THE ROLES OF CARBONIC ANHYDRASE ISOZYMES IN CANCER

Specific sulphonamide inhibitors of carbonic anhydrase also inhibit the growth, and suppress the invasion, of certain types of cancer cells in culture, suggesting potential for cancer therapy. Inhibition of cell growth may be mediated through a reduction in bicarbonate provision by the cytosolic CA II and mitochondrial CA V isozymes, for the synthesis of nucleotides and other cell components. It is hypothesized that suppression of invasive properties may be mediated through inhibition of the cancer-associated, cell surface isozymes, CA IX and CA XII, resulting in a less acidic extracellular pH. CA IX may be a useful marker for renal clear cell and cervical carcinomas and a valuable adjunct to PAP screening. CA XII may be a useful marker for colorectal tumours.