• Title/Summary/Keyword: Adhesion promoter

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Effect of Functionalized Binary Silane Coupling Agents by Hydrolysis Reaction Rate on the Adhesion Properties of 2-Layer Flexible Copper Clad Laminate (이성분계 실란 커플링제의 가수분해속도 조절에 의한 2-FCCL의 접착특성 변화 연구)

  • Park, U-Joo;Park, Jin-Young;Kim, Jin-Young;Kim, Yong-Seok;Ryu, Jong-Ho;Won, Jong-Chan
    • Polymer(Korea)
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    • v.35 no.4
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    • pp.302-307
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    • 2011
  • The parameters of silanol formation reaction of organosilane including solvent type, solution concentration, pH and hydrolysis time influence the adhesion property of 2 layer flexible copper clad laminate (FCCL). Especially, the hydrolysis reaction time of silane coupling agent affects the formation of the silanol groups and their self-condensation to generate oilgomeric structure to enhance the surface treatment as an adhesive promoter. In our study, we prepared the binary silane coupling agents to control hydrolysis reaction rate and surface energy after treatment of silane coupling agents for increasing the adhesive property between a copper layer and a polyimide layer. The surface morphology of rolled copper foil, as a function of the contents of the coated binary silane coupling agent, was fully characterized. As fabricated 2-layer FCCL, we observed that adhesive properties were changed by hydrolysis rate and surface energy.

WAVEs: A Novel and Promising Weapon in the Cancer Therapy Tool Box

  • Sakthivel, K.M.;Prabhu, V. Vinod;Guruvayoorappan, C.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1719-1722
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    • 2012
  • The Wiskott-Aldrich Syndrome Protein family Verprolin - homologous proteins (WAVEs), encoded by a metastasis promoter gene, play considerable roles in adhesion of immune cells, cell proliferation, migration and destruction of foreign agents by reactive oxygen species. These diverse functions have lead to the hypothesis that WAVE proteins have multi-functional roles in regulating cancer invasiveness, metastasis, development of tumor vasculature and angiogenesis. Differentials in expression of WAVE proteins are associated with a number of neoplasms include colorectal cancer, hepatocellular cancer, lung squamous cell carcinoma, human breast adenocarcinoma and prostate cancer. In this review we attempt to unify our knowledge regarding WAVE proteins, focusing on their potentials as diagnostic markers and molecular targets for cancer therapy.

The 14-3-3 Gene Function of Cryptococcus neoformans Is Required for its Growth and Virulence

  • Li, Jingbo;Chang, Yun C.;Wu, Chun-Hua;Liu, Jennifer;Kwon-Chung, Kyung J.;Huang, Sheng-He;Shimada, Hiro;Fante, Rob;Fu, Xiaowei;Jong, Ambrose
    • Journal of Microbiology and Biotechnology
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    • v.26 no.5
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    • pp.918-927
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    • 2016
  • Cryptococcus neoformans is a life-threatening pathogenic yeast that causes devastating meningoencephalitis. The mechanism of cryptococcal brain invasion is largely unknown, and recent studies suggest that its extracellular microvesicles may be involved in the invasion process. The 14-3-3 protein is abundant in the extracellular microvesicles of C. neoformans, and the 14-3-3-GFP fusion has been used as the microvesicle's marker. However, the physiological role of 14-3-3 has not been explored. In this report, we have found that C. neoformans contains a single 14-3-3 gene that apparently is an essential gene. To explore the functions of 14-3-3, we substituted the promoter region of the 14-3-3 with the copper-controllable promoter CTR4. The CTR4 regulatory strain showed an enlarged cell size, drastic changes in morphology, and a decrease in the thickness of the capsule under copper-enriched conditions. Furthermore, the mutant cells produced a lower amount of total proteins in their extracellular microvesicles and reduced adhesion to human brain microvascular endothelial cells in vitro. Proteomic analyses of the protein components under 14-3-3-overexpressed and -suppressed conditions revealed that the 14-3-3 function(s) might be associated with the microvesicle biogenesis. Our results support that 14-3-3 has diverse pertinent roles in both physiology and pathogenesis in C. neoformans. Its gene functions are closely relevant to the pathogenesis of this fungus.

Sodium Butyrate Alters Cell-Cell Interactions through Up-Regulation of E-Cadherin in Human Hepatocellular Carcinoma Cells (Sodium butyrate에 의한 E-cadherin의 발현증가와 세포간 상호작용의 변화)

  • Kwun, Hyun-Jin;Jang, Kyung-Lib
    • Journal of Life Science
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    • v.19 no.6
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    • pp.705-710
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    • 2009
  • Sodium butyrate (NaBt), a naturally occurring short chain fatty acid derived from carbohydrate metabolism in the gut, is known to exhibit strong anti-cancer potentials in various human cancer cells; however, its action mechanism is poorly understood. In the present study, we demonstrated that NaBt up-regulates levels of E-cadherin, a key cell adhesion molecule implicated as a tumor suppressor, in a cell type-specific manner. Although levels of p21, a potential activator for E-cadherin expression, were also up-regulated by treatment with NaBt in several types of cells, it does not seem to be associated with the activation of E-cadherin in the NaBt-treated cells. Instead, the data from promoter analysis suggest that NaBt up-regulates expression of E-cadherin at the transcription level by enhancing its promoter strength via a CCAAT-box. The elevated E-cadherin in the presence of NaBt was primarily localized at the cell-cell contacts, converting Hep3B cells into a more differentiated form.

Genetic disruption of ATAT1 causes RhoA downregulation through abnormal truncation of C/EBPβ

  • Jee-Hye Choi;Jangho Jeong;Jaegu Kim;Eunae You;Seula Keum;Seongeun Song;Ye Eun Hwang;Minjoo Ji;Kwon-Sik Park;Sangmyung Rhee
    • BMB Reports
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    • v.57 no.6
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    • pp.293-298
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    • 2024
  • Microtubule acetylation has been shown to regulate actin filament dynamics by modulating signaling pathways that control actin organization, although the precise mechanisms remain unknown. In this study, we found that the downregulation of microtubule acetylation via the disruption ATAT1 (which encodes α-tubulin N-acetyltransferase 1) inhibited the expression of RhoA, a small GTPase involved in regulating the organization of actin filaments and the formation of stress fibers. Analysis of RHOA promoter and chromatin immunoprecipitation assays revealed that C/EBPβ is a major regulator of RHOA expression. Interestingly, the majority of C/EBPβ in ATAT1 knockout (KO) cells was found in the nucleus as a 27-kDa fragment (referred to as C/EBPβp27) lacking the N-terminus of C/EBPβ. Overexpression of a gene encoding a C/EBPβp27-mimicking protein via an N-terminal deletion in C/EBPβ led to competitive binding with wild-type C/EBPβ at the C/EBPβ binding site in the RHOA promoter, resulting in a significant decrease of RHOA expression. We also found that cathepsin L (CTSL), which is overexpressed in ATAT1 KO cells, is responsible for C/EBPβp27 formation in the nucleus. Treatment with a CTSL inhibitor led to the restoration of RHOA expression by downregulation of C/EBPβp27 and the invasive ability of ATAT1 KO MDA-MB-231 breast cancer cells. Collectively, our findings suggest that the downregulation of microtubule acetylation associated with ATAT1 deficiency suppresses RHOA expression by forming C/EBPβp27 in the nucleus through CTSL. We propose that CTSL and C/EBPβp27 may represent a novel therapeutic target for breast cancer treatment.

Lactosylceramide Mediates the Expression of Adhesion Molecules in TNF-${\alpha}$ and IFN ${\gamma}$-stimulated Primary Cultured Astrocytes

  • Lee, Jin-Koo;Kim, Jin-Kyu;Park, Soo-Hyun;Sim, Yun-Beom;Jung, Jun-Sub;Suh, Hong-Won
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.5
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    • pp.251-258
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    • 2011
  • Here we have investigated how lactosylceramide (LacCer) modulates gene expression of adhesion molecules in TNF-${\alpha}$ and IFN ${\gamma}$ (CM)-stimulated astrocytes. We have observed that stimulation of astrocytes with CM increased the gene expression of ICAM-1 and VCAM-1. D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and N-butyldeoxynojirimycin (NBDNJ), inhibitors of glucosylceramide synthase (GLS) and LacCer synthase (galactosyltransferase, GalT-2), inhibited the gene expression of ICAM-1 and VCAM-1 and activation of their gene promoter induced by CM, which were reversed by exogenously supplied LacCer. Silencing of GalT-2 gene using its antisense oligonucleotides also attenuated CM-induced ICAM-1 and VCAM-1 expression, which were reversed by LacCer. PDMP treatment and silencing of GalT-2 gene significantly reduced CM-induced luciferase activities in NF-${\kappa}B$, AP-1, GAS, and STAT-3 luciferase vectors-transfected cells. In addition, LacCer reversed the inhibition of NF-${\kappa}B$ and STAT-1 luciferase activities by PDMP. Taken together, our results suggest that LacCer may play a crucial role in the expression of ICAM-1 and VCAM-1 via modulating transcription factors, such as NF-${\kappa}B$, AP-1, STAT-1, and STAT-3 in CM-stimulated astrocytes.

Loss of Expression and Aberrant Methylation of the CDH1 (E-cadherin) Gene in Breast Cancer Patients from Kashmir

  • Asiaf, Asia;Ahmad, Shiekh Tanveer;Aziz, Sheikh Aejaz;Malik, Ajaz Ahmad;Rasool, Zubaida;Masood, Akbar;Zargar, Mohammad Afzal
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6397-6403
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    • 2014
  • Background: Aberrant promoter hypermethylation has been recognized in human breast carcinogenesis as a frequent molecular alteration associated with the loss of expression of a number of key regulatory genes and may serve as a biomarker. The E-cadherin gene (CDH1), mapping at chromosome 16q22, is an intercellular adhesion molecule in epithelial cells, which plays an important role in establishing and maintaining intercellular connections. The aim of our study was to assess the methylation pattern of CDH1 and to correlate it with the expression of E-cadherin, clinicopathological parameters and hormone receptor status in breast cancer patients of Kashmir. Materials and Methods: Methylation specific PCR (MSP) was used to determine the methylation status of CDH1 in 128 invasive ductal carcinomas (IDCs) paired with the corresponding normal tissue samples. Immunohistochemistry was used to study the expression of E-cadherin, ER and PR. Results: CDH1 hypermethylation was detected in 57.8% of cases and 14.8% of normal adjacent controls. Reduced levels of E-cadherin protein were observed in 71.9% of our samples. Loss of E-cadherin expression was significantly associated with the CDH1 promoter region methylation (p<0.05, OR=3.48, CI: 1.55-7.79). Hypermethylation of CDH1 was significantly associated with age at diagnosis (p=0.030), tumor size (p=0.008), tumor grade (p=0.024) and rate of node positivity or metastasis (p=0.043). Conclusions: Our preliminary findings suggest that abnormal CDH1 methylation occurs in high frequencies in infiltrating breast cancers associated with a decrease in E-cadherin expression. We found significant differences in tumor-related CDH1 gene methylation patterns relevant to tumor grade, tumor size, nodal involvement and age at diagnosis of breast tumors, which could be extended in future to provide diagnostic and prognostic information.

Pathways Analysis of Gleditsia spina Extract on Changes of Gene Expression in Human Melanoma cells (조각자(皂角刺)가 악성흑색종 세포주에 미치는 영향)

  • Kim, Bu-Yeo;Lim, Se-Hyun;Lee, Byoung-Ho;Lim, Chi-Yeon;Kim, Yong-Seong;Cho, Su-In
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.3
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    • pp.47-62
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    • 2009
  • Glenditsia spina (GS) can resolve carbuncle, relive swelling, dispel wind and destroy parasites. For these reasons, GS has been widely used as dermatologic agent clinically. In this study, the specific pathways of anti-proliferative effect of GS on human derived melanoma cells were identified. The molecular profile was measured using microarray technique to identify up- or down-regulated genes in SK-MEL-2 cell line. Pathway analysis was done by listing percentage of pathway involvement, and the represented pathways were obtained from KEGG. The transcription factor binding sequences were obtained by Transfac database. By the promoter analysis, up-regulated genes by GS were mainly associated with MAPK, Regulation of actin cytoskeleton, Wnt, Focal adhesion and Long term potentiation pathway. Down-regulated genes by GS were mainly associated with MAPK and Antigen processing and presentation pathway. And some of the transcription factors like Sp1 and NF-Y in up-regulated genes and Oct-1 in down-regulated genes by GS also identified.

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Improvement of electromigration characteristics in using Ai interlayer (Cu 배선에 Al층간 물질 첨가에 의한 EM특성 개선)

  • 이정환;박병남;최시영
    • Journal of the Korean Vacuum Society
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    • v.10 no.4
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    • pp.403-410
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    • 2001
  • Acceleration in integration density and speed performance of ULSI circuits require miniaturization of CMOS and interconnections as well as higher current density capabilities for transistors. A leading candidate to substitute Al-alloy is Cu, which has lower resistivity and higher melting point. So we can expect much higher electromigration resistance. In this paper, we are going to explain the major features of EM for MOCVD Cu according to variant conditions. We compared the life time and activation energy of MOCVD Cu with those of I-beam Cu and AA in the same conditions. The electromigration experiments were performed with Cu/Al/TiN multilayer. Experimental results shows that the deposition rate and electromigration characteristics of Cu thin film were improved by the Al interlayer.

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