3D models for the analysis of tumor infiltration by monocytes-macrophages

Abstract

An analytical review of literature data of modern studies of monocyte migration (movement) in tumor microenvironment using various three-dimensional models of monocyte migration in tumor microenvironment is presented. The given literature data can serve as a characteristic of three-dimensional models as an optimal platform for studying the functions of both individual cell populations of immune cells and whole cell ensembles in the development and therapy of malignant neoplasms. One of the most important characteristics of a three-dimensional model, which has a significant impact on its prognostic ability, is the cellular composition used. The given data clearly demonstrate the importance of the diversity of cell types of the used models, including the introduction of stromal cells (in particular, fibroblasts). Various cell types form a complex system of interactions, thus forming three-dimensional models closest to native organismal conditions. Different types of tumor cells and their individual cell lines are of no less high importance for prognostic ability. For example, tumor spheroids that contain different types of cancer cells show a different secretory profile. As such, the pattern of monocyte infiltration and polarization may differ depending on the type of tumor cell line. In addition to the components themselves used to create the 3D model, the nature of the organization of the above components (different cell types and populations, as well as structural extracellular components) is important. Therefore, this analytical review contains a separate structural section including the analysis of the diversity of structural groups of three-dimensional tumor models. Among the variety of the mentioned structural groups the following should be mentioned: suspensions of multicomponent cancer spheroids, various variants of microfluidic systems and a separate group of organoids - miniature models of native organs and tissues. Thus, this analytical review demonstrates the importance of further optimization of three-dimensional tumor models in order to obtain even more effective means of reproducing the native structure of the tumor microenvironment.