Metallothionein in testicular germ cell tumors and drug resistance: clinical correlation

Background. Metallothioneins (MT) are endogenous metalloproteins involved in the homeostasis of essential metals and detoxification of toxic metals. Some recent experimental studies suggested tumor resistance to cis-diamminedichloroplatin may be associated with overexpression of MT in the tumor. Methods. The presence of MT in 33 primary testicular germ cell tumor specimens was assessed immunohistochemically using a rabbit polyclonal rat liver MT antibody that cross-reacted with human MT. The data were correlated with the patients' clinical course. Results. Seminomas stained weakly or not at all for MT, regardless of the clinical stage. Most nonseminomas stained heavily for MT. The more advanced staged nonseminomas tended to stain more heavily for MT. Conclusions. In view of the considerable experimental evidence as well as some inferential clinical data involving MT in cis-diamminedichloroplatin resistance, there appears to be a role for MT in cis-diamminedichloroplatin resistance in germ cell tumors. Further studies to elucidate the role of MT in germ cell tumor chemore-sistance are warranted.