Tumour-educated macrophages promote tumour progression and metastasis

Evidence from clinical and experimental studies indicates that macrophages promote solid-tumour progression and metastasis. Macrophages are educated by the tumour microenvironment, so that they adopt a trophic role that facilitates angiogenesis, matrix breakdown and tumour-cell motility — all of which are elements of the metastatic process. During an inflammatory response, macrophages also produce many compounds — ranging from mutagenic oxygen and nitrogen radicals to angiogenic factors — that can contribute to cancer initiation and promotion. Macrophages therefore represent an important drug target for cancer prevention and cure.