Figure 8. Cartoon illustrating key bioenergetics changes in NSCLC cells.

Cancer cells exhibit enhanced expression levels of the rate-limiting heme biosynthetic enzyme, 5-aminolevulinic acid synthase (ALAS) and the heme uptake proteins HCP1 and HRG1. As such, heme availability in cancer cells is substantially increased, leading to increased production and levels of various oxygen-utilizing hemoproteins, such as cytochrome c, cytoglobin, Cox-2 and cytochrome P450. The increase in these hemoproteins ultimately leads to intensified oxygen consumption and the generation of cellular energy by respiration. This in turn causes increased cellular energy production, cell proliferation, migration and colony formation.