• Title/Summary/Keyword: non-specific binding

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Screening of ${\beta}$-Catenin/TCF Transcription Factor Inhibitors in Medicinal Herb Extracts

  • Choe, Ye-Dang;Na, Byung-Jo;Park, Se-Yeon
    • The Journal of Korean Medicine
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    • v.32 no.3
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    • pp.35-43
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    • 2011
  • Objectives: This study was performed to screen target-specific inhibitors of ${\beta}$-catenin/TCF signaling whose functional activation plays an important role in early events in carcinogenesis. Methods: To investigate the activation or suppression of ${\beta}$-catenin/TCF transcription, we established a transiently transfected cell line with a constitutively active ${\beta}$-catenin mutant gene whose product is not degraded. This cell line was also co-transfected with luciferase reporter gene constructs containing either an optimized (TOPflash) or mutant (FOPflash) TCF-binding element. We investigated cytotoxic effects using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt (MTS) assay. To find effective inhibitors of ${\beta}$-catenin/TCF signaling from medicinal herbs, the crude extracts of 99 types of medicinal herbs were screened using a luciferase assay system in HEK-293 and SH-SY5y cells. Results: At a concentration of $50{\mu}g$/ml, extracts of Angelica koreanae radix, Cannabis sativa semen, Ephedrae intermedia Schrenk radix, and Vitis rotundifolia fruit showed the following inhibitory effects on ${\beta}$-catenin/TCF signaling: $40{\pm}5.6%$, $23{\pm}6.1%$, $8{\pm}5.1%$, and $22{\pm}9.8%$ in ${\beta}$-catenin-activated HEK-293 cells and $9{\pm}4.7%$, $39{\pm}8.1%$, $39{\pm}6.4%$, and $42{\pm}10.1%$ in ${\beta}$-catenin-activated SH-SY5y cells, respectively. Crude extracts of E. radix were isolated by silica gel column chromatography, and two non-polar fractions of these extracts showed inhibitory effects on ${\beta}$-catenin/TCF signaling. Conclusions: In this study, we established a transiently transfected cell line as a screening system and found that various medicinal herb extracts had inhibitory effects on ${\beta}$signaling.

Inhibition of Inducible Nitric Oxide Synthase and Cyclooxygenase-2 by Gamijihwang-tang Via Suppression of Nuclear Factor-B Activation in RAW 264.7 cells

  • Jang Du-Hyun;Kim Ji-Young;Han Eun-Hee;Park Hee-Ok;Kim Dong-Hee;Jeong Hye-Gwang;Yoo Dong-Yeol
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.5
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    • pp.1405-1410
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    • 2005
  • Asthma is recognized today as an inflammatory disease of the lung characterized by acute non-specific airway hypersensitiveness in association with chronic pulmonary inflammation. Gamijihwang-tang(GJT), a fortified prescription of YMJHT, is applied for the treatments of chronic coughing and asthma, and post-delivery coughing and asthma in the gynecology. Also in the clinical practice, GJT is known to be very effective for controlling coughing and asthma as a cold sequoia. In this study, we investigated the effects of GJT on the lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production, and on the level of inducible nitric oxide synthase (iNOS) and Cyclooxygenase-2 expression in murine macrophage RAW 264.7 cells. We found that GJT inhibited LPS-induced NO and $PGE_2$ production in a dose dependent manner. Furthermore, GJT inhibited the expression of LPS-induced iNOS and COX-2 protein and mRNA expression in RAW 264.7 macrophages. Treatment with GJT of RAW 264.7 cells transfected with a reporter construct indicated a reduced level of LPS-induced nuclear factor-KB (NF-kB) activity and effectively lowered NF-kB binding as measured by transient transfection assay. These results suggest that the main inhibitory mechanism of the GJT may be the reduction of iNOS and COX-2 gene expression through blocking of NF-kB activation.

Anti-IgE mAb Suppresses Systemic Anaphylaxis through the Inhibitory IgG Receptor Fc ${\gamma}$ RIIb in Mice - Interaction between Anti-IgE and Fc ${\gamma}$ RIIb -

  • Kang, Nam-In;Jin, Zhe-Wu;Lee, Hern-Ku
    • IMMUNE NETWORK
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    • v.7 no.3
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    • pp.141-148
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    • 2007
  • Background: Anti-IgE mAb which binds circulating but not receptor-bound IgE has been shown to be effective in treatment for asthma and other allergic diseases. However, the mechanisms by which anti-IgE mAb influences the pathophysiological responses are remained to be illustrated. This study was undertaken to examine the therapeutic efficacy of non-anaphylactogenic anti-mouse IgE mAb using murine models of IgE-induced systemic fatal anaphylaxis. Methods: Active systemic anaphylaxis was induced by either penicillin V(Pen V) or OVA and passive systemic anaphylaxis was induced by either anaphylactogenic anti-mouse IgE or a mixture of anti-chicken gamma globulin (CGG) IgG1 mAb and CGG. The binding of the Fc portion of anti-IgE to CHO-stable cell line expressing mouse Fc ${\gamma}$ RIIb was examined using flow cytometry. Fc fragments of anti-IgE mAb were prepared using papain digestion. The expression of phosphatases in lungs were assessed by Western blotting and immunohistochemistry. Results: Anti-IgE mAb prevented IgE- and IgG-induced active and passive systemic fatal reactions. In both types of anaphylaxis, anti-IgE mAb suppressed antigen-specific IgE responses, but not those of IgG. Anti-IgE mAb neither prevented anaphylaxis nor suppressed the IgE response in Fc ${\gamma}$ RIIb-deficient mice. The Fc portion of anti-IgE mAb was bound to murine Fc ${\gamma}$ RIIb gene-transfected CHO cells and inhibited systemic anaphylaxis. Anti-IgE mAb blocked the anaphylaxis-induced downregulation of Fc ${\gamma}$ RIIb-associated phosphatases such as src homology 2 domain-containing inositol 5-phosphatase (SHIP) and phosphatase and tensin homologue deleted on chromosome ten (PTEN). Conclusion: Anti-IgE mAb prevented anaphylaxis by delivering nonspecific inhibitory signals through the inhibitory IgG receptor, Fc ${\gamma}$ RIIb, rather than targeting IgE.

MicroRNA Analysis in Normal Human Oral Keratinocytes and YD-38 Human Oral Cancer Cells

  • Kim, Hye-Ryun;Park, Eu-Teum;Cho, Kwang-Hee;Kim, Do-Kyung
    • International Journal of Oral Biology
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    • v.36 no.4
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    • pp.179-185
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    • 2011
  • MicroRNAs (miRNAs) are small non-coding RNAs that mediate gene expression at the post-transcriptional level by degrading or repressing targeted mRNAs. These molecules are about 21-25 nucleotides in length and exert their effects by binding to partially complementary sites in mRNAs, predominantly in the 3'-untranslated region (3'-UTR). Recent evidence has demonstrated that miRNAs can function as oncogenes or tumor suppressors through the modulation of multiple oncogenic cellular processes in cancer development, including initiation, cell proliferation, apoptosis, invasion and metastasis. In our present study, we examined the expression profile of miRNAs related to oral cancer cell growth inhibition using normal human oral keratinocytes (NHOK) and YD-38 human oral cancer cells. By miRNA microassay analysis, 40 and 31 miRNAs among the 1,769 examined were found to be up- and down-regulated in YD-38 cells compared with NHOK cells, respectively. Using qRT-PCR analysis, the expression levels of miR-30a and miR-1246 were found to be increased in YD-38 cells compared with NHOK cells, whereas miR-203 and miR-125a were observed to be decreased. Importantly, the overexpression of miR-203 and miR-125a significantly inhibited the growth of YD-38 cells. This finding and the microarray data indicate the involvement of specific miRNAs in the development and progression of oral cancer.

Microfluidic Array for Simultaneous Detection of Antigen-antibody Bindings (항원-항체 결합의 동시 검출을 위한 미세 유체 어레이)

  • Bae, Young-Min
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.4
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    • pp.102-107
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    • 2011
  • In this paper, a microfluidic array biochip for simultaneously detecting multiple antigen-antibody bindings was designed and implemented. The biochip has the single channel in which microreaction chambers are serially connected, and the antibody-coated microbeads are packed in each microreaction chamber. In addition, the weir structure was fabricated in the microchannel using the gray-scale photolithography in order to trap the microbeads in the microreaction chamber. Three kinds of antibodies were chosen, and the antibodies were immobilized onto the microbeads by the streptavidin-biotin conjugation. In the experiment, as the fluorescence-labeled antigens were injected into the microchannel, the antigen-antibody bindings were completed in 10 minutes. When the solution with multiple antigens was injected into the microchannel, it was observed that the fluorescence intensity increased in only the corresponding microreaction chambers with few non-specific binding. The microfluidic array biochip implemented in this study provides, even with the consumption of tiny amount of sample and fast reaction time to simultaneously detect multiple immunoreactions.

Identification of Amino Acid Residues Involved in Xylanase Activity from Bacillus Pumilus TX703 (Bacillus Pumilus TX703 유래 Xylanase의 활성에 관여하는 아미노산 잔기의 확인)

  • Park Young-Seo
    • Journal of Life Science
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    • v.15 no.4 s.71
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    • pp.633-640
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    • 2005
  • The purified xylanase from Bacillus pumilus TX703 was modified with various chemical modifiers to determine the active sites of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results assumed that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and W-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.

Fabrication of fiber-optic evanescent wave immunosensor and its measuring characteristics (광섬유 소산파를 이용한 면역 센서 제조 및 그 특성)

  • Choi, Ki-Bong;Youn, Hee-Ju;Cha, Seung-Hee;Choi, Jung-Do
    • Journal of Sensor Science and Technology
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    • v.6 no.5
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    • pp.356-361
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    • 1997
  • Fiber-optic evanescent wave sensor was designed and fabricated to detect mouse immunoglobulin G(IgG) with decladed optical fiber on which anti-mouse IgG was immobilized. A sensitivity obtained by any direct or competitive method was lower than $1\;{\mu}g/m{\ell}$. Anti-mouse IgG was immobilized on 93.9% of core surface of optical fiber by simple adsorption method. The effect of postcoating using bovine serum albumin to remove non-specific binding was not observed. As the ratio of fluorescein to mouse IgG increased, the fluorescence signal increased, but that increase showed no linear relationship. Our fiber-optic sensor system could be used as immunosensor by measuring evanescent fluorescence in antigen-antibody reaction with good sensitivity below $1{\mu}g/m{\ell}$ level.

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Protective efficacy of attenuated Salmonella Typhimurium strain expressing BLS, Omp19, PrpA, or SOD of Brucella abortus in goats

  • Leya, Mwense;Kim, Won Kyong;Ochirkhuyag, Enkhsaikhan;Yu, Eun-Chae;Kim, Young-Jee;Yeo, Yoonhwan;Yang, Myeon-Sik;Han, Sang-Seop;Lee, John Hwa;Tark, Dongseob;Hur, Jin;Kim, Bumseok
    • Journal of Veterinary Science
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    • v.22 no.2
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    • pp.15.1-15.13
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    • 2021
  • Background: Attenuated Salmonella strain can be used as a vector to transport immunogens to the host antigen-binding sites. Objectives: The study aimed to determine the protective efficacy of attenuated Salmonella strain expressing highly conserved Brucella immunogens in goats. Methods: Goats were vaccinated with Salmonella vector expressing individually lipoprotein outer-membrane protein 19 (Omp19), Brucella lumazine synthase (BLS), proline racemase subunit A (PrpA), Cu/Zn superoxide dismutase (SOD) at 5 × 109 CFU/mL and challenge of all groups was done at 6 weeks after vaccination. Results: Among these vaccines inoculated at 5 × 109 CFU/mL in 1 mL, Omp19 or SOD showed significantly higher serum immunoglobulin G titers at (2, 4, and 6) weeks post-vaccination, compared to the vector control. Interferon-γ production in response to individual antigens was significantly higher in SOD, Omp19, PrpA, and BLS individual groups, compared to that in the vector control (all p < 0.05). Brucella colonization rate at 8 weeks post-challenge showed that most vaccine-treated groups exhibited significantly increased protection by demonstrating reduced numbers of Brucella in tissues collected from vaccinated groups. Real-time polymerase chain reaction revealed that Brucella antigen expression levels were reduced in the spleen, kidney, and parotid lymph node of vaccinated goats, compared to the non-vaccinated goats. Besides, treatment with vaccine expressing individual antigens ameliorated brucellosis-related histopathological lesions. Conclusions: These results delineated that BLS, Omp19, PrpA, and SOD proteins achieved a definite level of protection, indicating that Salmonella Typhimurium successfully delivered Brucella antigens, and that individual vaccines could differentially elicit an antigen-specific immune response.

Analysis of H3K4me3-ChIP-Seq and RNA-Seq data to understand the putative role of miRNAs and their target genes in breast cancer cell lines

  • Kotipalli, Aneesh;Banerjee, Ruma;Kasibhatla, Sunitha Manjari;Joshi, Rajendra
    • Genomics & Informatics
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    • v.19 no.2
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    • pp.17.1-17.13
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    • 2021
  • Breast cancer is one of the leading causes of cancer in women all over the world and accounts for ~25% of newly observed cancers in women. Epigenetic modifications influence differential expression of genes through non-coding RNA and play a crucial role in cancer regulation. In the present study, epigenetic regulation of gene expression by in-silico analysis of histone modifications using chromatin immunoprecipitation sequencing (ChIP-Seq) has been carried out. Histone modification data of H3K4me3 from one normal-like and four breast cancer cell lines were used to predict miRNA expression at the promoter level. Predicted miRNA promoters (based on ChIP-Seq) were used as a probe to identify gene targets. Five triple-negative breast cancer (TNBC)-specific miRNAs (miR153-1, miR4767, miR4487, miR6720, and miR-LET7I) were identified and corresponding 13 gene targets were predicted. Eight miRNA promoter peaks were predicted to be differentially expressed in at least three breast cancer cell lines (miR4512, miR6791, miR330, miR3180-3, miR6080, miR5787, miR6733, and miR3613). A total of 44 gene targets were identified based on the 3'-untranslated regions of downregulated mRNA genes that contain putative binding targets to these eight miRNAs. These include 17 and 15 genes in luminal-A type and TNBC respectively, that have been reported to be associated with breast cancer regulation. Of the remaining 12 genes, seven (A4GALT, C2ORF74, HRCT1, ZC4H2, ZNF512, ZNF655, and ZNF608) show similar relative expression profiles in large patient samples and other breast cancer cell lines thereby giving insight into predicted role of H3K4me3 mediated gene regulation via the miRNA-mRNA axis.

Chemoquiescence with Molecular Targeted Ablation of Cancer Stem Cells in Gastrointestinal Cancers

  • Jong-Min Park;Young-Min Han;Migyeong Jeong;Eun Jin Go;Napapan Kangwan;Woo Sung Kim;Ki Baik Hahm
    • Journal of Digestive Cancer Research
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    • v.4 no.1
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    • pp.1-9
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    • 2016
  • The abundance of multi-drug resistance ATPase binding cassette and deranged self-renewal pathways shown in cancer stem cells (CSCs) played a crucial role in tumorigenesis, tumor resistance, tumor recurrence, and tumor metastasis. Therefore, elucidation of CSCs biology can improve diagnosis, enable targeted treatment, and guide the follow up of GI cancer patients. In order to achieve chemoquiescence, seizing cancer through complete ablation of CSCs, CSCs are rational targets for the design of interventions that will enhance responsiveness to traditional therapeutic strategies and contribute in the prevention of local recurrence as well as metastasis. However, current cancer treatment strategies fail to either detect or differentiate the CSCs from their non-tumorigenic progenies mostly due to the absence of specific biomarkers and potent agents to kill CSCs. Recent advances in knowledge of CSCs enable to produce several candidates to ablate CSCs in gastrointestinal (GI) cancers, especially cancers originated from inflammation-driven mutagenesis such as Barrett's esophagus (BE), Helicobacter pylori-associated gastric cancer, and colitis-associated cancer (CAC). Our research teams elucidated through revisiting old drugs that proton pump inhibitor (PPI) and potassium competitive acid blocker (p-CAB) beyond authentic acid suppression, chloroquine for autophage inhibition, sonic hedgehog (SHH) inhibitors, and Wnt/β-catenin/NOTCH inhibitor can ablate CSCs specifically and efficiently. Furthermore, nanoformulations of these molecules could provide an additional advantage for more selective targeting of the pathways existing in CSCs just like current molecular targeted therapeutics and sustained action, while normal stem cells intact. In this review article, the novel approach specifically to ablate CSCs existing in GI cancers will be introduced with the introduction of explored mode of action.

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