Unlikely role of glycolytic enzyme alpha-enolase in cancer metastasis and its potential as a prognostic biomarker

Reliance on glycolysis for energy production is considered a hallmark of cancer and the glycolytic enzyme a-enolase is overexpressed in a range of cancer types. However, recent studies have revealed that a-enolase is involved in a variety of unrelated physiological processes and can be found in multiple unexpected cellular locations. This review focuses on the unlikely role of a-enolase as an extracellular plasminogen-binding receptor localised to the plasma membrane. Conversion of plasminogen to plasmin on the surface of cancer cells enhances their ability to invade through stroma by activating collagenases and degrading fibrin as well as extracellular matrix proteins. Increased expression of a-enolase is associated with increased migration and invasion of cancer cells, and decreased metastasis-free survival in patients with several cancer types, including non-small cell lung, pancreatic, breast and colorectal cancers. Due to its overexpression in a range of cancer types and multi-functional roles in key areas of tumour metabolism and metastasis, a-enolase may be useful as a universal cancer prognostic biomarker or therapeutic target.