A comparative study of LAMPs and YKL-40 tissue expression in glial tumors

YKL-40 is a glycoprotein believed potentially to be a marker of various pathological processes. High levels of YKL-40 have been found in cancer and chronic inflammatory diseases. The function of the glycoprotein is not completely known yet. A possible involvement in angiogenesis and tumor aggressiveness is supposed. Lysosome-associated membrane glycoproteins (LAMP) 1 and 2 are highly conserved proteins with still undefined biological functions. There is evidence that they are implicated in autophagy, angiogenesis and tissue remodeling. The aim of the present study was to investigate the potential relationship between the tissue expression of YKL-40, LAMP-1 and LAMP-2 in glial tumors. LAMPs and YKL-40 expression was determined by immunohistochemistry in 36 glial tumors. A morphometric analysis of the intensity of tissue expression was performed with the Quick-photo Micro 2.3. system. Area (μm), perimeter (μm), and expression level (%) of the three glycoproteins were calculated. LAMPs were found on cell membranes of glial and endothelial cells, while YKL-40 was detected in the cytoplasm of these cells. Intensive immunohistochemical reaction was present in tumor cells. LAMP-2 showed a more intensive staining compared to LAMP-1. We present the first comparative study of YKL-40 and LAMPs in astroglial tumors. The relationship between the expression of the three glycoconjugates indicates a possible participation in the processes of angiogenesis and tissue remodeling during tumor development.