• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.959-965
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• 2005

Investigation of structure-activity relationships of novel quinazolines has identified 7,8-dihydro-[1,4]dioxino-[2,3-g]quinazolines as a potent inhibitor of EGFR. These compounds have a benzodioxane framwork, which was prepared by regioselective O-alkylation of ethyl 3,4-dihydroxy benzoate by epoxide ring opening. Compounds 3f and 3k were more potent than ZD-1839 in EGF enzyme and EGFR autophosporylation inhibition assays.

• Tuberculosis and Respiratory Diseases
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• v.75 no.5
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• pp.181-187
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• 2013

The emergence of new therapeutic agents for non-small cell lung cancer (NSCLC) implies that histologic subtyping and molecular predictive testing are now essential for therapeutic decisions. Histologic subtype predicts the efficacy and toxicity of some treatment agents, as do genetic alterations, which can be important predictive factors in treatment selection. Molecular markers, such as epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement, are the best predictors of response to specific tyrosine kinase inhibitor treatment agents. As the majority of patients with NSCLC present with unresectable disease, it is therefore crucial to optimize the use of tissue samples for diagnostic and predictive examinations, particularly for small biopsy and cytology specimens. Therefore, each institution needs to develop a diagnostic approach requiring close communication between the pulmonologist, radiologist, pathologist, and oncologist in order to preserve sufficient biopsy materials for molecular analysis as well as to ensure rapid diagnosis. Currently, personalized medicine in NSCLC is based on the histologic subtype and molecular status. This review summarizes strategies for tissue acquisition, histologic subtyping and molecular analysis for predictive testing in NSCLC.

• Tuberculosis and Respiratory Diseases
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• v.86 no.1
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• pp.14-22
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• 2023

A significant proportion of patients with non-small cell lung cancer (NSCLC) is diagnosed in the early and resectable stage. Despite the use of platinum-based adjuvant chemotherapy, there was only a marginal increase in overall survival and a 15% decrease in relapse. With the advents of immunotherapy and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), the landscape of adjuvant treatment in completely resectable NSCLC is changing. Postoperative radiotherapy can be beneficial to patients who underwent surgical resection in certain clinical settings. In addition, new biomarkers that predict efficacy of EGFR TKI and immunotherapy as adjuvant treatment are also necessary. In this review, recent updates in adjuvant treatment in resectable NSCLC were briefly explained.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.127-134
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• 2014

A great interest is emerging about green tea as a tool against human cancer proliferation or inflammation, as pointed out by recent reports describing the inhibitory action of epigallocatechin gallate (EGCG) on angiogenesis, urokinase, metalloproteinases, and induction of inducible nitric oxide synthase. We proposed that EGCG may regulate a multi target signaling having wider spectra of action than those actions of single enzymes. CSK (c-terminal Src kinase) protein is a non-receptor tyrosine kinase involved in the cross-talk and mediation of many signaling pathways that promote cell proliferation, adhesion, invasion, migration, and tumorigenesis. Based on the knowledge that CSK activation is important for cancer proliferation we hypothesized that CSK could be a target of EGCG. Here we showed that EGCG effectively suppressed the growth of CSK MEF cell when compare with CSK knockout MEF cell growth. These results indicate that EGCG could be used as a chemoprevention to modulate CSK signal pathway in inflammatory processes and tumor formation.

• Nutrition Research and Practice
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• v.17 no.5
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• pp.844-854
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• 2023

BACKGROUND/OBJECTIVES: Fucoidan, a polysaccharide content in brown algae, has been reported to inhibit the growth of cancer cells. The present study aimed to investigate the suppression effects of fucoidan on A549 non-small cell lung cancer cells migration. MATERIALS/METHODS: The anti-migratory activity of fucoidan in A549 cells was examined by wound healing assay and phalloidin-rhodamine staining in response to fucoidan (0-100 ㎍/mL) treatment for 48 h. Western blot analysis was performed to clarify the protein expressions relevant to migratory activity. RESULTS: Fucoidan (25-100 ㎍/mL) significantly suppressed A549 cells migration together with reduced the intensity of phalloidin-rhodamine which detect filopodia and lamellipodia protrusions at 48 h of treatment. The protein expression indicated that fucoidan significantly suppressed the phosphorylation of focal adhesion kinase (FAK), Src, and extracellular signal-related kinase (ERK). In addition, the phosphorylation of p38 in A549 cells was found to be increased. CONCLUSIONS: Our data conclude that fucoidan exhibits anti-migratory activities against lung cancer A549 cells mediated by inhibiting ERK1/2 and FAK-Src pathway.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.336-343
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• 2011

The neurotrophins, required for the survival and differentiation of the nervous system, are known to be important for the development of the reproductive tissues. However, the signals initiating the growth of follicles, gamete development, and transport and the development of zygote in the reproductive system of cows remain ambiguous. The purpose of the present study was to identify the transcripts and proteins of Neurotrophin 4 (NT4) and its receptor tyrosine kinase B (TrkB) in bovine reproductive tissues. The transcripts and immunoreactivity of NT4 and TrkB proteins were detected by reverse transcription polymerase chain reaction and western blot analysis. Using immunohistochemistry, the specific immunoreactivity of NT4 and TrkB were detected in the oocytes of primordial follicles and in the growing primary follicles. The NT4 and TrkB immunoreactivity was predominantly observed in granulosa cells, cumulus granulosa cells, cumulus oocyte complexes, theca cells of mature follicles, as well as in the oviduct epithelial cells, uterine gland cell, and epithelium cells of the uterus during the follicular and luteal phases in cows. Expressions of NT4 and TrkB mRNAs were not significantly different among the ovary, oviduct, and uterus of the follicular phase. For the luteal phase, the expression of NT4 mRNA in the ovary was significantly higher than that in the oviduct and uterus, and the expression of TrkB mRNA in the oviduct was significantly higher than that in the ovary and uterus, as determined by fluorescence quantitative reverse transcription polymerase chain reaction. The expression of NT4 mRNA was significantly higher than that of TrkB mRNA in the ovary and uterus, whereas NT4 mRNA expression was lower than that of TrkB mRNA in the oviduct during the luteal phase. The present study hypothesizes that NT4 participates in the regulation of both gonads and extra-gonadal reproductive tissues in cows.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.211-226
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• 2019

Pig CD45, the leukocyte common antigen, is encoded by the PTPRC gene and CD45 is a T cell-type specific tyrosine phosphatase with alternative splicing of its exons. The CD45 is a coordinated regulator of T cell antigen receptor (TCR) signal transduction achieved by dephosphorylating the phosphotyrosine of its substances, including $CD3{\zeta}$ chain of TCR, Lck, Fyn, and Zap-70 kinase. A dysregulation of CD45 is associated with a multitude of immune disease and has been a target for immuno-drug discovery. To characterize its key structural features with the effects of regulating TCR signaling, this study predicted the unknown structure of pig CD45RO (the smallest isoform) and the complex structure bound to the ITAM (REEpYDV) of $CD3{\zeta}$ chain via homology modeling and docking the peptide, based on the known human CD45 structures. These features were integrated into the structural plasticity of extracellular domains and functional KNRY and PTP signature motifs (the role of a narrow entrance into ITAM binding site) of the tyrosine phosphatase domains in a cytoplasmic region from pig CD45RO. This contributes to the selective recognition of phosphotyrosine from its substrates by adjusting the structural stability and binding affinity of the complex. The characterized features of pigCD45RO can be applied in virtual screening of the T-cell specific immunomodulator.

• Molecules and Cells
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• v.27 no.1
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• pp.39-45
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• 2009

Ligand-dependent or independent oligomerization of receptor protein tyrosine kinase (RPTK) is often an essential step for receptor activation and intracellular signaling. The novel oncogene with kinase-domain (NOK) is a unique RPTK that almost completely lacks an ectodomain, expresses intracellularly and activates constitutively. However, it is unknown whether NOK can form oligomer or what function oligomerization would have. In this study, two NOK deletion mutants were generated by either removing the ectodomain ($NOK{\Delta}ECD$) or including the endodomain (NOK-ICD). Co-immunoprecipitation demonstrated that the transmembrane (TM) domain of NOK was essential for its intermolecular interaction. The results further showed that NOK aggregated more closely as lower order oligomers (the dimer- and trimer-sized) than either deletion mutant did since NOK could be crosslinked by both Sulfo-EGS and formaldehyde, whereas either deletion mutant was only sensitive to Sulfo-EGS. Removing the NOK TM domain (NOK-ICD) not only markedly promoted higher order oligomerization, but also altered the subcellular localization of NOK and dramatically elevated the NOK-mediated constitutive activation of extracellular signal-regulated kinase (ERK). Moreover, NOK-ICD but not NOK or $NOK{\Delta}ECD$ was co-localized with the upstream signaling molecule RAS on cell membrane. Thus, TM-mediated intermolecular contacting may be mainly responsible for the constitutive activation of NOK and contribute to the autoinhibitory effect on RAS/MAPK signaling.

• Genomics & Informatics
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• v.12 no.2
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• pp.58-63
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• 2014

The tyrosine-protein kinase Tec (TEC) is a member of non-receptor tyrosine kinases and has critical roles in cell signaling transmission, calcium mobilization, gene expression, and transformation. TEC is also involved in various immune responses, such as mast cell activation. Therefore, we hypothesized that TEC polymorphisms might be involved in aspirin-exacerbated respiratory disease (AERD) pathogenesis. We genotyped 38 TEC single nucleotide polymorphisms in a total of 592 subjects, which comprised 163 AERD cases and 429 aspirin-tolerant asthma controls. Logistic regression analysis was performed to examine the associations between TEC polymorphisms and the risk of AERD in a Korean population. The results revealed that TEC polymorphisms and major haplotypes were not associated with the risk of AERD. In another regression analysis for the fall rate of forced expiratory volume in 1 second ($FEV_1$) by aspirin provocation, two variations (rs7664091 and rs12500534) and one haplotype (TEC_BL2_ht4) showed nominal associations with $FEV_1$ decline (p=0.03-0.04). However, the association signals were not retained after performing corrections for multiple testing. Despite TEC playing an important role in immune responses, the results from the present study suggest that TEC polymorphisms do not affect AERD susceptibility. Findings from the present study might contribute to the genetic etiology of AERD pathogenesis.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.217-222
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• 2007

In the last 5 years the Epidermal Growth Factor Receptor (EGFR) has emerged as one of the most important targets for drug development in oncology. Monoclonal antibodies targeting the external domain of EGFR have been shown to have clinical benefits in colorectal and head and neck cancer when combined with chemotherapy and/or radiation. Also the targeting of the epithelial growth factor receptor (EGFR) kinase domain using the closely related inhibitors gefitinib and erlotinib has generally been ineffective against solid tumors, many of which over express the receptor. We found that there were some differential expressions according to primary antibodies of the EGFR protein which being used as one of the histological tumor markers for non-small cell lung cancer (NSCLC). We also found that there are some differential expressions according to antibodies, the pH of the antigen retrieval (AR) buffer solutions and kinds of enzymes. There were some differential expressions according to the secondary antibodies and the detection systems. We analyzed the correlations between the immunohistochemical expressions of the EGFR protein and the gene mutations of the EGFR. The differences between automatic stainers and manual staining methods were also evaluated.