Metabolic regulation of macrophages in tumor microenvironment

Purpose of review Insight into the metabolic changes in cancer has become so important that cancer is regarded as a disease entity full of metabolic implications. We summarize the recent findings pertaining to cancer cell-derived metabolic changes that regulate the function of macrophages to favor cancer cell survival, and the reported approaches to reverse these changes. Recent findings Since the observation and dramatic revitalization of the Warburg effect, metabolic changes were thought to be confined in cancer cells. However, the Warburg effect has recently been proven to exist in various types of immune cells in tumor tissue. A growing number of publications now indicate that cancer cells interact with other cells in the tumor microenvironment, not only through traditional inflammatory mediators, but also through oncometabolites, and that metabolic changes in immune cells by oncometabolites are the key factors favoring the survival of cancer cells and pro-tumoral function of immune cells. Notably, these metabolic changes do not occur uniformly in tumor progression. Summary Understanding of the complex metabolic interactions in the tumor microenvironment can not only set a new paradigm for tumor progression, but also provide new breakthroughs to control cancer by modulation of function in tumor-associated macrophages.