• Title/Summary/Keyword: high-level expression

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Identification and Isolation of Differentially Expressed Gene in Response to Cold Stress in a Green Alga, Spirogyra varians (Zygnematales)

  • Han, Jong-Won;Yoon, Min-Chul;Lee, Key-Pyoung;Kim, Gwang-Hoon
    • ALGAE
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    • v.22 no.2
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    • pp.131-139
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    • 2007
  • The expression of genes responding to cold stress in a freshwater alga, Spirogyra varians, was studied by using differential expression gene (DEG) method. A gene strongly up-regulated in 4°C was isolated and designated as SVCR2 (Spirogyra varians cold regulated) gene. The cDNA encoding SVCR2 was cloned using λZAP cDNA library of Spirogyra varians. The deduced amino acid had a sequence similarity with trans-membrane protein in Arabidopsis thaliana (Q9M2D2, 52.7%). Northern blot analysis demonstrated that transcript level of SVCR2 increased about 10 fold under low temperature (4°C), compared with that cultured at warm (20°C) conditions. The expression of SVCR2 was also affected by light conditions. When the plants were exposed to high light (HL) (1200 μmol photon m–2 s–1), the expression of SVCR2 began within 2 hrs. This gene expression lasted for 4 hrs and decreased afterwards. Under the blue light (470 nm) condition, the expression of this gene was induced in same way as HL treatment, even under less than 100 μmol photon m–2 s–1. But red light (650 nm) and UV-A irradiation did not affect the expression of SVCR2.

Prognostic Role of PTEN Gene Expression and Length of Survival of Breast Cancer Patients in the North East of Iran

  • Golmohammadi, Rahim;Rakhshani, Mohammad Hassan;Moslem, Ali Reza;Pejhan, Akbar
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.305-309
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    • 2016
  • PTEN protein is an important tumour suppressor factor detectable by immunohistochemistry. The goal of the present study was to investigate the prognostic role of PTEN gene expression focusing on length of survival in breast cancer patients. This descriptive-analytical study was conducted on 100 breast cancer cases referred to Sabzevar hospitals in the north east of Iran between 2010 and 2011, followed up to 2015. The PTEN gene expression of tumour tissue samples was determined using specific monoclonal antibodies. The data were analyzed using Chi-square test and Fisher's exact test. Patient length of survival was analyzed after 4 years of follow-up using the Cox regression model. The PTEN gene was expressed in 70 of 100 samples, while being found at a high level in all noncancerous samples. There was an inverse significant relationship between expression of PTEN and tumour stage and grade (p<0.001). In addition, expression of PTEN in invasive ductal tumours was less than in non-invasive tumours. There was also an inverse significant relationship between the likelihood of death and PTEN gene expression (p<0.01). These findings indicate that lack of PTEN gene expression can be sign for a worse prognosis and poor survival in breast cancer.

Evaluation of a New Episomal Vector Based on the GAP Promoter for Structural Genomics in Pichia pastoris

  • Hong In-Pyo;Anderson Stephen;Choi Shin-Geon
    • Journal of Microbiology and Biotechnology
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    • v.16 no.9
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    • pp.1362-1368
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    • 2006
  • A new constitutive episomal expression vector, pGAPZ-E, was constructed and used for initial screening of eukaryotic target gene expression in Pichia pastoris. Two reporter genes such as beta-galactosidase gene and GFPuv gene were overexpressed in P. pastoris. The expression level of the episomal pGAPZ-E strain was higher than that of the integrated form when the beta-galactosidase gene was used as the reporter gene in P. pastoris X33. The avoiding of both the integration procedure and an induction step simplified the overall screening process for eukaryotic target gene expression in P. pastoris. Nine human protein targets from the Core 50, family of Northeast Structural Genomics Consortium (http://www.nesg.org), which were intractable when expressed in E. coli, were subjected to rapid screening for soluble expression in P. pastoris. HR547, HR919, and HR1697 human proteins, which had previously been found to express poorly or to be insoluble in E. coli, expressed in soluble form in P. pastoris. Therefore, the new episomal GAP promoter vector provides a convenient and alternative system for high-throughput screening of eukaryotic protein expression in P. pastoris.

Diagnostic Value of miR-1260b in Cervical Cancer: A Pilot Study

  • Kim, Jungho;Park, Sunyoung;Lee, Hyeyoung
    • Biomedical Science Letters
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    • v.26 no.1
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    • pp.8-13
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    • 2020
  • Cervical cancer is the fourth most common cancer in women, with approximately 528,000 new cases and 266,000 women dying of it per year in the world. MicroRNAs have recently been in the spotlight as potential biomarkers that regulate gene expression and are involved in tumorigenesis. In the present study, we evaluated miR-1260b as a potential biomarker for screening of cervical cancer by quantitative reverse transcription PCR. We profiled the TCGA data of miR-1260b in 307 cervical cancer tissues. Then, miR-1260b expression levels in 10 cervical cancer tissues and 10 noncancerous tissues were investigated in a pilot study. miR-1260b was found to be significantly up-regulated in cervical cancer FFPE tissues as compared to those in cervical normal FFPE tissues (P = 0.006). The mean expression level of miR-1260b in late-stage (IIB-IVB) was higher than in those with early-stage (IA-IIA). Furthermore, high miR-1260b was found to be associated with high hTERT and Ki-67 mRNA expression, which are representative of tumor prognosis. The results of the pilot study suggest that miR-1260b may be used as a novel biomarker for improving the diagnosis of cervical cancer.

High NDRG3 expression facilitates HCC metastasis by promoting nuclear translocation of β-catenin

  • Shi, JiKui;Zheng, HongZhen;Yuan, LingYan
    • BMB Reports
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    • v.52 no.7
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    • pp.451-456
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    • 2019
  • NDRG1 has been reported to exert pivotal roles in tumor progression and metastasis via Wnt/${\beta}$-catenin signaling pathway. However, little is known about the role of NDRG3 in hepatocarcinogenesis despite its classification in the same subfamily of NDRG1. The present study was aimed to characterize the expression pattern and understand the biological roles of NDRG3 in hepatocarcinogenesis, as a means to exploit its therapeutic potential. It was observed that NDRG3 was up-regulated in HCC tissues and higher NDRG3 expression was associated with significantly shorter overall survival. Furthermore, a lower level of NDRG3 exhibited marked positive correlation with metastasis-free survival. In vitro and in vivo experiments revealed that knock-down of NDRG3 inhibits HCC metastasis and angiogenesis. We further demonstrated that activation of WNT/${\beta}$-catenin signaling and enhanced CSC-like properties were responsible for NDRG3-mediated promoting effect on HCC. In conclusion, the principal findings demonstrated that high NDRG3 expression facilitates HCC metastasis via regulating the turnover of ${\beta}$-catenin, as well as provides a potential therapeutic target for future therapeutic interventions.

Effects of Glucose Repression and Plasmid Copy Number on Cloned Gene Expression in Recombinant Yeast (재조합 효모에서의 포도당 억제와 Plasmid 수가 유전자 발현에 미치는 영향)

  • 홍억기
    • KSBB Journal
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    • v.9 no.3
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    • pp.339-345
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    • 1994
  • Deletions between UASG and the GALI TATA box reduced glucose repression and allowed constitutive expression of the gene product in the absence of galactose. The relative inducer level (ratio of galactose/glucose concentrations) affected the extent of gene expression and glucose repression. Glucose repression was reduced by a factor of 2 to 5 as the relative inducer level increased. In the medium containing galactose only, induction of ${\beta}$-galactosidase synthesis by galactose increased with plasmid copy number. On the contrary, plasmid copy number did not affect significantly ${\beta}$-galactosidase synthesis in the medium containing both glucose and galactose (2% glucose+2% galactose), which might be due to glucose repression caused by high glucose concentration. However, when the medium contained the relatively high inducer level (0.4% glucose+0.8% galactose), ${\beta}$-galactosidase synthesis increased with plasmid copy number, indicating that the beneficial effect of higher galactose concentration was weaker than the repressive effect of higher glucose concentration.

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A Practical Algorithm for Selective Harmonic Elimination in Five-Level Converters

  • Golshan, Farzad;Abrishamifar, Adib;Arasteh, Mohammad
    • Journal of Power Electronics
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    • v.18 no.6
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    • pp.1650-1658
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    • 2018
  • Multilevel converters are being widely used in medium-voltage high-power applications including motor drive systems, utility power transmission, and distribution systems. Selective harmonic elimination (SHE) is a well-known modulation method to generate high quality output voltage waveforms. This paper presents a new simple practical method for generating a generalized five-level waveform without selected low order harmonics. This method is based on a phase-shifted expression for the SHE problem, which can analytically calculate the exact values of switching angles and the feasible modulation index range for three-level and five-level waveforms. The proposed method automatically determines the number of transitions between levels and generates proper output waveform without solving complex trigonometric equations. Due to the simplicity of the computational burden, the real-time implementation of the proposed algorithm can be performed by a simple processor. Simulation and experiment results verify the correctness and effectiveness of the proposed method.

Development of Recombinant Chinese Hamster Ovary Cell Lines Producing Human Thrombopoietin or Its Analog

  • Chung, Joo-Young;Ahn, Hae-Kyung;Lim, Seung-Wook;Sung, Yun-Hee;Koh, Yeo-Wook;Park, Seung-Kook;Lee, Gyun-Min
    • Journal of Microbiology and Biotechnology
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    • v.13 no.5
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    • pp.759-766
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    • 2003
  • Recombinant Chinese hamster ovary (rCHO) cell lines expressing a high level of human thrombopoietin (hTPO) or its analog, TPO33r, were obtained by transfecting expression vectors into dihydrofolate reductase-deficient (dhfr) CHO cells and subsequent gene amplification in media containing stepwise increments in methotrexate (MTX) level such as 20, 80, and 320 nM. The parental clones with a hTPO expression level $>0.40\;{\mu}g/ml$ (27 out of 1,200 clones) and the parental clones with a TPO33r expression level $>0.20\;{\mu}g/ml$ (36 out of 400 clones) were subjected to 20 nM MTX. The clones that displayed an increased expression level at 20 nM MTX were subjected to stepwise increasing levels of MTX such as 80 and 320 nM. When subjected to 320 nM MTX, most clones did not display an increased expression level, since the detrimental effect of gene amplification on growth reduction outweighed its beneficial effect of specific TPO productivity ($q_{TPO}$) enhancement at 320 nM MTX. Accordingly, the highest producer subclones ($1-434-80^{*}$ for hTPO and $2-3-80^{*}$ for TPO33r), whose $q_{TPO}$ was 2- to 3-fold higher than that of their parental clones selected at 80 nM MTX, were isolated by limiting dilution method and were established as rCHO cel1 lines. The $q_{TPO}$ of $1-434-80^{*}\;and\;2-3-80^{*}\;was\;5.89{\pm}074\;and\;1.02{\pm}0.23\;{\mu}g/10^6$ cells/day, respectively. Southern and Northern blot analyses showed that the enhanced $q_{TPO}$ of established rCHO cell lines resulted mainly from the increased TPO gene copy number and subsequent increased TPO mRNA level. The hTPO and TPO33r produced from the established rCHO cell lines were biologically active in vivo, as demonstrated by their ability to elevate platelet counts in treated mice.

Expression of High Mobility Group Box - B1 (HMGB-1) and Matrix Metalloproteinase-9 (MMP-9) in Non-small Cell Lung Cancer (NSCLC)

  • Wang, Jing-Luan;Wu, Da-Wei;Cheng, Zhao-Zhong;Han, Wei-Zhong;Xu, Sheng-Wei;Sun, Ni-Na
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.12
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    • pp.4865-4869
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    • 2014
  • Objective: This study evaluated the expression level of high mobility group box-B1 (HMGB-1) and matrix metalloproteinase-9 (MMP-9) in non-small cell lung cancer (NSCLC) inmorder to reveal any relation with development and prognosis. Methods: NSCLC and normal tissues were selected from 30 patients at age of 30-73, and used for RT-PCR and Western blot analyses of HMGB-1. A total of 100 paraffin embedded NSCLC tissues were also isolated from patients through surgical resection, and used for detection of HMGB-1 by immunohistochemistry. In addition, 50 samples were also applied for MMP-9 detection, and 30 normal tissues were considered as controls. Correlation analysis of HMGB-1 and MMP-9 was carried out by Pearsons correlation coefficient. Results: The average expression level of HMGB-1 in NSCLC patients was significantly higher than in normal lung tissues. In addition, patients in III-IV period exhibit significantly higher positive rate of HMGB-1 when compared with I-II period cases. Furthermore, a positive correlation with HMGB-1 was found in the expression of MPP-9. Conclusion: HMGB-1 was highly expressed in NSCLC, which may become a prognostic and predictive marker for NSCLC. Besides, MPP-9 was positively correlated with HMGB-1.

A Study on the Self-expression, Stage Confidence, Commitment and Satisfaction of Fashion Models (패션모델의 자기표현력, 무대 자신감, 몰입과 만족도에 관한 연구)

  • Park, Keun-Jung;Kim, Young-Sam
    • Journal of Fashion Business
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    • v.22 no.2
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    • pp.118-133
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    • 2018
  • This study investigated the effect a fashion model's self-expression has on stage confidence, commitment, and satisfaction. The differences in stage confidence, commitment and satisfaction were analyzed by comparing the frequency of fashion show experiences. A survey was conducted using convenience sampling of professional male and female fashion models at fashion venues (Dongdaemoon Design Plaza) and model agencies from March 2, 2017 through April 10, 2017. A total of 248 questionnaires were obtained and SPSS 21.0 was used for data analysis. The results of this study are as follows. First, the analysis indicated a fashion model's self-expression factors, including movement, meaning, and individuality, had positively impacted the model's psychological and physical confidence, while acting ability negatively impacted such confidences. Secondly, movement meaning, expressive impulse, and individuality had positive impacts on behavioral commitment. A model's expressive impulse was also found to have a positive impact on cognitive commitment. In addition, acting ability negatively impacted behavioral commitment, while it affected cognitive commitment positively. Third, a high level of psychological and physical confidences about fashion shows, as well as a high level of behavioral and cognitive commitment, had a positive impact on fashion-show satisfaction. There were significant differences in cognitive commitment and fashion-show satisfaction by frequency of fashion show experiences. The findings can be utilized to understand the psychological factors that affect a fashion model's performance in order to increase the model's fashion-show satisfaction. It is also expected to provide useful information to enhance the quality of fashion shows.