LAUSR

From Hanahan and Weinberg’s original description of six hallmarks of cancer (self-sufficiency in growth signals, insensitivity to growth-inhibitory signals, evasion of apoptosis, limitless replicative potential, sustained angiogenesis, and tissue invasion and metastasis) (1), it took only 11 years to add in 2011, based on an increasing body of research, two “emerging hallmarks of cancer”: deregulating cellular energetics and avoiding immune destruction (2). Hanahan and Weinberg also pointed out that, besides cancer cells, tumors contain a repertoire of recruited normal cells that contribute to create the “tumor microenvironment” (2). Deregulating cellular energetics is perhaps most commonly known as metabolic reprogramming, a process that can take place in tumor cells (3), as well as in tumor-infiltrating immune cells (4). The interplay between specific metabolic pathways, in the context of cell maturation, activation, differentiation, and effector functions of immune cells, is currently referred to as immuno-metabolism (5). Metabolic reprogramming and avoiding immune destruction are closely interrelated, since metabolic intermediates from tumor cells may suppress the immune response (4). The research topic “Immuno-metabolism in tumor microenvironment,” here presented, covers several aspects of tumor and immune cell metabolism, as well as the cell–cell interplay within the tumor, at the metabolic level. In addition, some metabolic-oriented cancer therapies are reviewed (Molon et al.; Ohta; Romero-Garcia et al.; Salazar-Ramiro et al.; Zhang and Ertl).