ENO1 (alpha-enolase 1)

Class

Humanized monoclonal antibody

Pathway

Anti-ENO1 antibody binding enolase-1, a glycolytic enzyme with tumor-cell-surface moonlighting functions implicated in multiple myeloma pathobiology

ENO1, or alpha-enolase, is an enzyme that catalyzes a step of glycolysis, the metabolic pathway cells use to convert glucose into usable energy. Beyond this classic role inside the cell, ENO1 has a secondary, "moonlighting" function: in certain cells, especially aggressive cancer cells, a portion of the enzyme relocates to the outer cell surface. There it can act as a receptor for plasminogen, a blood protein that, once activated to plasmin, breaks down surrounding tissue barriers. This surface activity has been linked to tumor cell invasion, spread, and evasion of immune surveillance in several cancers, including multiple myeloma, a malignancy of antibody-producing plasma cells in the bone marrow. Because antibodies are large molecules that cannot enter cells, they can selectively engage this cell-surface pool of ENO1 without disturbing the enzyme's essential internal metabolic role. An anti-ENO1 monoclonal antibody is designed to bind this exposed protein, potentially blocking its pro-invasive signaling and flagging the tumor cell for destruction by the immune system. This approach reflects a broader strategy in oncology of repurposing antibodies against proteins that are normally intracellular but become abnormally displayed on the surface of malignant cells.