Effects of Second-Generation Platinum Analogs on Isolated PM-2 DNA and Their Cytotoxicity in Vitro and in Vivo1

broken linear (Form III) PM-2 DNA, however, was not affected in a manner similar to Form II or Form I PM-2 DNA species. The purposes of the present study were (a) to categorize the second-generation platinum congeners based on in vitro DNA interactions, (b) to study the structure activity relationships of platinum-DNA interactions, and (C) to determine if the in vitro cytotoxicity and in vivo antitumor activity of second-generation platinum analogs correlate with their ability to interact with PM 2 DNA, recognizing, of course, that factors other than DNA interactions may be of equal or greater importance. trans Diamminedichloroplatinum(Il), for example, has been shown to produce unwinding of DNA but is a less potent cytotoxic agent than COOP(3).