• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1154-1158
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• 2013

Ganciclovir resistance of human cytomegalovirus is associated with mutations in the viral UL97 gene and poses severe problems for immunocompromised patients. In this study, PCR-based restriction fragment length polymorphism and sequencing analyses detected the UL97 D605E mutation in all five clinical isolates from patients with ganciclovir-resistant human cytomegalovirus infection during prolonged ganciclovir therapy, whereas the M460V mutation was only present in 1 of 5 isolates. On the other hand, the detection rates of the D605E mutation in the stored available DNA samples from the donor and allogeneic stem cell transplantation recipients were 66.7% and 93.7%, respectively, suggesting that the presence of D605E mutation was not associated with the ganciclovir exposure. Although the D605E mutation may not be related to ganciclovir resistance, we suggest that this mutation could be an important molecular marker of human cytomegalovirus evolution in East Asian countries. Moreover, the restriction fragment length polymorphism method using the restriction enzyme HaeIII, which is generally used to detect the UL97 A591V mutation, could also detect the D605E mutation and may therefore be a useful tool for future research on the investigation of UL97 gene mutations.

• Annals of Laboratory Medicine
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• v.38 no.6
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• pp.591-598
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• 2018

Background: Forkhead box P3 (FOXP3) is an important marker of regulatory T cells. FOXP3 polymorphisms are associated with autoimmune diseases, cancers, and allograft outcomes. We examined whether single nucleotide polymorphisms (SNPs) at the FOXP3 locus are associated with clinical outcomes after allogenic hematopoietic stem cell transplantation (HSCT). Methods: Five FOXP3 SNPs (rs5902434, rs3761549, rs3761548, rs2232365, and rs2280883) were analyzed by PCR-sequencing of 172 DNA samples from allogenic HSCT patients. We examined the relationship between each SNP and the occurrence of graft-versus-host disease (GVHD), post-HSCT infection, relapse, and patient survival. Results: Patients with acute GVHD (grades II-IV) showed higher frequencies of the rs3761549 T/T genotype, rs5902434 ATT/ATT genotype, and rs2232365 G/G genotype than did patients without acute GVHD (P =0.017, odds ratio [OR]=5.3; P =0.031, OR=2.4; and P =0.023, OR=2.6, respectively). Multivariate analysis showed that the TT genotype of rs3761549 was an independent risk factor for occurrence of acute GVHD (P =0.032, hazard ratio=5.6). In contrast, the genotype frequencies of rs3761549 T/T, rs5902434 ATT/ATT, and rs2232365 G/G were lower in patients with post-HSCT infection than in patients without infection (P =0.026, P =0.046, and P =0.031, respectively). Conclusions: rs3761549, rs5902434, and rs2232365 are associated with an increased risk of acute GVHD and decreased risk of post-HSCT infection.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.4
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• pp.415-422
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• 2019

Human epidermal stem cells(ESCs) residing in the basement membrane of the skin have an important role in maintenance of skin homeostasis of epidermal layer. Although, ESCs provide new cells to repair damaged tissue in response to tissue injury, subsets of stem cells remain in the quiescent state protected from differentiation and senescence for prolonged survivals. In this perspective, the stem cell niche, which is specific microenvironment composed of niche cells and an extracellular matrix(ECM), supplies the relevant signal to save stem cells from microenvironmental damages. The expression of stemness marker on the surface of ESCs contributes to the attachment on their ECM of the basement membrane, which lead to growth potential and apoptotic resistance against environmental stimuli. In this study, we observed that UV irradiation, a major factor of environmental stimuli, reduced the expression of α2, β1 and α6 integrin in ESCs. Rhus Semialata M extract(RSE) showed inhibitory effect on the UVB-induced reduction of integrin expression. Furthermore, RSE could upregulate the expression of Col-IV and Laminin, which contribute to the attachment of ESCs. These results indicated that RSE could be a potent ingredient for the protection of ESCs from UV irradiation by increasing the expression of integrin and substrate ECM components at their niche.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.690-696
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• 1996

It has been known that many kinds of cancer are caused by continued proliferation or abnormal differentiation. Thus, recent approaches to anticancer therapy have been focused on developing drugs that induce differentiation of cancer cells to normal cells. A typical differentiation agent, all trans-retinoic acid, is unsuitable for anticancer drug because all trans-retinoic acid produces unfavorable side effects and cytotoxicity in normal cells. Therefore, we have screened some new differentiation-inducing compounds obtained from marine organisms using F9 teratocarcinoma stem cells as a model system. We observed that fatty acid. glycolipid, saponin, sphingosine and sterol compounds of marine organisms had differentiation-inducing activity in F9 cells, were determined by morphological changes and Northern blot analysis. The expression of differentiation marker genes, such as laminin B1, type IV collagen and retinoic acid receptor beta were induced by treatment with those compounds.

• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.247-252
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• 2004

Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo. Human ES cells have the capacity to differentiate into various types of cells in the body. Human ES cells are indefinite source of cells for cell therapy in various degenerative disorders including neuronal disorders. Directed differentiation of human ES cells is a prerequisite for their clinical application. The objective of this study is to develop the culture condition for the derivation of neural precursor cells from human ES cells. Neural precursor cells were derived from human ES cells in a stepwise culture condition. Neural precursor cells in the form of neural rosette structures developed into neurospheres when cultured in suspension. Suspension culture of neurospheres has been maintained over 4 months. Expressions of nestin, soxl, sox2, pax3 and pax6 transcripts were upregulated during differentiation into neural precursor cells by RT-PCR analysis. In contrast, expression of oct4 was dramatically downregulated in neural precursor cells. Immunocytochemical analyses of neural precursor cells demonstrated expression of nestin and SOX1. When induced to differentiate on an adhesive substrate, neuro-spheres were able to differentiate into three lineages of neural systems, including neurons, astrocytes and oligo-dendrocytes. Transcripts of sox1 and pax6 were downregulated during differentiation of neural precursor cells into neurons. In contrast, expression of map2ab was elevated in the differentiated cells, relative to those in neural precursor cells. Neurons derived from neural precursor cells expressed NCAM, Tuj1, MAP2ab, NeuN and NF200 in immunocytochemical analyses. Presence of astrocytes was confirmed by expression of GFAP immuno-cytochemically. Oligodendrocytes were also observed by positive immuno-reactivities against oligodendrocyte marker O1. Results of this study demonstrate that a stepwise culture condition is developed for the derivation of neural precursor cells from human ES cells.

• Journal of Life Science
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• v.22 no.12
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• pp.1644-1650
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• 2012

The aim of this study was to screen the polymorphisms and distribution of each genotype of insertion/ deletion (indel) markers which were found in a preliminary comparative study of bovine genomic sequence databases. Comparative bioinformatic analyses were first performed between the nucleotide sequences of Bovine Genome Project and those of expressed sequence tag (EST) database, and a total of fifty-one species of indel markers were screened. Of these, forty-two indel markers were evaluated, and nine informative indel markers were ultimately selected for population analysis. Nucleotide sequences of each marker were re-sequenced and their polymorphic patterns were typed in six cattle breeds: Holstein, Angus, Charolais, Hereford, and two Korean native cattle breeds (Hanwoo and Jeju Black cattle). Cattle breeds tested in this study showed polymorphic patterns in eight indel markers but not in the Indel-15 marker in Charolais and Holstein. The results of analysis for Jeju Black cattle (JBC) population indicated an observed heterozygosity (Ho) that was highest in HW_G1 (0.600) and the lowest in Indel_29 (0.274). The PIC value was the highest in HW_G4 (0.373) and lowest in Indel_6 (0.305). These polymorphic indel markers will be useful in supplying genetic information for parentage tests and traceability and to develop a molecular breeding system for improvement of animal production in cattle breeds as well as in the JBC population.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.215-220
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• 2007

This study was conducted to examine the establishment of bovine ES-like cells having pluripotency. The hatched blastocysts derived from culture of in vitro fertilized embryos for 10 to 12 days dissociated mechanically into ICM-and trophectoderm-rich clumps using needle, and cultured onto mitotically-inactivated MEF feeder layer. The primary colonies originated from ICM cells were detached mechanically 7 days after seeding and subsequent subculture was conducted at intervals of every 5 to 7 days. Two ES -like cell lines were established and maintained over 40 passages. Self-renewal of the established lines was confirmed by examining the alkaline phosphatase activity, stem cell-specific marker profiles including SSEA isotopes, Oct-4 and STAT3. Moreover, the established cell lines could produce anchorage-independent embryoid bodies (EBs) with gradual decrease of Oct-4 transcript level in time-dependent manner.

• Journal of Life Science
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• v.26 no.7
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• pp.835-846
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• 2016

Chemo-resistance is the biggest issue of effective cancer therapy. ABCG2 is highly correlated with multi-drug resistance, and represent a typical phenotype of multiple cancer stem-like cells. Accumulating evidence recently reported that oncolytic viruses represent a new strategy for multiple aggressive cancers and drug resistant cancers including cancer stem cell-like cells and ABCG2 expressing cells. In this study, we generated an evolutionally engineered vaccinia virus, SLJ-496, for drug-resistant cancer therapy. We first showed that SLJ-496 treatment enhanced tumor affinity using cytopathic effect assay, plaque assay, as well as cell viability assay. Next, we clearly demonstrated that in vitro SLJ-496 treatment represents significant cytotoxic effect in multiple cancers including colorectal cancer cells (HT-29, HCT-116, HCT-8), gastric cancer cells (AGS, NCI-N87, MKN-28), Hepatocellular carcinoma cells (SNU-449, SNU-423, SNU-475, HepG2), as well as mesothelioma cell (NCI-H226, NCI-H28, MSTO-221h). Highly ABCG2 expressing HT-29 cells represent cancer stem like phenotype including stem cell marker expression, and self-renewal bioactivities. Interestingly, we demonstrated that in vitro treatment of SLJ-496 showed significant cytotoxicity effect, as well as viral replication capacity in ABCG2 overexpressing cell. In addition, we also demonstrated the cytotoxic effect of SLJ-496 in Adriamycin-resistant cell lines, SNU-620 and ADR-300. Taken together, these findings provide us a pivotal clue that cancer therapy using SLJ-496 vaccinia virus might be new therapeutic strategy to overcome ABCG2 expressing cancer stem-like cell and multiple chemo-resistance cancer cells.

• Journal of Life Science
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• v.28 no.12
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• pp.1455-1460
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• 2018

Due to a rapidly expanding aging population, the incidence of degenerative bone disease has increased, and efforts to handle the issue using regenerative medicine have become more important. In order to control various bone diseases such as osteoarthritis and osteoporosis, regenerative medicine utilizing adult stem cells has been extensively studied. And it is now clear that the mitochondrial energy metabolism, oxidative phosphorylation, is important for the process of stem cell differentiation. Interestingly, a recent study reported that salicylate promotes mitochondrial biogenesis by regulating the expression of $PGC-1{\alpha}$ in murine cells. However, the possible effects of salicylate on osteogenic differentiation through increased mitochondrial biogenesis in stem cells remain unknown. Thus, here we investigated whether salicylate could influence osteogenic differentiation and mitochondrial biogenesis of periosteum-derived mesenchymal stem cells (POMSCs). We found that salicylate treatments of POMSCs undergoing osteogenic differentiation increased the activity of alkaline phosphatase, a well-known early marker of bone cell differentiation. In addition, we observed that mitochondrial mass was increased by salicylate treatments in POMSCs. Together, these results indicate that salicylate can enhance osteogenic differentiation and mitochondrial biogenesis in POMSCs. Therefore, the findings in this study suggest that small molecules augmenting mitochondrial function such as salicylate can be a novel modulator for osteogenic differentiation and regenerative medicine.

• Reproductive and Developmental Biology
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• v.32 no.2
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• pp.135-140
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• 2008

Recent studies on nuclear transfer and induced pluripotent stem cells have demonstrated that differentiated somatic cells can be returned to the undifferentiated state by reversing their developmental process. These epigenetically reprogrammed somatic cells may again be differentiated into various cell types, and used for cell replacement therapies through autologous transplantation to treat many degenerative diseases. To date, however, reprogramming of somatic cells into undifferentiated cells has been extremely inefficient. Hence, reliable markers to identify the event of reprogramming would assist effective selection of reprogrammed cells. In this study, a transgene construct encoding enhanced green fluorescent protein (EGFP) under the regulation of human Oct4 promoter was developed as a reporter for the reprogramming of somatic cells. Microinjection of the transgene construct into pronuclei of fertilized mouse eggs resulted in the emission of green fluorescence, suggesting that the undifferentiated cytoplasmic environment provided by fertilized eggs induces the expression of EGFP. Next, the transgene construct was introduced into human embryonic fibroblasts, and the nuclei from these cells were transferred into enucleated porcine oocytes. Along with their in vitro development, nuclear transfer embryos emitted green fluorescence, suggesting the reprogramming of donor nuclei in nuclear transfer embryos. The results of the present study demonstrate that expression of the transgene under the regulation of human Oct4 promoter coincides with epigenetic reprogramming, and may be used as a convenient marker that non-invasively reflects reprogramming of somatic cells.