• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.605-608
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• 2006

Genetically modified (GM) ingredients found in imported raw materials and processed foods were monitored in the province Gyeongin in Korea. The analysis was performed according to "Testing methods for genetically modified foods of food standards and specifications" established in Korea. We received 120 items from the Gyeongin Regional KFDA. Only two of the 120 items analyzed in the samples, were contaminated with GM ingredients. However, we could not analyze the internal standard gene from 12 processed foods. We found that the extracted total DNA of the above 12 samples were extracted and found to be degraded. The total DNA contained a very small fragment of less than 300 base pair. Therefore, it seems that the total DNA is not large enough to serve as the template DNA for PCR analysis.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6783-6787
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• 2015

Background: Despite consistent pharmacogenetic effects of CYP2D6 on tamoxifen exposure, there is considerable controversy regarding the validity of CYP2D6 as a predictor of tamoxifen outcome. Understanding the current state of evidence in this area and its limitations is important for the care of patients who require endocrine therapy for breast cancer. Materials and Methods: A total of 101 patients with breast cancer who received tamoxifen therapy for at least 3 years, were genotyped for common alleles of the CYP2D6 gene by nested-PCR and restriction fragment length polymorphism PCR. Patients were classified as extensive or poor metabolizers (PM) based on CYP2D6*4 alleles in 3 different groups according to the menopause, Her2-neu status, and stage 3. Results: The mean age of the patients with the disease recurrence was $50.8{\pm}6.4$ and in non recurrent patients was $48.2{\pm}6.8$. In this study 63.3% (n=64) patients were extensive metabolizers and 36.6% (n=37) were poor metabolizers. Sixty four of the 101 patients (63.3%) were Her2-neu positive. For tamoxifen-treated patients, no statistically significant difference in rate of recurrence observed between CYP2D6 metabolic variants in stage 3 and post-menopausal patients. However, there was a significant association between CYP2D6 genotype and recurrence in tamoxifen-treated Her2-neu positive patients. Compared with other women with breast cancer, those with Her2-neu positive breast cancer and extensive metabolizer alleles had a decreased likelihood of recurrence. Conclusions: This study for the first time demonstrated significant effects of CYP2D6 extensive metabolizer alleles on risk of recurrence in Her2-neu positive breast cancer patients receiving adjuvant tamoxifen therapy. Therefore, CYP2D6 metabolism, as measured by genetic variation, can be a predictor of breast cancer outcome in Her2-neu positive women receiving tamoxifen.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4017-4023
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• 2012

Background and Aim: Polymorphisms in methylenetetrahydrofolate reductase (MTHFR) are known to be associated with predisposition for certain cancers. This study aimed to evaluate the effects of lifestyle factors, family history and genetic polymorphisms in MTHFR C677T and A1298C on rectal cancer risk and possible interactions with lifestyle factors in Northeast Thailand. Methods: A hospital-based case-control study was conducted during 2002-2006 with recruitment of 112 rectal cancer cases and 242 non-rectal cancer patient controls. Information was collected using a structured-questionnaire. Blood samples were obtained for assay of MTHFR C677T and A1298C genotypes by polymerase chain reaction with restriction fragment length polymorphism (PCR-RFLP) techniques. Associations between lifestyle factors, family history and genetic polymorphisms v.s. rectal cancer risk were assessed using logistic regression analysis. Results: Subjects with frequent and occasional constipation had a higher risk ($OR_{adj.}$=14.64; 95%CI=4.28-50.04 and $OR_{adj.}$=2.15; 95%CI=1.14-4.06), along with those who reported ever having hemorrhoids ($OR_{adj.}$=2.82; 95%CI=1.36-5.84) or a family history of cancer ($OR_{adj.}$=1.90; 95%CI=1.06-3.39). Consumption of a high level of pork was also associated with risk ($OR_{adj.}$=1.82; 95%CI=1.05-3.15). Interactions were not observed between MTHFR and other risk factors. Conclusions: This study suggested that the risk factors for rectal cancer in the Thai population are bowel habits, having had hemorrhoids, a family history of cancer and pork consumption.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6505-6510
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• 2012

Background: CYP2E1 encodes an enzyme which is mainly involved in bioactivation of potential carcinogens such as N-nitrosamines. Polymorphisms in the gene have been reported to be associated with cancer. The aim of this study was to evaluate genotype distributions and allele frequencies of five CYP2E1 polymorphisms in Iran Materials and Methods: Two hundred healthy individuals of an Iranian population from the southwest were included in this study. PCR-restriction fragment length polymorphism and Tetra-ARMS PCR methods were applied for CYP2E1 genotyping. Results: The allele frequencies for $^*5B$, $^*6$, $^*7B$, $^*2$, and $^*3$ were calculated to be 1.5%, 16%, 28.5%, 0%, and 2.75% respectively. Results of this study showed that no significant differences in genotype and allele frequencies of five single nucleotide polymorphisms with respect to the gender and tribes. The chi-square test showed that the genotype frequencies of $CYP2E1^*5B$ were similar to Caucasians, but the distribution of $CYP2E1^*6$ genotypes was similar to Asians. The frequencies of $CYP2E1^*2$ (0%) and $CYP2E1^*3$ (2.75%) alleles were within the range for Caucasians and Orientals. In the case of $CYP2E1^*7B$, the data werelimited. Accordingly, the results were only compared with Europeans and the comparison showed significant differences. Conclusions: In conclusion, ethnic and geographic differences may explain discrepancies in the prevalence of CYP2E1 polymorphisms.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4217-4222
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• 2016

Purpose: To compare the expression level of CK 15 in normal esophageal and esophageal squamous-cell carcinoma (ESCC) tissues and analyse possible functions of CK15 in occurrence and development. Materials and Methods: Immunohistochemistry was used to compare CK14, CK15 and proliferating cell nuclear antigen (PCNA) expression levels in ESCCs. Expression level of CK15 was also assessed by Western blotting. In addition, levels of CK15, cytokeratin 19 fragment antigen 21-1 (CYFRA21-1) and PCNA were detected in serum by enzymelinked immunosorbent assay (ELISA) and chemiluminescence methods. Relationships between clinicopathological parameters and CK14 and CK15 expression were then analyzed. Results: According to immunohistochemistry, in esophageal and intraepithelial neoplasia (SIN) tissues, the expression of CK14, CK15 and PCNA localized to basal layer of the epithelium. CK14 and CK15 levels were higher in normal esophageal squamous epithelial tissue than in SIN and ESCC, and greater in highly differentiated than poorly differentiated carcinoma tissue. By Western blotting, we found more pronounced expression of CK15 in normal esophageal tissue, compared with carcinoma tissue. The specificity of changed CK15 and CYFRA21-1 expression was respectively 90.0% and 96.7% in serum of ESCC patients. Joint detection could improve the sensitivity of esophageal carcinoma diagnosis. Relationships between CK14, CK15 expression and clinical parameters were not statistically significant (P>0.05). Postoperative survival in patients of CK14, CK15 positive expression was longer than with negative expression ($x^2=4.35$, P=0.037; $x^2=9.852$, P=0.002). Conclusions: CK15 expression decreased in esophageal squamous cell carcinoma tissue and serum of esophageal squamous carcinoma patients. We infer that CK15 may play an important role for the occurrence and development of esophageal squamous-cell carcinoma. In the future, CK15 may be used for the diagnosis, treatment and prognostic evaluation of esophageal squamous-cell carcinoma.

• Journal of the Korean Chemical Society
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• v.48 no.5
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• pp.483-490
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• 2004

We have developed a novel polymerase chain reaction (PCR)-microchip gel electrophoresis (MGE) method based on the sieving gel mixture of commercially available poly(vinylpyrrolidone) (PVP) and hydroxy ethyl cellulose (HEC) for the rapid detection and diagnosis of the orf virus (ORFV) from Korean indigenous goat. After amplification of 594-bp DNA fragment from the B2L gene of ORF virus, the amplicon was analyzed by the MGE separation. The glass microfluidic chip (64 mm total length (36 mm effective length)${\times}$90 ${\mu}$m width${\times}$20 ${\mu}$m depth) allowed the fast detection and diagnosis of ORFV in the mixture of 1.0% PVP ($M_r$ 360,000) and 1.0% HEC ($M_r$250,000) as a sieving matrix with better resolution and reproducibility of DNA fragments. Under the electric field of 277.8 V/cm, the 594-bp DNA was analyzed within 4 min. Compared to traditional slab gel electrophoresis, the PCR-MGE method was twenty times faster and an effective clinical method for the quantitative analysis of ORFV.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.2
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• pp.141-147
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• 2004

Objective: To investigate the association between endometriosis and polymorphisms of N-acetyl transferase 2 (NAT2), glutathione S-transferase M1 (GSTM1), and cytochrome P450 (CYP) 1A1 genes in Korean infertile patients. Materials and Methods: A total of 303 infertile patients who had undertaken diagnostic laparoscopy during January, 2001 through December, 2003 at Samsung Cheil Hospital enrolled in this study. The patients were grouped according to laparoscopic findings: minimal to mild endometriosis (group I: n=147), moderate to severe endometriosis (group II: n=57), normal pelvic cavity (n=99). Peripheral blood was obtained and genomic DNA was extracted. The genotypes of each genes were analyzed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). For NAT2, RFLP was used to detect the wild type (wt) and mutant (mt) alleles, enabling classification into slow (mt/mt) or fast (wt/wt or wt/mt) acetylation genotypes. For GSTM1, PCR was used to distinguish active (+/- or +/+) from null (-/-) genotypes. For CYP1A1, MspI digestion was used to detect the wild type (A1A1), heterozygote (A1A2) or mutant (A2A2) genotypes. Result: The genotype frequencies of NAT2 slow acetylator was 12.8%, 10.9%, 12.8% in group I, group II and control, respectively. The genotype frequencies of GSTM1 null mutation was 55.3%, 41.8%, 53.2% in group I, group II and control, respectively. The genotype frequencies of CYP1A1 MspI polymorphism was 16.3%, 9.1%, 18.1% in group I, group II and control, respectively. No significant difference was observed between endometriosis and normal controls in the genotype frequencies of the NAT2, GSTM1, CYP1A1 MspI polymorphism. Conclusion: The NAT2, GSTM1, CYP1A1 gene polymorphism may not be associated with the susceptibility of endometriosis in Korean women.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.209-215
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• 1996

DNA polymorphisms were analyzed for 8 clones of the green peach aphid, Myzus persicae Sulzer, by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). The insect has different host preferences and was even classified into two different species, M. persicae Sulzer and Myzus nicotinae Blackman by their morphological characters, but this point is still in arguement. To identify the differences between two types of the green peach aphid by RAPD-PCR, the template DNA was extracted from 4 clones each of tobacco-feeding and non-tobacco-feeding forms and one hundred primers of 10-nucleotideslong were tested in PCR. The amplified DNAs were analyzed by agarose gel electrophoresis. Eighty-three primers gave amplified DNA fragments with 1 to 22 in number and 500 to 20,000 base pairs in length, but no amplification was observed in the other 17 primers. The average number of fragment per each amplification was about 13. In the case of 82 out of 83 random primers, band patterns of amplified DNA were identical among 8 clones, even though some differences were noticed in the intensity of specific bands. Polymorphism was detected by only one primer within the tobacco-feeding forms, but not between the two host types. The results did not detect any relationship between RAPD polymorphism and their host preference.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.36-36
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• 2017

Out of twenty common protein amino acids, there are many kinds of non protein amino acids (NPAAs) that exist as secondary metabolites and exert ecological functions in plants. Mimosine (Mim), one of those NPAAs derived from L. leucocephala acts as an iron chelator and reversely block mammalian cell cycle at G1/S phases. Cysteine (Cys) is decisive for protein and glutathione that acts as an indispensable sulfur grantor for methionine and many other sulfur-containing secondary products. Cys biosynthesis includes consecutive two steps using two enzymes-serine acetyl transferase (SAT) and O-acetylserine (thiol)lyase (OASTL) and appeared in plant cytosol, chloroplast, and mitochondria. In the first step, the acetylation of the ${\beta}$-hydroxyl of L-serine by acetyl-CoA in the existence of SAT and finally, OASTL triggers ${\alpha}$, ${\beta}$-elimination of acetate from OAS and bind $H_2S$ to catalyze the synthesis of Cys. Mimosine synthase, one of the isozymes of the OASTLs, is able to synthesize Mim with 3-hydroxy-4-pyridone (3H4P) instead of $H_2S$ for Cys in the last step. Thus, the aim of this study was to clone and characterize the cytosolic (Cy) OASTL gene from L. leucocephala, express the recombinant OASTL in Escherichia coli, purify it, do enzyme kinetic analysis, perform docking dynamics simulation analysis between the receptor and the ligands and compare its performance between Cys and Mim synthesis. Cy-OASTL was obtained through both directional degenerate primers corresponding to conserved amino acid region among plant Cys synthase family and the purified protein was 34.3KDa. After cleaving the GST-tag, Cy-OASTL was observed to form mimosine with 3H4P and OAS. The optimum Cys and Mim reaction pH and temperature were 7.5 and $40^{\circ}C$, and 8.0 and $35^{\circ}C$ respectively. Michaelis constant (Km) values of OAS from Cys were higher than the OAS from Mim. Inter fragment interaction energy (IFIE) of substrate OAS-Cy-OASTL complex model showed that Lys, Thr81, Thr77 and Gln150 demonstrated higher attraction force for Cys but 3H4P-mimosine synthase-OAS intermediate complex showed that Gly230, Tyr227, Ala231, Gly228 and Gly232 might provide higher attraction energy for the Mim. It may be concluded that Cy-OASTL demonstrates a dual role in biosynthesis both Cys and Mim and extending the knowledge on the biochemical regulatory mechanism of mimosine and cysteine.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.161-161
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• 2017

Seed endophytes are very remarkable groups of bacteria for their unique abilities of being vertically transmitted and conserved. As plants attain hybrid vigor and heterosis in the process of crossbreeding, this might also lead to the changes in the community structure and diversity of plant endophytes in the hybrid plants ultimately affecting the endophytes of the seeds. It would be interesting to characterize how seed endophyte composition change over time. The objective of this study is to gain insights into the influence of natural crossbreeding and parental lineage in the seed bacterial endophytic communities of two pure inbred lines exploring contributions of the two most important sources of plant endophytes - colonization from external sources and vertical transmission via seeds. Total genomic DNA was isolated from rice seeds and bacterial DNA was selectively amplified by PCR. The diversity of endophytic bacteria was studied through Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis. Diversity between the original parents and the pure inbred line may show significant differences in terms of richness, evenness and diversity indices. Heat maps reveal astonishing contributions of both or either parents (IR29 ${\times}$ Pokkali and AT401 ${\times}$ IR31868) in the shaping of the bacterial seed endophytes of the hybrid, FL478 and IC32, respectively. Most of the T-RFs of the subsequent pure inbred line could be traced to any or both of the parents. Comparison of common and genotype-specific T-RFs of parents and their offspring reveals that majority of the T-RFs are shared suggesting higher transmission of bacterial communities common to both parents. The parents influence the bacterial community of their offspring. Unique T-RFs of the offspring also suggest external sources of colonization particularly as the seeds are cultivated in different ecogeographical locations. This study showed that host parental lines contributed greatly in the shaping of bacterial seed endophytes of their offspring. It also revealed transmission and potential conservation of core seed bacterial endophytes that generally become the dominant microbiota in the succeeding generations of plant hosts.