Morphofunctional activity of npm1 protein in tubularbreast cancer in cats

The carcinogenesis of mammary gland tumors in cats is characterized by its uniformity with respect to cellular structures, due to this, it is possible to analyze the effect of individual signature patterns on the mechanism of cancer occurrence well. To do this, it is necessary to determine the functional state of individual proteins that begin to express both inside and on the surface of the nuclear structure. Some multifunctional proteins in the region of nucleolar organizers form the activity of the nucleus, which is closely related to the regulation of the cell cycle. The nucleophosmin protein is an essential cellular protein that is involved in a number of pathways, including mRNA transport, chromatin remodeling, apoptosis, and genome stability. It is poorly expressed by resting cells, but its overexpression leads the cell to stimulate division and increase metastatic potential. Therefore, the aim of our study was to study the expression of the nucleophosmin protein (NPM1) at different histological gradations of tubular carcinoma in mammary glands in cats (n=13). The review presents the results of the histological structure of tubular carcinoma from the highly differentiated to the low-differentiated type. When studying the material, it was revealed that tumor emboli were recorded in 5 samples of G3 tumors in lymphatic vessels that were located cross-border, and macrometastasis, occupying about 70% of the parenchyma of the cortical substance, was also recorded in one sample of the lymph node. When performing an immunohistochemical study (IHC), it was determined that immunopositive sites were noted in the nucleolar localization, while a staining score was recorded, which corresponded to moderate (++) for highly differentiated tumors and strong (+++) for low-grade ones. Thus, when this marker was overexpressed, chromatin disorganization occurred in the nucleolus with an increase in subcomputments in the nucleus, which subsequently led to an increase in the metastatic potential characteristic of G3 tumors.