Review on Tumour Microenvironment Cell Types Associated with Metastatic Cancer

The Tumour microenvironment (TME) is a highly dynamic and perpetually altering entity of cancer development, progression, invasion, and dissemination. TME is interspersed with cellular components such as immune cells, blood vessels and stromal cells, and non-cellular components comprising extracellular matrix (ECM) and exosomes. Different cancer types possess distinct phenotypes of TME. The intricate processes of TME facilitate uncontrolled bulk formation, and chaotic vascularization, supporting oxygen and blood availability, along with the removal of metabolic wastes and aberrant metastatic colonization and seeding. Tumour masses are embedded with diverse innate and adaptive immune system cell milieu, capable of performing both pro and anti-tumorigenic effects. The nexus underpinning cancer cells and associated TME, such as cell-cell or cell-ECM interactions, play a key role in determining safe and effective therapeutic interventions. This review mainly emphasizes different roles of various cell types involved in the tumour microenvironment in the progression and promotion of metastatic potencies of tumour cells. We have further suggested that the targeting of all these cell types in the tumour microenvironment may give better cancer therapies in the near future.