Influence of Chemotherapy on the Relationship between MicroRNA Levels in the Lymph with Thymus Structure in Experimental Breast Cancer

The relationship between the expression levels of microRNAs (miR-21, miR-221, miR-222, and miR-429) and morphometric parameters of the thymus was studied in female Wistar rats with breast cancer receiving and not receiving chemotherapy. In breast cancer, the following positive relationships were revealed: miR-221 in the subcapsular zone of the cortical substance with medium lymphocytes, miR-221 in the central part of the cortical substance with immunoblasts and macrophages, miR-429 in the subcapsular zone of the cortical substance with mitotically dividing cells, miR-429 in the central part of the medullary substance with macrophages, and miR-21 with medium lymphocytes of the thymus. In the subcapsular zone of the cortical substance, proliferative activity and the number of cells with pyknotic nuclei were increased. After chemotherapy, the relationship of microRNAs in the lymph with transformations in the thymus can indicate destructive processes in the breast tumor in comparison with breast cancer without treatment and indicate strengthening of the antitumor immunity, a decrease in the number of dying cells, and lymphoid depletion of the morphofunctional zones of the thymic parenchyma. Positive relationships of miR-21 with medium and small lymphocytes, miR-221 and miR-429 with epithelial cells, miR-222 with macrophages in the central part of the cortex, and miR-222 with macrophages in the central part of the medulla were found.

Source: Bulletin of Experimental Biology and Medicine - October 20, 2023 Category: Biology Source Type: research