Structural changes of DNA induced by mono- and binuclear cancer drugs.
The structural features of the drug-DNA adducts resulted from treatment of DNA with the platinum based mononuclear drug cisplatin and the binuclear drug [{trans-PtCl(NH3)2}2H2N(CH2)4NH2]Cl2 or bis(platin) have been investigated by atomic force microscopy (AFM). Reduction in the contour length of the DNA fragments has been observed after cisplatin treatment while, compaction and aggregation are found to be the primary structural modifications following treatment with the binuclear drug. The intermolecular interaction upon bis(platin) treatment leads to observation of highly condense aggregates without a distinct sight of single isolated DNA molecule. These differences in drug binding indicate that unlike the mononuclear drug cisplatin, bis(platin) causes extensive interhelical/intermolecular cross-linking through its multiple linking sites. To our knowledge, this is the first report of a comparative AFM study to monitor the effects of a mono- and a binuclear platinum anti-cancer drug on DNA structure. These observations should provide clues towards explaining the distinct biological activities of the two drugs.
Mukhopadhyay
R
R
Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh, India. rupa@iNANO.dk
Dubey
P
P
Sarkar
S
S
D000538:Aluminum Silicates / Q000737:chemistry; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002945:Cisplatin / Q000494:pharmacology; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004247:DNA / Q000737:chemistry* / Q000187:drug effects*; D018736:DNA Adducts; D007091:Image Processing, Computer-Assisted; D046911:Macromolecular Substances / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D009690:Nucleic Acid Conformation / Q000187:drug effects*
D000538:Aluminum Silicates; D000970:Antineoplastic Agents; D003432:Cross-Linking Reagents; D018736:DNA Adducts; D046911:Macromolecular Substances; D004247:DNA; D002945:Cisplatin; C011934:mica