DLL1 (Delta-like ligand 1) is a transmembrane protein belonging to the Delta/Serrate/Lag (DSL) family of Notch ligands, which plays a critical role in mediating cell-cell communication through the Notch signaling pathway. This pathway is evolutionarily conserved and regulates diverse cellular processes, including cell differentiation, proliferation, and apoptosis. DLL1 binds to Notch receptors on adjacent cells, triggering proteolytic cleavage of the receptor and release of the Notch intracellular domain (NICD), which translocates to the nucleus to modulate gene expression.
DLL1 is essential in embryonic development, particularly in neurogenesis, angiogenesis, and immune cell differentiation. Dysregulation of DLL1 expression or Notch signaling is implicated in cancers, inflammatory diseases, and developmental disorders. In cancer, DLL1 may act as an oncogene or tumor suppressor depending on the context, influencing tumor growth, metastasis, and drug resistance.
Antibodies targeting DLL1 are valuable tools for both research and therapeutic applications. In research, they are used to inhibit DLL1-Notch interactions in vitro and in vivo, enabling mechanistic studies of Notch signaling in development and disease. Therapeutically, DLL1-blocking antibodies are explored for cancers with aberrant Notch activation, such as breast cancer or glioblastoma. Conversely, agonist antibodies may enhance Notch signaling for regenerative purposes.
DLL1 antibodies are also employed in diagnostic assays (e.g., immunohistochemistry, flow cytometry) to detect DLL1 expression in tissues or cells. Commercial antibodies are typically validated for specificity across species (human, mouse) and applications (Western blot, immunofluorescence). Researchers must select clones carefully, as signaling outcomes can vary based on epitope recognition.