The Relevance of Alpha-1-Acid Glycoprotein in Human Cancer: A Minireview

Alpha-1 acid glycoprotein (AGP-1) is a glycoprotein synthesized mainly by hepatocytes. Recently has been speculated that AGP-1 plays an important role in cancer, but its exact biological function is still confusing. Remarkable is the observation that several types of cancer, including hepatic carcinoma, gastric adenocarcinoma, epithelial ovarian cancer, and lung cancer, present an increased expression and secretion of the AGP-1 protein. Furthermore, in some cases, the increase in plasma AGP-1 levels seems to correlate with tumor progression, as they return to normal after chemotherapy treatment. AGP-1 has been allocated as a multifunctional protein with the capacity to modulate the immune response, decrease the chemotaxis and bind chemotherapy compounds, affecting their biodistribution and cytotoxic effectiveness. Because of these capabilities, it has been suggested that AGP-1 could play a role in not only modulate the cancer immune response but have active participation in the surveillance and cancer progression. The accurate evaluation of quantity and quality of AGP-1 in cancer may prove as a new marker can be used to determine the cancer progression or which tumors will respond to which treatments in order to predict the likelihood of drug resistance.

Keywords: Alpha-1 acid glycoprotein; Orosomucoid; Cancer; Biomarker; Acute-phase protein