Poly-N-acetyllactosamine epitope on CD147 (Basigin) and CD98 (SLC3A2) associated glycans (Poly-LacNAc-CD147/CD98)

The poly-N-acetyllactosamine (poly-LacNAc) epitope on CD147 and CD98 is a tumor-associated carbohydrate structure found on the surface of various malignant cells, including B-cell lymphomas and several types of carcinomas [Saitoh et al., JBC, 1997]. CD147 (Basigin) and CD98 (SLC3A2) are transmembrane glycoproteins that serve as scaffolds for these extended glycan chains, which are often upregulated during oncogenic transformation [UniProt P35613, P08195]. Biologically, CD147 plays a critical role in promoting tumor invasion by inducing matrix metalloproteinases, while CD98 is essential for amino acid transport and integrin-mediated signaling. The presence of poly-LacNAc on these specific proteins facilitates cell-cell interactions and modulates the functional activity of the underlying protein scaffolds. This epitope is specifically recognized by the monoclonal antibody 5E9, which was historically misidentified as an anti-transferrin receptor antibody but was later shown to target this unique glycan configuration. Because this specific glycosylation pattern is more prevalent on tumor cells than on most resting normal cells, it serves as a promising target for targeted therapies such as antibody-drug conjugates and CAR-T cells. Therapeutic intervention aims to exploit this differential glycosylation to achieve tumor-specific cytotoxicity while minimizing damage to healthy tissues.

Other names

5E9 antigenPoly-N-acetyllactosamine on Basigin and SLC3A2Tumor-associated poly-LacNAc epitopeEMMPRIN-associated poly-LacNAcCD147/CD98 glycan epitope

Binding of monoclonal antibodies (such as 5E9) to the specific poly-N-acetyllactosamine carbohydrate chains on CD147 and CD98, leading to immune-mediated cell lysis via antibody-dependent cellular cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC), or serving as a targeting moiety for the delivery of cytotoxic payloads [Saitoh et al., JBC, 1997].