Carbonic anhydrase IX (CAIX) is a member of the carbonic anhydrase family - enzymes that enable the rapid conversion of carbon dioxide and water into carbonic acid, protons, and bicarbonate ions. Carbonic anhydrases have a widespread role in regulating pH in normal tissues and are abundantly found in all mammalian tissues. CAIX itself is one of the most hypoxically-inducible genes due to its stability and membrane location. It has become a reliable hypoxia histochemical marker, as well as an important diagnostic marker for various cancers, most notably renal cell carcinoma (RCC). A Swiss group used the CAIX antibody in their differential PET imaging studies with tracers in preclinical mouse models (1). These investigators were establishing and monitoring three different osteosarcoma phenotypes for metabolic activity, hypoxia, and bone remodeling, and histology and immunohistochemistry (IHC) with the CAIX antibody enabled them to confirm their PET findings.
Immunohistochemistry: Carbonic Anhydrase IX Antibody
Pistollato, et. al. used the CAIX antibody to map networks and make strong correlations between intratumoral conditions, tumor phenotype, and tumor resistance to chemotherapy in highly proliferative glioblastoma multiforme (GBM) tumors (2). A multivariate analysis of prognostic factors in patients with advanced RCC relied upon a panel of profiling antibodies, including the CAIX antibody, to demonstrate the strength of markers such as HIF-1 alpha, PTEN, p21, thrombocytosis, neutrophilia, and CAIX over others that were not as promising (3). Some recent and interesting studies from the Netherlands using the CAIX antibody suggest that newly designed dual-targeting anti-CAIX drugs combine both strong anti-tumor efficacies with beneficially low off-target effects (4).
Novus Biologicals offers CAIX reagents for your research needs including:
