Detection of merkel cell polyomavirus in gynaecological diseases

Abstract

Merkel cell polyomavirus (MCPyV) is an oncogenic virus exist in about 80% of Merkel Cell Carcinoma (MCC), an aggressive human skin cancer. Evidence of MCPyV existing in other kind of skin neoplasms such as cutaneous squamous cell carcinomas (SCCs) has been reported. Since the major type of cervical cancer is SCCs, MCPyV may be associated with cervical cancer tumorigenesis. A Japanese research group has documented the presence of MCPyV DNA in both cervical SCCs and cervical adenocarcinomas (ACs) from Japanese patients. Nevertheless, the association between MCPyV and cervical cancer remains inconclusive and the prevalence of MCPyV in cervical cancer may show demographic variation. This study is aimed to examine whether MCPyV is present in some of the most common gynaecological cancers, namely cervical cancer, ovarian cancer, endometrial cancer, and gestational choriocarcinoma, in Hong Kong patients.

Genomic DNA was obtained from 50 cases of cervical cancer, 20 cases of ovarian cancer, and 35 common gynaecological cancers cell lines. Genomic DNA extracted from four MCC samples were used as positive controls. The integrity of the samples was first checked by β-globin PCR. Detection of MCPyV was then performed by MCPyV Large T antigen (LT-ag) PCR. Our PCR analysis showed that only 1 out of 50 (2%) of the cervical cancer samples was positive for MCPyV DNA. The PCR product was purified and cloned for sequencing analysis. Comparing the LT-ag sequence obtained from the only MCPyV positive cervical cancer with reference sequence and with the MCPyV sequence from one of the control cases revealed the presence of different MCPyV variants in Hong Kong patients. None of the ovarian cancer, endometrial cancer, or choriocarcinoma was positive for MCPyV. Our data did not support the notion that MCPyV is associated with gynaecological malignancies. MCPyV may hence be a fairly specific oncogenic agent for Merkel cell carcinoma.