SOLUBLE FORM OF CARBONIC ANHYDRASE IX (s-CA IX), ASSAYS TO DETECT s-CA IX AND CA IX's COEXPRESSION WITH HER-2/neu/c-erbB-2

摘要

Disclosed herein among other MN/CA IX-related inventions is the discovery of a soluble MN/CA IX (s-CA IX) in body fluids, such as, urine and serum. Said s-CA IX comprises the extracellular domain of CA IX or portions thereof. The predominant s-CA IX species is the extracellular domain comprising a proteoglycan­like (PG) domain and carbonic anhydrase (CA) domain, and having a molecular weight of about 50/54 kilodaltons (kd) upon Western blot. A smaller s-CA IX form of about 20 to about 30 kd comprising the CA domain or parts thereof, not linked to the PG domain, has also been found in body fluids. Also disclosed are diagnostic/prognostic methods for precancer and cancer that detect or detect and quantitate said s-CA IX in body fluids, particularly the CA IX extracellular domain comprising the PG and CA domains having a molecular weight of about 50/54 kd. Also disclosed herein is the coexpression of CA IX and HER-2/neu/c-erbB-2 that provides parallel, alternative and potentially synergistic diagnostic/prognostic and therapeutic strategies for pre-cancer and cancer.