Merkel cell polyomavirus in Merkel cell carcinoma of Italian patients

Background: Merkel cell carcinoma (MCC) is a rare but very aggressive human malignancy of elderly or immunosuppressed patients. Clonal integration of a new human polyomavirus, the Merkel cell polyomavirus (MCPyV), has been reported in MCC patients. The main objective of the study was the detection of MCPyV and viral expression in clinical samples of Italian patients who were diagnosed MCC. Findings: DNA and RNA were extracted from nine MCCs to detect the presence of MCPyV. Viral large T gene (LT1 and LT3), and viral capsid gene (VP1) were detected by polymerase chain reaction (PCR) based methods, and the amplified PCR products were subjected to direct sequencing. The presence of viral T antigen and/or viral capsid DNA sequences was demonstrated in eight of the nine MCC lesions, whereas RNA transcripts were detected in three MCCs. Conclusions: These findings indicate a potential role of MCPyV in the pathogenesis of at least a subset of MCCs.