Immunohistochemical detection of P-glycoprotein and GSTP1-1 in testis cancer.

P-glycoprotein (Pgp) and pi-class glutathione S-transferase (GSTP1-1) are thought to be correlated with multiple drug resistance. In immunohistochemical staining, non-seminomatous germ cell tumours, which are more refractory than seminomas to anti-cancer chemotherapy, frequently expressed Pgp and GSTP1-1. Western blot analysis demonstrated lower amount of GSTP1-1 in seminoma than in teratoma. These results suggest that Pgp and GSTP1-1 might contribute to drug resistance in testis cancers.