• Title/Summary/Keyword: Gene regulation

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Low Expression of the bcl2 Gene in Gastric Adenocarcinomas in Mazandaran Province of Iran

  • Mirmajidi, Seyedeh Habibeh;Ataee, Ramin;Barzegar, Ali;Nikbakhsh, Novin;Shaterpour, Mohammad
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.6067-6071
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    • 2015
  • Background: Gastric cancer accounts for about 8% of the total cancer cases and 10% of total cancer deaths worldwide. It is the second lethal cancer after esophageal cancer and is considered the fourth most common cancer in north and northwest Iran. The bcl2 family has a key role in the regulation of apoptosis and change in its expression can contribute to cancer. This study initially scheduled to determine the expression of bcl2 gene in tissue samples of adenocarcinoma cancer patients. Materials and Methods: A total of 10 samples of gastric adenocarcinoma and 10 of normal tissues from Sari hospital were selected and after DNA extraction from tissues, bcl2 gene expression assayed by real-time PCR. Results: Our results demonstrated higher expression of the bcl2 gene in control compared with cancer and marginal cancer tissues. Conclusions: On one hand BCL2 plays an important role as an oncogene to inhibit apoptosis; on the other hand, it can initiate cell cycle arrest at G0 stage. Our observed association between its expression and patient survival is quite conflicting and may be tissue-specific. The data suggest expression both tumoural and non-tumoral(marginal) groups have lowered expression than controls (P>0.05). Due to the low number of samples we could not examine the relationship with clinicopathological features. However, bcl-2 expression may be important for prognostic outcome or a useful target for therapeutic intervention.

Participation of SRE4, an URE1 Enhancer Core Sequence, in the Sterol-Mediated Transcriptional Upregulation of the Human Apolipoprotein E Gene

  • Min, Jung-Hwa;Paik, Young-Ki
    • BMB Reports
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    • v.31 no.6
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    • pp.565-571
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    • 1998
  • The expression of the endogenous human apolipoprotein(apo)E gene was significantly induced when HepG2 cells were treated with exogenous 25-hydroxy-cholesterol. This sterol-mediated apoE gene upregulation appears to require the participation of a positive element for the apoE gene transcription (PET) ( -169/ -140), a core sequence of upstream regulatory element (URE)1 enhancer of the human apoE gene. This PET was renamed as sterol regulatory element (SRE)4 based on its new role as a sensor for the level of intracellular sterol. Furthermore, a gel mobility shift analysis showed that binding activity of the SRE4 binding protein (BP) obtained from HepG2 cells was induced by sterol treatment, while that from either MCF7 or BT20 cells remained unchanged. Binding activity of SRE4BP was also induced in mouse macrophage cells, J774A.1, by sterol treatment, but it was drastically reduced when cells were subjected to treatment of AY-9944, a potent inhibitor for sterol synthesis. However, binding activity of Spl, which is a co-binding protein to the SRE4 region, remained the same in either condition, suggesting that SRE4BP (formally known as PETBP) may be mainly responsible for the sterol-mediated regulation of the apoE gene expression. Deletion analysis of the core binding site of SRE4BP by gel mobility shift assays showed that the minimal sequence of the SRE4BP binding appears to reside between -157 and -140, confirming the identity of SRE4 with the previously determined core sequence of URE1.

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Regulation of CYP 1A1 gene expression by retinoic acid receptor, retinoid X receptor and constitutive androstane receptor in rainbow trout hepatoma cells(RTH 149)

  • Kim, Ji-Sun;Yang, So-Yeun;Seo, Mi-Jung;Sheen, Yhun-Yhong
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2003.10a
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    • pp.179-179
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    • 2003
  • Exposure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes a variety of biological and toxicology effects, most of which are mediated by aryl hydrocarbon receptor (AhR). The ligand-bound AhR as a heterodimer with AhR nuclear translocator (ARNT) binds to its specific DNA recognition site, the dioxin-responsive element (DRE), and it results in increased transcription of CYP1A1 gene. Retinoic acid (RA) regulates the transcription of various genes for several essential functions through binding to two classes of nuclear receptors, the retinoic acid receptor (RAR) and retinoid X receptor (RXR). Constitutive androstane receptor (CAR) also regulates the transcription of gene. In this study, we have examined how RAR, RXR and CAR regulated CYP1A1 in rainbow trout hepatoma cell (RTH 149) using luciferase reporter gene assay system. We did transient transfection with CYP1A1 luciferase reporter gene and treated with TCDD, all-trans RA, 9-cis RA and phenobarbital. Treatment of all-trans RA, 9-cis RA or phenobarbital decreased the TCDD induced transcription of CYP1A1. When we did transient cotransfection with CYP1A1 luciferase reporter gene and RXR, as increase of RXR concentration, the TCDD induced transcription of CYP1A1 was decreased. Transfection with CAR also decreased the TCDD induced transcription of CYP1A1 in RTH 149 cells.

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Analysis of the Role of STAT Binding Site in the Drosophila raf Promoter Region Using Transgenic Flies (형질전환 초파리를 이용한 Drosophila raf 유전자 발현조절영역에 존재하는 STAT결합부위의 역할에 관한 연구)

  • Park, Hyun Sook;Kim, Young Shin;Kwon, Eun Jeong;Yoo, Mi Ae
    • Journal of Life Science
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    • v.9 no.1
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    • pp.50-57
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    • 1999
  • STATs activated by various cytokine and growth factors trigger a quick response in the nucleus and induce changes in gene expression. We have found the sequences homologous to STAT binding site in the 5'-flanking region of the D-raf gene. In this study, we examined role of the STAT binding site in D-raf gene promoter activity in vivo by using transgenic flies. The reporter plasmid pDraf-STATmut-lacZ was constructed by fusing D-raf promoter fragment having the base-substituted STAT binding site with the lacZ gene in a P-element vector. Transgenic flies bearing the Draf-STATmut-lacZ fusion genes were established by P-element mediated transformation. The expression of lacZ in transgenic flies bearing Draf-STATmut-lacZ fusion genes carrying base substitution in STAT site throughout various developmental stages was extensively reduced in comparison with that in transgenic flies bearing wild type Draf-lacZ fusion gene. These results show that the STAT binding site plays an important role in regulation of the D-raf gene.

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Comparative Analysis of Gene Expression in the Female Reproductive Organs

  • Kim, Min-Goo;Seo, Hee-Won;Choi, Yo-Han;Lee, Chang-Kyu;Ka, Hak-Hyun
    • Journal of Embryo Transfer
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    • v.24 no.2
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    • pp.77-87
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    • 2009
  • To understand molecular and cellular mechanisms of many gene products in the female reproductive organs including the ovary and uterine endometrium as well as during embryo development, researchers have developed and utilized many effective methodologies to analyze gene expression in cells, tissues and animals over the last several decades. For example, blotting techniques have helped to understand molecular functions at DNA, RNA and protein levels, and the reverse transcription-polymerase chain reaction (RT-PCR) method has been widely used in gene expression analysis. However, some conventional methods are not sufficient to understand regulation and function of genes expressed in very complex patterns in many organs. Thus, it is required to adopt more high-throughput and reliable techniques. Here, we describe several techniques used widely recently to analyze gene expression, including annealing control based-PCR, differential display-PCR, expressed sequence tag, suppression subtractive hybridization and microarray techniques. Use of these techniques will help to analyze expression pattern of many genes from small scale to large scale and to compare expression patterns of genes in one sample to another. In this review, we described principles of these methodologies and summarized examples of comparative analysis of gene expression in female reproductive organs with help of those methodologies.

Expression of Neurotensin/Neuromedin N Precursor in Murine Mast Cells

  • Ahn, Hyun-Jong;Cho, Jeong-Je
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.6
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    • pp.495-501
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    • 2001
  • We have cloned the mouse neurotensin/neuromedin N (NT/N) gene from the murine mast cell line Cl.MC/C57.1 for the first time. The murine NT/N cDNA clone consisted of 765 nucleotides and coded for 169 peptide residues with an N-terminal signal peptide, and the C-terminal region contained of one copy of neurotensin (NT) and one copy of neuromedin N (NN). Total of four Lys-Arg dibasic motifs were present; one each at the middle of the open reading frame, at the N-terminal of NN, at the C-terminal of NT, and between NN and NT. Amino acid sequence analysis of the mouse NT/N revealed 90% homology to that of the rat NT/N gene. NT/N is expressed in murine mast cell lines (Cl.MC/C57.1 and P815), but not in murine bone marrow-derived mast cells (BMMCs), murine macrophage cell line (RAW 264.7), nor in murine T cell line (EL-4). NT/N mRNA in C1.MC/C57.1 is highly inducible by IgE cross-linking, phorbol myristate acetate, neurotensin, and substance P. Following the treatment of demethylating agent, 5-azacytidine (5-azaC), the NT/N gene was induced in BMMCs in response to IgE cross-linking. 5-azaC-treated BMMCs did not express the NT/N gene without additional stimuli. These findings suggested that the regulation of NT/N gene expression was dependent on the effects of not only gene methylation but also enhancer and/or repressor proteins acting on the NT/N promoter.

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Expression of peroxiredoxin I regulated by gonadotropins in the rat ovary

  • Lee, Yu-Il;Kang, Woo-Dae;Kim, Mi-Young;Cho, Moon-Kyoung;Chun, Sang-Young
    • Clinical and Experimental Reproductive Medicine
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    • v.38 no.1
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    • pp.18-23
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    • 2011
  • Objective: Peroxiredoxins (Prxs) play an important role in regulating cellular differentiation and proliferation in several types of mammalian cells. This report examined the expression of Prx isotype I in the rat ovary after hormone treatment. Methods: Immature rats were injected with 10 IU of pregnant mare's serum gonadotropin (PMSG) to induce the growth of multiple preovulatory follicles and 10 IU of human chorionic gonadotropin (hCG) to induce ovulation. Immature rats were also treated with diethylstilbestrol (DES), an estrogen analogue, to induce the growth of multiple immature follicles. Northern blot analysis was performed to detect gene expression. Cell-type specific localization of Prx I mRNA were detected by in situ hybridization analysis. Results: During follicle development, ovarian Prx I gene expression was detected in 3-day-old rats and had increased in 21-day-old rats. The levels of Prx I mRNA slightly declined one to two days following treatment with DES. A gradual increase in Prx I gene expression was observed in ovaries obtained from PMSG-treated immature rats. Furthermore, hCG treatment of PMSG-primed rats resulted in a gradual stimulation of Prx I mRNA levels by 24 hours (2.1-fold increase) following treatment, which remained high until 72 hours following treatment. In situ hybridization analysis revealed the expression of the Prx I gene in the granulosa cells of PMSG-primed ovaries and in the corpora lutea of ovaries stimulated with hCG for 72 hours. Conclusion: These results demonstrate the gonadotropin and granulosa cell-specific stimulation of Prx I gene expression, suggesting its role as a local regulator of follicle development.

miR-7b Promoter Contains Negative Gene Elements (네거티브 유전자 조절인자를 포함하는 마이크로RNA, miR-7b의 프로모터)

  • Choi, Ji-Woong;Lee, Heon-Jin
    • Journal of Life Science
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    • v.21 no.12
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    • pp.1784-1788
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    • 2011
  • The typical miRNA and its nearby host gene are co-expressed by sharing the same promoter. We assumed that miR-7b and its host gene FICT might use an identical promoter for their brain specific gene expression. Sequence comparison of the genomic DNA of mouse miR-7b, human miR-7-3 and their host genes by using the bioinformatic tools revealed high sequence homology and several putative transcription factor-binding sites on the promoter region. In order to probe the hypothesis we used a luciferase vector system into which we cloned the 5' upstream conserved region of miR-7b and FICT. The putative promoter region showed decreased luciferase activity, suggesting that the 5' upstream of miR-7b and FICT contain a negative regulator for gene expression.

Altered Gene Expression Profiles in the Lungs of Streptozotocin-induced Diabetic Mice

  • Kim, Jung-Hyun;Rasaei, Roya;Park, Sujin;Kim, Ji-Young;Na, Sunghun;Hong, Seok-Ho
    • Development and Reproduction
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    • v.24 no.3
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    • pp.197-205
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    • 2020
  • Diabetes mellitus is a common heterogeneous metabolic disorder, characterized by deposition of extracellular matrix, oxidative stress, and vascular dysfunction, thereby leading to gradual loss of function in multiple organs. However, little attention has been paid to gene expression changes in the lung under hyperglycemic conditions. In this study, we found that diabetes inuced histological changes in the lung of streptozotocin-induced diabetic mice. Global gene expression profiling revealed a set of genes that are up- and down-regulated in the lung of diabetic mice. Among these, expression of Amigo2, Adrb2, and Zbtb16 were confirmed at the transcript level to correlate significantly with hyperglycemia in the lung. We further evaluated the effect of human umbilical cord-derived perivascular stem cells (PVCs) on these gene expression in the lung of diabetic mice. Our results show that administration of PVC-conditioned medium significantly suppressed Amig2, Adrb2, and Zbtb16 upregulation in these mice, suggesting that these genes may be useful indicators of lung injury during hyperglycemia. Furthermore, PVCs offer a promising alternative cell therapy for treating diabetic complications via regulation of gene expression.

Positive Regulation of Pyoluteorin Biosynthesis in Pseudomonas sp. M18 by Quorum-Sensing Regulator VqsR

  • Huang, Xianqing;Zhang, Xuehong;Xu, Yuquan
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.828-836
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    • 2008
  • The biocontrol rhizobacterium Pseudomonas sp. M18 can produce two kinds of antibiotics, namely pyoluteorin (Plt) and phenazine-1-carboxylic acid (PCA), and is antagonistic against a number of soilborne phytopathogens. In this study, a luxR-type quorum-sensing regulatory gene, vqsR, was identified and characterized immediately downstream of the Plt gene cluster in strain MI8. A vqsR-inactivated mutant led to a significant decrease in the production of Plt and its biosynthetic gene expression. However, this was restored when introducing the vqsR gene by cloning into the plasmid pME6032 in trans. The vqsR mutation did not exert any obvious influence on the production of PCA and its biosynthetic gene expression and the production of N-acylhomoserine lactones (C4 and C8-HSLs) and their biosynthetic gene rhlI expression. Accordingly, these results introduce VqsR as a regulator of Plt production in Pseudomonas spp., and suggest that the regulatory mechanism of vqsR in strain M18 is distinct from that in P. aeruginosa. In addition, it was demonstrated that vqsR mutation did not have any obvious impact on the expression of Plt-specific ABC transporters and other secondary metabolic global regulators, including GacA, RpoS, and RsmA.