• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.95-101
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• 2008

Purpose: Hydrogen peroxide which is one of the reactive oxygen species has been seen to cause various diseases, various cellular disinfections, gene transformation and cell death. The goals of this study were to determine the protective effect of EGCG against $H_2O_2$-induced apoptotic death in conjunctival cell lines. Methods: We measured cell viability by MTT assay and analyzed DNA fragmentation to check up a distinctive feature in cell death and measured the removal ability of free radicals by DPPH free radical scavenging assay and evaluated the oxygen free radical's quantity in the cell by DCFH-DA assay. The mRNA expression in the cell were examined by RT-PCR. Results: Cell viability and free radical scavening activites was significantly increased in dose dependently after cell was exposed to EGCG. And DNA fragmentation and intracellular ROS was decreased. It was showed the mRNA expression which increase of bcl-2, bcl-xL expression and decrease of bax expression. Conclusions: From these results, it suggests that EGCG has an antioxidant effect and protects conjunctival cell lines from the $H_2O_2$-mediated apoptosis through the modulation of the mRNA expression.

• Journal of Genetic Medicine
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• v.12 no.2
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• pp.100-108
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• 2015

Purpose: Conventional methods for the prenatal detection of fetal RhD status involve invasive procedures such as fetal blood sampling and amniocentesis. The identification of cell-free fetal DNA (cffDNA) in maternal plasma creates the possibility of determining fetal RhD status by analyzing maternal plasma DNA. However, some technical problems still exist, especially the lack of a positive control marker for the presence of fetal DNA. Therefore, we assessed the feasibility and accuracy of fetal RHD genotyping incorporating the RASSF1A epigenetic fetal DNA marker from cffDNA in the maternal plasma of RhD-negative pregnant women in Korea. Materials and Methods: We analyzed maternal plasma from 41 pregnant women identified as RhD-negative by serological testing. Multiplex real-time PCR was performed by amplifying RHD exons 5 and 7 and the SRY gene, with RASSF1A being used as a gender-independent fetal epigenetic marker. The results were compared with those obtained by postnatal serological analysis of cord blood and gender identification. Results: Among the 41 fetuses, 37 were RhD-positive and 4 were RhD-negative according to the serological analysis of cord blood. There was 100% concordance between fetal RHD genotyping and serological cord blood results. Detection of the RASSF1A gene verified the presence of cffDNA, and the fetal SRY status was correctly detected in all 41 cases. Conclusion: Noninvasive fetal RHD genotyping with cffDNA incorporating RASSF1A is a feasible, reliable, and accurate method of determining fetal RhD status. It is an alternative to amniocentesis for the management of RhD-negative women and reduces the need for unnecessary RhIG prophylaxis.

• Journal of Korean Biological Nursing Science
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• v.12 no.3
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• pp.127-132
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• 2010

Purpose: The aim of this study is to evaluate the effect of Xanthium sibiricum Patr. on carcinogenesis. Method: Water extract from Xanthium sibiricum Patr. (XPW) was prepared and investigated for the potential antitumor activity and inhibition of benzo[a]pyrene-DNA adduct formation and free radical formation. Result: It was shown that the water possess considerable toxicity toward tumor cell lines. Concentration of XPW at 1.0 mg/mL and 2.5 mg/mL resulted in more than 30% inhibition of growth in HeLa cells. Toxicity of XPW to A549 revealed that 54% inhibition of growth at concentration of 2.5 mg/mL. At concentrations of 0.5 mg/mL, 1.0 mg/mL and 2.5 mg/mL of XPW, the binding of [$^3H$]B[a]P metabolites to DNA of human Chang cell was inhibited by 19%, 33%, and 41%, respectively. There 18% and 32% inhibition in the free radical formation with XPW at the concentration of 1.0 mg/mL and 2.5 mg/mL, respectively. Conclusion: Water extract from Xanthium sibiricum Patr. (XPW) has antitumor and cancer chemopreventive activities.

• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.3
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• pp.168-173
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• 2018

Gastric cancer is still the leading cause of cancer deaths, especially in Asian countries. Recently, many studies have analyzed cell-free nucleic acids (cfNAs) circulating in the blood, for the early diagnosis of cancer and monitoring its progression. Circulating tumor nucleic acids (ctNAs) originate in a tumor and contain tumor-related genetic or epigenetic alterations. This review defines the nomenclatures of each form of cfNAs and describes the characteristics of circulating tumor DNA (ctDNA) and microRNA (miRNA), two major forms of ctNAs studied in gastric cancer research to date. We compare available studies on ctDNA, and explain trends observed in studies of miRNAs in gastric cancers. As these new blood-based biomarkers have attracted increasing attention, we have discussed several important points to be considered before the clinical translation of ctNA detection. We have also discussed the current status of research in this field, and clinical applications of specific ctNAs as tumor markers for gastric cancer diagnosis.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.775-783
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• 2005

The ethanol extract of the peony root (Paeonia Lactiflora Pall, Paeoniaceae) as well as its major active components including gallic acid and methyl gallate were evaluated for their protective effects against free radical generation and lipid peroxidation. In addition, the protective effects against hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line were examined. The ethanol extracts of the peony root (PREs) and its active constituents, gallic acid and methyl gallate, exhibited a significant free radical scavenging effect against 1,1-diphenyl-2-picryl hydrazine (DPPH) radical generation and had an inhibitory effect on lipid peroxidation, as measured by the level of malondialdehyde (MDA) formation. The PREs did not have any pro-oxidant effect. They strongly inhibited the hydrogen peroxide-induced DNA damage from NIH/3T3 fibroblasts, as assessed by single cell gel electrophoresis. Furthermore, the oral administration of 50% PRE (50% ethanol extract of peony root), gallic acid and methyl gallate potently inhibited the formation of micronucleated reticulocytes (MNRET) in the mouse peripheral blood induced by a $KBrO_3$ treatment in vivo. Therefore, PREs containing gallic acid and methyl gallate may be a useful antigenotoxic antioxidant by scavenging free radicals, inhibiting lipid peroxidation and protecting against oxidative DNA damage without exhibiting any pro-oxidant effect.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.153-158
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• 2003

The genome-wide program of gene expression during the cell division cycle response to serum free media in chinese hamster ovary(CHO) cells was characterized using cDNA microarrays. Many transcripts of genes showed variation during the cell cycle. Characterization is critical step toward understanding the basic cell cycle processes and serum-free media role in CHO cells

• Journal of Plant Biology
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• v.9 no.1_2
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• pp.1-6
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• 1966

Using the Chlorella cells which had been uniformly labeled with $^{32}P$, the distribution of phosphorus in various fractions of cell material was investigated. Uniformly $^{32}P$-labeled Chlorella cells were further grown in a P-free medium, and some protions of the cells were taken out at intervals during the culture, and subjected to analyze the contents of $^{32}P$ in various fractins of the cell constituents. 2. Analysis of the $^{32}P$-labeled Chlorella cells showed that the highest in P-content was the fraction of RNA followed by those of lipid, RNA-polyphosphate complex, acid-insoluble polyphosphate, acid-soluble polyphosphate, DNA and protein. 3. During the culture of $^{32}P$-labeled Chlorella cells in a P-free medium, amounts of phosphate in DNA, protein and lipid fractions increased, while the P-contents in the fraction of RNA-polyphosphate complex decreased as well as those of acid-insoluble polyphosphate and acid-soluble polyphosphate fractions. 4. It was inferred that phosphorus used in the syntheses of DNA and protein was taken from polyphosphates of the cells, and RNA-polyphosphate complex would play an important role as a phosphate pool.

• Biomedical Science Letters
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• v.11 no.2
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• pp.103-108
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• 2005

2-Deoxyribonolactone (dL) arises as a major DNA damage induced by a variety of agents, involving free radical attack and oxidation of C1'-deoxyribose in DNA. We investigated whether dL lesions can be repaired in mammalian cells and the mechanisms underlying the role of DNA polymerase $\beta$ in processing of dL lesions. Pol $\beta$ appeared to be trapped by dL residues, resulting in stable DNA-protein cross-links. However, repair DNA synthesis at site-specific dL sites occurred effectively in cell-free extracts, but predominantly accompanied by long-patch base excision repair (BER) pathway. Reconstitution of long-patch BER demonstrated that FEN1 was capable of removing the displaced flap DNA containing a 5'-dL residue. Cellular repair of dL lesions was largely dependent on the DNA polymerase activity of Pol $\beta$. Our observations reveal repair mechanisms of dL and define how mammalian cells prevent cytotoxic effects of oxidative DNA lesions that may threaten the genetic integrity of DNA.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.292-297
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• 2022

Direct injection of CRISPR/Cas9 into zygotes enables the production of genetically modified nonhuman primates (NHPs) essential for modeling specific human diseases, such as Usher syndrome, and for developing novel therapeutic strategies. Usher syndrome is a rare genetic disease that causes loss of hearing, retinal degeneration, and problems with balance, and is attributed to a mutation in MYO7A, a gene that encodes an uncommon myosin motor protein expressed in the inner ear and retinal photoreceptors. To produce an Usher syndrome type 1B (USH1B) rhesus macaque model, we disrupted the MYO7A gene in developing zygotes. Identification of appropriately edited MYO7A embryos for knockout embryo transfer requires sequence analysis of material recovered from a trophectoderm (TE) cell biopsy. However, the TE biopsy procedure is labor intensive and could adversely impact embryo development. Recent studies have reported using cell-free DNA (cfDNA) from embryo culture media to detect aneuploid embryos in human in vitro fertilization (IVF) clinics. The cfDNA is released from the embryo during cell division or cell death, suggesting that cfDNA may be a viable resource for sequence analysis. Moreover, cfDNA collection is not invasive to the embryo and does not require special tools or expertise. We hypothesized that selection of appropriate edited embryos could be performed by analyzing cfDNA for MYO7A editing in embryo culture medium, and that this method would be advantageous for the subsequent generation of genetically modified NHPs. The purpose of this experiment is to determine whether cfDNA can be used to identify the target gene mutation of CRISPR/Cas9 injected embryos. In this study, we were able to obtain and utilize cfDNA to confirm the mutagenesis of MYO7A, but the method will require further optimization to obtain better accuracy before it can replace the TE biopsy approach.

• Journal of Genetic Medicine
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• v.12 no.2
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• pp.66-71
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• 2015

Down syndrome screening with cell-free DNA (cfDNA) in the maternal plasma has recently received much attention in the prenatal diagnostic field. Indeed, a large amount of evidence has already accumulated to show that screening tests with cfDNA are more sensitive and specific than conventional maternal serum and/or ultrasound screening. Globally, more than 1,000,000 of these noninvasive prenatal tests (NIPTs) have been performed to date. There are several different methods for NIPTs that are currently commercially available, including shotgun massively parallel sequencing, targeted massively parallel sequencing, and single nucleotide polymorphism (SNP)-based methods. All of these methods have their own advantages and disadvantages. In this review, I will focus specifically on the SNP-based NIPT.