Cell-surface tumor antigen (TAA) (TAA)

Cell-surface tumor antigens are molecules, primarily proteins, glycoproteins, or glycolipids, located on the external membrane of cancer cells that differentiate them from healthy cells (National Cancer Institute, 2023). These antigens are broadly categorized into tumor-specific antigens (TSAs), which are unique to malignant cells due to mutations or viral infections, and tumor-associated antigens (TAAs), which are overexpressed or abnormally timed in tumors but also found at lower levels in normal tissues (Abbott et al., 2020). They play diverse biological roles, including acting as growth factor receptors or differentiation markers that drive tumor progression and survival (Nature Reviews Cancer, 2018). In oncology, these antigens serve as the primary targets for precision medicines such as monoclonal antibodies, antibody-drug conjugates (ADCs), and chimeric antigen receptor (CAR) T-cell therapies (Journal of Hematology & Oncology, 2021). While highly effective, targeting these antigens faces challenges such as "on-target, off-tumor" toxicity when antigens are shared with healthy tissues and the development of resistance through antigen loss or heterogeneity (Frontiers in Oncology, 2020).

Other names

Tumor-associated antigenTumor-specific antigenCancer cell surface markerOncofetal antigenNeoantigen

Therapeutic agents target these antigens to induce cell death via antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), direct signaling inhibition, or the delivery of cytotoxic payloads (ADCs) and engineered immune cells (CAR-T) (Nature Reviews Drug Discovery, 2023; Journal of Hematology & Oncology, 2021).