• Title/Summary/Keyword: Induction expression

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ERCC1 Expression Can Predict Response to Platinum-Based Induction Chemotherapy in Head and Neck Cancer Cases

  • Ameri, Ahmad;Mortazavi, Nafiseh;Ahmadi, Helaleh Khoshbakht;Novin, Kambiz
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.87-91
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    • 2016
  • To investigate whether excision repair cross complementing-group1 (ERCC1) expression status could serve as a bio-predictor of response to platinum-based induction chemotherapy for head and neck cancers (HNCs) patients with a diagnosis of epithelial HNC were studied retrospectively. Paraffin embedded tumor samples of the patients were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) to determine ERCC1 expression status and its correlation with response to platinum-based induction chemotherapy was investigated. Of 44 included patients, 33 were male (75%) and 11 were female (25%) with a mean age of 53 years. Some 36% of patients whose tumor samples had high ERCC1 expression showed no response to induction chemotherapy. The value for patients with low ERCC1 expression was 9% and the difference was statistically significant (p=0.03). The ERCC1 expression state did not significantly vary between patient groups according to sex, age, primary tumor site, and tumor and node stage. Our study indicates that ERCC1 expression status detected by RT-PCR might serve as a bio-predictor of response to platinum-based induction chemotherapy for epithelial HNCs.

Effect of Galactose Feeding Strategy on Heterologous Human Lipocortin-I Production in the Fed-Batch Culture of Saccharomyces cerevisiae Controlled by the GAL10 Promoter

  • Chung, Bong-Hyun;Kim, Byung-Moon;Rhee, Sang-Ki;Park, Young-Hoon;Nam, Soo-Wan
    • Journal of Microbiology and Biotechnology
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    • v.5 no.4
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    • pp.224-228
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    • 1995
  • Fed-batch fermentations were conducted to produce human lipocortin-I (LC1), a potential anti-inflammatory agent, from recombinant Sacchromyces cerevisiae carrying a galactose-inducible expression system. The cell growth, expression level of LC1, and the plasmid stability were investigated under various LC1 induction modes performed by three different galactose feeding strategies. Galactoe was fed to induce the expression of LCl from the beginning (initial induction) of culture or when the cell concentration reached 120 OD (mid-phase induction) or 300 OD (late induction). Among the three galactose-induction modes tested, the initial induction mode yielded the best result with respect to a final expression level of LC1. Fedbatch fermentation with initial induction mode produced LC1 at a conentration of 220 mg/l, which corresponded to 1.38- and 1.53-fold increases over those produced by mid-phase and late induction modes.

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Regulation of the expression of nhaA gene coding $Na^{+}$/$H^{+}$ antiporter A of escherichia coli

  • Seo, Sung-Yum;Lee, Seung-Heon
    • Journal of Microbiology
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    • v.33 no.2
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    • pp.120-125
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    • 1995
  • .betha.-galactosidase activity of Escherichia coli cells containing operon fusion nhaA'-'lacZ was monitored to study the regulation of expression of nhaA gene under various conditions. The expression of the fusion was enhanced only by chemicals containing Na$^{+}$ or Li$^{+}$. This Na$^{+}$ or Li$^{+}$. This Na$^{+}$(Li$^{+}$)-specific enhancement of .betha.-galactosidase activity represented the increase in the rate of synthesis of .betha.-galactosidase rather than the decrease in the breakdown rate. The induction pattern was influenced by copy numbers of the gene. Induction by Na$^{+}$ or Li$^{+}$ was concentration and time dependent, reaching maximum 5-6 fold induction after 2 hours at 0.4-0.5 M for Na$^{+}$ or at 0.25-0.35 M for Li$^{+}$, Although the expression was induced at much lower concentration of Na$^{+}$ at alkaline pH values than at neutral pH in the presence of Na$^{+}$, alkaline pH itself did ot induced the expression of the fusion in the absence of Na$^{+}$. Temperature shift and growth phase of culture did not affect the level of induction.he level of induction.

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The Dependency of the Expression Level of Recombinant Protein by the Drop of Alkali Consumption Rate after Induction (발현유도에 의한 알칼리 소비속도의 감소가 재조합 단백질 생산에 미치는 영향)

  • Hur, Won
    • KSBB Journal
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    • v.21 no.4
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    • pp.236-240
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    • 2006
  • IPTG induction caused a sudden drop of alkali consumption rate during cultivation of a recombinant E. coli with ${\beta}$-galactosidase structural gene under T7 promoter on a plasmid. A series of batch cultivations showed the positive correlation of the decrease of alkali consumption and the level of expression. However, repeated IPTG induction did not cause any variation of alkali consumption rate. Supplementation of medium even at stationary phase enhanced the level of ${\beta}$-galactosidase expression. These results suggests that the drop of alkali consumption rate by IPTG induction represents the rate of expression.

Analysis of ROS and Apoptosis of Porcine Skin-derived Stem-like Cells after Differentiation Induction into Mesodermal Cell Types

  • Bae, Hyo-Kyung;Lee, Hwa-Yeon;Park, Yeo-Reum;Park, Choon-Keun;Yang, Boo-Keun;Cheong, Hee-Tae
    • Journal of Embryo Transfer
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    • v.31 no.1
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    • pp.89-95
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    • 2016
  • The present study was conduct to examine the $H_2O_2$ expression level and apoptosis-related gene expression levels inporcineskin-derived stem cell-like cells (pSSCs) after adipogenic, chondrogenic, and osteogenic differentiation induction. The pSSCs were obtained by digestion of porcine ear skin biopsy and cultured in each induction medium for 21 to 26 days to induce adipogenic, chondrogenic, and osteogenic differentiation, respectively. The $H_2O_2$ levels of pSSCs after induction culture were evaluated by staining with 2'7'-dichlorodihydrofluorescein diacetate ($H_2DCFDA$). The apoptotic gene expression of pSSCs after induction culture was also estimated by RT-PCR. The pSSCs have a potential to differentiate into three mesodermal cell types (adipocytes, chondrocytes, and osteoblasts). Non-induced control and chondrogenic-induced cells were showed higher $H_2DCFDA$ intensity (P<0.05) than adipogenic- and osteogenic-induced cells. The relative expression of Bax/Bcl-2 level was significantly low (P<0.05) in adipogenic- and osteogenic-induced cells compared to non-induced control. However, there was no difference in the relative expression of Bax/Bcl-2 level among differentiation induction groups. The result of the present study shows that the apoptosis of pSSCs is not detrimentally increased by differentiation induction culture, although chondrogenic-induced pSSCs showed high ROS generation level and apoptotic index similarly to those of non-induced cells.

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).

Effects of Angelicae Gigantis Radix on Gene Expression of Ovarian Tissue in Polycystic Ovary Syndrome Rats (당귀(當歸)가 다낭성난소증후군이 유발된 흰쥐 난소조직의 유전자 발현에 미치는 영향)

  • Ryu, Ki-Jun;Cho, Sung-Hee
    • The Journal of Korean Obstetrics and Gynecology
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    • v.24 no.3
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    • pp.28-47
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    • 2011
  • Objectives: This study was performed to investigate the effects of Angelicae gigantis Radix (AGR) which is one of the most useful herbal-drug to treat patients with Polycystic Ovary Syndrome (PCOS) in Oriental medicine on gene expression of ovary tissue. Methods: The effects of AGR on gene expression of ovary tissue resected from PCOS induced rats using single injection of $\ss$-Estradiol 17-valerate (EV) was measured using microarray technique, and the functional analysis on these genes was conducted. Results: Total 2,812 genes were up-regulated or down-regulated, 1,421 genes were up-regulated, 1,391 genes were down-regulated by induction of PCOS. Up-regulated genes were mainly involved in biological function such as cell signalling pathways and inflammatory response. Expression levels of 1,442 genes were restored to those of naive animals by administration of AGR. 558 genes were restored to those of naive animals, which were lowered by induction of PCOS. 884 genes were lowered to naive levels, which were elevated by induction of PCOS. The functions of restored genes were partially involved in the restoration of expression levels, which were changed by induction of PCOS. Especially, up-regulated gene by induction of PCOS were mainly involved in these changes. These results mean restorative effects of AGR on damaged functions by induction of PCOS. The network of total protein interactions was measured using cytoscape program, and some key molecules, such as IRS2, MCM10, ORC2L related in up-regulated genes, CTBP2, CD44, RHOA, related in down-regulated genes that can be used for elucidation of therapeutical mechanism of medicine in future were identified. Conclusion: Restored genes by AGR were thought to have common pathways related in regulation of gene expressions. Especially, genes in restored expression levels by AGR, which were up-regulated by induction of PCOS, were regulated by 9 of common transcription factors, genes in restored expression levels by AGR, which were down-regulated by induction of PCOS, were involved in 25 of common transcription factors.

PV.1 Suppresses the Expression of FoxD5b during Neural Induction in Xenopus Embryos

  • Yoon, Jaeho;Kim, Jung-Ho;Kim, Sung Chan;Park, Jae-Bong;Lee, Jae-Yong;Kim, Jaebong
    • Molecules and Cells
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    • v.37 no.3
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    • pp.220-225
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    • 2014
  • Suppression of bone morphogenetic protein (BMP) signaling induces neural induction in the ectoderm of developing embryos. BMP signaling inhibits neural induction via the expression of various neural suppressors. Previous research has demonstrated that the ectopic expression of dominant negative BMP receptors (DNBR) reduces the expression of target genes down-stream of BMP and leads to neural induction. Additionally, gain-of-function experiments have shown that BMP downstream target genes such as MSX1, GATA1b and Vent are involved in the suppression of neural induction. For example, the Vent1/2 genes are involved in the suppression of Geminin and Sox3 expression in the neural ectodermal region of embryos. In this paper, we investigated whether PV.1, a BMP downstream target gene, negatively regulates the expression of FoxD5b, which plays a role in maintaining a neural progenitor population. A promoter assay and a cyclohexamide experiment demonstrated that PV.1 negatively regulates FoxD5b expression.

ZFP36L1 and AUF1 Induction Contribute to the Suppression of Inflammatory Mediators Expression by Globular Adiponectin via Autophagy Induction in Macrophages

  • Shrestha, Aastha;Pun, Nirmala Tilija;Park, Pil-Hoon
    • Biomolecules & Therapeutics
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    • v.26 no.5
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    • pp.446-457
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    • 2018
  • Adiponectin, a hormone predominantly originated from adipose tissue, has exhibited potent anti-inflammatory properties. Accumulating evidence suggests that autophagy induction plays a crucial role in anti-inflammatory responses by adiponectin. However, underlying molecular mechanisms are still largely unknown. Association of Bcl-2 with Beclin-1, an autophagy activating protein, prevents autophagy induction. We have previously shown that adiponectin-induced autophagy activation is mediated through inhibition of interaction between Bcl-2 and Beclin-1. In the present study, we examined the molecular mechanisms by which adiponectin modulates association of Bcl-2 and Beclin-1 in macrophages. Herein, we demonstrated that globular adiponectin (gAcrp) induced increase in the expression of AUF1 and ZFP36L1, which act as mRNA destabilizing proteins, both in RAW 264.7 macrophages and primary peritoneal macrophages. In addition, gene silencing of AUF1 and ZFP36L1 caused restoration of decrease in Bcl-2 expression and Bcl-2 mRNA half-life by gAcrp, indicating crucial roles of AUF1 and ZFP36L1 induction in Bcl-2 mRNA destabilization by gAcrp. Moreover, knock-down of AUF1 and ZFP36L1 enhanced interaction of Bcl-2 with Beclin-1, and subsequently prevented gAcrp-induced autophagy activation, suggesting that AUF1 and ZFP36L1 induction mediates gAcrp-induced autophagy activation via Bcl-2 mRNA destabilization. Furthermore, suppressive effects of gAcrp on LPS-stimulated inflammatory mediators expression were prevented by gene silencing of AUF1 and ZFP36L1 in macrophages. Taken together, these results suggest that AUF1 and ZFP36L1 induction critically contributes to autophagy induction by gAcrp and are promising targets for anti-inflammatory responses by gAcrp.

Construction of Improved Tetracycline-Inducible Expression System for the Effective Regulation of Transgene Expression (외래 유전자의 효율적인 발현 조절을 위한 개선된 Tetracycline-Inducible Expression System의 구축)

  • Koo, Bon-Chul;Kwon, Mo-Sun;Kim, Teo-An
    • Reproductive and Developmental Biology
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    • v.33 no.1
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    • pp.63-69
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    • 2009
  • In this study we tried to construct a more efficient tetracycline-inducible gene expression system by replacing previous key elements with more advance ones. At the beginning, we substituted PGK (phophoglycerate kinase) promoter for CMV (cytomegalovirus) promoter to control "$rtTA2^sM2$" which has been known for high induction efficiency in response to tetracycline. With this modification, expression of the EGFP marker gene under the induction condition was significantly increased. Next, we replaced "TRE" fragment with a modified version named "TRE-tighf" which has been reported to have higher affinity and specificity to the transactivator by minor base change of the "TRE" DNA fragment sequence. Use of "TRE-tighf" instead of "TRE" resulted in more than 10 fold increment in terms of induction efficiency and significant decrement of background expression in non-inducible condition. By combining PGK promoter and "TRE-tight" fragment, we could upgrade previous tetracycline-inducible system to show more stringent turn on/off gene switch ability and stronger expression of the gene of our interest. Use of this newly developed system must be very helpful to the studies of gene expression, especially to the transgenic animal study in which non-controllable constitutive expression of the transgene has been one of the urgent problems to be solved.