Expression analysis of epithelial cadherin and related proteins in IBH-6 and IBH-4 human breast cancer cell lines.
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 beta-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. In this study expression of E-cadherin and related proteins in IBH-6 and IBH-4 cell lines was evaluated. In IBH-6 and IBH-4 cell extracts, only an 89 kDa E-cadherin form (Ecad89) was detected, which is truncated at the C-terminus and is present at low levels. Moreover, 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. beta-catenin accompanied E-cadherin localization, and actin stress fibers were identified in both cell types. E-cadherin mRNA levels were remarkably low in IBH-6 and IBH-4 cells. The E-cadherin mRNA and genomic sequence encoding exons 14-16 could not be amplified 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. In conclusion, IBH-6 and IBH-4 breast cancer cells show down-regulation of E-cadherin expression with aberrant protein localization, and up-regulation of Twist; these features can be related to their invasive/metastatic characteristics.
Lapyckyj
Lara
L
Instituto de Biología y Medicina Experimental, National Research Council of Argentina (CONICET), C1428ADN Buenos Aires, Argentina.
Castillo
Lilian Fedra
LF
Matos
María Laura
ML
Gabrielli
Nieves María
NM
Lüthy
Isabel Alicia
IA
Vazquez-Levin
Mónica Hebe
MH
D000199:Actins / Q000378:metabolism; D015703:Antigens, CD; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D005091:Exons; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007473:Ion Channels; D008562:Membrane Glycoproteins / Q000378:metabolism; D008840:Microfilament Proteins; D008856:Microscopy, Fluorescence; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D022502:Stress Fibers / Q000378:metabolism; D051879:Twist-Related Protein 1 / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
D000199:Actins; D015703:Antigens, CD; C513384:CDH1 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; C451410:FXYD5 protein, human; D007473:Ion Channels; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; C103173:TWIST1 protein, human; D051879:Twist-Related Protein 1; D051176:beta Catenin