 0. 001, p=0.8; Controls: D' =0.29, r2: 0.08, p=0.02). Carriers of the "3 tandem repeats_insertion" haplotype (3R_ins) were 2 times more likely to have lung cancer [2 (95%CI: 1.13-3.48), p=0.061]. Conclusions: Genetic polymorphism of TS at 3 'UTR and its haplotype analysis may modulate the risk of lung cancer in Jordanians. The 6bp ins/del polymorphism of TS at 3 'UTR is more informative than TSER polymorphism in predicting increased risk.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5427-5433
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• 2013

5-Azacytidine (5-azaC) was originally identified as an anticancer drug (NSC102876) which can cause hypomethylation of tumor suppressor genes. To assess its effects on runt-related transcription factor 3 (RUNX3), expression levels and the promoter methylation status of the RUNX3 gene were assessed. We also investigated alteration of biologic behavior of esophageal carcinoma TE-1 cells. MTT assays showed 5-azaC inhibited the proliferation of TE-1 cells in a time and dose-dependent way. Although other genes could be demethylated after 5-azaC intervention, we focused on RUNX3 gene in this study. The expression level of RUNX3 mRNA increased significantly in TE-1 cells after treatment with 5-azaC at hypotoxic levels. RT-PCR showed 5-azaC at $50{\mu}M$ had the highest RUNX3-induction activity. Methylation-specific PCR indicated that 5-azaC induced RUNX3 expression through demethylation. Migration and invasion of TE-1 cells were inhibited by 5-azaC, along with growth of Eca109 xenografts in nude mice. In conclusion, we demonstrate that the RUNX3 gene can be reactivated by the demethylation reagent 5-azaC, which inhibits the proliferation, migration and invasion of esophageal carcinoma TE-1 cells.

• Molecules and Cells
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• v.26 no.1
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• pp.93-99
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• 2008

Transcriptional silencing is regulated by promoter methylation and histone modifications such as methylation and acetylation. We constructed a Schizosaccaromyces pombe reporter strain, KCT120a, to identify modifiers of transcriptional silencing, by inserting the $ura4^+$ gene into a heterochromatic telomere region. Two compounds inhibited the activity of histone deacetylases, induced acetylation of histone H3 and caused apoptotic cell death in HeLa cells. Expression of gelsolin and $p21^{waf1/cip1}$ also increased, as it does in response to HDAC inhibitors such as TSA. Therefore, these compounds appear to be potent inhibitors of HDACs, and hence potential anti-cancer drugs. Our observations suggest that a yeast cell-based assay system for transcriptional silencing may be useful for identifying histone deacetylase inhibitors and other agents affecting chromatin remodeling.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.6
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• pp.495-501
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• 2001

We have cloned the mouse neurotensin/neuromedin N (NT/N) gene from the murine mast cell line Cl.MC/C57.1 for the first time. The murine NT/N cDNA clone consisted of 765 nucleotides and coded for 169 peptide residues with an N-terminal signal peptide, and the C-terminal region contained of one copy of neurotensin (NT) and one copy of neuromedin N (NN). Total of four Lys-Arg dibasic motifs were present; one each at the middle of the open reading frame, at the N-terminal of NN, at the C-terminal of NT, and between NN and NT. Amino acid sequence analysis of the mouse NT/N revealed 90% homology to that of the rat NT/N gene. NT/N is expressed in murine mast cell lines (Cl.MC/C57.1 and P815), but not in murine bone marrow-derived mast cells (BMMCs), murine macrophage cell line (RAW 264.7), nor in murine T cell line (EL-4). NT/N mRNA in C1.MC/C57.1 is highly inducible by IgE cross-linking, phorbol myristate acetate, neurotensin, and substance P. Following the treatment of demethylating agent, 5-azacytidine (5-azaC), the NT/N gene was induced in BMMCs in response to IgE cross-linking. 5-azaC-treated BMMCs did not express the NT/N gene without additional stimuli. These findings suggested that the regulation of NT/N gene expression was dependent on the effects of not only gene methylation but also enhancer and/or repressor proteins acting on the NT/N promoter.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.625-634
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• 2019

Background: Ginsenoside Rg3, a derivative of steroidal saponins abundant in ginseng, has a range of effects on cancer cells, including anti-cell proliferation and anti-inflammation activity. Here, we investigate two long noncoding RNAs (lncRNAs), STXBP5-AS1 and RFX3-AS1, which are hypomethylated and hypermethylated in the promoter region by Rg3 in MCF-7 cancer cells. Methods: The lncRNAs epigenetically regulated by Rg3 were mined using methylation array analysis. The effect of the lncRNAs on the apoptosis and proliferation of MCF-7 cells was monitored in the presence of Rg3 or Korean Red Ginseng (KRG) extract after deregulating the lncRNAs. The expression of the lncRNAs and their target genes was examined using qPCR and Western blot analysis. The association between the expression of the target genes and the survival rate of breast cancer patients was analyzed using the Kaplan-Meier Plotter platform. Results: STXBP5-AS1 and RFX3-AS1 exhibited anti- and pro-proliferation effects, respectively, in the cancer cells, and the effects of Rg3 and KRG extract on apoptosis and cell proliferation were weakened after deregulating the lncRNAs. Of the genes located close to STXBP5-AS1 and RFX3-AS1 on the chromosome, STXBP5, GRM1, RFX3, and SLC1A1 were regulated by the lncRNAs on the RNA and protein level. Breast cancer patients that exhibited a higher expression of the target genes of the lncRNAs had a higher metastasis-free survival rate. Conclusion: The current study is the first to identify lncRNAs that are regulated by the presence of Rg3 and KRG extract and that subsequently contribute to inhibiting the proliferation of cancer cells.

• Journal of Life Science
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• v.18 no.4
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• pp.580-584
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• 2008

$O^6-methylguanine-DNA$ methyltransferase (MGMT) is a DNA repair protein that protects cells against the carcinogenic effects of alkylating agents. The loss of MGMT expression was commonly known due to hypermethylation of CpG islands in its promoter region. We evaluated the expression of MGMT by immunohistochemistry in order to examine the relationship between loss of MGMT expression and clinicopathological characteristics in 74 Korean patients with non-small cell lung cancers. Loss of MGMT was detected in 25 (33.8%) of 74 cases. The loss of MGMT expression was frequently seen in the adenocarcinoma than in the squamous cell carcinoma (p=0.021). However, there was no significant differences between loss of MGMT expression and other clinicopathological characteristics, including age, gender, smoking status, tumor size, tumor T stage, and lymph node metastasis (p>0.05). In conclusion, loss of MGMT expression was related with the histologic type of lung cancer. Further methylation study of MGMT promoter is needed to evaluate the relationships with immunohistochemical expression of MGMT and to clarify the role of MGMT in lung cancer.