Detection of Merkel cell polyomavirus in Merkel cell carcinomas and small cell carcinomas by PCR and immunohistochemistry

作者：Jung Hun Soon; Choi Yoon La; Choi Jong Sun; Roh Ji Hyeon; Pyon Jai Kyong; Woo Kyong Je; Lee Eun Hee; Jang Kee Taek; Han Joungho; Park Chan Sik; Park Young Soo; Shin Young Kee^*

来源：Histology and Histopathology, 2011, 26(10): 1231-1241.

• Merkel cell carcinoma
• Merkel cell polyomavirus
• Small cell carcinoma

Recently, the clonal integration of a new human polyomavirus (Merkel cell polyomavirus or MCPyV) has been reported in Merkel cell carcinoma (MCC). In order to investigate the presence of MCPyV in small cell carcinomas (SCCs) and small round cell tumors (SRCTs), we collected formalin-fixed paraffin-embedded tissue specimens including 14 MCCs, 24 SCCs, 7 Ewing sarcoma/primitive neuroectodermal tumors (ES/PNETs) and 5 neuroblastomas. We also collected specimens of other cancers including 12 malignant melanomas, 10 breast, 10 ovarian and 20 gastric cancers.
We used 3 primer sets for which the sequences were previously published (LT1, LT3, and VP1) and 3 newly designed primer sets (LT1-1, LT1-1a, and LT3a). Quantitative real-time PCR was also performed with the LTq primer set. Nested PCR using the LT3a primer set detected more cases of MCPyV infection in MCC. In total, 12 of 14 (85.7%) MCC cases were positive for MCPyV by PCR, which was consistent with published data. Some SCC specimens were also positive for MCPyV (37.5%) by PCR. PCR products from MCC and SCC cases showed premature truncation and frameshift mutation. Furthermore, one case of ES/PNET and one gastric carcinoma showed MCPyV DNA. However, MCPyV DNA and transcript were only detected in MCCs with quantitative real-time PCR analysis. In addition, 11 of 13 (84.6%) MCC cases and 6 of 23 (26.1%) SCC cases showed immunoreactivity with monoclonal antibodies against MCPyV large T-antigen. Considering both PCR and IHC results, MCPyV was detected in all MCCs tested.
The presence of MCPyV in all MCC cases tested and in some SCC cases suggests that MCPyV may be involved in the malignant transformation.

• 出版日期2011-10