In: Chemistry
Cancer cells, even when sufficient oxygen is available, produce large amounts of lactate. It has been observed that the concentration of fructose-2,6-bisphoshate is much higher in cancer cells than in normal cells. Why would this result in anaerobic metabolism being favored, even when oxygen is available ?
Cancer cells use aerobic glycolysis for ATP production. This is called Warburg effect. This might be due to following conditions:
1. In mammalian cells, glucose availability is no problem so the cancer cells continue anaerobic respiration.
2. It is the adaptation of cancer cells for hypoxia. When cancer cells divide at very high rates, there will be induced hypoxia. In order to survive, cancer cells have adapted to anaerobic respiration. This can be illustrated by following fact.
Pyruvate kinase is the key enzyme for switch between aerobic and anaerobic respiration. Pyruvate kinase has tow isoforms:
a) M1 isoform: It is present in most adult cells.
b) M2 isoform: It is present during embryonic development and in cancer cells.
Pyruvate kinase is a gatekeeper to the mitochondria. M2 isoform don't allow Kreb cycle by blocking entry to mitochondria thus promoting anaerobic respiration
These are the some facts to explain Warbrug's effect in cancer cells.