• 대한자원환경지질학회:학술대회논문집
• /
• 대한자원환경지질학회 2003년도 춘계 학술발표회 논문집
• /
• pp.7-14
• /
• 2003

The precious-meta] mineralization of epithermal type in the Korean Peninsula, which is spread over a broader range of ca. 110 to 60 Ma with a major population between 90 and 70 Ma, mainly occurred along the NE-trending major strike-slip fault systems (i.e., the Gongju and Gwangju ones) that commonly include volcano-tectonic depressions and calderas. The occurrence of epithermal mineralization during Late Cretaceous clearly indicates that the geologic setting of the Korean Peninsula changed to the favorable depth of ore formation with very shallow-crustal environments (〈1.0 kb) accompanied with gold-silver (-base-meta]) mineralization. Epithermal gold-silver deposits in Korea are primarily distinguished as sediment-dominant and volcanic-dominant basins by using criteria of varying alteration, ore and gangue mineralogy deposited by the interaction of different ore-forming fluids with host rocks and meteoric waters. These differences between the central and southern portions are causally linked to the tectonic evolution of the Peninsula during the Cretaceous time. In the Early Cretaceous, the sinistral strike-slip movements due to the oblique subduction of the Izanagi Plate resulted in the Gongju and Gwangju fault systems in the central portion of the Korean Peninsula, which was accompanied with a number of sediment-dominant basins formed along these faults. During the Late Cretaceous, the mode of convergence of the Izanagi Plate changed to northwesteward so that orthogonal convergence occurred with a calc-alkaline volcanism. As results, volcanic-dominant basins were developed in the southern portion of the Peninsula, accompanied with volcano-tectonic depressions and caldera-related fractures. The magmatism and related fractures during Late Cretaceous may play an important role in the formation of geothermal systems. Thus, such fault zones may be favorable environments for veining emplacement that is closely related to the precious-metal mineralization of epithermal type in the Korean Peninsula.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권6호
• /
• pp.2757-2760
• /
• 2016

Gastric cancer (GC) is the fourth most prevalant cancer and the second leading cause of cancer-related mortality worldwide. As in other cancers gastric carcinogenesis is multifactorial involving environmental, genetic and epigenetic components. Epigenetic silencing due to hypermethylation of tumour suppressor genes is one of the key events in gastric carcinogenesis. This study was aimed to analyse the hypermethylation status of the E-Cadherin (CDH1) gene promoter in GCs in the ethnic Kashmiri population. In this study a total of 80 GC patients were recruited. Hypermethylation in tumour tissue was detected by methylation specific PCR (MS-PCR). Hypermethylation of CDH1 promoter was observed in 52 (65%) of gastric carcinoma cases which was significantly much higher than adjacent normal tissue [$p{\leq}0.0001$]. Further the frequency of CDH1 promoter methylation was significantly different with intestinal and diffuse types of gastric cancer [55.7% vs 82.1%; p<0.05]. Moreover females and cases with lymph node invasion had higher frequencies of CDH1 hypermethylation [$P{\leq}0.05$]. Thus the current data indicate a vital role of epigenetic alteration of CDH1 in the causation and development of gastric cancer, particularly of diffuse type, in our population.

• 한국산림과학회지
• /
• 제78권4호
• /
• pp.372-380
• /
• 1989

주요(主要) 조림수종(造林樹種)의 하나인 현사시나무를 Agrobacterium rhizogenes의 agropine 계통(系統)인 A4를 이용(利用)하여 유전적(遺傳的)으로 형질전환(形質轉換)시켰다. 형질전환(形質轉換) 여부는 조직(組織)내의 opine(agropine) 존재를 분석(分析)하여 확인(確認)하였다. 형질전환(形質轉換)으로 얻어진 hairy root는 1/4MS+sucrose 30g/L에서 가장 좋은 생장(生長)을 보였으며, 식물체(植物體) 재분화(再分化)는 BAP 0.5mg/l를 첨가한 MS배지(培地)에 배양(培養)하였을 때 가장 좋은 결과(結果)를 얻었다. 재분화(再分化)된 식물체(植物體)는 뿌리가 많고 형태적(形態的)으로 변형(變形)되어 정상의 식물(植物)과 구별(區別)할 수 있었다. 부분적(部分的)으로 뿌리부분(部分)만 형질전환(形質轉換) 시킴으로써 보다 많은 뿌리를 가진 개체(個體)로 만들 수 있었고 이는 임목(林木)의 지상부(地下部) 형질개량(形質改良)에 유리(有利)한 것으로 나타났다.

• International Journal of Oral Biology
• /
• 제45권4호
• /
• pp.190-196
• /
• 2020

Several factors, including genetic and environmental insults, impede protein folding and secretion in the endoplasmic reticulum (ER). Accumulation of unfolded or mis-folded protein in the ER manifests as ER stress. To cope with this morbid condition of the ER, recent data has suggested that the intracellular event of an unfolded protein response plays a critical role in managing the secretory load and maintaining proteostasis in the ER. Tauroursodeoxycholic acid (TUDCA) is a chemical chaperone and hydrophilic bile acid that is known to inhibit apoptosis by attenuating ER stress. Numerous studies have revealed that TUDCA affects hepatic diseases, obesity, and inflammatory illnesses. Recently, molecular regulation of ER stress in tooth development, especially during the secretory stage, has been studied. Therefore, in this study, we examined the developmental role of ER stress regulation in tooth morphogenesis using in vitro organ cultivation methods with a chemical chaperone treatment, TUDCA. Altered cellular events including proliferation, apoptosis, and dentinogenesis were examined using immunostaining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. In addition, altered localization patterns of the formation of hard tissue matrices related to molecules, including amelogenin and nestin, were examined to assess their morphological changes. Based on our findings, modulating the role of the chemical chaperone TUDCA in tooth morphogenesis, especially through the modulation of cellular proliferation and apoptosis, could be applied as a supporting data for tooth regeneration for future studies.

• Biomolecules & Therapeutics
• /
• 제30권4호
• /
• pp.368-379
• /
• 2022

Hyaluronic acid (HA), a ligand of CD44, accumulates in some types of tumors and is responsible for tumor progression. The nuclear factor erythroid 2-like 2 (NRF2) regulates cytoprotective genes and drug transporters, which promotes therapy resistance in tumors. Previously, we showed that high levels of CD44 are associated with NRF2 activation in cancer stem like-cells. Herein, we demonstrate that HA production was increased in doxorubicin-resistant breast cancer MCF7 cells (MCF7-DR) via the upregulation of HA synthase-2 (HAS2). HA incubation increased NRF2, aldo-keto reductase 1C1 (AKR1C1), and multidrug resistance gene 1 (MDR1) levels. Silencing of HAS2 or CD44 suppressed NRF2 signaling in MCF7-DR, which was accompanied by increased doxorubicin sensitivity. The treatment with a HAS2 inhibitor, 4-methylumbelliferone (4-MU), decreased NRF2, AKR1C1, and MDR1 levels in MCF7-DR. Subsequently, 4-MU treatment inhibited sphere formation and doxorubicin resistance in MCF7-DR. The Cancer Genome Atlas (TCGA) data analysis across 32 types of tumors indicates the amplification of HAS2 gene is a common genetic alteration and is negatively correlated with the overall survival rate. In addition, high HAS2 mRNA levels are associated with increased NRF2 signaling and poor clinical outcome in breast cancer patients. Collectively, these indicate that HAS2 elevation contributes to chemoresistance and sphere formation capacity of drug-resistant MCF7 cells by activating CD44/NRF2 signaling, suggesting a potential benefit of HAS2 inhibition.

• Genomics & Informatics
• /
• 제21권2호
• /
• pp.22.1-22.15
• /
• 2023

Kidney renal clear cell carcinoma (KIRC) is one of the most aggressive cancer type of the urinary system. Metastatic KIRC patients have poor prognosis and limited therapeutic options. Ankyrin 3 (ANK3) is a scaffold protein that plays important roles in maintaining physiological function of the kidney and its alteration is implicated in many cancers. In this study, we investigated differential expression of ANK3 in KIRC using GEPIA2, UALCAN, and HPA databases. Survival analysis was performed by GEPIA2, Kaplan-Meier plotter, and OS-kirc databases. Genetic alterations of ANK3 in KIRC were assessed using cBioPortal database. Interaction network and functional enrichment analyses of ANK3-correlated genes in KIRC were performed using GeneMANIA and Shiny GO, respectively. Finally, the TIMER2.0 database was used to assess correlation between ANK3 expression and immune infiltration in KIRC. We found that ANK3 expression was significantly decreased in KIRC compared to normal tissues. The KIRC patients with low ANK3 expression had poorer survival outcomes than those with high ANK3 expression. ANK3 mutations were found in 2.4% of KIRC patients and were frequently co-mutated with several genes with a prognostic significance. ANK3-correlated genes were significantly enriched in various biological processes, mainly involved in peroxisome proliferator-activated receptor (PPAR) signaling pathway, in which positive correlations of ANK3 with PPARA and PPARG expressions were confirmed. Expression of ANK3 in KIRC was significantly correlated with infiltration level of B cell, CD8+ T cell, macrophage, and neutrophil. These findings suggested that ANK3 could serve as a prognostic biomarker and promising therapeutic target for KIRC.

• 식물조직배양학회지
• /
• 제24권4호
• /
• pp.239-256
• /
• 1997

Plants belonging to the category of 2n apomixis or agamospermy form embryos and seeds without the processes of normal meiosis and syngamy. Seeds produced in this way have identical genotype of their maternal parent. Three different types of agamospermy are recognized: diplospory, apospory, and adventitious (adventive) embryony. $F_1$ hybrid cultivars cannot be used as seed sources in the next ($F_2$) generation because this generation would be extremely variable as a result of genetic segregation. Hybrid vigor is also reduced in the $F_2$ generation. Therefore, parental stocks for hybrid seed production need to be maintained and cross must be continuously repeated. Agamospermic 2n apomixis would make it possible to fix the genotype of a superior variety so that clonal seeds faithfully representing that genotype could be continuously and cheaply produced independent of pollination. That is, $F_1$ hybrid seeds could be produced for many generations without loss of vigor or genotype alteration. Production of apomictic $F_1$ hybrid seed would be simplified because line isolation would not be necessary to produce seed or to maintain parental lines, and the use of male-sterile lines could be avoided. Overall, apomixis would enable a significant reduction in hybrid seed production costs. Additionally, the production of clonal seed is not only important for seed propagated crops, but also for the propagation of heterozygous fruit trees and timbers. Clonal seed would help avoid costly and time-consuming vegetative propagating methods that are currently used to ensure the large-scale production of these plants. Apomixis is scattered throughout the plant kingdom, but few important agricultural crops possess this trait Therefore, most research to date has centered on introgressing the trait of apomixis into agricultural crops such as wheat, maize, and some forage grasses from wild distant relatives by traditional cross breeding. The classical breeding approach, however is slow and often impeded by many breeding barriers. These problems could be surmounted by taking mutagenesis or molecular approach. Arabidopsis thaliana is a tiny sexually reproducing plant and is convenient in constructing and screening in molecular researches. Male-sterile mutants of Arabidopsis are particularly suitable genetic background for mutagenesis and screening for apomictic mutants. Molecular approaches towards isolating the genes controlling the apomictic process are feasible. Direct isolation of genes conferring apomixis development would greatly facilitate the transfer of this trait to wide variety of crops. Such studies are now in progress.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권13호
• /
• pp.5449-5454
• /
• 2014

Although genetic characteristics are considered to be a factor influencing the geographic variation in the prevalence of gallbladder cancer (GBC), they have not been well studied in Bolivia, which has a high prevalence rate of GBC. The purpose of this study was to examine the frequency of TP53 and K-ras mutations in Bolivian patients with GBC and to compare them with our previous data obtained in other high-GBC-prevalence countries, namely Japan, Chile, and Hungary. DNA was extracted from cancer sites in paraffin-embedded tissue from 36 patients using a microdissection technique. TP53 mutations at exons 5 to 8 and K-ras mutations at codons 12, 13 and 61 were examined using direct sequencing techniques. The data obtained were compared with those in the other high-GBC-prevalence countries. Of the 36 patients, 18 (50.0%) had a TP53 mutation (one mutation in each of 17 patients and three mutations in one patient), and only one (2.8%) had a K-ras mutation. Of the 20 TP53 mutations, 12 were of the transition type (60.0%). This rate was significantly lower than that in Chile (12/12, P<0.05). In addition, three mutations were of the CpG transition type (15.0%), which is a feature of endogenous mutation. All three were found in the hot spot region of the TP53 gene. In contrast, G:C to T:A transversion was found in Bolivia, suggesting the presence of exogenous carcinogens. Our findings suggest that the development of GBC in Bolivia is associated with both exogenous carcinogens and endogenous mechanisms. The identification of an environmental risk factor for GBC is needed to confirm these findings.

• Clinical and Experimental Reproductive Medicine
• /
• 제34권3호
• /
• pp.179-188
• /
• 2007

목 적: 본 연구에서는 삼핵산 반복서열 확장에 의해 발병하는 헌팅톤병, 척수소뇌성 운동실조증과 X-염색체 취약 증후군 등에 대한 착상전 유전진단을 시행하기 위한 전임상 검사에서 진단 방법을 최적화하는 과정을 통해 얻은 결과들에 대해 기술하고자 한다. 연구방법: 단일 림프구를 이용한 임상전 검사에서는 서로 다른 allele를 갖고 있는 환자의 단일 세포를 사용하였으며, 헌팅톤병과 척수소뇌성 운동실조증에서는 fluorescent semi-nested PCR 시행 후 fragment analysis를 수행하였다. X-염색체 취약 증후군의 경우 multiple displacement amplification (MDA) 방법을 이용한 whole genome amplification에서 얻어진 MDA 산물로 fluorescent PCR을 시도하였다. 결 과: 헌팅톤병의 경우 단일 림프구 시료 모두에서 CAG repeats 증폭에 성공하여 100.0%의 증폭성공률과 14.0% allele drop-out (ADO) rate를, 척수소뇌성 운동실조증의 경우 94.7%의 증폭성공률과 5.6%의 ADO rate을 나타내었다. X-염색체 취약 증후군의 경우 fluorescent semi-nested PCR 방법만으로는 단일 림프구 시료에서 CGG repeats이 증폭되지 않았지만, MDA 산물을 이용한 fluorescent PCR 결과 84.2%의 증폭성공률과 31.3%의 ADO rate을 얻을 수 있었다. 결 론: 본 연구를 통해 헌팅톤병과 척수소뇌성 운동실조증의 착상전 유전진단에는 fluorescent semi-nested PCR 방법의 적용이 가능함을 확인하였으며, X-염색체 취약 증후군의 경우에는 MDA를 이용한 fluorescent PCR 방법을 사용해야 함을 알 수 있었다. 유전자의 변이에 대한 분석이 쉽지 않은 단일 유전자 이상에 대한 착상전 유전진단의 경우 다양한 유전자 분석 방법을 이용한 단일 세포에서의 진단 방법의 최적화 연구가 필수적으로 선행되어야 할 것으로 사료된다.

• Clinical and Experimental Pediatrics
• /
• 제45권2호
• /
• pp.183-191
• /
• 2002

목 적 : 본 연구에서는 임상적으로 XLA로 진단받고 현재 치료 중인 한가족 3명 환아의 가계를 대상으로 말초혈액 단핵구의 Btk 단백질 발현과 Btk 유전자 변이를 분석하고자 하였다. 방 법 : 환아 말초혈액 단핵구의 Btk 발현도를 항 Btk 항체를 이용한 유세포계측을 통해 분석하고 PCR-SSCP 및 직접 염기서열 분석에 의해 Btk 유전자 변이를 분석하였다. 결 과 : 유세포 계측 및 PCR-SSCP에 의하여 가계내의 환자 3명 및 보인자 4명을 확인하였으며 환아들의 단핵구의 Btk 발현도를 조사한 결과 2.7% 미만으로 건강인에 비해 매우 유의한 감소를 나타내었다. 유전자 변이 분석 결과 Btk 유전자 exon 3에서 점돌연변이($T{\rightarrow}C$)가 발견되어 61번째 아미노산의 치환이 일어난 과오돌연변이를 확인할 수 있었다. 동일한 유전형을 지닌 3명의 환아들은 임상적으로 매우 다양한 표현형을 나타내었다. 특히 환아들의 혈청 IgG level이 낮을수록 임상 양상은 심한 소견을 보였다. 결 론 : 본 연구 결과를 종합해 볼 때 임상적으로 XLA로 진단된 환아와 가족에 대한 항 Btk 항체를 이용한 유세포계측 및 PCR-SSCP 방법은 XLA 환아 및 보인자의 진단에 매우 유용하며 신속하게 적용될 수 있는 기법으로 생각된다. 또한 분자유전학 기법을 이용하여 환아의 유전자 변이를 검색한 결과 Btk의 PH 도메인 내 한개의 과오돌연변이를 검색하여 XLA를 최종 확진할 수 있었다.