Modern views on the role of main components of stroma and tumor microinvironment in invasion, migration and metastasis

Abstract

Summary. The review presents modern ideas about tumor microenvironment, which most researchers recognize as the main “player” in tumor cell invasion, cell migration and metastasis. The current data on the main components of the stroma and the microenvironment, which play the role of the driving force in tumor progression, are analyzed. In particular, the review highlights the issues of origin, biological traits, phenotypic plasticity, functional heterogeneity of activated fibroblasts — myofibroblasts and tumor-associated fibroblasts, which in recent years have received much attention. Such components of the extracellular matrix proteome as collagen and matrix metalloproteinases are discussed in detail. They are mostly produced by activated fibroblasts and, on the one hand, initiate the development of desmoplasia due to type I collagen and, on the other hand, promote degradation of extracellular matrix proteins due to metalloproteinases, which generally leads to tissue remodeling that promotes tumor progression. Possibilities of using the most important indicators of extracellular matrix remodeling as potential markers and targets of clinical strategy are discussed.

The Role of Different Immunocompetent Cell Populations in the Pathogenesis of Head and Neck Cancer—Regulatory Mechanisms of Pro- and Anti-Cancer Activity and Their Impact on Immunotherapy

“…Recent studies in human cancers have confirmed that the cellular and non-cellular composition of the tumour immune microenvironment (TME), particularly the activity of cytotoxic T cells, can be an essential factor that can predict clinical outcomes [ 36 , 52 ]. In the TME, the successive steps of initiation, growth and invasion at the primary tumour site, up to extravasation and colonisation of tumour cells at the metastasis site, are governed by a complex network of signalling pathways and intercellular interactions between tumour stroma components, immune cells and neoplastic cells [ 52 , 53 , 54 ].…”

“…Growing evidence indicates that the immunocompetent cells in the TME may contribute to tumour initiation and progression. Interactions between neoplastic cells and the innate immune cells may result in an environment and local niche that favours tumour spread and metastasis [ 39 , 52 , 53 , 54 ].…”