• 한국안광학회지
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• 제13권3호
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• pp.95-101
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• 2008

목적: 활성산소종의 하나인 $H_2O_2$는 DNA, RNA에 직접적인 손상을 주어 유전자를 변형시키고 세포고사를 일으켜 각종 질환을 일으키는 발병인자로 알려져 있다. 본 연구는 결막 세포주에서 일어나는 $H_2O_2$에 의한 세포고사에서 EGCG의 보호효과를 알아보고자 실험하였다. 방법: 세포의 생존율은 MTT assay로 확인하였고, 세포고사의 형태적인 특징은 DNA 단절화을 통해 확인하였으며, EGCG의 자유라디칼 제거능력을 측정하기 위해 DPPH free radical 소거능을 실시하고, 세포내 활성산소량의 평가를 위한 DCFH-DA assay를 시행하였다. 세포내의 mRNA 발현은 RTPCR을 시행하여 밴드 양상을 확인하였다. 결과: 세포생존율과 프리라디칼 소거능은 EGCG의 처리 농도 의존적으로 증가하였고, DNA 분절화와 세포내 활성산소량은 감소하였다. mRNA 합성에서 bcl-2, bcl-xL의 발현은 증가하였고, bax 발현은 감소되었다. 결론: EGCG는 $H_2O_2$로 세포고사를 유도한 결막 세포주에서 항산화효과를 나타냈으며, EGCG가 anti-apoptosis 관련한 mRNA의 발현을 증가시켜 결막 세포주의 산화적 손상을 억제함으로서 세포보호효과를 나타냈음을 확인할 수 있었다.

• Journal of Genetic Medicine
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• 제12권2호
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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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• 제12권3호
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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.

• 대한상부위장관⦁헬리코박터학회지
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• 제18권3호
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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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• 제28권7호
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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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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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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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• 제9권1_2호
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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.

• 대한의생명과학회지
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• 제11권2호
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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.

• 한국동물생명공학회지
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• 제37권4호
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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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• 제12권2호
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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.