Expression of Vimentin, α-SMA, and CD34 in Malignant Mammary Tumors in Dogs

Introduction. At the contemporary stage of mammary tumor studies, the microenvironment is considered a key factor contributing to neoplasia formation and metastasis. Therefore, the greatest attention is paid to the cellular composition of the mammary tumor microenvironment, in which the most widespread elements are the stromal cancer-associated fibroblasts (CAFs). However, in veterinary oncology, stromal markers of malignant mammary tumors are insufficiently studied. The aim of the present study is to investigate the expression of tumor marker proteins, i.e. vimentin, α-SMA, and CD34, in the stroma of the malignant mammary tumor microenvironments in dogs.

Materials and Methods. The objects of the study that was conducted in the period from 2022 to 2024 were the female dogs of various breeds and ages (n=26). The materials studied were the mammary tumors. A comprehensive range of histological and immunohistochemical studies was conducted in compliance with the standard techniques.
Results. It has been established that in different histological types and degrees of canine mammary tumor malignancy, the fibroblastic differentiation lineage cells demonstrate a high expression of vimentin and α-SMA and a low expression of CD34, which indicates their differentiation into CAFs.
Discussion and Conclusion. The obtained results can be used as basic applied data in the study of carcinogenesis in veterinary oncology.

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