METALLOTHIONEIN IN TESTICULAR GERM-CELL TUMORS AND DRUG-RESISTANCE - CLINICAL CORRELATION

Background. Metallothioneins (MT) are endogenous metalloproteins invol ved in the homeostasis of essential metals and detoxification of toxic metals. Some recent experimental studies suggested tumor resistance t o 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 r abbit polyclonal rat liver MT antibody that cross-reacted with human M T. The data were correlated with the patients' clinical course. Result s. Seminomas stained weakly or not at all for MT, regardless of the cl inical stage. Most nonseminomas stained heavily for MT. The more advan ced staged nonseminomas tended to stain more heavily for MT. Conclusio ns. In view of the considerable experimental evidence as well as some inferential clinical data involving MT in cis-diamminedichloroplatin r esistance, there appears to be a role for MT in cis-diamminedichloropl atin resistance in germ cell tumors. Further studies to elucidate the role of MT in germ cell tumor chemoresistance are warranted.