Glypican-3 is expressed in chromophobe renal cell carcinomas

Glypicans are core proteins of heparan sulfate proteoglycans that have numerous functions. Glypican-3 (GPC3) expression has been detected to be altered in several tumors, including hepatocellular carcinoma, breast carcinoma, and embryonic malignancies. To date, no information on GPC3 status in renal cell carcinoma is available. The material for the study consisted of 625 cases of renal tumors diagnosed at our institution. Tissue microarrays were constructed using all acceptable quality tissue blocks. Immunohistochemistry for GPC3 was performed with 1G12 antibody (BioMosaics). We found strong positive staining in 15 cases, moderate in 4 and weak in 68. The reactivity was particularly evident in chromophobe renal cell carcinomas (32/40). Our findings are of note in cases when GPC3 may be used in differential diagnosis of tumors of uncertain primary location.