Targeting Cell Metabolism as Cancer Therapy.

Cancer cells exhibit altered metabolic pathways to keep up with biosynthetic and reductionoxidation needs during tumor proliferation and metastasis. The common induction of metabolic pathways during cancer progression, regardless of cancer histio- or genotype, makes cancer metabolism an attractive target for therapeutic exploitation. Emerging data suggest that these altered pathways may even result in resistance to anticancer therapies. Identifying specific metabolic dependencies that are unique to cancer cells has proved challenging in this field, limiting the therapeutic window for many candidate drug approaches. Cancer cells display significant metabolic flexibility in nutrient-limited environments, hampering the longevity of suppressing cancer metabolism through any singular approach. Combinatorial "synthetic lethal" approaches may have a better chance for success and promising strategies are reviewed here. The dynamism of the immune system adds a level of complexity, as various immune populations in the tumor microenvironment often share metabolic pathways with cancer, with successive alterations during immune activation and quiescence. Decoding the reprogramming of metabolic pathways within cancer cells and stem cells, as well as examining metabolic symbiosis between components of the tumor microenvironment, would be essential to further meaningful drug development within the tumor's metabolic ecosystem. In this article, we examine evidence for the therapeutic potential of targeting metabolic alterations in cancer, and we discuss the drawbacks and successes that have stimulated this field.