Oncofetal tumor antigen (OFA) (OFA)

Oncofetal tumor antigens represent a diverse group of proteins that are highly expressed during embryonic and fetal development but are absent or significantly downregulated in normal adult tissues [NCI Dictionary, 2024]. These antigens frequently undergo de-repression during oncogenesis, leading to high expression levels in various malignancies, which makes them ideal candidates for diagnostic biomarkers and therapeutic targets [Sauer et al., 2020]. Well-known examples include Carcinoembryonic Antigen (CEA), Alpha-fetoprotein (AFP), and Glypican-3 (GPC3). In clinical practice, they are used to monitor treatment response and disease recurrence through serum assays [NIH, 2023]. Therapeutically, they are targeted by a variety of modalities including monoclonal antibodies, antibody-drug conjugates (ADCs), and chimeric antigen receptor (CAR) T-cell therapies, leveraging the restricted expression profile to minimize damage to healthy tissues [Man et al., 2022]. Their biological roles often involve critical processes such as cell-cell adhesion, migration, and the regulation of growth factor signaling pathways, which contribute to the aggressive phenotype of cancer cells [Sauer et al., 2020].

Other names

Oncofetal antigensFetal antigensCarcinofetal antigensOnco-fetal antigens

Drugs targeting oncofetal antigens typically utilize monoclonal antibodies or CAR-T cells to induce antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), or direct T-cell mediated lysis of tumor cells expressing the antigen [Sauer et al., 2020]. Some agents, such as bispecific T-cell engagers, redirect T-cells to the tumor site by binding both the oncofetal antigen and the CD3 receptor on T-cells [Bacac et al., 2016]. Additionally, certain therapies may block the signaling pathways or adhesion functions mediated by these proteins to inhibit tumor growth and metastasis [Man et al., 2022].