Colorectal cancer-associated antigen A7 (Antigen A7)

Antigen A7 is a cell-surface glycoprotein with a molecular weight of approximately 45 kDa, primarily recognized as a specific biomarker for colorectal and pancreatic cancers. It was first characterized by its reactivity with the murine monoclonal antibody A7 (Mab A7), showing high specificity for human colon cancer cell lines such as SW1116 and WiDr while exhibiting minimal expression in normal tissues. The antigen is distinct from the more common carcinoembryonic antigen (CEA) and serves as a valuable target for tumor-localized therapy and diagnostic imaging. In the context of drug development, Antigen A7 has been extensively studied as a target for antibody-drug conjugates (ADCs) and radioimmunotherapy. Notably, neocarzinostatin (NCS) and mitomycin C (MMC) have been covalently linked to the A7 antibody to create conjugates like A7-NCS, which demonstrated superior tumoricidal activity and reduced systemic toxicity in early-phase clinical trials compared to unconjugated drugs. Furthermore, the A7 antibody has been coupled to magnetic particles (A7-FML) to enhance magnetic resonance imaging (MRI) of colorectal tumors, providing a pathway for both theranostic applications and precision oncology.

Other names

A7 antigen45 kDa colorectal cancer-associated glycoproteinA7-recognizing antigenColon cancer-associated antigen A7Psoriasin (S100A7) [Shared name]Insulin receptor-related receptor (IRR/INSRR) [Shared name in bone research]

Antibody-drug conjugate (ADC) mediated delivery of cytotoxic payloads to tumor cells; Targeted contrast enhancement for magnetic resonance imaging (MRI) via magnetic particle conjugation.