Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Apoptosis or programmed cell death occurs in a wide variety of cell types when adhesion to extracellular matrix (ECM) is denied. Invasion and metastasis by tumor cells involve the loss of normal cell-ECM contacts and require independence from such control mechanisms. We studied whether the immortalized thyroid cell line TAD-2 is a model suitable to investigate thyroid cell-ECM interaction, and we analyzed the role of integrin-fibronectin (FN) interaction in apoptosis. Adhesion, spreading, and cytoskeleton organization in TAD-2 cultured cells were dependent upon integrin-FN interaction. Cell spreading and cytoskeletal organization were coupled to deposition of insoluble FN induced by serum. Expression of integrin-FN receptors was demonstrated by flow cytofluorometry with specific antibodies, and strong integrin-dependent adhesion was demonstrated by attachment assays to immobilized FN. Apoptosis, occurring in different culture conditions, was determined by cell morphology and DNA electrophoretic analysis and quantitated by flow cytometry in propidium iodide-stained cells. Thyroid cells underwent apoptosis in the presence of serum when adhesion was prevented by specific peptides that inhibit integrin binding to FN (RGD-containing peptides) or by coating the culture plates with agar. In serum-free cultures, apoptosis was prevented by insoluble FN immobilized on the plates, but not by soluble FN. These results suggest that the TAD-2 cell line is a good model to study thyroid cell-ECM interaction, that FN, assembled into insoluble matrix, is required for cytoskeletal organization and to prevent thyroid cell apoptosis, and that integrin-mediated adhesion is involved in this process.
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PMID:Fibronectin is required to prevent thyroid cell apoptosis through an integrin-mediated adhesion mechanism. 976 83

Adhesion of tumor cells to the extracellular matrix (ECM) is a crucial step for the development of metastatic disease and is mediated by specific integrin receptor molecules (IRM). The pattern of metastatic spread differs substantially among the various histotypes of thyroid cancer (TC). However, IRM have only occasionally been characterized in TC until now. IRM expression was investigated in 10 differentiated (FTC133, 236, 238, HTC, HTC TSHr, XTC, PTC4.0/4.2, TPC1, Kat5) and two anaplastic TC cell lines (ATC, C643, Hth74), primary cultures of normal thyroid tissue (Thy1,3), and thyroid cancer specimens (TCS). Expression of 16 IRM (beta1-4, beta7, alpha1-6, alphaV, alphaIIb, alphaL, alphaM, alphaX) and of four IRM heterodimers (alpha2beta1, alpha5beta1, alphaVbeta3, alphaVbeta5), was analyzed by fluorescent-activated cell sorter (FACS) and immunohistochemical staining. Thyroid tumor cell adhesion to ECM proteins and their IRM expression in response to thyrotropin (TSH) was assessed. Follicular TC cell lines presented high levels of integrins alpha2, alpha3, alpha5, beta1, beta3 and low levels of alpha1, whereas papillary lines expressed a heterogenous pattern of IRM, dominated by alpha5 and beta1. ATC mainly displayed integrins alpha2, alpha3, alpha5, alpha6, beta1 and low levels of alpha1, alpha4 and alphaV. Integrin heterodimers correlated with monomer expression. Evaluation of TCS largely confirmed these results with few exceptions, namely alpha4, alpha6, and beta3. The ability of TC cell lines to adhere to purified ECM proteins correlated with IRM expression. TSH induced TC cell adhesion in a dose-dependent fashion, despite an unchanged array of IRM expression or level of a particular IRM. Thyroid carcinoma cell lines of different histogenetic background display profoundly different patterns of IRM expression that appear to correlate with tumor aggressiveness. In vitro adhesion to ECM proteins and IRM expression concur. Finally, TSH-stimulated adhesion of thyroid tumor cell lines to ECM may not be associated with altered IRM expression.
Thyroid 2005 Sep
PMID:Differential pattern of integrin receptor expression in differentiated and anaplastic thyroid cancer cell lines. 1618 9