IBYME   02675
INSTITUTO DE BIOLOGIA Y MEDICINA EXPERIMENTAL
Unidad Ejecutora - UE
artículos
Título:
Expression analysis of Epithelial Cadherin and related Proteins in IBH-6 and IBH-4 Human Breast Cancer Cell Lines
Autor/es:
LAPYCKYJ, L.; CASTILLO, L.F.; MATOS, M.L.; GABRIELLI, N.M.; LUTHY, I.A.; VAZQUEZ LEVIN, M.H.
Revista:
JOURNAL OF CELLULAR PHYSIOLOGY
Editorial:
Wiley Interscience
Referencias:
Año: 2009
ISSN:
0021-9541
Resumen:
Introduction: Epithelial cadherin (E-cadherin) is a 120 KDa cell-cell adhesion molecule involved in the establishment of epithelial adherens junctions. It is connected to the actin cytoskeleton by adaptor proteins such as β-catenin. Loss of E-cadherin expression/function has been related to tumor progression and metastasis. Several molecules associated with down-regulation of E-cadherin have been described, within them neural cadherin, Twist and dysadherin. Human breast cancer cell lines IBH-6 and IBH-4 were developed from ductal primary tumors and show characteristic features of malignant epithelial cells. This study was undertaken to evaluate the expression of E-cadherin and related proteins in IBH-6 and IBH-4 cell lines. Methods: E-cadherin, β-catenin and F-actin were localized in cells using fluorescent confocal microscopy, and protein forms were identified by Western immunoblotting. Evauation of E-cadherin mRNA was done by PCR analysis. Expression of neural cadherin, dysadherin and Twist was also evaluated in these cells. Unless specified, MCF-7 cells served as control.Results: In IBH-6 and IBH-4 cell extracts, only an 89 KDa E-cadherin protein form (Ecad89) was detected, which is truncated at the C-terminus and is present in significantly lower levels (<30%) than those of the full length 120 KDa E-cadherin found in MCF-7 cells. In IBH-6 and IBH-4 cells, no accumulation of the 86 KDa E-cadherin ectodomain and of the 38 KDa CTF1 fragment was observed. IBH-6 and IBH-4 cells showed an intracellular scattered E-cadherin localization pattern that contrasted with protein detection in the membranes of MCF-7 cells. β-catenin accompanied E-cadherin localization, and actin stress fibers were identified in both IBH-6 and IBH-4 cells. E-cadherin mRNA levels were remarkably low in IBH-6 and IBH-4 cells, about 1000 times less than in MCF-7. The E-cadherin mRNA sequence encoding exons 14 to 16 could not be amplified by nested RT-PCR in either cell line. Neither the mRNA nor the protein of neural cadherin and dysadherin were detected. Up-regulation of Twist mRNA was found in both cell lines. Conclusions: IBH-6 and IBH-4 breast cancer cells show down-regulation of E-cadherin, with an aberrant protein cellular localization and up-regulation of Twist; these features can be related to their invasive and/or metastatic characteristics.