Expression of Glypican 3 in low and high grade urothelial carcinomas

Oguz Aydin, Levent Yildiz, Sancar Baris, Cihad Dundar, Filiz Karagoz

Glypican-3 (GPC3) is an oncofetal protein which is encoded by GPC3 gene and takes role in the regulation of cell division and apoptosis. Overexpression of GPC3 has been reported in some types of cancer such as hepatocellular carcinoma (HCC), melanoma, squamous cell carcinoma of the lungs and testicular germ cell tumors. The aim of this study was to investigate the immunohistochemical expression of GPC3 in the non-neoplastic urothelium and in urothelial carcinoma (UC). We also aimed to explore the alterations in the GPC3 expression according to the grade and the invasiveness of UC. GPC3 expression was studied in 108 UC cases by using immunohistochemistry. Each section was evaluated in terms of the extensiveness and intensity of GPC3 staining. Scores of immunostaining were correlated with tumor grade and stage. GPC3 expression was observed in 38 cases (35.2%). GPC3 expression was positive in 43.6% of high and in 13.3% of low grade UC (p: 0.003). In 19 UC cases biopsy also harbored non-neoplastic urothelium which showed no staining for GPC3. The difference in staining percentages between low and high grade UCs, suggests that GPC3 staining could be used as an adjunctive marker in cases where the distinction between the low and high grade tumors is difficult. In addition, lack of staining in the non-neoplastic urothelial areas in 19 cases raises the possibility of the use of GPC3 staining for the distinction between neoplastic and non-neoplastic urothelium, especially in punch biopsy samples. Based on our results potential role of GPC3 in urothelial carcinogenesis warrants further investigation, especially the potential use of GPC3 for therapeutic and diagnostic purposes. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2260833001522844.