• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.821-825
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• 2018

A copy number amplification system for yeast artificial chromosomes (YACs) was combined with simultaneous overexpression of genes integrated into a YAC. The chromosome VII (1,105 kb) was successfully split to 887 kb, 44 kb containing the element for copy number amplification, and a 184-kb split-YAC. The 44-kb split-mini YAC was amplified a maximum of 9-fold, and the activity of the reporter enzymes integrated into the split-mini YAC increased about 5-7-fold. These results demonstrate that the mini-YAC containing a targeted chromosome region can be readily amplified, and the specific genes in the mini-YAC could be overexpressed by increasing the copy number.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6311-6318
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• 2012

Background: HER2/neu overexpression due to gene amplification is an important factor in breast cancer, modifying the sensitivity to anti-HER2 monoclonal antibody therapy. The clinical significance of HER2 expression in non small cell lung carcinoma (NSCLC) is currently under evaluation. The tumor suppressor gene PTEN negatively regulates the HER2/PI3K/Akt signalling pathway. The purpose of this study was to evaluate the role of simultaneous alteration in HER2 and PTEN protein expression in relation to biological behaviour of NSCLCs. Materials and Methods: Protein expression was determined by immunohistochemistry in sixty-one (n=61) NSCLC cases along with CISH for HER2 gene analysis and detection of chromosome 17 aneuploidy. Patients were followed-up for a period of 34 to 41 months after surgery. Results: HER2 overexpression (2+/3+score) was detected in 17 (27.9%) patients while loss of PTEN expression was observed in 24 (39.3%) cases, low expression in 29 (47.6%) and overexpression in 8 (13.1%). Simultaneous HER2 overexpression and PTEN low/loss of expression were correlated with metastasis (71.4% vs 36.2% p=0.03). Analysis in the subgroup of 22 patients of pTNM stage III with lymph node status N1 or N2 revealed that there was a relationship between the number of positive regional lymph node groups and simultaneous deregulation of the two genes (p=0.04). Multivariate analysis determined that HER2 overexpression was associated with an increasing risk of developing metastases (OR: 4.3; 95%CI: 1.2-15.9; p: 0.03) while PTEN overexpression was associated with lower risk (OR: 0.1; 95%CI: 0.1, 1.0; p: 0.05). Conclusions: Simultaneous HER2/PTEN deregulation is a significant genetic event that leads to a more aggressive phenotype of NSCLC.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.704-710
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• 2008

Glutamate availability in the argF-argR-proB${\Delta}$ strain of Corynebacterium glutamicum was increased by addition of glutamate to the cell or inactivation of the phosphoenolpyruvate carboxykinase activity and simultaneous overexpression of the pyruvate carboxylase activity to assess its effect on L-ornithine production. When glutamate was increased in an L-ornithine-producing strain, the production of L-ornithine was not changed. This unexpected result indicated that the intracellular concentration and supply of glutamate is not a rate-limiting step for the L-ornithine production in an L-ornithine-producing strain of C. glutamicum. In contrast, overexpression of the L-ornithine biosynthesis genes (argCJBD) resulted in approximately 30% increase of L-ornithine production, from 12.73 to 16.49 mg/g (dry cell weight). These results implied that downstream reactions converting glutamate to L-ornithine, but not the availability of glutamate, is the rate-limiting step for elevating L-ornithine production in the argF-argR-proB${\Delta}$ strain of C. glutamicum.

• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1617-1620
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• 2014

Background: Evidence shows direct link of HER2 to increased glycolysis and over production of lactate dehydrogenase (LDH). HER2 overexpression, high LDH and low glucose pleural levels are associated with poor prognosis in lung cancer. Here, their relationships were investigated. Materials and Methods: HER2 positivity was studied using immunohistochemistry in non-small cell lung cancer. Glucose and LDH levels were measured using commercial colorimetric kits. Results: Of 42 patients (29 adenocarcinoma and 13 squamous cell carcinoma), 28 (66.7%) were HER2-negative, 14 (33.3%) were HER2- positive, including 9 (21.4%) weakly stained (1+) and 5 (11.9%) moderately stained (2+) samples. The relationship between HER2 and glucose and LDH levels were tested in 20 newly diagnosed lung cancer patients who had simultaneous pleural and serum samples. Pleural and serum LDH levels were increased, and pleural glucose levels were decreased with the scale of HER2 positivity, and that the difference in glucose levels between HER2-negative group and HER2-positive patients scored at 2+ reached statistical significance (p=0.02). This latter group all had pleural glucose levels below 40 mg/dl. Conclusions: For the first time, we showed a significant association between low pleural glucose level and overexpression of HER2 in lung cancer. Further investigations are warranted to disclose the association of HER2 with low pleural glucose levels in other populations, with a larger sample size, in malignant pleural effusions caused by other types of cancer, and finally to assess employment as a screening tool for finding HER2-positive cases of lung cancer.

• 생명과학회지
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• 제26권1호
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• pp.17-22
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• 2016

에탄올은 산업적으로 매우 가치 있는 물질이지만, 효모세포에 있어서 에탄올의 축적은 세포 독성과 목적산물의 생산성을 감소시키는 스트레스원이다. 따라서 효모세포에 있어서 에탄올 내성의 증가는 에탄올 생산성 증대와 밀접한 관계가 있는 중요한 요소라고 할 수 있다. 본 연구에서는 에탄올 내성을 증가시키기 위해 YDJ1과 PEP5 유전자를 목적 유전자로 선정하여 이들 유전자의 과발현과 과발현에 따른 상호발현조절을 분석하여 에탄올 내성 메커니즘의 일부를 해명하고자 한다. YDJ1과 PEP5 유전자를 ADH1 promoter 하류에 연결시켜 pA-YDJ1과 pA-PEP5 plasmid를 구축하고 각각 BY4742, BY4742△ydj1와 BY4742△pep5 균주에 도입하였다. YDJ1과 PEP5 유전자의 과발현에 의해서 BY4742△ydj1/pA-YDJ1과 BY4742△pep5/pA-PEP5 균주의 에탄올내성이 숙주세포의 수준까지 회복되었음을 확인 할 수 있었다. 이 두 유전자의 상호발현조절을 조사하기 위해, BY4742△ydj1△pep5 균주에서 YDJ1과 PEP5 유전자의 과발현을 시도해본 결과, BY4742△ydj1△pep5/pA-YDJ1, pA-PEP5 균주의 경우, 8% 에탄올 배지에서 BY4742 균주의 약 90%정도 까지 에탄올 내성이 회복됨을 확인하였다. BY4742△ydj1△ pep5/pA-YDJ1, pA-PEP5 균주에서 YDJ1 유전자는 PEP5 유전자의 과발현을 더욱더 유도하여 에탄올 내성을 증가시켰으며, 이는 YDJ1 유전자가 PEP5 유전자의 상위에서 발현을 부분적으로 조절한다고 생각 할 수 있다.

• BMB Reports
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• 제51권2호
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• pp.57-58
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• 2018

An accurate diagnostic marker for detecting early-stage hepatocellular carcinoma (eHCC) is clinically important, since early detection of HCC remarkably improves patient survival. From the integrative analysis of the transcriptome and clinicopathologic data of human multi-stage HCC tissues, we were able to identify barrier-to-autointegration factor 1 (BANF1), procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3 (PLOD3) and splicing factor 3b subunit 4 (SF3B4) as early HCC biomarkers which could be detected in precancerous lesions of HCC, with superior capabilities to diagnose eHCC compared to the currently popular HCC diagnostic biomarkers: GPC3, GS, and HSP70. We then showed that SF3B4 knockdown caused G1/S cell cycle arrest by recovering $p27^{kip1}$ and simultaneously suppressing cyclins, and CDKs in liver cancer cells. Notably, we demonstrated that aberrant SF3B4 overexpression altered the progress of splicing progress of the tumor suppressor gene, kruppel like factor 4 (KLF4), and resulted in non-functional skipped exon transcripts. This contributes to liver tumorigenesis via transcriptional inactivation of $p27^{kip1}$ and simultaneous activation of Slug genes. Our results suggest that SF3B4 indicates early-stage HCC in precancerous lesions, and also functions as an early-stage driver in the development of liver cancer.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 추계학술대회
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• pp.49-58
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• 2002

Oxidative stress derived from reactive oxygen species (ROS) is one of the major damaging factors in plants exposed to environmental stress. In order to develop the platform technology to solve the global food and environmental problems in the 21s1 century, we focus on the understanding of the antioxidative mechanism in plant cells, the development of oxidative stress-inducible antioxidant genes, and the development of transgenic plants with enhanced tolerance to stress. In this report, we describe our recent results on industrial transgenic plants by the gene manipulation of antioxidant enzymes. Transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts were developed and were evaluated their protection effects against stresses, suggesting that simultaneous overexpression of both SOD and APX in chloroplasts has synergistic effects to overcome the oxidative stress under unfavorable environments. Transgenic tobacco plants expressing a human dehydroascorbate reductase gene in chloroplasts were showed the protection against the oxidative stress in plants. Transgenic cucumber plants expressing high level of SOD in fruits were successfully generated to use the functional cosmetic purpose as a plant bioreactor. In addition, we developed a strong oxidative stress-inducible peroxidase promoter, SWPA2 from sweetpotato (Ipomoea batatas). We anticipate that SWPA2 promoter will be biotechnologically useful for the development of transgenic plants with enhanced tolerance to environmental stress and particularly transgenic cell lines engineered to produce key pharmaceutical proteins.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2777-2783
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• 2015

Background: Nestin is associated with neoplastic transformation. However, the mechanisms by which nestin contributes regarding invasion and malignancy of gastric adenocarcinoma (GAC) remain unknown. Recent studies have shown that the epithelial-mesenchymal transition (EMT) is important in invasion and migration of cancer cells. In the present study, we aimed to investigate the expression of nestin and its correlation with EMT-related proteins in GAC. Materials and Methods: The expression of nestin and EMT-related proteins was examined in GAC specimens and cell lines by immunohistochemistry and Western blotting. Clinicopathological features and survival outcomes were retrospectively analyzed. Results: Positive nestin immunostaining was most obviously detected in the cytoplasm, nucleus or both cytoplasm and nucleus of tumor cells in 19.2% (24/125) of GAC tissues, which was significantly higher than that in normal gastric mucosa tissues (1.7%, 1/60) (p=0.001). Nestin expression was closely related to several clinicopathological factors and EMT-related proteins (E-cadherin, vimentin and Snail) and displayed a poor prognosis. Interestingly, simultaneous cytoplasmic and nuclear nestin expression correlated with EMT-related proteins (E-cadherin, vimentin and Snail) (p<0.05) and lymph node metastasis (p=0.041) and a shorter survival time (p<0.05), but this was not the case with cytoplasmic or nuclear nestin expression. Conclusions: Nestin, particularly expression in both cytoplasm and nucleus, might be involved in regulating EMT and malignant progression in GAC, with potential as an unfavorable indicator in tumor diagnosis and a target for clinical therapy.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 춘계학술대회
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• pp.49-58
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• 2002

각종 환경스트레스에 의해 생체 내에서 과량으로 생성되는 독성의 활성산소종 (ROS)은 산화스트레스를 유발시켜 식물의 질병, 노화 및 세포사멸을 촉진시킨다. 연구팀은 21세기 당면한 지구규모의 환경, 식량 및 보건문제 해결에 기여할 수 있는 기발기술 (plateform technology)를 개발하기 위하여 식물 세포의 항산화기구 규명, 산화스트레스 유도성 항산화효소 유전자 개발, 스트레스 내성식물 개발에 관한 연구를 수행하고 있다. 여기에서는 항산화효소 유전자를 이용한 산업용식물체 개발에 관한 연구팀의 최근 연구결과를 중심으로 소개하였다. SOD와 APX 유전자를 엽록체에 동시에 발현시킨 담배식물체는 MV, 건조 등 여러 스트레스에 대한 내성을 나타내어, 복합 스트레스내성 농작물개발에 활용이 기대된다. 인체 DHAR 유전자를 엽록체에 도입시킨 담배식물체는 정상적으로 DHAR 유전자를 발현시켰으며, MV 등 여러 스트레스에 대한 내성을 나타내었다. 피부 노화방지 등에 관여하여 ROS를 제거하는 SOD를 과실에 과발현시킨 형질전환오이를 성공적으로 개발하여, SOD 오이는 기능성화장품의 용도로 제품개발이 기대된다. 또한 고구마에서 산화스트레스에 특이적으로 발현하는 POD (SWA2) promoter를 개발하였다. SWPAS2 Pormoter는 스트레스내성 및 의료용 단밸질 등 고부가가치 생리활성물질을 생산할 수 있는 산업용 형질전환 식물체 및 배양세포주 개발에 이용될 수 있을 것으로 기대된다.

• Journal of Plant Biotechnology
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• 제29권2호
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• pp.69-77
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• 2002

각종 환경스트레스에 의해 생체 내에서 과량으로 생성되는 독성의 활성산소종 (ROS)은 산화스트레스를 유발시켜 식물의 질병, 노화 및 세포사멸을 촉진시킨다. 연구팀은 21세기 당면한 지구규모의 환경, 식량 및 보건문제 해결에 기여할 수 있는 기반기술 (plateform technology)를 개발하기 위하여 식물세포의 항산화기구 규명. 산화스트레스 유도성 항산화효소 유전자 개발. 스트레스 내성식물 개발에 관한 연구를 수행하고 있다. 여기에서는 항산화효소 유전자를 이용한 산업용식물체 개발에 관한 연구팀의 최근 연구결과를 중심으로 소개하였다. SOD와 APX 유전자를 엽록체에 동시에 발현시킨 담배 식물체는 MV, 건조 등 여러 스트레스에 대한 내성을 나타내어, 복합 스트레스내성 농작물개발에 활용이 기대된다 인체 DHAR 유전자를 엽록체에 도입시킨 담배식물체는 정상적으로 DHAR 유전자를 발현시켰으며, MV 등 여러 스트레스에 대한 내성을 나타내었다. 피부 노화방지 등에 관여하여 ROS를 제거하는 SOD를 과실에 과발현시킨 형질전환오이를 성공적으로 개발하여. SOD 오이는 기능성화장품의 용도로 제품개발이 기대된다. 또한 고구마에서 산화스트레스에 특이적으로 발현하는 POD (SWPA2.) promoter를 개발하였다. SWPA2 promoter는 스트레스내성 및 의료용 단백질 등 고부가가치 생리활성물질을 생산할 수 있는 산업용 형질전환 식물체 및 배양세포주 개발에 이용될 수 있을 것으로 기대된다.