Comparative analysis of the expression of ERBIN and Erb-B2 in normal human skin and cutaneous carcinomas.
BACKGROUND
ERBIN is a binding partner of Erb-B2, an orphan receptor within the Erb-B family critically involved in the regulation of cell growth and differentiation. Although its function remains unclear, ERBIN is thought to affect the polarity of epithelial cells and cell growth via the Ras signalling pathway.


OBJECTIVE
To examine and compare the tissue distribution and the expression levels of ERBIN and Erb-B2 in normal skin and in cutaneous carcinomas.


METHODS
Fifteen cases of basal cell carcinoma (BCC), 12 cases of squamous cell carcinoma (SCC) and five cases of keratoacanthoma (KA) were analysed by immunohistochemistry on paraffin-embedded sections using anti-ERBIN and anti-Erb-B2 antibodies.


RESULTS
ERBIN and Erb-B2 had a similar distribution in normal human skin. They were primarily localized at the plasma membrane in differentiated keratinocytes and in duct cells from eccrine glands, whereas they were localized diffusely in the cytoplasma of basal keratinocytes. In both SCC and KA the subcellular distribution of ERBIN and Erb-B2 remained unchanged, whereas both proteins were redistributed from the plasma membrane into cytosolic aggregates in BCC.


CONCLUSIONS
The subcellular localization of ERBIN in normal human skin is similar to that of Erb-B2 and varies with cell differentiation. Based on our findings and on the biological activities of Erb-B2, it is conceivable that disturbed expression or functioning of ERBIN and Erb-B2 is implicated in the development of the malignant phenotype of BCC.
Lebeau
S
S
Department of Dermatology, University Hospital of Geneva, 24 Rue Micheli-du-Crest, CH-1211 Geneva, Switzerland.
Masouyé
I
I
Berti
M
M
Augsburger
E
E
Saurat
J-H
JH
Borradori
L
L
Fontao
L
L
D048868:Adaptor Proteins, Signal Transducing; D015153:Blotting, Western / Q000379:methods; D002280:Basal Cell Carcinoma / Q000737:chemistry*; D002294:Carcinoma, Squamous Cell / Q000737:chemistry*; D002352:Carrier Proteins / Q000032:analysis*; D016022:Case-Control Studies; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D006801:Humans; D015603:Keratinocytes / Q000737:chemistry*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D012867:Skin / Q000737:chemistry; D012878:Skin Neoplasms / Q000737:chemistry*
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; C413364:ERBIN protein, human