Immunohistochemical and western blot expression of MMPs, TIMPs, and cytokeratin 10 in feline squamous cell carcinoma

Background: Feline oral and cutaneous squamous cell carcinoma (SCC) are aggressive neoplasms characterized by high local invasiveness. Given its spontaneous occurrence and molecular similarities, feline SCC represents a robust comparative model for human head and neck squamous cell carcinoma (HHNSCC). This pilot study aimed to characterize the expression of metalloproteinases (MMPs), their tissue inhibitors (TIMPs), and cytokeratin 10 (CK10) in relation to Papillomavirus (PV) status, and to explore the viral-molecular relationship in feline oncology. Methods: test. Results: PV DNA was identified in 6/10 samples. IHC analysis revealed that MMPs (-2, -9, -13, -14) exhibited stronger cytoplasmic and nuclear immunostaining compared to the more restricted signals of TIMPs and CK10, showing a strong inverse correlation with MMP-2, linking invasiveness to dedifferentiation. Significant positive correlations were found between MMP-9/TIMP-3 and MMP-2/MMP-9. TIMP-2 expression was significantly higher in PV-negative samples. Western blot confirmed these results, showing consistent bands. Conclusion: This pilot study provides the first characterization of MMPs, TIMPs, and CK10 in feline SCC, establishing a foundation for future research into feline PV species and reinforce the value of the feline model in comparative oncology.