Significant overexpression of the Merkel cell polyomavirus (MCPyV) large T antigen in Merkel cell carcinoma.
BACKGROUND
The purpose of this study was to determine the expression pattern of the Merkel cell polyomavirus (MCPyV) large T-protein antigen in patients with Merkel cell carcinoma.


METHODS
A tissue microarray (TMA) containing 30 specimens was constructed and stained for the MCPyV large T protein. Immunohistochemical expression was determined semiquantitively and was compared to patients' outcome.


RESULTS
Nuclear expression of MCPyV large T protein was detected in 29 of 30 specimens (97%). In particular, 60% to 100%, 30% to 60%, and 10% to 30% of tumor cells were positive in 27 specimens (90%), 1 (3%), and 1 (3%), respectively. There was no difference in positivity between primary and metastatic lesions. Clinical data could not be correlated to MCPyV large T-protein expression.


CONCLUSIONS
MCPyV large T protein was significantly overexpressed in 97% of all specimens. Although we could not demonstrate a predictive effect, MCPyV large T protein may represent a molecular marker with utility in pathological diagnosis as well as a potential new therapeutic target in patients with Merkel cell carcinoma.
Department of Otolaryngology-Head and Neck Surgery/Surgical Oncology, University Health Network, Princess Margaret Hospital, Toronto, Ontario, Canada.
Boban M
BM
Erovic
Ayman
A
Al Habeeb
Luke
L
Harris
David P
DP
Goldstein
Danny
D
Ghazarian
Jonathan C
JC
Irish
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D001707:Biopsy, Needle; D015266:Carcinoma, Merkel Cell / Q000235:genetics* / Q000401:mortality / Q000628:therapy / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D059965:Merkel cell polyomavirus / Q000276:immunology; D008875:Middle Aged; D027601:Polyomavirus Infections / Q000276:immunology* / Q000401:mortality / Q000503:physiopathology; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000235:genetics* / Q000401:mortality / Q000628:therapy / Q000821:virology; D016019:Survival Analysis; D014412:Tumor Virus Infections / Q000276:immunology* / Q000401:mortality / Q000503:physiopathology
D000952:Antigens, Polyomavirus Transforming; D004279:DNA, Viral