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Query: UMLS:C0242379 (lung cancer)
 71,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A human lung cancer cell line, PC 9, was analyzed to elucidate the molecular mechanisms of dysfunction of cadherin-mediated cell-cell adhesion in cancer. Although PC 9 cells strongly expressed E-cadherin at the cell membrane, which was indistinguishable immunochemically from functional E-cadherin, they did not show tight cell-cell adhesion and had reduced E-cadherin-mediated aggregation activity. Immunoprecipitation with E-cadherin and Western blot analysis revealed that PC 9 cells did not express alpha-catenin, a cadherin-associated protein, suggesting that this was the cause of the cadherin dysfunction in the cell line. In addition, Northern and Southern blot analyses disclosed homozygous deletion of part of the alpha-catenin gene, which might have resulted in the loss of alpha-catenin expression in PC 9 cells.
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PMID:Cadherin dysfunction in a human cancer cell line: possible involvement of loss of alpha-catenin expression in reduced cell-cell adhesiveness. 139 1

beta-Catenin has emerged as an important component of the adherens junctions between epithelial cells. As a result of studies of its interaction with the APC gene product, it has been implicated in the development of colorectal cancer. alpha-Catenin, beta-catenin, E-cadherin and APC appear to mediate contact inhibition in epithelia. As part of the study of the organization of the beta-catenin gene, we have isolated yeast artificial chromosomes (YACs) to characterize its intron/exon structure. YAC fluorescence in situ hybridization analysis and polymerase chain reaction analysis of somatic cell hybrid DNAs show that beta-catenin maps in the 3p21-22 region, the location of tumour-suppressor genes deleted in small-cell lung cancer (SCLC) and other disorders. beta-Catenin YACs will provide a source of microsatellite markers useful in loss of heterozygosity studies to assess the importance of beta-catenin deletions in SCLC.
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PMID:Yeast artificial chromosome cloning of the beta-catenin locus on human chromosome 3p21-22. 778 Jun 64

One crucial step in tumor metastasis is detachment of cells from the primary lesion. This involves down-regulation of homophilic binding intercellular adhesion molecules. To determine whether this occurs in metastasis of human small-cell lung cancer to lymph nodes, we examined expression of E-cadherin, carcinoembryonic antigen (CEA), and neural cell adhesion molecule (NACM) on cells from patients with small-cell lung cancer, some cells were obtained from primary lesions and others from lymph-node metastases. Cells in all of the five lines from primary lesions expressed E-cadherin, unlike those in all of the five lines from lymph-node metastases. Cells in all of the five lines from primary lesions expressed CEA, as did those in only one of the five cell lines from lymph-node metastases. Cells in lines from primary and metastatic lesions did not differ in the expression of NCAM (4/5 positive). Expression of E-cadherin and of CEA were closely correlated. Because E-cadherin and CEA are involved in the binding of epithelial cells, these findings demonstrate that metastasis of small-cell lung cancer to lymph nodes is associated with a lack of the epithelial intercellular adhesion molecules E-cadherin and CEA. The expression of these molecules is involved in the metastasis of small-cell lung cancer to lymph nodes.
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PMID:[Difference in expression of epithelial adhesion molecules between primary and metastatic lesions in small-cell lung cancer]. 895

The E-cadherin-mediated cell adhesion system acts as an "invasion suppressor" system, which is widely considered to be inactivated when the expression of E-cadherin is reduced and/or heterogeneous. To further investigate the molecular mechanisms responsible for dysfunction of this system in cancers, we examined human carcinoma cell lines lacking tight cell-cell adhesion. In KATO-III, established from stomach cancer, a point mutation of the E-cadherin gene resulted in a mRNA splicing error and markedly reduced E-cadherin expression. In another stomach cancer cell line, MKN 45, an 18-bp deletion of the E-cadherin gene caused a mRNA splicing error and a 4-amino-acid deletion, which was considered to alter the conformation around the key Ca(2+)-binding motif. In these two cell lines, the wild-type allele of the E-cadherin locus, which was assigned to chromosome 16q, was lost. Also in vivo, we found mutation of E-cadherin in breast cancers, where allele loss on chromosome 16 has frequently been reported. Thus, dysfunction of E-cadherin could be caused by a combination of the loss of one allele and a mutation in the remaining allele. Homologous deletion of part of the alpha-catenin gene, resulting in markedly reduced expression, was observed in a human lung cancer cell line, PC9. Recently, we also found mutations of beta-catenin in human carcinoma cell lines. These findings indicate the possible involvement of genetic abnormalities of various components in inactivation of the E-cadherin-mediated "invasion suppressor system" in cancers.
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PMID:Alterations of the cadherin-catenin cell adhesion system in cancers. 898 63

Desmosomes are key structures in cell-cell adhesion. In this study we examined the effect of n-6 essential fatty acids on the expression of desmoglein (Dsg), desmosomal cadherin and the formation of desmosomes in E-cadherin negative human breast, colon and lung cancer cells and melanoma cells. Electron microscopy revealed that cells cultured with gamma linolenic acid (GLA) showed increased cell-cell adhesion together with an increase in the formation of desmoglein-containing desmosomes. Western blotting studies of cellular proteins demonstrated that, following culture with fatty acids, Dsg expression was modified, with the greatest increase seen after GLA treatment. Other fatty acids increased Dsg expression, but to a lesser extent. It is concluded that GLA regulates desmosome-mediated cell-cell adhesion in human cancer cells, particularly in cells without E-cadherin.
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PMID:Regulation of desmosomal cell adhesion in human tumour cells by polyunsaturated fatty acids. 934 43

We used immunohistochemical staining to examine the expression of the gap junction proteins connexin32 and connexin43 and of the intercellular adhesion molecule, E-cadherin, that is thought to be a prerequisite for gap junctional intercellular communication (GJIC), in 24 specimens of human lung cancer. Connexin32 was not found in cancer tissue and there were significantly fewer spots of connexin43 in the poorly differentiated versus the well differentiated (P = 0.0005) and moderately differentiated (P = 0.0002) adenocarcinomas and in the poorly differentiated versus the well differentiated (P = 0.0182) and moderately differentiated (P = 0.004) squamous cell carcinomas of the lung. E-Cadherin was expressed in all but three cases of poorly differentiated non-small cell lung cancer that showed a heterogeneously decreased expression of E-cadherin. These findings suggest that GJIC is decreased in poorly differentiated non-small cell lung cancer.
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PMID:Expression of connexin32 and connexin43 gap junction proteins and E-cadherin in human lung cancer. 961 73

Cadherins are transmembrane cell adhesion molecules (CAMS) that mediate cell-cell interactions and are important for maintenance of epithelial cell integrity. This function is dependent on an indirect interaction between the cytoplasmic domain of the cadherin molecule with three cytoplasmic proteins known as alpha-, beta-, and gamma-catenin (-cat). Growing evidence suggests that alterations in cadherin or catenin expression or function may be important to the development of an invasive or metastatic phenotype. Immunohistochemical techniques were used to study the expression of the two major epithelial cadherins, E-cadherin (E-cad) and P-cadherin (P-cad) as well as alpha- and gamma-cat in normal bronchial epithelium and in a series of carefully TMN-staged pulmonary adenocarcinomas (n = 21) and squamous cell carcinomas (n = 7). The cadherin profile of normal pseudostratified bronchial epithelium was heterogeneous. Basilar cells strongly expressed P-cad, alpha- and gamma-cat, while columnar cells moderately expressed E-cad, alpha- and gamma-cat. In contrast to other epithelial tumors, E-cad on non-small cell lung carcinomas was actually upregulated, however, a decrease in P-cad expression was noted in 68%. At least one cadherin or catenin was downregulated, compared to normal bronchial epithelium, in 82% of tumors examined. With the exception of an association between loss of P-cad expression and poorly differentiated state, changes in cadherin and catenin expression levels were not significantly correlated to tumor stage, cell type, or nodal status. These findings illustrate that alteration of expression of cadherins and catenins are often found in non-small cell lung carcinoma when compared to the progenitor bronchial epithelium, and may play a role in the development of the malignant phenotype.
Lung Cancer 1999 Jun
PMID:Cadherin and catenin expression in normal human bronchial epithelium and non-small cell lung cancer. 1046 3

Because routine histopathological examination of primary non-small cell lung cancer does not predict disease outcome, we correlated disease outcome with the expression level of multiple genes that regulate distinct steps of the metastatic process in 60 formalin-fixed, paraffin-embedded, archival specimens of stage I lung carcinoma from patients undergoing curative surgery at the M. D. Anderson Cancer Center. The expression of E-cadherin (related to cell cohesion), type IV collagenase [matrix metalloproteinase (MMP)-2 and MMP-9, related to invasion], and three angiogenic molecules, basic fibroblast growth factor, vascular endothelial growth factor/vascular permeability factor, and interleukin 8, were examined by a colorimetric in situ mRNA hybridization technique. The expression levels of the individual genes analyzed by a Cox univariate analysis were not prognostic. In contrast, the ratio between expression of type IV collagenases (mean of the expression of MMP-2 and MMP-9) and E-cadherin, the MMP:E-cadherin ratio (measured at the periphery of each tumor), was significantly higher in patients with recurrent disease than in patients who remained disease free (P = 0.00003). Longer overall survival and reduced disease recurrence rates were significantly associated with a lower MMP:E-cadherin ratio (<2) by a Kaplan-Meier survival analysis (P = 0.0002 and P = 0.0001, respectively). Multiple covariate analyses of overall and disease-free survival also concluded that the MMP:E-cadherin ratio was a significant prognostic factor when corrected for age (P = 0.0001). Determination of this gene expression ratio in individual human lung cancers might therefore be used to direct tailored treatment for individual patients with resectable lung cancer.
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PMID:Differential expression of E-cadherin and type IV collagenase genes predicts outcome in patients with stage I non-small cell lung carcinoma. 1074 98

S100A4 has been implicated in the malignant phenotype of tumor cells, including cell motility, but the biological function is hardly known. A recent study suggests that S100A4-induced invasiveness in malignant tumor cells is partially caused by down-regulation of E-cadherin. To clarify the clinical significance of S100A4 and its association with E-cadherin-mediated cell-to-cell adhesion system, we examined their protein expressions in non-small cell lung cancer (NSCLC) specimens using immunohistochemical techniques. Expression of S100A4 was observed in 81 (60%) of 135 NSCLCs and correlated with progression of the pathological T factor (p<0.001), lymph node metastasis (p<0.005), and poor survival (p<0.05). Reduced expression of E-cadherin, alpha-catenin, and beta-catenin was observed in 64% (87 of 135), 50% (43 of 86), and 58% (50 of 86) of the specimens tested, respectively. The expression of E-cadherin closely correlated with differentiation and inversely with that of S100A4. Among these adhesion-associated molecules we found that alpha-catenin appeared to reflect most strikingly the presence of lymph node metastasis and the short survival periods of NSCLC patients. Furthermore, patients who showed S100A4-positive/alpha-catenin-negative expression had a significantly shorter survival than the patients with S100A4-negative/alpha-catenin-positive expression. These results indicate that S100A4, as well as alpha-catenin, plays a role in the progression and metastasis of NSCLCs and that simultaneous immunohistochemical detection of their expression may be useful to define a subpopulation of lung cancer patients with a possible poor prognosis.
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PMID:Clinical significance of S100A4 and E-cadherin-related adhesion molecules in non-small cell lung cancer. 1081 84

E-cadherin is a cell surface molecule that mediates cell-cell adhesion in normal epithelium. Disabled or aberrant E-cadherin expression increases cell motility and promotes the transition of well-differentiated adenoma to invasive carcinoma. To evaluate whether E-cadherin could serve as a biomarker of squamous cell differentiation, we analyzed its expression by immunohistochemistry in formalin-fixed, paraffin-embedded tissue sections of 7 head and neck cancer patients, 19 lung cancer patients, 73 esophageal cancer patients, 19 skin cancer patients, and 18 cervical cancer patients. E-cadherin was expressed at very high levels (93%-100%) in adjacent or distant normal squamous epithelia. Likewise, most (75-100%) well-differentiated squamous cell carcinomas (SCCs) also expressed E-cadherin. In contrast, poorly differentiated SCCs expressed less than 40% of E-cadherin. Furthermore, immunohistochemical analysis showed that the differentiation-inducing agent, all-trans retinoic acid, can up-regulate E-cadherin expression in esophageal SCC cells in vitro. Our data demonstrated that E-cadherin expression is associated with SCC differentiation and that may serve as a squamous cell differentiation marker.
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PMID:Expression of E-cadherin is associated with squamous differentiation in squamous cell carcinomas. 1092 48


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