Abstracts Category : Other

Investigation on triple helical cylinders' effects on human osteosarcoma U2OS cells

by Melika Hadjebi

The aim of this study is to investigate the activity of supermolecular iron and ruthenium cylinders and their interactions with the DNA replication fork, as the possible target of action for cylinders. The impacts of two homologues, triple helical iron(II) and ruthenium(II) homologous, as metallodrug agents on U20S cells are studied using different techniques. Both complexes demonstrate toxicity with significant IC50 values against U20S cells, although they improve the nongenotoxicity effect in this cell line. These outcomes contrast with the results of cisplatin, both in comet and MTT assays. In this study, cisplatin slightly damages the DNA helix and does not show significant cytotoxicity against the studied cells. The cellular uptake results prove that cells can absorb the ruthenium cylinder, but just one fifth of the total ruthenium concentration is detected inside the nucleus, and most is trapped in the membrane.Confocal microscopy is applied using two different methods (live- and fixed-cell microscopy), to survey the cellular uptake of cylinders in addition to their binding affinity to the DNA major groove. Hoechst is used for this purpose, as it is a well-known minor groove binder probe. Hoechst decrease in fluorescence as a result of cylinder replacement is not observed by these imaging techniques, and the results do not show cylinder interaction with the DNA major groove in U20S cells, despite previous results in other cell lines. Meanwhile, the protein immunoblot analysis does not produce desirable results regarding the DNA replication fork interaction with the ruthenium cylinder. The P-ChKl detection results for the iron cylinder could not be repeated, despite the fact that in some cases they do demonstrate stress on the replication fork.