Mucin 1, cleaved form (MUC1*) (MUC1*)

Mucin 1, cleaved form (MUC1*) is the truncated, oncogenic version of the Mucin 1 (MUC1) transmembrane protein, produced when the large, glycosylated N-terminal extracellular domain is enzymatically shed by proteases like ADAM17 (TACE) (Bamdad, 2008, PMID: 18444918). Unlike the full-length MUC1 found on normal apical surfaces, MUC1* remains on the cell membrane and functions as a powerful growth factor receptor that is activated by bivalent ligands such as NME7 (Hikita et al., 2008, PMID: 18832592). This activation triggers dimerization and stimulates downstream oncogenic signaling pathways, including the MAPK, PI3K/Akt, and JAK/STAT pathways, which drive cell proliferation, survival, and the maintenance of cancer stem cell pluripotency (Fessler et al., 2009, PMID: 19737957). MUC1* is highly expressed in over 75% of all solid tumors, including breast, ovarian, and lung cancers, but is essentially absent from healthy tissues (Minerva Biotechnologies). Therapeutic development focuses on MUC1*-specific monoclonal antibodies (e.g., HuMNC2) and CAR-T cell therapies (e.g., MUC1*-CAR-1xx) that target the unique extracellular epitope exposed only after cleavage, aiming to selectively destroy malignant cells while minimizing off-target toxicity.

Other names

MUC1-CMUC1-CTMUC1-CDMucin 1 C-terminal subunitMUC1 starCleaved Mucin 1

Inhibition of MUC1* dimerization, CAR-T cell-mediated cytotoxicity, Antibody-dependent cellular cytotoxicity (ADCC), and blockade of ligand-induced signaling.