Tumor progression mechanisms: Insights from the central immune regulation of tissue homeostasis (Review)

: Knowledge of the mechanisms underlying the spread of cancer at the cellular and molecular levels is expanding rapidly. However, the central regulators governing the initiation and the rate of tumor growth remain poorly established. The fundamental principles of innate and adaptive immunity may explain how immune cells generate a specific response to tumor tissue. In the current review, the functional features of the immune system that contribute to the maintenance of normal tissue homeostasis, as well as their disruption in malignant transformations, were analyzed. Experimental and clinical studies previously demonstrated the involvement of regulatory T-cells in the process of tumor metastasis in a tissue-specific manner. An understanding of the cross talk between lymphoid and tumor cells may provide an insight into cancer evolution in terms of the mechanisms of T-cell competency formation. Elucidating the mechanisms of tumor progression via central immune regulation has implications for the development of novel therapeutic agents that target immune checkpoints.