Department of Surgery and Anaesthesiology of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Vet Microbiol. 2012 Jul 6;158(1-2):33-41. doi: 10.1016/j.vetmic.2012.02.005. Epub 2012 Feb 11.
Squamous cell carcinoma (SCC) represents the most common genital malignant tumor in horses. Similar to humans, papillomaviruses (PVs) have been proposed as etiological agents and recently Equine papillomavirus type 2 (EcPV2) has been identified in a subset of genital SCCs. The goals of this study were (1) to determine the prevalence of EcPV2 DNA in tissue samples from equine genital SCCs, penile intraepithelial neoplasia (PIN) and penile papillomas, using EcPV2-specific PCR, (2) to examine the prevalence of latent EcPV2 infection in healthy genital mucosa and (3) to determine genetic variability within EcPV2 and to disentangle phylogenetic relationships of EcPV2 among PVs. EcPV2 DNA was detected in all but one penile SCC (15/16), in all PIN lesions (8/8) and penile papillomas (4/4). Additionally, EcPV2 DNA was demonstrated in one of two metastasized lymph nodes, one contact metastasis in the mouth, two vaginal and one anal lesion. In healthy horses, EcPV2 DNA was detected in 10% (4/39) of penile swabs but in none of vulvovaginal swabs (0/20). This study confirms the presence of EcPV2 DNA in equine genital SCCs and shows its involvement in anal lesions, a lymph node and contact metastases. Latent EcPV2 presence was also shown in normal male genital mucosa. We found that different EcPV2 variants cocirculate among horses and that EcPV2 is related to the Delta+Zeta PVs and is only a very distant relative of high-risk human PVs causing genital cancer. Thus, similar viral tropism and similar malignant outcome of the infection do not imply close evolutionary relationship.
鳞状细胞癌 (SCC) 是马属动物最常见的生殖器恶性肿瘤。与人类相似，乳头瘤病毒 (PVs) 被认为是致病因子，最近在一些生殖器 SCC、阴茎上皮内瘤变 (PIN) 和阴茎乳头状瘤中发现了马乳头瘤病毒 2 型 (EcPV2)。本研究的目的是：(1) 使用 EcPV2 特异性 PCR 确定组织样本中 EcPV2 DNA 在马属动物生殖器 SCC、阴茎 PIN 和阴茎乳头状瘤中的流行率，(2) 检测健康生殖器黏膜中潜伏性 EcPV2 感染的流行率，(3) 确定 EcPV2 内的遗传变异性，并解析 EcPV2 与 PVs 之间的系统发育关系。除了一个阴茎 SCC（15/16）外，所有的阴茎 SCC、所有的 PIN 病变（8/8）和阴茎乳头状瘤（4/4）都检测到了 EcPV2 DNA。此外，在两个转移的淋巴结、一个口腔接触转移灶、两个阴道和一个肛门病变中也检测到了 EcPV2 DNA。在健康马中，10%（4/39）的阴茎拭子中检测到 EcPV2 DNA，但 20 个阴道拭子中均未检测到（0/20）。本研究证实了 EcPV2 DNA 存在于马属动物的生殖器 SCC 中，并表明其参与了肛门病变、淋巴结和接触转移。还发现潜伏性 EcPV2 存在于正常雄性生殖器黏膜中。我们发现，不同的 EcPV2 变体在马中共同循环，EcPV2 与 Delta+Zeta PVs 有关，与导致生殖器癌症的高危人类 PVs 只有非常遥远的关系。因此，类似的病毒嗜性和感染的类似恶性结果并不意味着密切的进化关系。
