Immunohistochemical Analysis of Na+/K+-ATPase and Bone Morphogenetic Protein-2 Expressions in Both Parenchymal and Stromal Cells from Benign and Malignant Canine Mammary Tumors
Abstract Canine mammary tumors are the most common type of dog tumor, and they are similar to human breast tumors. Na+/K+-ATPase is a common plasma membrane ion pump with important physiological and pathophysiological functions. In mammary tumors, the tumor microenvironment was composed of a heterogeneous population of tumor cells and nearby endogenous stromal cells. Bone morphogenetic proteins (BMPs) regulate fetal development, tissue homeostasis and differentiation, and a variety of cellular functions. The purpose of this study is to examine the immunohistochemical expression of Na+/K+-ATPase and BMP-2 in tumoral and stromal cells from benign and malignant canine mammary tumors. In this study, ten benign and ten malignant mammary tumors from the archives of the Department of Pathology were used, with five normal breast tissues serving as controls. The results of the revealed that tumors had higher levels of Na+/K+-ATPase and BMP-2 expressions than normal mammary tissue. While both markers were expressed negatively or mildly in benign tumors, they increased significantly in malignant tumors. Both Na+/K+-ATPase and BMP-2 are expressed by tumoral and stromal cells in canine mammary tumors. When compared to compared to BMP-2, Na+/K+-ATPase expression was found to be more severe. This study found that Na+/K+-ATPase and BMP-2 can be used as markers of malignancy in canine mammary tumors and that stromal cells also play an important role in tumor progression. These findings also indicated that Na+/K+-ATPase and BMP-2 may be used for early diagnosis or as a potential target for treatment of canine and human breast tumors in the future.