In the years following its initial discovery NGAL was generally considered to be of interest as a component of the innate immune system. However as our knowledge of the biology of this molecule has improved it has become clear that NGAL may, if fact, be involved in many pathways and have multiple functions. NGAL has now perhaps become best known for its association with acute kidney injury and its potential to act as a biomarker for this condition. However more recent research has provided strong evidence that associates NGAL with other disease states, especially cancers and inflammatory conditions.
The association of NGAL with cancers is an active field of research. NGAL can be associated with both the growth and inhibition of malignancies. In general NGAL complexed with the MMP-9 protein seems to have an oncogenic effect, whereas NGAL’s interaction with the HIF-1a protein seems to have an inhibitory effect. Elevated NGAL levels have been found to be associated with a variety of solid organ tumour types including breast, ovary, lung, liver and pancreas. However the function of NGAL seems to be vary between different cancers and its potential role as a biomarker, prognostic marker or drug target is an area of considerable research interest.
NGAL is also known to be associated with benign diseases, in particular those associated with inflammation. NGAL expression has been observed to be upregulated is tissues associated with skin conditions such as psoriasis and parakeratosis. It has also been suggested that NGAL is associated with a number of other inflammatory conditions including periodontitis, myocarditis. and chronic obstructive pulmonary disease (COPD).
However as NGAL is the subject of vigorous and active research it is likely that new insights into the involvement of NGAL in health and disease will be found as more research is conducted into this interesting and medically significant molecule.