CD104. also known as integrin β4. is a transmembrane protein that forms a heterodimer with integrin α6 (α6β4). This integrin is primarily expressed in epithelial cells, where it plays a critical role in cell-matrix adhesion by binding to laminins in the basement membrane. Unlike other integrins, β4 contains a uniquely large cytoplasmic domain that interacts with intermediate filaments via proteins like plectin, contributing to the structural stability of hemidesmosomes. These junctional complexes anchor epithelial cells to the basement membrane, ensuring tissue integrity.
CD104 antibodies are essential tools in studying epithelial biology and diseases. In research, they help detect β4 expression in tissues or cell lines, aiding investigations into cell adhesion, migration, and signaling. Clinically, CD104 antibodies are used to diagnose genetic disorders like epidermolysis bullosa, where β4 mutations cause skin fragility. Additionally, α6β4 integrin is implicated in cancer progression, as its overexpression in tumors correlates with enhanced invasion, metastasis, and resistance to therapy. CD104 antibodies thus serve as biomarkers for aggressive cancers (e.g., breast, colorectal) and potential therapeutic targets.
Mechanistically, CD104’s signaling crosstalk with growth factor receptors (e.g., EGFR) underscores its role in regulating cell survival and proliferation. Antibodies blocking β4 function have shown promise in preclinical cancer models. However, challenges remain in understanding context-dependent roles, as β4 can act as both a tumor suppressor and promoter. Overall, CD104 antibodies remain pivotal in unraveling the dual roles of α6β4 integrin in homeostasis and disease.