TUMOR GROWTH ADHESION

Background. The concept that the key mechanism of the tumor process is the disruption of adhesive interactions is based on the participation of local, general and central mechanisms. Methods. Immunofluorescent, immunohistochemical, immunoenzyme, morphological, biochemical research methods, as well as statistical analysis were used in the research. Result. The local features of adhesion dysregulation include insufficient expression of histospecific adhesion molecules resulting from a genetic mutation, which damages an important mechanism of antitumor tissue defense, disrupting the processes of proliferation and differentiation. Deficiency of histononspecific homotypic adhesion molecules, which arises much later, escalates the disorders. This leads to general contact "breakdowns": firstly, to a decrease in the expression of ligands of the ß2 family of leukocyte integrins (LFA-1, Mac-1) on the surface of immune effectors, and secondly, to increased expression on tumor cells of molecules of adhesion to the substrate, late activation antigens VLA (very late activation) of the β1-integrin family. The first event limits the interaction of molecules of the ICAM family with their counterreceptors from the β2-integrin family, reducing the elimination of target cells by immune effectors, which contributes to shielding the tumor from immune surveillance. The second "breakdown" promotes tumor invasion and the formation of blood vessels - heterotypic adhesion with other cells and tissues, which additionally stimulates the processes of cell proliferation and tumor growth. Thus, adhesion molecules can be compared to a phoenix bird: disappearing at the beginning of the process (between "native" cells), they appear again, but in a different capacity (strengthening adhesion to "foreign" cells), elevating the totalitarian behavior of the tumor. It should be taken into account that tumor cells, due to adhesion dysregulation, lose their differentiation, losing their maturity, and are "isolated from society", being unable to carry out their specific, "adult" functions. Therefore, tumor growth can be considered as rapid aging of organ cells. Conclusion. Features of local adhesion dysregulation, which provides the basic properties of the tumor: loss of tissue control of proliferation, anaplasia, invasion, metastasis, deficiency of immune surveillance, can be controlled by central mechanisms involving the dopaminergic system, which is able, using immunoadhesive interactions, to reg