AFM studies of DNA structures extracted from adriamycin treated and non-treated Ehrlich tumor cells

Abstract

Atomic force microscopy (AFM), a unique tool to investigate drug treatment of cancer cells, was used to analyze the anti-neoplastic activity of adriamycin by comparing DNA structures of non-treated and adriamycin-treated Ehrlich tumor cells. The non-treated cells exhibited a highly branched intact chromatin structure, related to the intensive DNA replication in cancer cells. Images from adriamycin-treated tumor cells showed that the DNA chains were broken and the chromatin structure had been destroyed. Possible explanations for these effects of adriamycin are considered: breakage of hydrogen bonding, oxidation and intercalation effects, as well as the poisoning of topoisomerase enzyme. DNA fractal and multifractal analyses, performed in order to evaluate the degree of bond scission, showed that the treated DNA had become more fractal compared to non-treated DNA.