• Title/Summary/Keyword: High-level expression

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DLC-1 Expression Levels in Breast Cancer Assessed by qRT-PCR are Negatively Associated with Malignancy

  • Guan, Cheng-Nong;Zhang, Pei-Wen;Lou, Hai-Qing;Liao, Xiang-Hui;Chen, Bao-Ying
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1231-1233
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    • 2012
  • Objective: The aim of this study was to explore the expression of DLC-l in breast carcinoma and any association with tumor metastasis. Methods: 51 surgical specimens of human breast carcinoma, divided into high invasive and low invasive groups according to their clinicopathological features, 30 cases of adjacent normal tissue and 28 benign breast lesions were examined by qRT-PCR for expression of DLC-1. Results: Expression level of DLC-1 in adjacent normal tissue and benign breast lesion specimens was higher than that in breast carcinoma (P<0.0001); the values in the high invasive group with synchronous metastases were also lower than in the low invasive group (P=0.0275). The correlation between DLC-1 expression level and tumor progression and metastasis of breast cancer was negative. Conclusion: As an anti-oncogene, DLC-1 could play an important part in breast carcinoma occurrence, progression, invasiveness and metastasis. Detecting the changes of the expression of DLC-1 in the breast carcinoma may contribute to earlier auxiliary diagnosis of invasiveness, metastasis and recrudescence.

Expression of Recombinant Human Cytochrome P450 1A2 in Escherichia coli Bacterial Mutagenicity Tester Strain

  • Chun, Young-Jin
    • Archives of Pharmacal Research
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    • v.21 no.3
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    • pp.305-309
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    • 1998
  • Human cytochrome P450 1A2 is one of the major cytochrome P450s in human liver. It is known to be capable of activating a number of carcinogens such as arylamines and heterocyclic amines. In order to develop the new bacterial mutagenicity test system with human P450, a full length of human P450 1A2 cDNA inserted into pCW bacterial expression vector was introduced to Escherichia coli WP2 uvrA strain which is a well-known E. coli strain for bacterial reverse mutagenicity assay. Expressed human P450 1A2 showed typical P450 hemoprotein spectra. Maximum expression was achieved at 48 hrs after incubating at $30^{\circ}C$ in terrific broth containing ampicillin, IPTG and other supplements. High level expression of P450 1A2 in E. coli WP2 uvrA membranes was determined in SDS-PAGE. The well-known mutagens 2-aminoanthracene and MElQ increased the revertant colonies of E. coli WP2 uvrA expressing human P450 1A2 without an exogenous rat hepatic post-mitochondrial supernatant (S9 fraction) in a dose-dependent manner. The results show that the functional expression of human P450 in bacterial mutagenicity tester strain will provide a useful tool for studying the mechanism of the mutagenesis and carcinogenesis of new drugs and environmental chemicals.

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High-Level Expression of Human Cytochrome P450 3A4 by Co-Expression with Human Molecular Chaperone HDJ-1 (Hsp40)

  • Ahn, Tae-Ho;Yun, Chul-Ho
    • Archives of Pharmacal Research
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    • v.27 no.3
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    • pp.319-323
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    • 2004
  • Cytochrome P450 (CYP) 3A4 is of great interest because of its important roles in the oxidation of numerous drugs and xenobiotics. HDJ-1, a molecular chaperone in human, is known to assist the correct folding of unfolded proteins. To achieve a high yield of recombinant human CYP3A4 in Escherichia coli, the CYP3A4 encoding gene was co-expressed with the chaperone HDJ-1, under the control of an inducible tac promoter in a bicistronic format. The levels of expression of the CYP3A4 in the bicistronic construct reached up to 715 nmol $(liter culture)^{-1}$ within 16 h at $37^{\circ}C$, which was about a 3.3-fold increase compared to that of the CYP3A4 alone without the HDJ-1. By co-expression with HDJ-1, the catalytic activity of CYP3A4 was also increased by -15-fold. The amount of activity increase was similar to that of the CYP production at the whole cell level. The present over-expression system may be useful for the rapid production of large amounts of active CYP3A4 in E. coli.

Synergistic Effect of Lipopolysaccharide and Interferon-$\beta$ on the Expression of Chemokine Mig mRNA

  • Lee, Moon-Sook;Kim, Sung-Kwang;Kim, Hee-Sun
    • Journal of Microbiology and Biotechnology
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    • v.12 no.5
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    • pp.813-818
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    • 2002
  • Expression of monokine induced by IFN-$\gamma$(Mig) mRNA is well-known to strictly depend on Interferon-$\gamma$(IFN-$\gamma$). Lipopolysaccharide (LPS) alone Is weakly effective on Mig mRNA expression in mouse Peritoneal macrophages. This study was undertaken to investigate the synergistic effect of LPS and IFN-$\beta$ on chemokine Mig gene expression in mouse peritoneal macrophages. Although IFN-$\beta$ alone was minimally effective, LPS plus IFN-$\beta$ synergized to produce a high level of Mig mRNh. The synergistic effect of LPS and IFN-$\beta$ (LPS/IFN-$\beta$) on Mig mRNA expression was strain-specific. The most effective synergistic effect of LPS/IFN-$\beta$ on the mRNh expression was found in simultaneous stimulation of LPS/IFN-$\beta$. This synergy was modulated at the level of the gene transcription and was not dependent on a new protein synthesis. Synergistic effect of LPS/IFN-$\beta$ also required the activation of $NF-_KB$. Accordingly, these data suggest that LPS/IFN-$\beta$ synergizes the expression of Mig mRNA through a process that depends on a pretranscriptional level and/or coincident Mig mRNA transcription.

Induction of the T7 Promoter Using Lactose for Production of Recombinant Plasminogen Kringle 1-3 in Escherichia coli

  • Lim, Hyung-Kwon;Lee, Shi-Uk;Chung, Soo-Il;Jung, Kyung-Hwan;Seo, Jin-Ho
    • Journal of Microbiology and Biotechnology
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    • v.14 no.2
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    • pp.225-230
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    • 2004
  • A plasminogen kringle domain 1 to 3, rKl-3, was expressed in Escherichia coli under the control of T7 promoter. For the cost-effective production of rKl-3, the induction process was analyzed and optimized. Induction characteristics with lactose were analyzed in terms of induction time and inducer concentration in various culture conditions including batch and high-cell-density fed-batch cultures. In the fed-batch culture, the induction around 6 h after initiation of the DO-stat fed-batch culture resulted in the highest expression level of rKI-3 among the induction points examined. The highest demand of oxygen at this point was crucial for the maximum expression level of rKI-3. As the lactose concentration increased, the expression level also increased, though the expression level showed a plateau above a concentration of 14 mM of lactose. Lactose acted less specifically than IPTG since most of it was hydrolyzed to glucose and galactose. However, using lactose, the cell growth and the maximum expression level of rKl-3 increased by 20% and 24%, respectively, compared with those using IPTG in the fed-batch culture. The lactose seemed to be hydrolyzed by intracellular and extracellular $\beta$-galactosidase liberated by cell lysis at the same time. Residual concentration of glucose was maintained to a a limit of detection by high performance liquid chromatography, and galactose was not consumed by the host strain Escherichia coli BL2l(DE3).

ALDH1 in Combination with CD44 as Putative Cancer Stem Cell Markers are Correlated with Poor Prognosis in Urothelial Carcinoma of the Urinary Bladder

  • Keymoosi, Hossein;Gheytanchi, Elmira;Asgari, Mojgan;Shariftabrizi, Ahmad;Madjd, Zahra
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2013-2020
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    • 2014
  • Background: The aldehyde dehydrogenase 1 family member A1 (ALDH1A1) is one of the promising markers for identifying cancer stem cells in many cancer types, along with other markers including CD44. The aim of the present study was to evaluate the expression and clinical significance of putative cancer stem cell markers, CD44 and ALDH1A1, in a series of urothelial carcinomas of urinary bladder (UCUB) by tissue microarray (TMA). Materials and Methods: A total of 159 Urothelial Carcinomas (UC) including 96 (60%) low grade and 63 (40%) high grade carcinomas were immunohistochemically examined for the expression of CD44 and ALDH1A1. Correlations of the relative expression of these markers with clinicopathological parameters were also assessed. Results: High level expression of ALDH1A1 was found in 16% (25/159) of bladder UC which was significantly correlated with increased tumor size (p value=0.002), high grade (p value<0.001), pathologic stage (T1, p value=0.007 and T2, p value<0.001) and increased rate of recurrence (p value=0.013). A high level of CD44 expression was found in 43% (68/159) of cases, being positively correlated with histologic grade (p value=0.032) and recurrence (p value=0.039). Conclusions: Taken together, our results showed that ALDH1 was concurrently expressed in a fraction of CD44+ tumors and its expression correlated with poor prognosis in UCs. ALDH1A1 could be an ideal marker for targeted therapy of UCs in combination with conventional therapies, particularly in patients with high grade carcinomas. These findings indicate that cells expressing ALDH1A1 along with CD44 can be a potential therapeutic target in bladder carcinomas.

3'-Half of the Thrombopoietin cDNA Confers Higher Expression of Erythropoietin at the RNA Level but Not at the Protein Level

  • Kim, Tae-Won;Ji, Jin Woo;Chang, Ho Gun;Kim, Myoung Ok;Ryoo, Zae Young;Park, In Kook;Kim, Sun Jung
    • Molecules and Cells
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    • v.19 no.2
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    • pp.198-204
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    • 2005
  • Both erythropoietin (EPO) and the short-form thrombopoietin (TPO) were expressed at low levels whereas the long-form TPO was expressed at high levels in transgenic animals. To elucidate the role of carboxy-terminal half of the long-form TPO which is absent in the short-form, we generated recombinant TPO or EPO expression vectors which contain or lack the carboxy-terminal half of TPO and examined their expression in the HC11 and 293 cells. The long-form TPO was expressed higher than the short-form regardless of the cell types, transfection modes, and promoters. When 3'-half of the long-form TPO cDNA was placed downstream of the EPO cDNA to act as a 3'-untranslated region, expression of EPO was moderately increased at the RNA level, however, no remarkable increase was observed at the protein level. These results suggest that the low expression of EPO, as like as the short-form TPO, is due to absence of the 3'-half in the full-length TPO that confers stability both at the RNA and protein levels.

High-Level Expression of Recombinant Human Bone Morphogenetic Protein-4 in Chinese Hamster Ovary Cells

  • PARK JUNHO;YU SUNGRYUL;YOON JAESEUNG;BAEK KWANGHEE
    • Journal of Microbiology and Biotechnology
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    • v.15 no.6
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    • pp.1397-1401
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    • 2005
  • Bone morphogenetic protein-4 (BMP-4) is a signaling homodimeric molecule that acts as a morphogen to influence cell fate in a concentration-dependent manner. The limited supply of a pure preparation of BMP-4, due to very low level of their expression in vivo, makes it difficult not only to study the biological activities of BMPs, but also to use them as a clinical tool. For a large-scale production of BMP-4, human BMP-4 cDNA was expressed in Chinese hamster ovary (CHO) cells by a recently development vector system, which confers position-independent stable expression of the foreign genes. The CHO cell line expressing recombinant human BMP-4 (rhBMP-4) at the level of $7\;{\mu}g/ml$ could be obtained after stepwise selection with methotrexate. This level of expression is about 70 times higher than those previously reported. The partially processed form of BMP-4 as well as mature form could be detected, when the aliquots of culture media were analyzed by Western blot. The glycosylation pattern and biological activity of the rhBMP-4 were determined by glycosidase treatment and the induction rate of alkaline phosphatase in mouse osteoblastic cells.

Effect of Transcription Terminators on Expression of Human Lipocortin-1 in Recombinant Saccharomyces cerevisiae

  • Chung, Bong-Hyun;Kim, Byung-Moon;Nam, Soo-Wan;Park, Young-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.4 no.4
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    • pp.237-244
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    • 1994
  • The vector systems for the expression and secretion of human lipocortin-l (LC1) from Saccharomyces cerevisiae were constructed with GAL10 promoter and the prepro leader sequence of mating factor-$\alpha$1. They were further constructed to contain three different transcription terminators; GAL7 terminator, LCl terminator and a fused form of these two terminators. The expression and secretion levels of LCl were compared to investigate the effect of transcription terminators on the LCl gene expression. For the expression cassettes employing the GAL7 terminator or the terminator of fused form, the expression levels of LCl were measured by scanning the immunoreactive LCl protein bands, and were found to be 0.27 g/l and 0.32 g/l, respectively. The highest expression level of 0.54 g/l was obtained with the expression vector containing the LCl transcription terminator. In all expression cassettes, the majority of LCl proteins expressed were retained intracellularly, indicating a low secretion efficiency of about 5%. The high expression level of LCl was explained by the great content and stability of LCl mRNA transcribed from the LCl terminator-employing vector. The results of this study demonstrate that the LCl transcription terminator functions for the expression of LCl in S. cerevisiae better than the GAL7 terminator.

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The Relation of Trait anger and Anger Expression to Cardiovascular Responses and Depression in Middle-aged Korean Women (중년여성의 특성분노, 분노표현, 심혈관 반응과 우울)

  • Park Young-Joo;Baik Soonim;Choi Younghee;Shin Hyunjeong;Moon Sohyun;Khim Soonyong
    • Journal of Korean Academy of Nursing
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    • v.35 no.7
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    • pp.1371-1378
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    • 2005
  • Purpose: This study was designed to examine the relation of trait anger and anger expression to blood pressure, cholesterol, and depression in middle-aged Korean women. Methods: This descriptive correlational design was conducted using a convenient sample taken from the health center of K University Hospital located in Kyungki province, Korea. The subjects were 252 women aged 40 to 64 years. Spielberger's state trait anger expression inventory - Korean version and Beck's depression inventory were used for measuring trait anger, state anger, anger expression and depression. Data was analyzed by descriptive statistics, t-test, Pearson correlation, two-way ANOVA, and cluster analysis using a pc-SAS program. Results: The anger expression types by cluster analysis were Anger out/in type, Low anger expression type, and Anger control type. The level of cholesterol and depression were significantly higher in women with high anger in and high trait anger. In addition, the level of depression was significantly higher in women with a high anger temperament. Conclusions: Trait anger and anger in might be related to cholesterol and depression in women. However, this study does not reveal the relation between blood pressure and trait anger and anger expression.