GLUCOSE CATABOLISM IN CANCER-CELLS - AMPLIFICATION OF THE GENE ENCODING TYPE-II HEXOKINASE

Hexokinase type II is highly overexpressed in many cancer cells, where it plays a pivotal role in the high glycolytic phenotype, Here we dem onstrate by Southern blot analysis and fluorescence in situ hybridizat ion (FISH) that in the rapidly growing rat AS-SOD hepatoma cell line, enhanced hexokinase activity is associated with at least a 5-fold ampl ification of the type II gene relative to normal hepatocytes, This amp lification is located chromosomally, extends to the whole gene, and mo st likely occurs at the site of the resident gene. No rearrangement of the gene could be detected. Therefore, overexpression of hexokinase t ype II in AS-30D hepatoma cells may be based, at least in part, on a s table gene amplification, This is the first report describing the ampl ification of a hexokinase gene in a tumor cell line expressing the hig h glycolytic phenotype.