Cancer Extracellular Matrix Proteins Regulate Tumour Immunity

SIMPLE SUMMARY: The extracellular matrix (ECM) is the acellular part of a tissue, a meshwork of extracellular material produced and secreted by cells into the surrounding medium. The major function of the ECM is to provide structural and support to the surrounding cells. The ECM of malignant tumours is characterised as disorganized with increased production of some components compared to normal tissues. In this review we discuss how cancer ECM affects the tumour immunity and how we could exploit the ECM to boost the anti-tumour immune response. ABSTRACT: The extracellular matrix (ECM) plays an increasingly recognised role in the development and progression of cancer. Whilst significant progress has been made in targeting aspects of the tumour microenvironment such as tumour immunity and angiogenesis, there are no therapies that address the cancer ECM. Importantly, immune function relies heavily on the structure, physics and composition of the ECM, indicating that cancer ECM and immunity are mechanistically inseparable. In this review we highlight mechanisms by which the ECM shapes tumour immunity, identifying potential therapeutic targets within the ECM. These data indicate that to fully realise the potential of cancer immunotherapy, the cancer ECM requires simultaneous consideration.