• YAKHAK HOEJI
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• v.51 no.6
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• pp.415-423
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• 2007

This study was to evaluate the genotoxic effects of airborne particulate matters using single cell gell elec trophoresis (comet assay) in A549 human lung carcinoma cells. The total suspended particulate (TSP) was collected on back-up filter in Chuncheon, Kangwon Do, South Korea from April, 2003 to February, 2005. The concentrations of TSP, B(a)p and most of heavy metals seemed to be higher in spring and winter, and lower in summer. And they showed higher concentration in the commercial areas and the residential area having more traffics than in the rural area. It was found that A549 cells interacting with the organic extract of TSP showed more DNA single-strand breaks compare to untreated cells. The genotoxicity of the organic extract of TSP was increased with the pre-treatment of S-9 mixture during the culture or with the treatment of endonuclease after cell lysis. The DNA damage by the organic extract of TSP was higher in winter and the commercial area than in summer and the rural area. This study suggests that TSP, heavy metals and B(a)P analyzed showed significant variation depend on the seasons and the areas which are correlated with the DNA damage evaluated by Comet assay, indicating that genotoxic biomarker is useful for toxicological evaluation of air quality.

• YAKHAK HOEJI
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• v.52 no.5
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• pp.376-383
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• 2008

Chungkookjang (CKJ) is a fermented soybean product and one of favorite traditional foods in Korea. In this study, the alcoholic extract from Korean fermented soybean (CKJ) and its one of major flavonoids, genistein were evaluated for their protective effect against B(a)P induced cytotoxicity and DNA damage in HepG2 cells. CKJ extract and genistein decreased B(a)P-induced cell cytotoxicity. CKJ extract inhibited DNA single strand breaks evaluated by single cell gel electrophoresis. From RT-PCR study, it was revealed that CKJ extract decrease DNA damage induced in HepG2 cells expressing CYP1A1 and 1A2 by B(a)P. The metabolizing activities of CYP1A1 and CYP1A2, as measured by the 7-alkoxy resorufin O-deethylation (AROD) assay, showed that CKJ extract and genistein inhibited CYP1A1 and CYP1A2 activities. Genistein may contribute to these biological effects of CKJ extract at least in part. All these results indicate that CKJ extract and genistein may be useful for protection against B(a)P-induced cytotoxicity and DNA damage. Therefore, the alcoholic extract of Korean fermented soybean (CKJ) is suggested to be promising functional food which can prevent the cellular genotoxicity of dietary and lifestyle related carcinogens.

• Journal of Food Hygiene and Safety
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• v.17 no.2
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• pp.106-116
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• 2002

The 70% ethanol extract of Alpinia officinarum and its major flavonoid, galangin showed strong antioxidative effect on the lipid peroxidation of ethyl linolate with Fenton's reagent and free radical scavenging effect to DPPH radical generation. However, they did not reveal any pro-oxidant effect on bleomycin-Fe(III) dependent DNA degradation. They also showed the protective effect against $H_2O$$_2$, KO$_2$ or UV-induced cytotoxicity in mammalian cells. They also showed the suppressive effect of DNA damage induced by $H_2O$$_2$ or KO$_2$ with dose-dependent manner in single cell gel electrophoresis(SCGE) assay. On the other hand, they have an anticlastogenic effect against adriamycin-induced micronucleated reticulocyte in peripheral blood of mice. These results suggest that the mechanism of inhibition by 70% ethanol extract of Alpinia officinarum and galangin against reactive oxygen species (ROS)-induced genotoxicity or cytotoxicity is due, at least partly, to their antioxidative and free radical scavenging properties without pro-oxidant effect. All these results indicate that 70% ethanol extract of Alpinia officinarum and galangin may be useful for protection against ROS-induced cytotoxicity and DNA damage.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2691-2696
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• 2009

Effects of representative group II and transition metal ions on the stability of the $poly(dA){\cdot}[poly(dT)]_2$ triplex were investigated by the van’t Hoff plot constructed from a thermal melting curve. The transition, $poly(dA){\cdot}[poly(dT)]_2\;{\rightarrow}\;poly(dA){\cdot}poly(dT)\;+\;poly(dT)$, was non-spontaneous with a positive Gibb’s free energy, endothermic (${\Delta}H^{\circ}$ > 0), and had a favorable entropy change (${\Delta}S^{\circ}$ > 0), as seen from the negative slope and positive y-intercept in the van’t Hoff plot. Therefore, the transition is driven by entropy change. The $Mg^{2+}$ ion was the most effective at stabilization of the triplex, with the effect decreasing in the order of $Mg^{2+}\;>\;Ca^{2+}\;>\;Sr^{2+}\;>\;Ba^{2+}$. A similar stabilization effect was found for the duplex to single strand transition: $poly(dA){\cdot}poly(dT)\;+\;poly(dT)\;→\;poly(dA)\;+\;2poly(dT)$, with a larger positive free energy. The transition metal ions, namely $Ni_{2+},\;Cu_{2+},\;and\;Zn_{2+}$, did not exhibit any effect on triplex stabilization, while showing little effect on duplex stabilization. The different effects on triplex stabilization between group II metal ions and the transition metal ions may be attributed to their difference in binding to DNA; transition metals are known to coordinate with DNA components, including phosphate groups, while group II metal ions conceivably bind DNA via electrostatic interactions. The $Cd_{2+}$ ion was an exception, effectively stabilizing the triplex and melting temperature of the third strand dissociation was higher than that observed in the presence of $Mg_{2+}$, even though it is in the same group with $Zn_{2+}$. The detailed behavior of the $Cd_{2+}$ ion is currently under investigation.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.187-195
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• 1997

Purpose : To analyze the involvement of apoptosis regulatory genes p53, $p21^{wart/cip1}$ bax and bcl-2 in induction of apoptosis by radiation in murine tumors. Materials and methods : The radiation-sensitive ovarian carcinoma OCa-1, and the radiation-resistant hepatocarcinorna HCa-I were used. Tumors, 8 mm in diameter, were irradiated with 25 Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Results : Both tumors were positive for wild-type p53. Radiation inducesd apoptosis in OCa-1 but not in HCa-1. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h In OCa-1 radiation upregulated the expression of p53, $p21^{wart/cip1}$. and the bcl-2/bax ratio was decreased. In HCa-1 radiation increased the expression of both p53 and $p21^{wart/cip1}$, although the increase of the latter was small The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis Conclusions : The development of apoptosis required upregulation of both p53 and $p21^{wart/cip1}$ as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio Prevented apoptosis in the presence of upregulated p53 and $p21^{wart/cip1}$ . These findings indentified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for Predicting the outcome of cancer therapy with cytotoxic agents.

• Toxicological Research
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• v.22 no.2
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• pp.75-85
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• 2006

This study was designed to evaluate the possible DNA damaging effects of T-2 toxin using an alkaline single cell gel electrophoresis (SCGE) comet assay and also to investigate toxic effects in chickens. A total of 20 chickens were used in these experiments. Graded concentrations of dietary T-2 toxin (0, 4, 8, and $16{\mu}g/g$ of diet) were given to groups of 5 broiler chickens. In comet assay, The DNA damage was analysed by the tail extent moment (TEM) and tail length (TL), which were used as markers of DNA strand breaks in SCGE. A significant dose-dependent increase in the extent of DNA migration as well as in the percentage of cells with tails was observed after treatment with T-2 toxin (P<0.05). Treatment with the low T-2 toxin ($4{\mu}/g$ of diet) induced a relatively low level of DNA damage in comparison with the high T-2 toxin ($16{\mu}/g$ of diet) group. The growth rate was significantly reduced by concentrations of 8, and $16{\mu}/g$ of diet (P < 0.05). The feed conversion ratio were significantly affected by any concentrations (P < 0.05). The relative weight of the spleen, and lung was decreased by the growth inhibitory concentrations. The bursa of Fabricius, thymus, and kid- ney were decreased in relative weight by concentrations of $16{\mu}/g$ of diet. The relative weight of the liver and heart were unaffected. The hemoglobin (Hb), hematocrit (HCT), and mean corpuscular hemoglobin (MCH) were decreased at concentration of $16{\mu}/g$ of diet. As compared with control chickens, there was no marked change in serum components except uric acid in T-2 treated chickens. All lymphoid tissues retained atrophic and lymphoid cell depletion throughout the three weeks trial.

• IMMUNE NETWORK
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• v.2 no.4
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• pp.242-247
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• 2002

Background: Tumor necrosis factor-alpha (TNF-$\alpha$) is known to play an important role in various conditions such as inflammation, autoimmunity, apoptosis, insulin resistance and sleep induction. Five single nucleotide polymorphisms (SNPs) have been known to affect the transcriptional activities of TNF-$\alpha$: -1,031T/C, -863C/A, -857C/T, -308G/A and -238G/A. Methods: We have investigated 5 SNPs of the promoter region of TNF-$\alpha$ gene, the distribution of 5-locus TNF-$\alpha$ haplotypes, and their haplotypic associations with previously typed HLA-A, -B and -DRB1 loci in 107 healthy unrelated Koreans. TNF-$\alpha$ SNPs were typed using PCR-single-strand conformation polymorphism (SSCP) and PCR-restriction fragment length polymorphism (RFLP) methods. Results: The allele frequencies of -1,031C, -863A, -857T, -308A, and-238A, which are known as the high-producer-type, were 19.3%, 15.9%, 14.0%, 5.9%, and 2.9%, respectively. The frequency of -308A allele, known to be associated with autoimmune diseases, was 5.9% in Koreans which was lower than Caucasians (14~17%) and somewhat higher than Japanese (1.7%). Five most common TNF-$\alpha$ haplotypes (-1,031/-863/-857/-308/-238) comprised over 95% of total haplotypes: TCCGG (58.4%), CACGG (14.8%), TCTGG (13.7%), TCCAG (5.3%), and CCCGA (3.1%). Strong positive associations (P<0.001) were observed between TCCGG and B62; between CACGG and B51, $DRB1^*0901$; between TCTGG and B35, B54, B59, $DRB1^*1201$; and between TCCAG and A33, B58, $DRB1^*0301$, $DRB1^*1302$. Five most common extended haplotypes (>3%) comprised around 16% of total haplotypes: A33-B58-TCCAG-$DRB1^*1302$, A24-B52-TCCGG-$DRB1^*1502$, A33-B44-TCCGG-$DRB1^*1302$, A24-B7-TCCGG-$DRB1^*0101$, and A11-B62-TCCGG-$DRB1^*0406$. The distribution of extended HLA and TNF-$\alpha$ haplotypes showed that most of HLA haplotypes were almost exclusively associated with particular TNF-$\alpha$ haplotypes. Conclusion: The results obtained in this study would be useful as basic data for anthropologic studies and disease association studies in Koreans.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.4
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• pp.463-470
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• 2011

Gonadotropin-releasing hormone receptor (GnRHR) gene is expressed at the anterior pituitary gland and plays a key role in gonad development. This study aimed to investigate molecular genetic characteristics of the GnRHR gene and elucidate the effects of single nucleotide polymorphisms (SNPs) of GnRHR gene on sex steroid level in Japanese flounder (Paralichthys olivaceus). We used polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequencing of the GnRHR gene in 75 individuals. We identified three SNPs in the GnRHR gene: P1 locus (C759A and C830T) in the coding region of exon2 which were both linked together and P2 locus (G984T) in the coding region of exon3, which added a new transcript factor (ADR1) and a new methylation site (CG). Only C830T of P1 leads to amino acid changes Thr266Ile. Statistical analysis showed that P1 was significantly associated with $17{\beta}$-estradiol ($E_2$) level (p<0.01) and gonadosomatic index (GSI) (p<0.05). Individuals with genotype BB of P1 had significantly higher serum $E_2$ levels (p<0.01) and GSI (p<0.05) than those of genotype AA or AB. Another SNP, P2, synonymous mutation, was significantly associated with GSI (p<0.05). Individuals with genotype AB of P2 had significantly higher GSI (p<0.05) than that of genotype AA. In addition, there was a significant association between one diplotype based on three SNPs and reproductive traits. The genetic effects for both serum $E_2$ level and GSI of diplotype D4 were super diplotypes (p<0.05). These results suggest that the SNPs in Japanese Flounder GnRHR are associated with $E_2$ level and GSI.

• Journal of Radiation Protection and Research
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• v.27 no.3
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• pp.181-188
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• 2002

We investigated the effect of Paeonia japonica (PJ) on radiation-induced oxidative damage to macromolecules in vitro and in vivo. The PJ reduced the tail moment (TM) which was a marker of DNA strand break in single-cell gel electrophoresis (SCGE; comet assay) in the human peripheral blood lymphocytes. Lipid peroxidation in the liver of the ICR mouse, measured as malondialdehyde (MDA), was also reduced by PJ administration. Ethanol fraction of PJ was more effective than polysaccharide fraction of that on reduction of TM in SCGE and lipid peroxidation. Also, Their activities to scavenge DPPH radicals and hydroxyl radicals were observed in vitro, and the activities were due to its ethanol fraction. It is plausible that scavenging of flee radicals by PJ extract may have played an important role in providing the protection against the radiation-induced damage. These results indicated that Paeonia japonica might be a useful radioprotector, especially since it is a relatively nontoxic natural product.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2393-2399
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• 2013

Objective: Mitochondrial DNA (mtDNA) is considered a hotspot of mutations in various tumors. However, the relationship between microsatellite instability (MSI) and mtDNA copy number alterations in lung cancer has yet to be fully clarifieds. In the current study, we investigated the copy number and MSI of mitochondrial genome in lung carcinomas, as well as their significance for cancer development. Methods: The copy number and MSI of mtDNA in 37 matched lung carcinoma/adjacent histological normal lung tissue samples were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) assays for sequence variation, followed by sequence analysis and fluorogenic 5'-nuclease real-time PCR. Student's t test and linear regression analyses were employed to analyze the association between mtDNA copy number alterations and mitochondrial MSI (mtMSI). Results: The mean copy number of mtDNA in lung carcinoma tissue samples was significantly lower than that of the adjacent histologically normal lung tissue samples (p<0.001). mtMSI was detected in 32.4% (12/37) of lung carcinoma samples. The average copy number of mtDNA in lung carcinoma samples containing mtMSI was significantly lower than that in the other lung carcinoma samples (P<0.05). Conclusions: Results suggest that mtMSI may be an early and important event in the progression of lung carcinogenesis, particularly in association with variation in mtDNA copy number.