Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:B0FTZ7 (catenin)
 18,795 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic characteristics of scirrhous gastric carcinomas are overviewed. Scirrhous carcinomas of the stomach frequently show amplification of c-met and K-sam oncogenes as well as overexpression of 6.0 kb c-met abnormal transcript. For the formation of productive fibrosis and the diffuse infiltrative growth pattern of this malignancy, the essential factors would be not only the loss of cell adhesion molecule function through depressed expression or loss of cadherin or catenin, but also the synchronous overexpression of growth factors from the cancer cells including TGF-beta, PDGF, IGF-II and basic FGF with intimate cancer-stromal interaction through paracrine loop of IL-1 alpha/HGF system.
 ...
PMID:[Genetic characteristics of scirrhous gastric carcinomas]. 794 79

At least three proteins (alpha, beta, and gamma catenin) comprise the cytoplasmic domain of the cadherin cell-cell adhesion complex. We have cloned and sequenced human epithelial alpha(E)-catenin and have identified two distinct transcripts, designated alpha 1- and alpha 2-. The human alpha 1(E)-catenin transcript predicts a 907 aa sequence 97% identical to mouse alpha-catenin. The second transcript, alpha 2(E)-catenin, displays a 24 amino acid insertion after codon 812, yielding a 931 amino acid protein (GenBank #L23805). Analysis by RT-PCR and Northern blotting detects one or both transcripts in epithelial and non-epithelial tissues. Southern blotting indicates that both arise from a single gene. The alternative transcription site in alpha-catenin is analogous to the splice site in vinculin that creates met alpha-vinculin, extending the homology between alpha-catenin and vinculin. These data with the reported structure of other catenin genes suggest that vinculin and alpha-catenin generate a superfamily of proteins mediating membrane-cytoskeletal associations.
 ...
PMID:Molecular cloning reveals alternative splice forms of human alpha(E)-catenin. 794 18

Cadherin cell adhesion molecules play an essential role in creating tight intercellular association and are considered to work as an invasion suppressor system of cancer cells. They form a molecular complex with catenins, a group of cytoplasmic proteins including alpha- and beta-catenins. While alpha-catenin has been demonstrated to be crucial for cadherin function, the role of beta-catenin is not yet fully understood. In this study, we analyzed the cadherin-catenin system in two human cell lines, HSC-39 and its putative subline HSC-40A, derived from a signet ring cell carcinoma of stomach. These cells grow as loose aggregates or single cells, suggesting that their cadherin system is not functional. In these cell lines, an identical 321-base pair in-frame mRNA deletion of beta-catenin was identified; this led to a 107-amino-acid deletion in the NH2-terminal region of the protein. Southern blot analysis disclosed a homozygous deletion in part of the beta-catenin gene. On the other hand, these cells expressed E-cadherin, alpha-catenin, and plakoglobin of normal size. Immunoprecipitation analyses showed that E-cadherin was coprecipitated with the mutated beta-catenin but not with alpha-catenin, and antibodies against beta-catenin did not copurify alpha-catenin. However, the recombinant fusion protein containing wild-type beta-catenin precipitated alpha-catenin from these cells. These results suggest that the dysfunction of E-cadherin in these cell lines is due primarily to its failure to interact with alpha-catenin, and that this defect results from the mutation in beta-catenin. Thus, it is most likely that the association between E-cadherin and alpha-catenin is mediated by beta-catenin, and that this process is blocked by NH2-terminal deletion in beta-catenin. These findings indicate that genetic abnormality of beta-catenin is one of the mechanisms responsible for loosening of cell-cell contact, and may be involved in enhancement of tumor invasion in human cancers.
 ...
PMID:A truncated beta-catenin disrupts the interaction between E-cadherin and alpha-catenin: a cause of loss of intercellular adhesiveness in human cancer cell lines. 795 78

Catenins mediate the linkage of classical cadherins with actin microfilaments and are part of a higher order protein structure by which cadherins are connected to other cytoplasmic and transmembrane proteins. The ratio of actin-bound to free cadherin-catenin complex, which varies depending on the type and growth rate of cells, is thought to be altered by cellular signals, such as those associated with mitosis, polarization of cells and growth factors during development. EGF induces an immediate tyrosine phosphorylation of beta-catenin and gamma-catenin (plakoglobin). We show here an association of the EGF-receptor with the cadherin-catenin complex. Using recombinant proteins we demonstrate the interaction of EGF-receptor and beta-catenin in in vitro kinase assays. This interaction is mediated by the evolutionarily conserved central "core" region of beta-catenin. These results suggest that catenins represent an important link between EGF-induced signal transduction and cadherin function.
 ...
PMID:Beta-catenin mediates the interaction of the cadherin-catenin complex with epidermal growth factor receptor. 796 96

alpha-Catenins are a group of proteins associated with cadherin cell-cell adhesion molecules, and play indispensable roles in the function of the cadherins. alpha N-catenin, a subtype, was identified as a protein associated with N-cadherin. In this study, we investigated the expression pattern of alpha N-catenin in early chicken embryos, and compared it with that of N-cadherin. alpha N-catenin was first detected in the closed somites and neural tube, and, at later stages, in many other tissues including the central nervous system (CNS), skeletal muscles, various regions of the overlying ectoderm, and some endodermal layers. In the CNS and skeletal muscles, both alpha N-catenin and N-cadherin were strongly expressed, and their distribution patterns were similar. However, in some parts of the ectoderm and endoderm, only alpha N-catenin was expressed. On the other hand, various mesenchymal tissues and peripheral nerves strongly expressed N-cadherin, but their alpha N-catenin expression was, in general, weak. Thus, the expression of these two proteins did not always correlate with each other. These results suggest that cells use different combinations of a cadherin and an alpha-catenin in a tissue-specific manner.
 ...
PMID:Differential expression of alpha N-catenin and N-cadherin during early development of chicken embryos. 798 Oct 48

Catenins are peripheral cytoplasmic proteins originally identified in association with the mouse epithelial cell adhesion molecule E-cadherin. Molecular cloning and primary structure analysis demonstrated that alpha-catenin is homologous to vinculin and the beta-catenin is homologous to human plakoglobin and the Drosophila gene product armadillo. With the use of peptide-specific anti plakoglobin antibodies were confirm here that plakoglobin is a component of the cadherin-catenin complex and that it is most likely identical to gamma-catenin. We show that plakoglobin binds directly to E-cadherin. We consolidate the biochemical evidence for the existence of two distinct and separable E-cadherin-catenin complexes in the same cell. One complex is composed of E-cadherin, alpha- and beta-catenin, the other of E-cadherin, alpha-catenin and plakoglobin. A similar distinct association with catenins is also found for other cadherins. Comparison of different cell lines revealed that the relative amounts of the two complexes vary depending on cell types.
 ...
PMID:Distinct cadherin-catenin complexes in Ca(2+)-dependent cell-cell adhesion. 798

Phosphorylation of beta-catenin, an intracytoplasmic cadherin-binding protein, causes disruption of the cadherin-mediated cell adhesion system in cancer cells. A 185-kDa phosphorylated protein, identified as the c-erbB-2 gene product, was co-immunoprecipitated with the E-cadherin-catenin complex. Association of the c-erbB-2 gene product with the cadherin-catenin complex was proven to be mediated through beta-catenin and plakoglobin using an in vitro protein-protein precipitation system. These results indicate that the c-erbB-2 gene product associates with catenins and may regulate the cell adhesion and invasive growth of cancer.
 ...
PMID:c-erbB-2 gene product associates with catenins in human cancer cells. 799 5

Because the cell adhesion molecule epithelial cadherin (E-cadherin) is absent in many invasive carcinomas, we transfected the E-cadherin gene into E-cadherin-negative, invasive breast cancer cell lines BT549 and HS578t to investigate the role of E-cadherin in invasive behavior. Although the transfected E-cadherin could mediate calcium-dependent aggregation to E-cadherin-transfected L-cells, morphology and invasiveness of the breast cancer cells were not altered. We investigated the strength of the linkage of the transfected E-cadherin to the actin cytoskeleton by examining the Triton X-100 solubility of the transfected E-cadherin. In BT549 and HS578t cells, a large proportion of the transfected E-cadherin was Triton soluble, whereas in E-cadherin-positive MCF-7 cells, Triton-insoluble E-cadherin was apparent at cell-cell borders. Interaction of E-cadherin with the actin cytoskeleton is thought to be mediated by the E-cadherin-binding proteins alpha-catenin, beta-catenin, and plakoglobin. We found normal levels of alpha-catenin and beta-catenin in BT549 and HS578t cells; however, low levels of plakoglobin were expressed in these cells compared to those found in weakly invasive MCF-7 cells. Furthermore, levels of tyrosine phosphorylation of beta-catenin were elevated in E-cadherin-transfected BT549 and HS578t cells compared to MCF-7 cells. We conclude that other factors such as the expression and appropriate posttranslational modification of cadherin-associated proteins must be in place for E-cadherin to be fully functional, i.e., to alter invasiveness. During cancer progression, loss of E-cadherin expression itself or multiple other mechanisms that lead to loss of cell-cell adhesion (mutation, loss of catenin expression, alterations in phosphorylation) may contribute to a more metastatic phenotype.
 ...
PMID:Alterations in beta-catenin phosphorylation and plakoglobin expression in human breast cancer cells. 801 79

During cleavage, the mouse embryo expresses a variety of cell adhesion systems on its cell surfaces. We have reviewed biogenetic and assembly criteria for the formation of the uvomorulin/catenin, tight junction and desmosome adhesion systems as the trophectoderm differentiates. Each system reveals different mechanisms regulating molecular maturation. Adhesion processes contribute to the generation of distinct tissues in the blastocyst by modifying the expression pattern of blastomeres entering the non-epithelial inner cell mass lineage. Cell adhesion also influences the spatial organisation, but rarely the timing of expression, of proteins involved in trophectoderm differentiation.
 ...
PMID:Molecular maturation of cell adhesion systems during mouse early development. 802 78

Invasion is the cause of cancer malignancy. Invasion leads to metastasis and metastases turn cancer into an incurable disease. The only model of "true" invasion and metastasis is the natural human or animal tumor. Nevertheless, experimental models have largely contributed to the development of new concepts such as the multistep invasion process of metastasis, the growth-separate-from-invasion concept and the transient expression of the invasive phenotype by a subpopulation of cancer cells. All these aspects of invasion are considered within micro-ecosystems that are initiated by the cancer cells but in which host cells may play an equally important role. It is our opinion that invasion is regulated by the balance between the activation and inactivation of two sets of genes, invasion-promoter and invasion-suppressor genes. These genes encode molecules that determine the expression of the invasive and the noninvasive (normal) phenotype. E-cadherin is an invasion-suppressor gene product that belongs to the calcium-dependent homophilic cell-cell adhesion molecules. This transmembrane glycoprotein is involved not only in the mechanics of adhesion but also serves as a signal-transducer via its linkage with the catenins and the actin cytoskeleton. In human and in experimental cancers disturbance of the cadherin-catenin complex have been found at multiple levels. Candidate invasion-promoter molecules may be found among lytic enzymes and their associated molecules, motility factors and heterotypic cell-cell adhesion molecules. Investigation of the cellular interactions within the micro-ecosystem of bone metastasis has lead to the treatment of bone metastases with bisphosphonates. This application demonstrates the potential clinical benefit of a better understanding of the cellular and molecular mechanisms of cancer invasion and metastasis.
 ...
PMID:[When and why does cancer metastasize? An overview of current viewpoints OF the molecular mechanism of invasiveness]. 804 67


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>