• The korean journal of orthodontics
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• v.34 no.6 s.107
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• pp.537-543
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• 2004

Microsatellit markers are considered to be very promising genetic markers for genetic linkage analysis. The majority of the markers are as informative as in Caucasians but there are significant ethnic differences in the genetic variations. In order to investigate the genetic variations in the Korean and Japanese populations and their ethnic differences, 51 microsatellite marker loci spanning the whole human chromosome 1 were arranged from a commercially available set (ABI PRISM Linkage Mapping Set-HD5, Applied Biosystems, Foster City, CA, USA), and then determined the allelic frequencies and heterozygosities for these marker loci in the 90 unrelated Korean subjects and 90 unrelated Japanese subjects. Of all 51 markers tested, significant differences were observed when microsatellite allele frequency pattern of Korean was compared with those of Caucasian, while this pattern was highly similar between Korean and Japanese populations. Our data indicate that an extensive verification of public microsatellite markers in a particular population study should be undertaken prior to their linkage studies. Moreover, this information should facilitate genetic linkage studies of various hereditary diseases, especially in the Koreans and Japanese.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.260-265
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• 2005

Purpose: The protein kinase Chk1 is required for cell cycle arrest in response to DNA damage and is shown to play an important role in the G2/M checkpoint. The aim of this study was to investigate the relationship between microsatellite instability and frameshift mutation of the Chk1 gene in gastric cancers. Materials and Methods: The microsatellite instability was analyzed in 95 primary gastric carcinomas by using microdissection and 6 microsatellite markers. We also peformed single strand conformational polymorphism and sequencing to detect frameshift mutation of the Chk1 gene. Results: We found positive microsatellite instability in 19 (20%) of the 95 gastric cancers, 13 high- and 6 low-frequency microsatellite instability cases. The frameshift mutation of Chk1, which resulted in a truncated Chk1 protein, was detected in two high-frequency microsatellite instability cases. Conclusion: These data suggest that the microsatellite instability may contribute to the development of gastric carcinomas through inactivation of Chk1.

• Journal of Gastric Cancer
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• v.4 no.2
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• pp.109-120
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• 2004

Purpose: Individual gastric cancers demonstrate complicated genetic alterations. The PCR-based analysis of polymorphic microsatellite sequences on cancer-related chromosomes has been used to detect chromosomal loss and microsatellite instability. For the purpose of preoperative usage, we analyzed the correspondance rate of the microsatellite genotype between endoscopic biopsy and surgical specimens. Materials and Methods: Seventy-three pairs of biopsy and surgical specimens were examined for loss of heterozygosity and microsatellite instability by using 40 microsatellite markers on eight chromosomes. Microsatellite alterations in tumor DNAs were classified into a high-risk group (baselinelevel loss of heterozygosity: 1 chromosomal loss in diffuse type and high-level loss of heterozygosity: 4 or more chromosomal losses) and a low-risk group (microsatellite instability and low-level loss of heterozygosity: 2 or 3 chromosomal losses in diffuse type or $1\∼3$ chromosomal losses in intestinal type) based on the extent of chromosomal loss and microsatellite instability. Results: The chromosomal losses of the biopsy and the surgical specimens were found to be different in 21 of the 73 cases, 19 cases of which were categorized into a genotype group of similar extent. In 100 surgical specimens, the high-risk genotype group showed a high incidence of nodal involvement (19 of 23 cases: $\leq$5 cm; 23 of 24 cases: >5 cm) irrespective of tumor size while the incidence of nodal involvement for the low-risk genotype group depended on tumor size (5 of 26 cases: $\leq$5 cm; 18 of 27 cases: >5 cm). Extraserosal invasion was more frequent in large-sized tumor in both the high-risk genotype group ($\leq$5 cm: 12 of 23 cases; >5 cm: 23 of 24 cases) and the low-risk genotype group ($\leq$5 cm: 7 of 26 cases; >5 cm: 16 of 27 cases). The preoperative prediction of tumor invasion and nodal involvement based on tumor size and genotype corresponded closely to the pathologic tumor stage (ROC area >0.7). Conclusion: An endoscopic biopsy specimen of gastric cancer can be used to make a preoperative genetic diagnosis that accurately reflect the genotype of the corresponding surgical specimen.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.186-192
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• 2016

This study was conducted to develop microsatellite markers in Quercus variabilis using next generation sequencing. A total of 305,771 reads (384 bp on average) were generated on a Roche GS-FLX system, yielding 117 Mbp of sequences. The de novo assembly resulted in 7,346 contigs. A total of 606 contigs (20.75%) including 911 microsatellite loci were derived from the 2,921 contigs longer than 500 bp. A total of 180 primer sets were designed from the 911 microsatellite loci and screened in eight Q. variabilis individual trees sampled from a natural stand to obtain polymorphic loci. As a result, a total of thirteen polymorphic microsatellite loci were selected and used for estimating population genetic parameters in the 54 individual trees. The mean number of effective alleles was 4.996 ranging from 2.439 to 7.515. The observed heterozygosity and the expected heterozygosity ranged between 0.731 and 1.000 with an average of 0.873 and from 0.590 to 0.867 with an average of 0.766, respectively. Null alleles were not detected in all loci. No significant linkage disequilibrium was detected after Bonferroni correction in all loci. In the near future, these novel polymorphic microsatellite markers will be used to study population and conservation genetics of Q. variabilis of Korea in more detail.

• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.180-190
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• 2000

Background: Genomic instability, which is manifested by the replication error(RER) phenotype, has been proposed for the promotion of genetic alterations necessary for carcinogenesis. Merlo et al. reported frequent microsatellite instability in primary small cell lung cancers. However, Kim et al. found that instability occurred in only 1% of the loci tested and did not resemble the replication error-positive phenotype. The significance of microsatellite instability in the tumorigenesis of small cell lung cancer as well as the relationship between microsatellite instability and its clinical prognosis was investigated in our study. Methods: Fifteen primary small cell lung cancers were chosen for this study. The DNAs extracted from paraffin-embedded tissue blocks with primary tumor and corresponding control tissue were investigated. Forty microsatellite markers on chromosome 1p, 2p, 3p, 5q, 6p, 6q, 9p, 9q, 13q, and 17p were used in the microsatellite analysis. Results: Thirteen(86.7%) of 15 tumors exhibited LOH in at least one of the tested microsatellite markers. Three of 13 tumors exhibiting LOH lost a larger area in chromosome 9p. LOH was shown in 72.7% on chromosome 2p, 40% on 3p, 50% on 5q, 46.7% on 9p, 69.2% on 13q, and 66.7% on 17p(Table 1). Nine(60%) of 15 tumors exhibited shifted bands in at least one of the tested microsatellite markers. Nine cases exhibiting shifted bands showed altered loci ranging 2.5~52.5%(mean $9.4%\pm16.19$)(Table 2). Shifted bands occurred in 5.7% (34 of 600) of the loci tested(Table 2). Nine cases with shifted bands exhibited LOH ranging between 0~83.3%, and the median survival duration of those cases was 35 weeks. Six cases without shifted bands exhibited LOH ranging between 0~83.3%, and the median survival duration of those cases was 73 weeks. There was no significant difference between median survival durations of the two groups(p=0.4712). Conclusion: Microsatellite instability as well as the inactivation of several tumor suppressor genes may play important roles in the development and progression process of tumors. However, the relationship between microsatellite instability and its clinical prognosis in primary small cell lung cancer could not be established.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.148-154
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• 2001

Objectives: This study was designed to investigate the significance of serum SCC antigen, CA 19-9, CA 125 level and DNA microsatellite alterations (MSA) as prognostic factors and indicators for recurrences in the pre-treatment and post-treatment state, respectively in head and neck cancer patients. Materials and Methods: 120 patients who received curative treatment for head and neck cancer from 1995 to 2000 were followed up successfully, and were analyzed retrospectively. Thirty healthy subjects served as normal controls. Serum SCC Ag levels were measured by microparticle enzyme immunoassay technique via IMX SCC assay, CA 19-9 levels were measured by CA 19-9 RIA test kit, and CA 125 levels were measured by CA 125 IRMA kit. MSA were identified after PCR amplification. Heterozygosity was considered lost if the ratio of one allele was significantly decreased (>50%) in serum DNA compared with normal DNA from lymphocytes. Results: Preoperative tumor markers were higher in cancer patients than control, but not significant. Postoperative SCC Ag levels were lower than preoperative levels. The SCC Ag levels were remained low in no evidence of disease (NED) group, but increased in locoregional recurrence and distant metastasis group. CA 19-9 and CA 125 levels showed no correlation between levels and recurrences and were not decreased significantly after primary tumor removal. MSA were detected in five out of 21 cases, and highly detected in distant metastasis group. Conclusion: SCC Ag seems to be a helpful serum tumor marker for early detection of recurrence and distant metastasis of head and neck cancer after curative treatment. But, CA 19-9 and CA 125 were not reliable markers for head and neck tumors. MSA were not statistically significant because of the small number of study group. However they may be helpful for screening serum molecular markers for early detection of distant metastasis of head and neck cancers.

• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.311-315
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• 2004

The brown planthopper, Nilaparvata lugens, is among the most serious insect pests of rice. It is widely distributed in Asia, Australia and Pacific islands. An earlier mitochondrial DNA study revealed that there exist significant genetic differences between populations north and south of the Red River Delta region in Vietnam. However the mitochondrial DNA was not sufficiently variable to examine the sources of immigration. For a more detailed analysis of geographic population structure of N. lugens, we developed microsatellite markers. Thirty-seven putative microsatellite loci were isolated using a magnetic biotin method, and five primer pairs designed from the flanking regions of sequenced microsatellite clones were labeled with fluorescent. Of these five primer sets, two have proven to be useful across all the samples we used in this study. We used variation at these two microsatellite loci to test the hypothesis that N. lugens biotypes (1, 2, and 3) sampled from laboratory selection constituted distinct genetic units. Allele frequency differences among the three major biotype categories were not significantly different at one locus (27035). However, the other (7314) did show differences among the major three biotypes. The methods we describe here will be useful for studying population structure of crop pest and for tracking the patterns of migratory pest like the rice planthoppers.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.525-534
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• 2014

Microsatellite markers were used to identify 58 major commercial melon cultivars, and to assess hybrid seed purity of a melon breeding line known as '10H08'. A set of 412 microsatellite primer pairs were utilized for fingerprinting of the melon cultivars. Twenty-nine markers showed hyper-variability and could discriminate all cultivars on the basis of marker genotypes, representing the genetic variation within varietal groups. Cluster analysis based on Jaccard's distance coefficients using the UPGMA algorithm categorized 2 major groups, which were in accordance to morphological traits. The DNA bulks of female and male parents of breeding line '10H08' were tested with 29 primer pairs based on microsatellites to investigate purity testing of $F_1$ hybrid seeds, and 5 primer pairs exhibited polymorphism. One microsatellite primer pair (CMGAN12) produced unambiguous polymorphic bands among the parents. Among 192 seeds tested with CMGAN12, progeny possibly generated by self-pollination of the female parent were clearly distinguished from the hybrid progeny. These markers will be useful for fingerprinting melon cultivars and can help private seed companies to improve melon seed purity.

• Tuberculosis and Respiratory Diseases
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• v.49 no.4
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• pp.453-465
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• 2000

Background : Lung carcinogenesis is a multistage process involving alterations in multiple genes and diverse pathway. Mutational activation of oncogenes and inactivation of tumor suppressor genes, and subsequent increased genetic instability are the major genetic events. The p53 gene and FHIT gene as tumor suppressor genes contribute to the pathogenesis of lung cancer, evidenced by mutation, microsatellite instability(MI) and loss of heterozygosity(LOH). Methods : We analysed genetic mutations of p53 and FHIT gene in 29 surgical specimens of nonsmall cell lung cancer using PCR-single strand conformation polymorphism, DNA sequencing and RT-PCR. MI and LOH were analyzed in loci of D3S1285, D9S171, and TP53. Results : In 2 cases, point mutation of p53 gene was observed on exon 5. MI of 3 times and LOH of 14 times were observed in at least one locus. In terms of the location of microsatellite, D3S1285 as a marker of FH1T was observed in 5 cases out of 26 specimens; D9S171 as a marker of p16 in 5 out of 17; and TP53 as a marker of p53 in 7 out of 27. In view of histologic type, squamous cell carcinoma presented higher frequency of microsatellite alteration, compared to others. Mutation of FHIT gene was observed in 11 cases and 6 cases of those were point mutation as a silent substitution on exon 8. FHIT mRNA expression exhibited deletion on exon 6 to 9 in 4 cases among 15 specimens, presenting beta-actin normally. Conclusion : Our results show comparable frequency of genetic alteration in nonsmall cell lung cancer to previous studies of Western countries. Microsatellite analysis might have a role as a tumor marker especially in squamous cell carcinoma. Understanding molecular abnormalities involved in the pathogenesis could potentially lead to prevention, earlier diagnosis and the development of novel investigational approaches to the treatment of lung cancer.

• Tuberculosis and Respiratory Diseases
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• v.45 no.5
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• pp.975-983
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• 1998

Purpose: Frequent deletion of 3p in numerous cancer including lung cancer suggests the presence of tumor suppressor gene. 3p has been analysed by RFLP and PCR-LOH of microsatellite locus. In this study, we observed the deletion of 3p in Korean NSCLC by PCR-LOH of 4 microsatellite loci and investigated the clinical significance. Method: 62 surgically resected NSCLC DNA and normal lung DNA have been analysed by PCR-LOH at three dinucleotide[D3S1228 (3p14.1-14.3), D3S1067 (3p14.3-21.1), D3S1029 (3p21.1-21.3)] and one tetranucleotide[D3S1537 (3p 22-24.2)] repeat microsatellite loci. Results: Among 59 informative cases, 3p deletion by PCR-LOH at four microsatellite loci was found in 31 patients(52.5%). 3p deletion were found in 55% of squamous cell lung cancer and 47% of adenocarcinoma patients. No significant difference has been found in clinical parameters such as staging, smoking and survival according to the status of 3p deletion. Conclusion: Deletions in 3p have played an important role in Korean NSCLC though no clinical significance was detected.