Expression of β-catenin and cyclin D1 in Merkel cell carcinomas of the head and neck.
BACKGROUND
Merkel cell carcinomas (MCC) are very aggressive tumors of the sun-exposed skin with a high potential to metastasize. Little is known about the genesis of MCC and very few prognostic markers have been detected so far. The Wnt pathway protein β-catenin and the cell cycle protein cyclin D1 are two promotors of tumor growth and are expressed in a variety of malignant neoplasms such as lymphomas, thyroid, breast cancer, and many others.


METHODS
Tissue samples of 27 patients with MCC were immunohistochemically stained for β-catenin and cyclin D1 and correlated with overall survival of patients. In addition, western blot analysis was carried out in the two MCC cell lines MCC-13 and MCC-26.


RESULTS
β-catenin showed a cytoplasmatic expression of 10-30 % in 11 samples and an expression lower than 10 % in eight samples. Nuclear staining was visible in two samples. None of the 27 samples expressed cyclin D1.


CONCLUSIONS
Neither cyclin D1 nor β-catenin was expressed in a statistically significant manner, concluding that the development of MCCs is independent of β-catenin and cyclin D1 expression and these proteins are not suitable as prognostic markers. We could describe the expression pattern of cyclin D1 for the first time.
Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria, claudia.lill@meduniwien.ac.at.
Claudia
C
Lill
Sven
S
Schneider
Bahil
B
Ghanim
Markus
M
Brunner
Gregor
G
Heiduschka
Robert
R
Loewe
Dietmar
D
Thurnher
D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015266:Carcinoma, Merkel Cell / Q000175:diagnosis* / Q000378:metabolism*; D019938:Cyclin D1 / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D051176:beta Catenin / Q000378:metabolism*
D014408:Biomarkers, Tumor; C530104:CCND1 protein, human; C495270:CTNNB1 protein, human; D051176:beta Catenin; D019938:Cyclin D1