The NF-kB signalling pathway controls cell metabolism by directing the way cells produce energy from glucose, reports a paper online this week in Nature Cell Biology.
Normal cells start to consume glucose in a process called glycolysis, and then pass on the products to the cell’s energy factories, the mitochondria, where mitochondrial respiration occurs and energy production is completed. However, cancer cells often respond to the high metabolic demands of tumour growth by uncoupling glycolysis from mitochondrial respiration to increase biosynthesis of cellular building blocks.
Guido Franzoso and colleagues demonstrate that the NF-kB pathway controls the balance of these metabolic responses by regulating mitochondrial respiration. They show that NF-kB can increase the levels of a mitochondrial enzyme needed for respiration. This allows cells to adapt their metabolism and survive even when glucose becomes scarce. It could also potentially present a cell barrier to the effects of tumorigenic changes that increase proliferation by uncoupling glycolysis from respiration. However, in certain situations, reprogramming of energy pathways by NF-kB may also help cancer cells cope with the metabolic stresses they face.
These findings shed light on the metabolic regulation of normal and tumour cells, which could have implications in the study of cancer.