DNA interactions of 2-pyrrolinodoxorubicin, a distinctively more potent daunosamine-modified analogue of doxorubicin

Abstract

It was shown earlier that 2-pyrrolinodoxorubicin was 500-1000 times more active towards human and mouse cancer cells in vitro than parental doxorubicin. However, the biochemical factors responsible for such a large difference in potency between doxorubicin and 2-pyrrolinodoxorubicin are not clear at the molecular level. To provide this information, we have investigated in cell-free media by biochemical and biophysical methods interactions of both anthracyclines with DNA, effects of these interactions on activity of human topoisomerase II, human Bloom's syndrome helicase and prokaryotic T7 RNA polymerase, and the capability of these drugs to form DNA interstrand cross-links in formaldehyde-free medium. Experiments aimed at understanding the properties of double-helical DNA in the presence of doxorubicin and 2-pyrrolinodoxorubicin revealed only small differences in DNA modifications by these anthracyclines and resulting conformational alterations in DNA. Similarly, the ability of 2-pyrrolinodoxorubicin modifications of DNA to inhibit catalytic activity of topoisomerase II does not differ significantly from that of doxorubicin. On the other hand, we demonstrate that an important factor responsible for the markedly higher antiproliferative potency of DNA modifications by 2-pyrrolinodoxorubicin is capability of these modifications to inhibit downstream cellular processes which process DNA damaged by this drug and involve separation of complementary strands of DNA, such as DNA unwinding by helicases or RNA polymerases. In addition, the results are also consistent with the hypothesis that in particular the capability of 2-pyrrolinodoxorubicin to readily form DNA interstrand cross-links is responsible for inhibition of these processes in the cells treated with this analogue of doxorubicin.

Targeted Cancer Therapy with a 2-Deoxyglucose–Based Adriamycin Complex

“…Thus, it is feasible to covalently bind the amino group with carboxyl groups to form a stable amide bond. In addition, studies have shown that modification of the primary amino group could greatly reduce the cardiotoxicity, which is one of the main objectives to modify ADM (16).…”

Mitomycin C and doxorubicin elicit conflicting signals by causing accumulation of cyclin E prior to p21WAF1/CIP1 elevation in human hepatocellular carcinoma cells

“…Doxorubicin is another useful wide-spectrum anticancer drug with a mechanism of action distinct from that of mitomycin C (14). Doxorubicin efficiently intercalates between DNA bases, and a ternary drug-DNA-topoisomerase II 'cleavable complex' (15,16) is subsequently formed. Such structural changes ultimately inactivate topoisomerase, and excision and rejoining of the damaged region cannot proceed (17).…”

Utilizing DNA for functionalization of biomaterial surfaces

“…Some molecules like doxorubicin [86,87] and related molecules [88,89] can intercalate into the double strand of DNA and are typically available for biological interactions only after DNA is degraded. Other strategies aim at immobilizing BAM while simultaneously making them available for interaction with the surrounding biological system without necessitating DNA degradation; these are the methods that the following chapters will focus on.…”