The expression of p120ctn protein in breast cancer is independent of alpha- and beta-catenin and E-cadherin.
Several studies have reported loss or alteration of expression of E-cadherin in breast cancer and more recently changes in levels of expression of the catenins. We used immunofluorescence to examine E-cadherin, alpha-catenin, beta-catenin, and p120ctn (formerly p120CAS) expression in 91 cases of invasive ductal carcinoma. As expected, all four proteins co-localize to the junctional regions of the cells. Although nuclear localization has been described for beta-catenin in colonic polyps, no examples were found in these breast cancer cases. We found that, although alteration is common in the catenins and E-cadherin, complete loss, as exemplified by E-cadherin in lobular carcinoma (where E-cadherin is frequently mutated), is rarely seen. In contrast, the catenin-related protein p120ctn shows an expression pattern that is significantly unrelated to the other catenins (or E-cadherin), including complete loss of expression in approximately 10% of the cases. No statistically significant correlations with traditional prognostic indicators were observed with any of these proteins. We conclude 1) that expression of E-cadherin and alpha- and beta-catenin are generally retained at the membrane although frequently reduced or altered, 2) that complete loss of p120ctn expression is seen in approximately 10% of the cases, and 3) that there is a significant correlation in the expression of E-cadherin and the catenins but no correlation between these molecules and p120ctn, suggesting an absence of coordinate regulation.
Dillon
D A
DA
Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
D'Aquila
T
T
Reynolds
A B
AB
Fearon
E R
ER
Rimm
D L
DL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D015820:Cadherins / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D051177:Catenins; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D015331:Cohort Studies; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D010750:Phosphoproteins / Q000378:metabolism*; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D000095002:Delta Catenin
C495273:CTNNA1 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D051177:Catenins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D010750:Phosphoproteins; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D000095002:Delta Catenin; C000722347:CTNND1 protein, human