• Journal of Life Science
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• v.14 no.5
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• pp.732-740
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• 2004

MCM proteins are essential for eukaryotic DNA replication, playing roles in the initiation and elongation of DNA replication. MCM proteins expression is much higher in malignant tissues than normal tissues. Several reports have indicated the usefulness of MCM proteins as markers of cancer cells in histopathological diagnosis. However, the cause of enhanced expression of MCM proteins in cancer cells remain to be clarified. The purpose of this study is to examine the relative transcriptional activities of human mcm gene promoters in cancer and normal cells. The minimal promoter region required for transcription of a luciferase reporter gene was contained an E-box and one E2F site. In addition, luciferase activities from mcm7 and mcm2 promoter/luciferase gene reporter constructs were significantly increased in cancer cells at 8 times compared with normal cells. E-box and E2F binding site in the promoter of mcm genes are responsible for different mechanism of transcription regulation on the cellular environment.

• Journal of Acupuncture Research
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• v.20 no.5
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• pp.93-106
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• 2003

Objective : To investigate the possible molecular mechanism(s) of melittin as a candidate of anti-cancer drug, we examined the effects of the compound on the growth of human lung carcinoma cell line A549. Methods: MTT, morphological changes, DAPI staining, Western blot, RT-PCR and in vitro prostaglandin E2 (PGE2) accumulation assays were performed. Results: The anti-proliferative effect by melittin treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. Melittin induced apoptotic cell death in a concentration-dependent manner, which was associated with inhibition or degradation of apoptotic target proteins such as ${\beta}$-catenin, poly(ADP-ribose) polymerase(PARP) and phospholipase $C-{\gamma}1(PLC-{\gamma}1)$. Melittin treatment inhibited the expression of cyclooxygenase-2(COX-2) and accumulation of PGE2 in aconcentration-dependent fashion. In addition, Melittin treatment induced the down-regulation of telomerase reverse transcriptase(hTERT) and proto-oncogene c-myc expression of A549 cells. Conclusions: Taken together, these findings suggest that melittin-induced inhibition of human lung cancer cell proliferation is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products, and melittin may have therapeutic potential in human lung cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4607-4611
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• 2012

Objective: Endometrial cancer (EC) is the most common gynecologic malignancy. Identification of potential biomarkers of EC would be helpful for the detection and monitoring of malignancy, improving clinical outcomes. Methods: The Weighted Gene Co-expression Network Analysis method was used to identify prognostic markers for EC in this study. Moreover, underlying molecular mechanisms were characterized by KEGG pathway enrichment and transcriptional regulation analyses. Results: Seven gene co-expression modules were obtained, but only the turquoise module was positively related with EC stage. Among the genes in the turquoise module, COL5A2 (collagen, type V, alpha 2) could be regulated by PBX (pre-B-cell leukemia homeobox 1)1/2 and HOXB1(homeobox B1) transcription factors to be involved in the focal adhesion pathway; CENP-E (centromere protein E, 312kDa) by E2F4 (E2F transcription factor 4, p107/p130-binding); MYCN (v-myc myelocytomatosis viral related oncogene, neuroblastoma derived [avian]) by PAX5 (paired box 5); and BCL-2 (B-cell CLL/lymphoma 2) and IGFBP-6 (insulin-like growth factor binding protein 6) by GLI1. They were predicted to be associated with EC progression via Hedgehog signaling and other cancer related-pathways. Conclusions: These data on transcriptional regulation may provide a better understanding of molecular mechanisms and clues to potential therapeutic targets in the treatment of EC.

• Development and Reproduction
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• v.20 no.2
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• pp.141-147
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• 2016

Rad51 is a key component of homologous recombination (HR) to repair DNA double-strand breaks and it forms Rad51 recombinase filaments of broken single-stranded DNA to promote HR. In addition to its role in DNA repair and cell cycle progression, Rad51 contributes to the reprogramming process during the generation of induced pluripotent stem cells. In light of this, we performed reprogramming experiments to examine the effect of co-expression of Rad51 and four reprogramming factors, Oct4, Sox2, Klf4, and c-Myc, on the reprogramming efficiency. Co-expression of Rad51 significantly increased the numbers of alkaline phosphatase-positive colonies and embryonic stem cell-like colonies during the process of reprogramming. Co-expression ofRad51 significantly increased the expression of epithelial markers at an early stage of reprogramming compared with control cells. Phosphorylated histone H2AX (${\gamma}H2AX$), which initiates the DNA double-strand break repair system, was highly accumulated in reprogramming intermediates upon co-expression of Rad51. This study identified a novel role of Rad51 in enhancing the reprogramming efficiency, possibly by facilitating mesenchymal-to-epithelial transition and by regulating a DNA damage repair pathway during the early phase of the reprogramming process.

• Molecules and Cells
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• v.45 no.6
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• pp.425-434
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• 2022

The post-translational modification (e.g., phosphorylation) of estrogen receptor α (ERα) plays a role in controlling the expression and subcellular localization of ERα as well as its sensitivity to hormone response. Here, we show that ERα is also modified by UFM1 and this modification (ufmylation) plays a crucial role in promoting the stability and transactivity of ERα, which in turn promotes breast cancer development. The elevation of ufmylation via the knockdown of UFSP2 (the UFM1-deconjugating enzyme in humans) dramatically increases ERα stability by inhibiting ubiquitination. In contrast, ERα stability is decreased by the prevention of ufmylation via the silencing of UBA5 (the UFM1-activating E1 enzyme). Lys171 and Lys180 of ERα were identified as the major UFM1 acceptor sites, and the replacement of both Lys residues by Arg (2KR mutation) markedly reduced ERα stability. Moreover, the 2KR mutation abrogated the 17β-estradiol-induced transactivity of ERα and the expression of its downstream target genes, including pS2, cyclin D1, and c-Myc; this indicates that ERα ufmylation is required for its transactivation function. In addition, the 2KR mutation prevented anchorage-independent colony formation by MCF7 cells. Most notably, the expression of UFM1 and its conjugating machinery (i.e., UBA5, UFC1, UFL1, and UFBP1) were dramatically upregulated in ERα-positive breast cancer cell lines and tissues. Collectively, these findings implicate a critical role attributed to ERα ufmylation in breast cancer development by ameliorating its stability and transactivity.

• Asian Pacific Journal of Cancer Prevention
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• v.18 no.11
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• pp.2919-2923
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• 2017

Objective: Anthocyanins belong to a class of flavonoids, exhibiting antioxidant and anti-inflammatory actions have been reported to have anti-cancer effects. Here, we investigated whether anthocyanins can inhibit cancer cell proliferation, invasion, and angiogenesis in human lung cancer A549 cells, which are critically involved in cancer metastasis. Methods: We used anthocyanins from fruits of Vitis coignetiae Pulliat (AIMs) which has been used in Korean folk medicine for the treatment of inflammatory diseases and cancers. We have performed cell proliferation assays, cell invasion assay, gelatin zymography, wound healing assay and western blotting to examine whether anthocyanins can inhibit cancer cell proliferation, invasion, and angiogenesis in A549 cells. Result: AIMs did not inhibit cancer cell proliferation on A549 cells. Also, AIMs suppressed cancer migration, and invasion by supressing MMP-2 and MMP-9 expression. The Immuno-blotting results also revealed that AIMs suppressed the proteins involved in cancer proliferation (COX-2, C-myc, cyclin D1), migration and invasion (MMP-2, MMP-9), anti-apoptosis (XIAP, and c-IAP2), adhesion and angiogenesis (ICAM-1, VEGF). Conclusion: This study demonstrates that the anthocyanins isolated from fruits of Vitis coignetiae Pulliat inhibit cancer proliferation, cancer migration, and invasion that is involve in cancer-metastasis. This study provides evidence that AIMs might have anti-cancer effects on human lung cancer.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1245-1252
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• 2022

Induced pluripotent stem cells (iPSCs) can be generated from somatic cells using Oct4, Sox2, Klf4, and c-Myc (OSKM). Small molecules can enhance reprogramming. Licochalcone D (LCD), a flavonoid compound present mainly in the roots of Glycyrrhiza inflata, acts on known signaling pathways involved in transcriptional activity and signal transduction, including the PGC1-α and MAPK families. In this study, we demonstrated that LCD improved reprogramming efficiency. LCD-treated iPSCs (LCD-iPSCs) expressed pluripotency-related genes Oct4, Sox2, Nanog, and Prdm14. Moreover, LCD-iPSCs differentiated into all three germ layers in vitro and formed chimeras. The mesenchymal-to-epithelial transition (MET) is critical for somatic cell reprogramming. We found that the expression levels of mesenchymal genes (Snail2 and Twist) decreased and those of epithelial genes (DSP, Cldn3, Crb3, and Ocln) dramatically increased in OR-MEF (OG2^+/+/ROSA26^+/+) cells treated with LCD for 3 days, indicating that MET effectively occurred in LCD-treated OR-MEF cells. Thus, LCD enhanced the generation of iPSCs from somatic cells by promoting MET at the early stages of reprogramming.

• Journal of Microbiology and Biotechnology
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• v.34 no.6
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• pp.1222-1228
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• 2024

Protein-specific antibodies are essential for various aspects of protein research, including detection, purification, and characterization. When specific antibodies are unavailable, protein tagging is a useful alternative. Small epitope tags, typically less than 10 amino acids, are widely used in protein research due to the simple modification through PCR and reduced impact on the target protein's function compared to larger tags. The 2B8 epitope tag (RDPLPFFPP), reported by us in a previous study, has high specificity and sensitivity to the corresponding antibody. However, when attached to the C-terminus of the target protein in immunoprecipitation experiments, we observed a decrease in detection signal with reduced immunity and low protein recovery. This phenomenon was not unique to 2B8 and was also observed with the commercially available Myc tag. Our study revealed that C-terminal tagging of small epitope tags requires the addition of more than one extra amino acid to enhance (restore) antibody immunities. Moreover, among the amino acids we tested, serine was the best for the 2B8 tag. Our findings demonstrated that the interaction between a small epitope and a corresponding paratope of an antibody requires an extra amino acid at the C-terminus of the epitope. This result is important for researchers planning studies on target proteins using small epitope tags.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1186-1193
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• 2003

Purpose : Fragile sites are points on chromosomes which tend to break non-randomly when exposed to specific chemical agents or conditions of tissue culture. The chromosomal break induced by the antineoplastic drug, 1-${\beta}$-D-arabinofuranosyl-cytosine(Ara-c), was investigated to study the laboratory conditions in which the incidence of chromosomal break could be enhanced. Besides, the fragile sites induced by Ara-C were investigated and compared to the already known locations of the specific chromosomal alterations observed in specific neoplasms. Methods : T-lymphocytes from theree normal males and three females were cultured for 48 hours. Cells from each individual were exposed to the Ara-C for an additional 24 hours. After the caffeine was added during the last six hours culture, the metaphase chromosomes were prepared following the conventional method. A site was considered fragile if it was found to break two or more per 100 chromosomal breaks in more than four of six individuals tested. Results : Ara-C induced 252.1 chromosomal breaks per 100 mitotic cells and this result was significantly higher than that of the control, which induced 25.2 breaks(P<0.05). The incidence of the chromosomal break by Ara-C was higher, if cultured in the MEM-FA, which has no folic acid, than in the RPMI 1640 which contains enough folic acid(P<0.05). The most common break site by Ara-C was 3p14.2(FRA3B). There were 20 fragile sites induced by Ara-C. Among these 20 fragile sites, seven coincided with the locations of the mapped oncogenes, JUN, SKI, REL, N-MYC, FHIT, MET, ETS-1, and FOS. Conclusion : S phase specific chemotherapeutic agent, Ara-C, induced the expression of the chromosomal fragile sites effectively using the T-lymphocyte in vitro. Some of the fragile sites by Ara-C highly coincided with the oncogenes and neoplasm specific chromosome breakpoints. In this regard, the fragile sites reported here could provide the unknown neoplasm related chromosomal alternation points.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.232-239
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• 2019

In general, cloned pigs have been produced using the somatic cell nuclear transfer (SCNT) technique with various types of somatic cells; however, the SCNT technique has disadvantages not only in its low efficiency but also in the development of abnormal clones. This study aimed to compare early embryonic development and quality of SCNT embryos with those of induced pluripotent stem cells (iPSCs) NT embryos (iPSC-NTs). Ear fibroblast cells were used as donor cells and iPSCs were generated from these cells by lentiviral transduction with human six factors (Oct4, Sox2, c-Myc, Nanog, Klf4 and Lin28). Blastocyst formation rate in iPSC-NT (23/258, 8.9%) was significantly lower than that in SCNT (46/175, 26.3%; p < 0.05). Total cell number in blastocysts was similar between two groups, but blastocysts in iPSC-NT had a lower number of apoptotic cells than in SCNT (2.0 ± 0.6 vs. 9.8 ± 2.9, p < 0.05). Quantitative PCR data showed that apoptosis-related genes (bax, caspase-3, and caspase-9) were highly expressed in SCNT than iPSC-NT (p < 0.05). Although an early development rate was low in iPSC-NT, the quality of cloned embryos from porcine iPSC was higher than that of embryos from somatic cells. Therefore, porcine iPSCs could be used as a preferable cell source to create a clone or transgenic animals by using the NT technique.