As yin and yang, cancer and diabetes are metabolic disorders characterized by deregulated, yet opposing, metabolic alterations. These metabolic shifts reflect a complex network of defective underlying signaling pathways, which ultimately orchestrate both disease pathogenesis and progression. The Warburg effect portrays the chief metabolic phenotype in cancer and is reflected by the dominance of aerobic glycolysis over minimal-to-no viable oxidative phosphorylation in cancer. Conversely, during the pathogenesis of type 2 diabetes (T2D), oxidative phosphorylation is constantly heightened. In advanced insulin resistance and T2D, the metabolic landscape becomes more complex, with exacerbating metabolic alterations affecting oxidative phosphorylation in a tissue-specific manner. Promising nutritional adjuvants, such as alpha-lipoic acid and flavonoids, can reprogram metabolism and exert antitumor and antidiabetic effects. Other pharmacological agents, such as metformin, have therapeutic effects on cancer and T2D. Herein, we discuss the molecular mechanisms and signaling pathways involved in the metabolic shifts in cancer and T2D, and explore the therapeutic strategies under investigation that aim to reverse the metabolic shift in both disease scenarios.

Aerobic glycolysis in cancer cells, originally observed by Warburg 100 years ago, which involves production of lactate as the end product of glucose breakdown even in the presence of adequate oxygen, is the foundation for the current interest in cancer cell-specific reprograming of metabolic pathways. The renewed interest in cancer cell metabolism has now gone well beyond the original Warburg effect related to glycolysis to other metabolic pathways to include amino acid metabolism, one-carbon metabolism, pentose phosphate pathway, nucleotide synthesis, antioxidant machinery, etc. Since glucose and amino acids constitute the primary nutrients that fuel the altered metabolic pathways in cancer cells, the transporters that mediate the transfer of these nutrients and their metabolites not only across the plasma membrane but also across the mitochondrial and lysosomal membranes have become an integral component of expansion of the Warburg effect. In this review, we focus on the interplay between these transporters and metabolic pathways that facilitates the metabolic reprogramming which has become the hallmark of cancer cells. The beneficial outcome of this recent understanding of the unique metabolic signature surrounding the Warburg effect is the identification of novel drug targets for development of a new generation of therapeutics to treat cancer.