Possible mechanism for differences in sensitivity to cis-platinum in human prostate tumor cell lines

Two human prostate tumor cell lines which exhibit a 2.4-fold difference in sensitivity to cis-platinum (cis-Pt) were found to possess slightly different sulphydryl contents, and the presence of a metallothionein-like zinc-binding protein was demonstrated in the line exhibiting relative resistance to cis-Pt. Although these factors have been postulated to play a role in the mechanism(s) of resistance to cis-Pt in other cell types, preliminary data in this report suggest that differences found in drug uptake and subsequent binding to DNA are most likely responsible for variations in cis-Pt sensitivity displayed by these prostate tumor cell lines.