The protein, carbonic anhydrase IX, belongs to the carbonic anhydrase family which consists of enzymes that rapidly convert carbon dioxide and water into the end products of carbonic acid, protons, and bicarbonate ions. These enzymes play a widespread role in cells by regulating the pH of normal tissues, and are abundantly expressed in all mammalian tissues. Due to its stability and membrane location, CAIX is one of the most hypoxically-inducible genes, and has become a reliable hypoxia histochemical marker. CAIX also plays a role as an important diagnostic marker for various cancers, notably renal cell carcinoma (RCC). A detailed multivariate analysis of prognostic factors in advanced RCC patients depended upon an antibody panel that included the CAIX antibody – this study established the utility of markers such as HIF-1alpha, PTEN, p21, thrombocytosis, neutrophilia, and CAIX over other less promising candidates1.
Further RCC studies from Spain involved a retrospective profile in patients with the CAIX antibody, where biomarkers were analyzed in patients with advanced RCC who underwent cytokine or targeted drug treatments2. In complex network mapping of highly proliferative glioblastoma multiforme (GBM) tumors, Pistollato et al used the CAIX antibody to strongly correlate intratumoral hypoxia conditions with tumor phenotype and tumor resistance to chemotherapy3. A Belgian group of researchers studying breast cancer also employed the CAIX antibody to shed light on the role of hypoxia and angiogenesis in this particular type of cancer4. Their data suggests that the profile of both these processes in the primary tumor predict their later occurrence in lymph node metastases. CAIX9 expression is also linked to meningioma anaplastic phenotypes as established by Yoo et al from UCSF who used the CAIX antibody to demonstrate that hypoxia correlates with an aggressive phenotype5.
Novus Biologicals offers CAIX reagents for your research needs including: