Immunohistochemical profile of galectin-8 expression in benign and malignant tumors of epithelial, mesenchymatous and adipous origins, and of the nervous system

This study aims to investigate whether the immunohistochemical expression o f galectin-8 could be used as a diagnostic marker in tumor tissues of vario us histogenetic origins including specimens from epithelial (n=145), mesenc hymatous (n=16), adipous (n=10) and central and peripheral nervous system ( n=25) tissue, and 4 mesotheliomas. Immunohistochemical reactions were carri ed out with a polyclonal anti-galectin-8 antibody and histological slides f rom tissues derived from the files of the Laboratory of Anatomopathology of University Erasmus Hospital, Brussels. Formalin-fixed paraffin-embedded ti ssues of 45 normal cases as well as 41 benign and 114 malignant tumors were studied. Marked decreases in immunohistochemical galectin-8 expression wer e observed in colon (p=0.001), pancreas (p=0.007), liver (p=0.0008), skin ( p=0.002) and larynx (p=0.02) tissue when comparing malignant tissue to norm al tissue and/or benign tumors. The reverse relationship was observed for b reast tissue (p=0.007). No statistically significant differences (p >0.05) were detected when comparing normal tissue and/or benign to malignant tumor s in lung, bladder, kidney, prostate and stomach tissue. Significant galect in-8 expression was also measured in non-epithelial tissue including tumors of the. central and peripheral nervous system as well as in skeletal muscl e and mesotheliomas. Immunohistochemical monitoring of galectin-8 thus reve als an organ-type-dependent regulation of expression upon malignant transfo rmation of various tissue types of epithelial origin. This observation will prompt further studies to delineate any relationship with prognosis.