Immunohistochemical evaluation of cyclooxygenase expression in corneal squamous cell carcinoma in horses.

This research studied the expression of cyclooxygenase (COX) enzymes in the eye tissues of healthy horses and those with squamous cell carcinoma (SCC), a type of skin cancer. The results showed higher COX levels in cancer-affected equine corneas than in healthy ones, indicating COX could be involved in the development or progression of corneal SCC, and the use of COX-inhibitors might be a helpful complementary treatment.

Research Methodology

• The study involved 15 horses with SCC involving ocular tissues i.e. the cornea, eyelid, and third eyelid; and 5 healthy horses were used as controls.
• From the SCC-affected horses, the researchers obtained tissues from the cornea (5 horses), eyelid (5 horses), and third eyelid (5 horses).
• To compare, tissues from the same sites were collected from the 5 healthy horses.
• Both the affected and control tissues were then stained using immunohistochemical techniques to detect COX-1 and COX-2.
• A standard technique to evaluate the uptake of the stain was used, and computer-assisted image analysis of digital pictures was carried out to quantify this.

Research Findings

• The key finding was that both COX-1 and COX-2 immunoreactivity was significantly greater in the corneas of horses with SCC than in the control group.
• Notably, there were no significant differences observed in COX-1 or COX-2 immunoreactivity in SCC of the eyelid and the third eyelid, when compared to healthy tissues from the same sites. This indicates that the correlation between increased COX expression and SCC may be specific to the cornea.

Conclusions

• The results suggest that COX-1 and COX-2 could play a role in the development or progression of SCC in the corneas of horses.
• Based on this, the use of drugs that inhibit COX may be beneficial as an additional treatment strategy for corneal SCC in horses. This could potentially help to reduce the impact or spread of the cancer, though further research would be needed to confirm the effectiveness and safety of such an approach.