• Journal of Gastric Cancer
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• v.16 no.3
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• pp.141-151
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• 2016

Purpose: The aim of the present study was to elucidate the clinicopathological significance and diagnostic accuracy of immunohistochemistry (IHC) for determining the mesenchymal epidermal transition (c-MET) expression in patients with gastric cancer (GC). Materials and Methods: The present meta-analysis investigated the correlation between c-MET expression as determined by IHC and the clinicopathological parameters in 8,395 GC patients from 37 studies that satisfied the eligibility criteria. In addition, a concordance analysis was performed between c-MET expression as determined by IHC and c-MET amplification, and the diagnostic test accuracy was reviewed. Results: The estimated rate of c-MET overexpression was 0.403 (95% confidence interval [CI], 0.327~0.484) and it was significantly correlated with male patients, poor differentiation, lymph node metastasis, higher TNM stage, and human epidermal growth factor receptor 2 (HER2) positivity in IHC analysis. There was a significant correlation between c-MET expression and worse overall survival rate (hazard ratio, 1.588; 95% CI, 1.266~1.992). The concordance rates between c-MET expression and c-MET amplification were 0.967 (95% CI, 0.916~0.987) and 0.270 (95% CI, 0.173~0.395) for cases with non-overexpressed and overexpressed c-MET, respectively. In the diagnostic test accuracy review, the pooled sensitivity and specificity were 0.56 (95% CI, 0.50~0.63) and 0.79 (95% CI, 0.77~0.81), respectively. Conclusions: The c-MET overexpression as determined by IHC was significantly correlated with aggressive tumor behavior and positive IHC status for HER2 in patients with GC. In addition, the c-MET expression status could be useful in the screening of c-MET amplification in patients with GC.

• Korean Journal of Head & Neck Oncology
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• v.21 no.1
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• pp.15-20
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• 2005

Objectives: The hepatocyte growth factor(HGF)/c-Met pathway may play various roles in the carcinogenesis of various organs. Although HGF/c-Met signalling pathway has been shown to demonstrate various cellular responses including mitogenic, proliferative, morphogenic and angiogenic activities, the study on their expression related to clinicopathological parameters in thyroid tumor is relatively rare. So we want to find out the clinical significance of the c-Met in thyroid tumor. Materials and Methods: We assess the mRNA and protein expression of the c-Met genes by means of RT-PCR method and the immunohistochemical stain in 100 cases of thyroid tumors(50 papillary carcinomas, 10 follicular carcinomas, 20 follicular adenomas, 20 nodular hyperplasia). Results: By RT-PCR, c-Met mRNA was detected in 43(86%) in papillary carcinoma, 4(40%) in follicular carcinoma, 4(20%) in follicular adenoma and 2(10%) in nodular hyperplasia cases. By immunohistochemistry, c-Met protein expression was detected in 44(88%), 2(20%), 3(15%) and 1(5%). Expression of the c-Met mRNA and protein expression was significantly highly recognized in papillary carcinoma. The c-Met protein overexpression was significantly correlated with the grade of the differentiation. Conclusion: These results suggest that c-Met expression may be associated with thyroid papillary cancer progression. The differential expression of c-Met protein and mRNA suggests that these molecules may be a reliable diagnostic marker in thyroid papillary cancer.

• Journal of Chest Surgery
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• v.50 no.3
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• pp.153-162
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• 2017

Background: The mesenchymal-epithelial transition factor (MET) receptor can be overexpressed in solid tumors, including small cell lung cancer (SCLC). However, the molecular mechanism regulating MET stability and turnover in SCLC remains undefined. One potential mechanism of MET regulation involves the C-terminus of Hsp70-interacting protein (CHIP), which targets heat shock protein 90-interacting proteins for ubiquitination and proteasomal degradation. In the present study, we investigated the functional effects of CHIP expression on MET regulation and the control of SCLC cell apoptosis and invasion. Methods: To evaluate the expression of CHIP and c-Met, which is a protein that in humans is encoded by the MET gene (the MET proto-oncogene), we examined the expression pattern of c-Met and CHIP in SCLC cell lines by western blotting. To investigate whether CHIP overexpression reduced cell proliferation and invasive activity in SCLC cell lines, we transfected cells with CHIP and performed a cell viability assay and cellular apoptosis assays. Results: We found an inverse relationship between the expression of CHIP and MET in SCLC cell lines (n=5). CHIP destabilized the endogenous MET receptor in SCLC cell lines, indicating an essential role for CHIP in the regulation of MET degradation. In addition, CHIP inhibited MET-dependent pathways, and invasion, cell growth, and apoptosis were reduced by CHIP overexpression in SCLC cell lines. Conclusion: C HIP is capable of regulating SCLC cell apoptosis and invasion by inhibiting MET-mediated cytoskeletal and cell survival pathways in NCI-H69 cells. CHIP suppresses MET-dependent signaling, and regulates MET-mediated SCLC motility.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1010-1017
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• 2007

Two alternative pathways for methionine biosynthesis are known in Corynebacterium glutamicum: one involving transsulfuration (mediated by metB and metC) and the other involving direct sulfhydrylation (mediated by metY). In this study, MetB (cystathionine ${\gamma}-synthase$) and MetY (O-acetylhomoserine sulfhydrylase) from C. glutamicum were purified to homogeneity and the biochemical parameters were compared to assess the functional and evolutionary importance of each pathway. The molecular masses of the native MetB and MetY proteins were measured to be approximately 170 and 280 kDa, respectively, showing that MetB was a homotetramer of 40-kDa subunits and MetY was a homohexamer of 45-kDa subunits. The $K_m$ values for the O-acetylhomoserine catalysis effected by MetB and MetY were 3.9 and 6.4 mM, and the maximum catalysis rates were $7.4\;(k_{cat}=21\;S^{-1})\;and\;6.0\;(k_{cat}=28\;S^{-1})\;{\mu}mol\;mg^{-1}\;min^{-1}$, respectively. This suggests that both MetB and MetY can be comparably active in vivo. Nevertheless, the $K_m$ value for sulfide ions by MetY was 8.6mM, which was too high, considering the physiological condition. Moreover, MetB was active at a broad range of temperatures $(30\;and\;65^{\circ}C)$ and pH (6.5 and 10.0), as compared with MetY, which was active in a range from 30 to $45^{\circ}C$ and at pH values from 7.0 to 8.5. In addition, MetY was inhibited by methionine, but MetB was not. These biochemical data may provide insight on the role of the parallel pathways of methionine biosynthesis in C. glutamicum with regard to cell physiology and evolution.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.216-221
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• 2019

The c-Met protein is a receptor tyrosine kinase involved in cell growth, proliferation, survival, and angiogenesis of several human tumors. Overexpression of c-Met has been found in gastric cancers and correlated with a poor prognosis. Indirubin is the active component of Danggui Longhui Wan, which is a traditional Chinese antileukemic recipe. In the present study, we tested the anti-cancer effects of an indirubin derivative, LDD-1937, on human gastric cancer cells SNU-638. When we performed the in vitro kinase assay against the c-Met activity, LDD-1937 inhibited the activity of c-Met. This result was confirmed by immunoblot and immunofluorescence of phosphorylated c-Met. Immunoblot analysis showed that LDD-1937 decreased the expression of the Erk1/2, STAT3, STAT5, and Akt, downstream proteins of c-Met. In addition, LDD-1937 reduced the cell viability and suppressed colony formation and migration of SNU-638 cells. Furthermore, LDD-1937 induced $G_2/M$ phase arrest in the SNU-638 cells by decreasing the expression levels of cyclin B1 and CDC2. Cleaved-PARP, an apoptosis-related protein, was up-regulated in cells treated with LDD-1937. Overall, this study suggests that LDD-1937 may be a novel small-molecule with therapeutic potential for selectively inhibiting c-Met and c-Met downstream pathways in human gastric cancers overexpressing c-Met.

• Korean Journal of Bronchoesophagology
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• v.16 no.1
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• pp.39-46
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• 2010

Background and Objectives Various tumor markers have been studied in an attempt to evaluate and decide the optimal treatment of the patients with head and neek squamous cell carcinoma (HNSCC). A nuclear antigen Ki-67 is a proliferative marker of tumor cells in all phases of cell cycle except G0. c-met gene, the tyrosine kinase receptor for hepatocyte growth tactor, may play various roles in malignant transformation. The authors evaluated the prognostic significance of Ki-67 and c-Met in surgical specimens of HNSCC to determine the relationship with the various clinicopathological characteristics. Materials and Methods Formatin-fixed paraffin-embedded surgical specimens were obtained from 54 patients with HNSCC. Ki-67 and c-Met expressions were analyzed by immunohistochemical staning and were compared with the clinicopathological characteristics such as, pathologic differentiation, tumor stage, clinical stage and lymph node metastasis. Results Ki-67 and c-Met over-expression was detected in 66.7% and 90.7% in HNSCC. There was positive correlation of increased expression of Ki-67 with tumor stage. and clinical stage, increased expression of e-Met with tumor stage, clinical stage, and nodal status. The expression of c-Met had a significant positive relationship with Ki-67 index (p<0.05). Conclusion Therefore, Ki-67 and c-Met are useful markers of tumor progression, aggressiveness and prognosis in HNSCC.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1186-1190
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• 2008

Single-chain Fv (scFv) antibody against c-Met is expected to be employed in clinical treatment or imaging of cancer cells owing to the important biological roles of c-Met in the proliferation of malignancies. Here, we show that the productivity of scFv against c-Met in Escherichia coli is significantly influenced by the orientation of its variable domains. We generated anti-c-Met scFv antibodies with two different domain orders (i.e., $V_L$-linker-$V_H$ and $V_H$-linker-$V_L$), expressed them in the cytoplasm of E. coli trx/gor deleted mutant, and compared their specific activities as well as their productivities. Productivity of total and functional anti-c-Met scFv with $V_H/V_L$ orientation was more than five times higher than that with $V_L/V_H$ format. Coexpression of DsbC enhanced the yield of soluble amounts of anti-c-Met scFv protein for both constructs. The purified scFv antibodies of the two different formats exhibited almost the same antigen-binding activities. We also compared the productivities and specific activities of anti-c-Met diabodies with $V_H/V_L$ or $V_L/V_H$ formats and obtained similar results to the case of scFv antibodies.

• Korean Journal of Head & Neck Oncology
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• v.27 no.1
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• pp.3-11
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• 2011

Hepatocyte growth factor(HGF) and c-Met play an important role in the control of tumor growth and invasion, and they are known to be good prognostic indicators of patient outcome. Epigallocatechin-3-gallate (EGCG) has been shown to have chemopreventive and therapeutic properties by modulating multiple signal pathways regarding the control of proliferation and invasion of cells. In this study, we evaluated the role of c-Met in EGCG-induced inhibition of invasion and apoptosis in an oral cancer cell line. In KB cells where c-Met was knocked down with siRNA, we performed invasion assay and FACS with Annexin V-FITC/PT staining. In addition, we checked the change of mitochondrial membrane potential(MMP) and the generation of reactive oxygen species(ROS). EGCG-induced inhibition of invasiveness was significantly decreased after the knock-down of c-Met. EGCG-induced apoptosis, MMP change and ROS generation was also reduced in c-Met knock-ed-down KB cells. These results suggest that c-Met is involved in EGCG-induced apoptosis and inhibition of invasiveness of oral cancer cell line.

• Nutrition Research and Practice
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• v.16 no.3
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• pp.392-404
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• 2022

BACKGROUND/OBJECTIVES: Numerous studies have examined the relationship between drinking behaviors and metabolic syndrome (MetS) for adults, but these include very few studies for young adults. This study therefore undertook to investigate the association between drinking behaviors and components of MetS among adult drinkers aged 20-30 years. SUBJECTS/METHODS: Using the 2016-2018 Korea National Health and Nutrition Examination Survey data, drinking behaviors of adults in the age group 20-30 years were divided into 4 groups: 1) group A, good drinking habits; 2) group B, frequent binge drinking but not frequent drinking; 3) group C, frequent drinking but not frequent binge drinking; 4) group D, frequent drinking and binge drinking. The association between MetS components and drinking behaviors was analyzed by applying multiple logistic regression analysis. RESULTS: We determined the prevalence risk compared to group A. In men, the prevalence risk of high triglyceride (TG) increased 2.051-fold in group C and 1.965-fold in group D. Moreover, in group D, the prevalence risk of low high density lipoprotein cholesterol (HDL-C) increased 0.668-fold, high blood pressure (BP) increased 2.147-fold, and MetS increased 1.567-fold. In women, there was an increased prevalence risk of low HDL-C (0.353-fold) and MetS (3.438-fold) in group C, whereas group D showed increased prevalence risk of abdominal obesity (2.959-fold), high TG (1.824-fold, and low HDL-C (0.424-fold). CONCLUSIONS: Our study indicates that frequent drinking increases the risk of high TG, whereas frequent and binge drinking increases the risk of high TG, low HDL-C, high BP, and prevalence of MetS in men. In women, frequent drinking without binge drinking increases the risk of low HDL-C and MetS, whereas frequent and binge drinking increases the risk of abdominal obesity, high TG, and low HDL-C. We propose that improvements in the drinking behaviors can reduce the prevalence of MetS.

• Journal of the Korean Society for information Management
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• v.38 no.4
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• pp.153-171
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• 2021

This study suggested a method of utilizing METS based on DDI metadata to manage, preserve, and service datasets. DDI is a standard for statistical data processing, and there are currently two versions of DDI Codebook (DDI-C) and DDI Lifecycle (DDI-L). In this study, the main elements of DDI-C were mainly used. First the structures and elements of METS and DDI-C were first analyzed. And the mapping of the major elements of METS and DDI-C. The standard was finally taken as METS, the format to express it. Since METS and DDI-C do not show a perfect 1:1 mapping, the DDI-C element that best matches each element of the standard METS was selected. As a result, a new dataset management transmission standard METS using DDI-C metadata elements was designed and presented.