Delta-like canonical Notch ligand 3 (DLL3)

Delta-like canonical Notch ligand 3 (DLL3) is a single-pass transmembrane protein and a structurally divergent member of the Delta/Serrate/Lag2 (DSL) family of Notch ligands[1][3][5][7]. Unlike canonical Notch ligands, DLL3 primarily localizes to the Golgi apparatus and is only displayed on the cell surface when overexpressed; it does not directly bind or activate Notch receptors but acts as a cell-autonomous inhibitor of Notch signaling through intracellular retention mechanisms[1][2][3]. DLL3 is involved in key developmental processes such as neurogenesis and somitogenesis, with mutations causing skeletal defects (as in Jarcho-Levin syndrome)[1][5]. In adult tissues, DLL3 expression is limited but markedly upregulated in high-grade neuroendocrine tumors like small cell lung cancer (SCLC), making it a validated target for antibody-drug conjugates and selective immunotherapies. Targeting DLL3 can induce tumor cell apoptosis; however, drug development efforts (e.g., ROVA-T) have faced challenges due to limited efficacy and safety concerns[1][3][5]. As a disease biomarker, DLL3 protein expression is associated with poor prognosis in SCLC and serves as a selection tool for investigational targeted therapies[1][3][5].

Other names

Delta-like 3 (DLL3)Drosophila Delta-like protein 3Protein delta homolog 3

Antibody-drug conjugates (ADC) targeting DLL3: selective delivery of cytotoxic agents to DLL3-expressing tumor cells, inducing apoptosis Bispecific T-cell engagers: recruit T cells to DLL3-expressing tumor cells, promoting immune-mediated cytotoxicity