Carbonic anhydrase IX is a marker of hypoxia and correlates with higher Gleason scores and ISUP grading in prostate cancer

Background Carbonic anhydraseIX is a member of α- carbonic anhydrasesthat is preferentially expressed in solid tumors. It enables bicarbonate transport across the plasma membrane, neutralizing intracellular pHand conferring to cancer cells a survival advantage in hypoxic/acidic microenvironments. Overexpression of carbonic anhydraseIX in cancer tissues is regulated by hypoxia inducible factor1α − mediated transcription and the enzyme is considered a marker of tumor hypoxiaand poor outcome. The role of carbonic anhydraseIX in prostate cancer has not been fully clarified and controversy has arisen on whether this enzyme is overexpressed in hypoxic prostate cancer tissues.