Carbohydrates expressed on cell surface not only alter during carcinogenesis but also play important roles in cancer invasion and metastasis. Clinical significances of glycolipid and glycoprotein expression in urological malignancies were reported. In bladder tumor, large amounts of ganglioside GM 3 accumulate in superficial, compared with invasive bladder tumors and exogenous GM 3 inhibits the invasive potential of bladder tumor cells. A murine bladder carcinoma cell line (MBT-2) was transfected with a GM 3 synthase cDNA, because this line does not naturally express GM 3. Stable transfectants that over-expressed GM 3 were characterized by a reduced potential for cell proliferation, motility, invasion, xenograft tumor growth. N-acetylglucosaminyltransferase-V (GnT-V) may play important roles in early carcinogenesis of bladder tumor. Core 2-GnT (C 2-GnT) was up-regulated according to invasiveness of bladder tumor. In testicular tumor, Gb 3 was accumulated in seminoma and non-seminomatous germ cell tumors. Gb 3 may be a new marker of testicular tumors, especially seminomas, for which useful markers are so far lacking. Differentiation between seminoma and malignant lymphoma is sometimes difficult by histopathological findings but it is considered to be greatly facilitated by examination of the pattern of glycolipid expression. Only the presence or absence of galactosylgloboside (Gb 5), but of no other glycolipids or gangliosides, clearly correlated with metastatic potential in patients with seminoma. Immunohistochemistry using anti-C 2-GnT monoclonal antibody revealed high positive rate in embryonal carcinoma and choriocarcinoma, indicating possible involvement of C 2-GnT in hematogenous metastasis of testicular tumors. For prostate cancer, we analyzed lectin-binding activity of serum prostate specific antigen (PSA) to clarify cancerous change of carbohydrates expressed on PSA. Maackia amurensis (MAA) bound fraction of free PSA showed distinct difference between prostate cancer and benign prostate hypertrophy.
