NCIt definition : A IgM monoclonal antibody (MoAb) against 78-kDa glucose-regulated protein (GRP78;
also called BiP or HSPA5), with potential proapoptotic and antineoplastic activities.
Upon intravenous administration of the anti-GRP78 monoclonal antibody PAT-SM6, the
MoAb strongly binds to GRP78, thereby preventing the activation of multiple GRP78-mediated
pathways and blocking the GRP78-induced suppression of apoptotic pathways. This eventually
leads to the induction of tumor cell apoptosis and a reduction in tumor cell proliferation.
GRP78, the endoplasmic reticulum (ER) chaperone and unfolded protein response (UPR)
regulator, is overexpressed on the surface of a variety of cancer cell types; its
expression is associated with increased tumor cell survival and proliferation, as
well as angiogenesis and resistance to chemotherapy.;