Roles of neutrophil gelatinase-associated lipocalin (NGAL) in human cancer

Cancer remains one of the major cause of death in the Western world. Although,it has been demonstrated that new therapies can improve the outcome of cancerpatients, still many patients relapse after treatment. Therefore, there is a need toidentify novel factors involved in cancer development and/or progression. Recently,neutrophil gelatinase-associated lipocalin (NGAL) has been suggested as a key playerin different cancer types. Its oncogenic effect may be related to the complex NGAL/MMP-9. In the present study, NGAL was analyzed at both transcript and protein levelsin different cancer types by analysing 38 public available microarray datasets andthe Human Protein Atlas tool.NGAL transcripts were significantly higher in the majority of solid tumorscompared to the relative normal tissues for every dataset analyzed. Furthermore,concordance of NGAL at both mRNA and protein levels was observed for 6 cancertypes including bladder, colorectal, liver, lung, ovarian, and pancreatic. All metastatictumors showed a decrease of NGAL expression when compared to matched primarylesions.According to these results, NGAL is a candidate marker for tumor growth in afraction of solid tumors. Further investigations are required to elucidate the functionof NGAL in tumor development and metastatic processes.