Comparison of the levels of Equus caballus papillomavirus type 2 (EcPV-2) DNA in equine squamous cell carcinomas and non-cancerous tissues using quantitative PCR.

This research paper explores the connections between Equus caballus papillomavirus type 2 (EcPV-2) infection and equine squamous cell carcinomas (SCCs) found in horses. It particularly investigates the frequency and quantity of EcPV-2 DNA in SCCs, healthy tissues, and other common sites prone to equine SCC development using quantitative PCR (qPCR) methods.

Objective of the Study

• The primary goal of this research was to develop a quantitative PCR (qPCR) assay to determine the viral load in a range of equine tissue samples. This included examining SCC lesions, non-SCC penile lesions, and tissues without observable lesions from areas prone to SCCs in healthy horses.

Findings on Equine Penile SCC Lesions

• The study found that EcPV-2 DNA was significantly more present, and in higher quantities, in equine penile SCC lesions compared to healthy penile mucosa or non-SCC penile lesions.
• This discovery supports the hypothesis that EcPV-2 plays a crucial role in the development of penile SCCs in horses.
• The research also suggests that EcPV-2 infection in the penile regions of horses is rare in the absence of SCCs.

Findings on Other SCC-prone Sites

• Normal vulval mucosa samples were found to rarely contain EcPV-2 DNA, and none of the nictitating membrane samples had EcPV-2 DNA. This finding indicates that asymptomatic EcPV-2 infection at these sites is not common.
• EcPV-2 DNA was detected in both SCCs and normal samples from the oral cavity or pharynx. However, there were no notable differences in the rate of infection or the number of viral copies between SCCs and normal mucosal samples. The role of EcPV-2 in SCC development in these locations is still unclear, requiring further investigation.