6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene family overexpression in human lung tumor.

The 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB) is a family of bifunctional enzymes which is responsible for maintaining the cellular levels of fructose-2,6-bisphosphate, a powerful allosteric activator of glycolysis. Here we report the overexpression of PFKFB-1, -2, -3 and -4 mRNA in the human lung cancers when compared with corresponding normal tissues counterparts as well as PFKFB-4 and -3 protein levels. The lung carcinoma cell line A549, under conditions of normal oxygen tension, has also shown increased transcript levels of PFKFB-2, -3 and -4 when compared to normal tissues. Moreover, hypoxia highly induced the expression of PFKFB-2, PFKFB-3 and especially PFKFB-4 isozymes are highly induced in the lung carcinoma cells. Thus, our results' clearly demonstrated overexpression of PFKFB gene family isozymes in the lung cancers and they possible role in the Warburg effect.