Novel polyamide amidine anthraquinone platinum(II) complexes: cytotoxicity, cellular accumulation, and fluorescence distributions in 2D and 3D cell culture models

1- and 1,5-Aminoalkylamine substituted anthraquinones (AAQs, 1C3 and 1,5C3) were peptide coupled to 1-, 2-, and 3-pyrrole lexitropsins to generate compounds that incorporated both DNA minor groove and intercalating moieties. The corresponding platinum(II) amidine complexes were synthesized through a synthetically facile amine-to-platinum mediated nitrile 'Click' reaction. The precursors as well as the corresponding platinum(II) complexes were biologically evaluated in 2D monolayer cells and 3D tumour cell models. Despite having cellular accumulation levels that were up to five-fold lower than that of cisplatin, the platinum complexes had cytotoxicities that were only three-fold lower. Accumulation was lowest for the complexes with two or three pyrrole groups, but the latter was the most active of the complexes exceeding the activity of cisplatin in the MDA-MB-231 cell line. All compounds showed moderate to good penetration into spheroids of DLD-1 cells with the distributions being consistent with active uptake of the pyrrole containing complexes in regions of the spheroids starved of nutrients

Platinum binding preferences dominate the binding of novel polyamide amidine anthraquinone platinum(II) complexes to DNA

Complexes incorporating a threading anthraquinone intercalator with pyrrole lexitropsin and platinum(II) moieties attached were developed with the goal of generating novel DNA binding modes, including the targeting of AT-rich regions in order to have high cytotoxicities. The binding of the complexes to DNA has been investigated and profiles surprisingly similar to that for cisplatin were observed; the profiles were different to those for a complex lacking the pyrrole lexitropsin component. The lack of selective binding to AT-rich regions suggests the platinum binding was dominating the sequence selectivity, and is consistent with the pyrrole lexitropsin slowing intercalation. The DNA unwinding profiles following platinum binding were evaluated by gel electrophoresis and suggested that intercalation and platinum binding were both occurring

Cancer: evolutionary, genetic and epigenetic aspects

There exist two paradigms about the nature of cancer. According to the generally accepted one, cancer is a by-product of design limitations of a multi-cellular organism (Greaves, Nat Rev Cancer 7:213–221, 2007). The essence of the second resides in the question “Does cancer kill the individual and save the species?” (Sommer, Hum Mutat 3:166–169, 1994). Recent data on genetic and epigenetic mechanisms of cell transformation summarized in this review support the latter point of view, namely that carcinogenesis is an evolutionary conserved phenomenon—a programmed death of an organism. It is assumed that cancer possesses an important function of altruistic nature: as a mediator of negative selection, it serves to preserve integrity of species gene pool and to mediate its evolutionary adjustment. Cancer fulfills its task due apparently to specific killer function, understanding mechanism of which may suggest new therapeutic strategy