Arginine vasopressin-neurophysin II-copeptin precursor (pro-AVP) (pro-AVP)

Arginine vasopressin-neurophysin II-copeptin precursor (pro-AVP) is a 164-amino acid protein that serves as the precursor for the antidiuretic hormone vasopressin, its carrier protein neurophysin II, and the C-terminal glycopeptide copeptin (UniProt P01185). In healthy physiology, this precursor is synthesized in the hypothalamus and processed into its constituent peptides during axonal transport to the posterior pituitary. However, in small cell lung cancer (SCLC), the AVP gene is frequently overexpressed, and the resulting pro-AVP protein is often incompletely processed and aberrantly displayed on the cell surface (North, 1991). This "neurophysin-related surface antigen" or "C-terminal region of pro-vasopressin" acts as a unique tumor-associated antigen because its surface expression is largely absent in normal tissues (Friedmann et al., 1994). Monoclonal antibodies such as MAG-1 and ONS-M21 have been developed to target this surface-expressed precursor for diagnostic imaging and the delivery of cytotoxic payloads like radioisotopes (North et al., 1998). Targeting this molecule offers a potential therapeutic window for SCLC, although care must be taken regarding potential cross-reactivity with the hypothalamus or the induction of paraneoplastic syndromes like SIADH (North, 2000).

Other names

Neurophysin-related surface antigenC-terminal region of pro-vasopressinPro-vasopressinPro-AVPAVP-NPII-CPCopeptinNeurophysin IIVasopressin-associated glycopeptideVAG

Monoclonal antibody-mediated targeting of cell-surface antigens to deliver cytotoxic payloads or induce immune-mediated cell death.