Hanvit Institute for Medical Genetics

Daegu, South Korea

Hanvit Institute for Medical Genetics

Daegu, South Korea

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Lee J.-H.,Keimyung University | Gwon G.-J.,Keimyung University | Kim D.-K.,Keimyung University | Kim D.-K.,Hanvit Institute for Medical Genetics
International Journal of Clinical and Experimental Pathology | Year: 2017

Colorectal cancer is a heterogeneous disorder than arises via multiple distinct pathways, from tubular adenomas (TAs) and serrated polyps (SPs), which are clinically, morphologically, and molecularly different. We examined mitochondrial D-loop polymorphism in colorectal precancerous lesions, including TAs and SPs. DNA was isolated from paired normal and tumoral tissues in 78 TAs and 34 SPs. Mitochondrial D-loop polymorphism (D146, D150, D152, D310, and D514), KRAS and BRAF mutations, and microsatellite instability (MSI) were analyzed by direct sequencing and pyrosequencing. D146, D310, and D514 were polymorphic in these patients and their distributions were significantly different between TAs and SPs. D146 and D310 polymorphism was associated not with KRAS and BRAF mutations, but with MSI and other mitochondrial polymorphism each other. Our data suggest that mitochondrial D-loop polymorphism may play an important role in development of colorectal precancerous lesions and contribute to regulate their progression to TAs or SPs.


Lee J.-H.,Keimyung University | Choi I.-J.,Keimyung University | Song D.-K.,Keimyung University | Kim D.-K.,Keimyung University | Kim D.-K.,Hanvit Institute for Medical Genetics
Cancer Genetics and Cytogenetics | Year: 2010

Hypoxia, one of the key tumor microenviromental factors, promotes genetic instability, which is the hallmark of human cancers. Many recent studies have demonstrated that hypoxia by itself can lead to conditions that elevate mutagenesis and inhibit the DNA repair process in cancer. The aim of this study was to investigate the cytogenetic damage and DNA repair functions in human peripheral lymphocytes exposed to hypoxia by means of sister chromatid exchange and nuclear and mitochondrial microsatellite instability (nMSI and mtMSI), respectively. Primary lymphocyte cultures obtained from blood samples of 40 healthy donors were exposed to hypoxia for 12 and 24 hours. Genomic DNA was then isolated from the fixed lymphocytes to analyze the DNA repair process by nMSI and mtMSI. The present results revealed gradual increases in SCE for both exposure times, compared to the controls, but there was no significant correlation between hypoxia and MSI. The SCE assay showed that hypoxia by itself may induce mutagenesis by causing DNA damage in normal cells. However, the DNA repair function through MSI analysis was intact. © 2010 Elsevier Inc. All rights reserved.


Lee J-H.,Keimyung University | Hwang I.,Keimyung University | Kang Y.-N.,Keimyung University | Choi I.-J.,Keimyung University | And 2 more authors.
PLoS ONE | Year: 2015

Clinical value of mitochondrial DNA has been described in colorectal cancer (CRC). To clarify its role in colorectal carcinogenesis, mitochondrial microsatellite instability (mtMSI) and other markers were investigated in CRCs and their precancerous lesions, as a multitier genetic study. DNA was isolated from paired normal and tumoral tissues in 78 tubular adenomas (TAs), 34 serrated polyps (SPs), and 100 CRCs. mtMSI, nucleus microsatellite instability (nMSI), KRAS mutation, and BRAF mutation were investigated in these tumors and their statistical analysis was performed. mtMSI was found in 30% of CRCs and 21.4% of precancerous lesions. Mitochondrial copy number was higher in SPs than TAs and it was associated with mtMSI in low grade TAs. KRAS and BRAF mutations were mutually exclusive in TAs and SPs. CRCs with mtMSI showed shorter overall survival times than the patients without mtMSI. In CRCs without nMSI or BRAF mutation, mtMSI was a more accurate marker for predicting prognosis. The genetic change of mitochondrial DNA is an early and independent event in colorectal precancerous lesions and mtMSI and mitochondrial contents are associated with the tubular adenoma-carcinoma sequence, resulting in poor prognosis. This result suggested that the genetic change in mitochondrial DNA appears to be a possible prognosis marker in CRC. © 2015 Lee et al.


Lee C.-W.,Keimyung University | Lee J.-H.,Keimyung University | Jung E.-Y.,Keimyung University | Choi S.-O.,Keimyung University | And 4 more authors.
Journal of Korean Medical Science | Year: 2011

Congenital central hypoventilation syndrome with Hirschsprung's disease, also known as Haddad syndrome, is an extremely rare disorder with variable symptoms. Recent studies described that congenital central hypoventilation syndrome had deep relation to the mutation of the PHOX2B gene in its diagnosis and phenotype. We report a newborn male infant with clinical manifestations of recurrent hypoventilation with hypercapnea and bowel obstruction. These clinical manifestations were compatible with congenital central hypoventilation syndrome and Hirschsprung's disease, and polyalanine 26 repeats in the PHOX2B gene supported the diagnosis of congenital central hypoventilation. We described a first case of Haddad syndrome in Korean and its clinical and genetic characteristics were discussed. © 2011 The Korean Academy of Medical Sciences.


Lee J.-H.,Keimyung University | Eom K.-S.,Keimyung University | Song D.-K.,Keimyung University | Suh S.-I.,Keimyung University | And 2 more authors.
Drug and Chemical Toxicology | Year: 2016

Objective: Many studies have shown that melatonin (MLT) has an anti-genotoxic effect in various tissues and cell lines. The aim of this study was to investigate the anti-genotoxic effect of MLT on normal human peripheral lymphocytes by assessing sister chromatid exchange (SCE) in vitro and in vivo. Materials and methods: Cells were treated with 50 and 200 μM of MLT. The human volunteers (n = 20) for the in vivo study were administered a single dose of 3 mg MLT daily for 2 weeks. After sufficient time for its clearance, 1.5 mg of MLT daily was then administered to the same volunteers at same the period. Results: Our results demonstrated the anti-genotoxic effect of MLT in human blood lymphocyte in vitro and in vivo. In vitro, hypoxia increased the SCE frequency compared to the control and both doses of MLT significantly decreased the SCE frequency in the hypoxic cells (p < 0.001). In vivo, oral administration of 3 mg MLT significantly increased the frequency of SCE, yet a small increase of SCE by hypoxia was found. Oral administration of 1.5 mg MLT showed no DNA damage but it had an anti-genotoxic effect. Discussion and conclusion: MLT may prove useful for reducing the genotoxic effects of hypoxia in peripheral lymphocytes and suggest its possible role for ischemic diseases. © 2015 Informa Healthcare USA, Inc.


Lee H.,Keimyung University | Lee J.-H.,Keimyung University | Kim D.-K.,Keimyung University | Kim D.-K.,Hanvit Institute for Medical Genetics | And 4 more authors.
International Journal of Medical Sciences | Year: 2015

Colorectal cancer is a heterogeneous disorder than arises via multiple distinct pathways, from tubular adenomas (TAs) and sessile serrated adenomas (SSAs), which are clinically, morphologically, and molecularly different. We examined PIK3CA amplification in colorectal precancerous legions, including TAs and SSAs. DNA was isolated from paired normal and tumoral tissues in 64 TAs and 32 SSAs. PIK3CA amplification, KRAS mutation, and BRAF mutation were analyzed by real-time PCR and pyrosequencing. PIK3CA amplification was found in 25% of TAs and 9.4% of SSAs, respectively. KRAS and BRAF mutations were mutually exclusive in both TAs and SSAs. In TAs, PIK3CA amplification was associated with left side and it was mutually exclusive with KRAS mutation. These results suggest that PIK3CA amplification may be early and important event in colorectal carcinogenesis and may drive the development of left-side TAs independently with KRAS mutation. © 2015 Ivyspring International Publisher.


Jeong C.-W.,Keimyung University | Lee J.-H.,Keimyung University | Sohn S.-S.,Keimyung University | Ryu S.-W.,Keimyung University | And 2 more authors.
Cancer Epidemiology | Year: 2010

Background: Genetic instability in gastric cancer represents a key molecular step that occurs early in the carcinogenesis process. To clarify the role of genetic instability in the progression from gastric dysplasia to gastric cancer, mitochondrial microsatellite instability (mtMSI) was studied in gastric cancer and gastric dysplasia. Methods: DNA was isolated from paired normal and tumoral tissues in 24 patients with gastric dysplasia (low grade) and 49 patients with gastric cancer. mtMSI was analyzed using eight microsatellite markers. mtMSI in gastric dysplasia was studied prospectively to elucidate the relation between mtMSI and gastric carcinogenesis. Results: mtMSI was found in 5 (10.2%) of 49 gastric cancer patients. The mtMSI phenotype was not associated with age, gender, and Helicobacter pylori infection. However, all of the mtMSI was found in intestinal-type gastric cancer (20.8%, p = 0.02). In gastric dysplasia, mtMSI was detected in 3 (12.5%) of 24 patients with gastric dysplasia. mtMSI-positive gastric dysplasia showed a poor prognosis statistically compared to mtMSI negative through progression to high-grade dysplasia or gastric cancer. Conclusions: These data suggest that mtMSI may be an early and important event in the progression of gastric carcinogenesis, especially in intestinal-type gastric cancer. © 2010 Elsevier Ltd.


Lee J.-H.,Keimyung University | Ryu T.-Y.,Keimyung University | Cho C.-H.,Keimyung University | Kim D.-K.,Keimyung University | Kim D.-K.,Hanvit Institute for Medical Genetics
Pathology and Oncology Research | Year: 2011

Uterine leiomyomas are benign tumors of the uterus that arise clonally from smooth muscle cells of the myometrium and are the most common reason for hysterectomies. The aim of this study was to evaluate mitochondrial microsatellite instability (mtMSI) in uterine leiomyomas and leiomyosarcomas to clarify the molecular pathogenetic distinction between these tumors. DNA was isolated from paired normal and tumoral tissues in 50 patients with uterine leiomyomas and 14 patients with leiomyosarcomas. mtMSI was analyzed by using eight microsatellite markers. Our result showed that mitochondrial microsatellite instability was not found in all uterine leiomyomas. However, 3 (21.4%) of 14 patients with leiomyosarcomas had mtMSI and the frequencies of mtMSI in these tumors were significantly different (p<0.01). Distinctive characteristics of mitochondrial genetic instability in uterine leiomyomas and leiomyosarcomas suggested the potential of mtMSI as a marker for differential diagnosis between them. © Arányi Lajos Foundation 2010.


Hong J.-M.,Dartmouth College | Lee J.-H.,Keimyung University | Gwon G.-J.,Keimyung University | Kim D.-K.,Keimyung University | Kim D.-K.,Hanvit Institute for Medical Genetics
APMIS | Year: 2014

Uterine leiomyomas are benign tumors of the uterus that arise clonally from smooth muscle cells of the myometrium and are very common reason for hysterectomy. The aim of this study was to evaluate microsatellite instability (MSI) in uterine leiomyomas using a set of MSI markers by Promega Corporation (Madison, WI, USA) and the Bethesda guideline. DNA was isolated from paired normal and tumoral tissues in 50 patients with uterine leiomyomas and MSI was analyzed by using seven microsatellite markers. Our result showed that microsatellite stability was found in all uterine leiomyomas. These data confirm the genetic status of uterine leiomyomas for the first time in Korean populations, and suggest that uterine leiomyomas have genetic stability in Korean. © 2013 APMIS. Published by John Wiley & Sons Ltd.

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