• Title/Summary/Keyword: Absence of expression

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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.

Ceramide-Mediated c-jun Gene Expression in U-937 Cells (U-937 세포에 있어서 세라마이드에 의한 c-jun 유전자 발현의 조절)

  • Kim, Won-Ho;Kim, Mie-Young;Choi, Kyung-Hee
    • YAKHAK HOEJI
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    • v.41 no.1
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    • pp.81-85
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    • 1997
  • Ceramide has been suggested as an important mediator of the effects of extracellular agonists on cell growth inhibition, differentiation, apoptosis. However the biochemical sign aling mechanism involved in transducing the effects of ceramide on leukemia cell differentiation is still unclear. In these respects, we examined the regulatory effects of ceramide on c-jun gene expression during differentiation. In U-937 cells. ceramide increased c-jun mRNA levels in a time-dependent manner. The half life, of c-jun mRNA was 30 min. In contrast, inhibition of protein synthesis with cycloheximide in the absence, of transcription with actinomycin D increased the half-life of c-jun mRNA in ceramide-treated U-937 cells to more than 90 min. In order to examine whether ceramide-inhibited c-jun gene expression is regulated through ceramide-activated protein phosphatase (CAPP), a direct target for the action of ceramide, okadaic acid were treated to the cells. Okadaic acid inhibited enhancement of c-jun mRNA induced by C2-ceramide in a dose-dependent manner. These results suggested that ceramide increases c-jun mRNA level during differentiation in U-937 cells and regulates the gene expression on posttranscriptional level. In addition, we provide the evidence that CAPP is involved in ceramide-induced c-jun gene expression in U-937 cells.

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Dexmedetomidine Modulates Histamine-induced Ca2+ Signaling and Pro-inflammatory Cytokine Expression

  • Yang, Dongki;Hong, Jeong Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.5
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    • pp.413-420
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    • 2015
  • Dexmedetomidine is a sedative and analgesic agent that exerts its effects by selectively agonizing ${\alpha}2$ adrenoceptor. Histamine is a pathophysiological amine that activates G protein-coupled receptors, to induce $Ca^{2+}$ release and subsequent mediate or progress inflammation. Dexmedetomidine has been reported to exert inhibitory effect on inflammation both in vitro and in vivo studies. However, it is unclear that dexmedetomidine modulates histamine-induced signaling and pro-inflammatory cytokine expression. This study was carried out to assess how dexmedetomidine modulates histamine-induced $Ca^{2+}$ signaling and regulates the expression of pro-inflammatory cytokine genes encoding interleukin (IL)-6 and -8. To elucidate the regulatory role of dexmedetomidine on histamine signaling, HeLa cells and human salivary gland cells which are endogenously expressed histamine 1 receptor were used. Dexmedetomidine itself did not trigger $Ca^{2+}$ peak or increase in the presence or absence of external $Ca^{2+}$. When cells were stimulated with histamine after pretreatment with various concentrations of dexmedetomidine, we observed inhibited histamine-induced $[Ca^{2+}]_i$ signal in both cell types. Histamine stimulated IL-6 mRNA expression not IL-8 mRNA within 2 hrs, however this effect was attenuated by dexmedetomidine. Collectively, these findings suggest that dexmedetomidine modulates histamine-induced $Ca^{2+}$ signaling and IL-6 expression and will be useful for understanding the antagonistic properties of dexmedetomidine on histamine-induced signaling beyond its sedative effect.

Wave propagation in a two-temperature fiber-reinforced magneto-thermoelastic medium with three-phase-lag model

  • Said, Samia M.;Othman, Mohamed I.A.
    • Structural Engineering and Mechanics
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    • v.57 no.2
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    • pp.201-220
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    • 2016
  • A general model of equations of the two-temperature theory of generalized thermoelasticity is applied to study the wave propagation in a fiber-reinforced magneto-thermoelastic medium in the context of the three-phase-lag model and Green-Naghdi theory without energy dissipation. The material is a homogeneous isotropic elastic half-space. The exact expression of the displacement components, force stresses, thermodynamic temperature and conductive temperature is obtained by using normal mode analysis. The variations of the considered variables with the horizontal distance are illustrated graphically. Comparisons are made with the results of the two theories in the absence and presence of a magnetic field as well as a two-temperature parameter. A comparison is also made between the results of the two theories in the absence and presence of reinforcement.

Biomarker-directed Targeted Therapy in Colorectal Cancer

  • John M. Carethers
    • Journal of Digestive Cancer Research
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    • v.3 no.1
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    • pp.5-10
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    • 2015
  • With advances in the understanding of the biology and genetics of colorectal cancer (CRC), diagnostic biomarkers that may predict the existence or future presence of cancer or a hereditary condition, and prognostic and treatment biomarkers that may direct the approach to therapy have been developed. Biomarkers can be ascertained and assayed from any tissue that may demonstrate the diagnostic or prognostic value, including from blood cells, epithelial cells via buccal swab, fresh or archival cancer tissue, as well as from cells shed into fecal material. For CRC, current examples of biomarkers for screening and surveillance include germline testing for suspected hereditary CRC syndromes, and stool DNA tests for screening average at-risk patients. Molecular biomarkers for CRC that may alter patient care and treatment include the presence or absence of microsatellite instability, the presence or absence of mutant KRAS, BRAF or PIK3CA, and the level of expression of 15-PGDH in the colorectal mucosa. Molecularly targeted therapies and some general therapeutic approaches rely on biomarker information. Additional novel biomarkers are on the horizon that will undoubtedly further the approach to precision or individualized medicine.

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Correlation between chromosome abnormalities and genomic imprinting in developing human - 1) Frequent biallelic expression of insulin-like growth factor II (IGF2) in gynogenetic Ovarian Teratomas: Uncoupling of H19 and IGF2 imprinting

  • Choi, Bo-Hwa;Lee, In-Hwan;Chun, Hyo-Jin;Kang, Shin-Sung;Chang, Sung-Ik
    • Journal of Genetic Medicine
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    • v.2 no.1
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    • pp.41-47
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    • 1998
  • Human uniparental gestations such as gynogenetic ovarian teratomas provide a model to evaluate the integrity of parent-specific gene expression - i.e. imprinting - in the absence of a complementary parental genetic contribution. The few imprinted genes characterized so far include the insulin-like growth factor-2 gene (IGF2) coding for a fetal growth factor and H19 gene whose normal function is unknown but it is likely to act as an mRNA. IGF2 is expressed by the paternal allele and H19 by the maternal allele. This reciprocal expression is quite interesting because both H19 and IGF2 genes are located close to each other on chromosome 11p15.5. In situ RNA hybridization analysis has shown variable expression of the H19 and IGF2 alleles according to the tissue origin in 11 teratomas. Especially, Skin, derivative of ectoderm, is expressed conspicuously. We examined imprinting of H19 and IGF2 in teratomas using PCR and RT-PCR of exonic polymorphism. H19 and IGF2 transcript could be expressed either biallelically or monoallelically in the teratomas. Biallelic expression (i.e., loss of imprinting) of IGF2 occurred in 5 out of 6 mature teratomas and 1 out of 1 immature teratoma. Biallelic expression of H19 occurred in 4 out of 10 mature teratomas and 1 out of 1 immature teratoma. Expression levels of H19 and IGF2 transcript using the semi-quantitative RT-PCR had no relation between monoallelic and biallelic expression. Moreover, IGF2 biallelic expression did not affect allele-specificity or levels of H19 expression. These results demonstrate that both genes, H19 and IGF2, can be imprinted, expressed and regulated independently and individually of each other in ovarian teratoma.

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Characterization of cadC and cadR Mutants in Mediating the Expression of the Salmonella typhimurium cadBA Operon (Salmonella typhimurium cadBA 오페론의 발현에 관여하는 돌연변이체의 선별 및 그 특성)

  • 방성호;박용근
    • Korean Journal of Microbiology
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    • v.37 no.4
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    • pp.259-264
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    • 2001
  • It has been well known that the expression of S. typhimurium cadBA operon requires at least two extracellular signals: low pH and high concentration of lysine. To better understand the nature of pH-dependent and lysine dependent signal transduction, mutants were isolated in JF2238(cadA-lacZ) by Tn10 insertion, spontaneous mutagenesis, and EMS treatment. Two mutants were isolated from JF2238, expressed as a cadA-lacZ operon fusion in various growth conditions, and analyzed to have mutations in cadC, a gene encoding a function necessary for transcriptional activation of cadBA. One isolate (cadC6) conferred pH-independent and lysine-independent cadBA expression and the other(cadC4) showed pH-independent and lysine-dependent cadBA expression. cadR::Tn10 and cadR4 mutants were expressed in the absence of exogenously added lysine. They were also resistant to thiosine and complemented by lysP clone from E. coli. Thus, in the absence of exogenous lysine, cadR is a negative regulator of cadBA expression. Cadaverine, the product of lysine decarboxylation, was shown to inhibit expression of cadA-lacZ fusion in cad $C^+$ cell.

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Expression of Vimentin and Ki-67 Proteins in Cervical Squamous Cell Carcinoma and their Relationships with Clinicopathological Features

  • Yu, Jian-Qin;Zhou, Qing;Zheng, Yun-Fei;Bao, Ying
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4271-4275
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    • 2015
  • Objectives: To investigate the expression of vimentin and Ki-67 proteins in cervical squamous cell carcinoma (CSCC) and their relationships with patient clinicopathological features. Materials and Methods:Fifty-seven CSCC samples archived in Department of Pathology in the First Affiliated Hospital of Wenzhou Medical University were selected. The expression of vimentin and Ki-67 proteins in CSCC tissue were detected using immunohistochemical SP method, and correlations between them and their relationships with clinicopathological features were analyzed. Results: Among 57 CSCC tissues, there were 43 with positive expression of Vimentin, and the positive rate was 75.4%; there were 57 cases with positive expression of Ki-67, and the positive rate came up to 100.0%. The results of Pearson correlation analysis displayed that the expression of vimentin had a significantly-positive correlation with Ki-67 in CSCC tissue (r=0.984, co0.000). The expression of both Ki-67 and vimentin was intimately associated with the presence or absence of local invasion and lymph node metastasis as well as differentiated degrees of the tumor (P=0.003, 0.017, 0.000; P=0.001, 0.008, 0.003) instead of the age, tumor size and clinical staging (P>0.05). Conclusions: Epithelial-mesenchymal transition (EMT) tends to appear in poorly-differentiated CSCC tissue, and the up-regulation of vimentin expression is accompanied by high expression of Ki-67, suggesting that invasion and metastasis readily occur in these tumor cells.

Effect of CXCR4 and CD133 Co-expression on the Prognosis of Patients with Stage II~III Colon Cancer

  • Li, Xiao-Feng;Guo, Xiao-Guang;Yang, Yong-Yan;Liu, Ai-Yong
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.1073-1076
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    • 2015
  • Background: To explore the relationship between CXCR4, CD133 co-expression and clinicopathological features as well as prognosis of patients with phase II~III colon cancer. Materials and Methods: Forty-nine paraffin-embedded samples of tumor tissue and epithelial tissue adjacent to cancer were collected from patients with colon cancer undergoing radical surgery in Baotou Cancer Hospital from January, 2010 to June, 2011. CXCR4 and CD133 expression was detected using immunohistochemistry and its relationship with clinicopathological features and the 3-year survival rate was analyzed. Results: In the tumor tissue and colonic epithelial tissue adjacent to cancer, the positive expression rates of CXCR4 were respectively 61.2% (30/49) and 8.16% (4/49), while those of CD133 being 36.7% (18/49) and 6.12% (3/49). CXCR4 and CD133 expression in tumor tissue was not related to patient age, gender, primary focal sites, tumor size, TNM staging, histological type, tumor infiltration depth and presence or absence of lymphatic metastasis, but CXCR4 and CD133 co-expression was associated with TNM staging and lymphatic metastasis. The 3-year survival rate of patients with CXCR4 and CD133 co-expression was 27.3% (3/11), and that of the remainderwas 76.3% (29/38), the difference being significant ($X^2=7.0206$, p=0.0081). Conclusions: CXCR4 and CD133 co-expression may be a risk factor for poor prognosis of patients with stage II~III colon cancer.

Effect of Low Doses of Genistein and Equol on Protein Expression Profile in MCF-7 Cells

  • Kim, Jang-Hoon;Lim, Hyun-Ae;Lee, Jeong-Soon;Sung, Mi-Kyung;Kim, Young-Kyoon;Yu, Ri-Na;Kim, Jong-Sang
    • Food Science and Biotechnology
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    • v.14 no.6
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    • pp.854-859
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    • 2005
  • Although action modes of equol and genistein have been extensively studied, their precise roles in tumor cells remain elusive. To address possible effects of these compounds on protein expression in mammary tumor cells, proteins modulated in MCF-7 mammary tumor cells when incubated in absence and presence of 10 uM equol or genistein were identified through 2-dimensional gel electrophoresis, MALDI-TOF MS/MS, and NCBInr database search using Mascot software. Most proteins differentially expressed in MCF-7 cells after treatment with 10 uM genistein or equol were identified as being the same. Exposure to both compounds caused decreased cellular expression of RNA-binding protein regulatory subunit and oncogene DJ1 tubulin beta-1 chain, and increased expression of heterogeneous ribonucleoproteins F and L, KH-type splicing regulatory protein, and translation elongation factor EF-Tu precursor. Genistein and equol at dose used in this study showed common action mechanism.