H 2 S metabolism in colon cancer cells: Effect of hypoxia
Hydrogen sulfide (H2S) plays key roles in human (patho)physiology. Synthesized endogenously by known enzymatic systems, H2S is mainly metabolized through a mitochondrial sulfide-oxidizing pathway that comprises sulfide:quinone oxidoreductase (SQR) and a few other enzymes. H2S degradation through this pathway is coupled to electron injection into the respiratory chain and, thus, to stimulation of ATP synthesis. In cancer cells, H2S was reported to be synthesized at high levels and to stimulate energy metabolism and cell proliferation.