The enigmatic role of lipocalin 2 in human cancer. The multifunctional protein neutrophil gelatinase-associated lipocalin (NGAL) and its ambiguous role in human neoplasias

Neutrophil gelatinase-associated lipocalin (NGAL) has been originally identified as a 25 kDa protein covalently linked to neutrophil gelatinase B. It is an acute phase protein involved in innate immunity with an important role in intracellular iron transport. It is currently one of the most ambiguous protein involved in tumorigenesis. In cancer development, its role is contradictory and not yet completely clarified. NGAL induces proliferation and angiogenesis, favorite invasion and metastasis. But it can also inhibits proliferation and induce apoptosis. It is likely that the dual contradictory effects of NGAL (pro-neoplastic and anti-tumoral) are neoplasiaspecific and influenced largely by the type of molecule it is complexed with.