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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 21
pubmed:dateCreated
2002-10-1
pubmed:abstractText
Within epithelial tissue, cells are held together by specialized lateral junctions. At particular stages of development and in pathological processes such as metastasis, cells break down the intercellular junctions, separate from the epithelial sheet and migrate individually. Despite the importance of these processes, little is understood about the regulatory mechanisms of active cell separation. In view of the effects of insulin-like growth factor I (IGF-I) on mammary gland development and cancer, we developed a model using MCF-7 human breast cancer cells in which the process of cell separation can be induced by IGF-I. The separation was enhanced in MCF-7 cells overexpressing the IGF-IR and blocked in the cells expressing a dead-kinase mutant of this receptor. Activation of the IGF-IR resulted in a rapid formation of motile actin microspikes at the regions of cell-cell contacts, disorganization of mature adherens junctions and the onset of cell migration. In cell separation, the signaling between the IGF-IR kinase and actin required phosphatidylinositol 3 (PI 3)-kinase-generated phospholipids but not MAP kinases and was mediated by alpha-actinin. The activity of MEK1/2 kinases was needed for consecutive cell migration. This work also defined a new function for alpha-actinin. Upon IGF-IR activation, green fluorescence protein (GFP)-labeled alpha-actinin concentrated at the base of actin microspikes. Deletion of the N-terminal actin-binding domain of alpha-actinin prevented this redistribution, indicating that this domain is necessary. Detection of the C-terminal tail of alpha-actinin reduced the number of microspikes, showing that alpha-actinin has a role in the development of microspikes and is not passively reorganized with filamentous actin. We suggest that the signaling pathway from the IGF-IR kinase through the PI-3 kinase to alpha-actinin participates in the rapid organization of actin into microspikes at the cell-cell junctions and leads to active cell separation, whereas signaling through ERK1/2 MAP kinases controls cell migration following cell separation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Actinin, http://linkedlifedata.com/resource/pubmed/chemical/Actins, http://linkedlifedata.com/resource/pubmed/chemical/Green Fluorescent Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Insulin-Like Growth Factor I, http://linkedlifedata.com/resource/pubmed/chemical/Luminescent Proteins, http://linkedlifedata.com/resource/pubmed/chemical/MAP Kinase Kinase 1, http://linkedlifedata.com/resource/pubmed/chemical/MAP2K1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase..., http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Protein-Serine-Threonine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Receptor, IGF Type 1, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
115
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4149-65
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:12356918-Actinin, pubmed-meshheading:12356918-Actins, pubmed-meshheading:12356918-Breast Neoplasms, pubmed-meshheading:12356918-Carcinoma, pubmed-meshheading:12356918-Cell Adhesion, pubmed-meshheading:12356918-Cell Communication, pubmed-meshheading:12356918-Cell Movement, pubmed-meshheading:12356918-Epithelial Cells, pubmed-meshheading:12356918-Female, pubmed-meshheading:12356918-Green Fluorescent Proteins, pubmed-meshheading:12356918-Humans, pubmed-meshheading:12356918-Insulin-Like Growth Factor I, pubmed-meshheading:12356918-Intercellular Junctions, pubmed-meshheading:12356918-Luminescent Proteins, pubmed-meshheading:12356918-MAP Kinase Kinase 1, pubmed-meshheading:12356918-Microscopy, Electron, pubmed-meshheading:12356918-Mitogen-Activated Protein Kinase Kinases, pubmed-meshheading:12356918-Neoplasm Metastasis, pubmed-meshheading:12356918-Phosphatidylinositol 3-Kinases, pubmed-meshheading:12356918-Protein Structure, Tertiary, pubmed-meshheading:12356918-Protein-Serine-Threonine Kinases, pubmed-meshheading:12356918-Pseudopodia, pubmed-meshheading:12356918-Receptor, IGF Type 1, pubmed-meshheading:12356918-Recombinant Fusion Proteins, pubmed-meshheading:12356918-Signal Transduction, pubmed-meshheading:12356918-Tumor Cells, Cultured
pubmed:year
2002
pubmed:articleTitle
Functional role of alpha-actinin, PI 3-kinase and MEK1/2 in insulin-like growth factor I receptor kinase regulated motility of human breast carcinoma cells.
pubmed:affiliation
Department of Microbiology, University of Pennsylvania, 3610 Hamilton Walk, 211 Johnson Pavilion, Philadelphia PA 19104, USA. guvakova@mail.med.upenn.edu
pubmed:publicationType
Journal Article