biostudies-literatureUnknown3(12)Weynand JHerein we report on the study of novel dinuclear ruthenium(ii) complexes designed to target and to photo-react with G-quadruplex telomeric DNA. Upon irradiation, complexes efficiently generate guanine radical cation sites as photo-oxidation products. The compounds also display efficient cell penetration with localization to the nucleus and show strong photocytotoxicity toward osteosarcoma cells. Thanks to a microscopic-based telomere dysfunction assay, which allows the direct visualization of DNA damage in cells, we brought the first evidence of forming photo-oxidative damage at telomeres in cellulo. This emphasizes interesting prospects for the development of future cancer phototherapies.RSC chemical biology1375-1379https://www.ebi.ac.uk/biostudies/studies/S-EPMC9709782biostudies-literaturePhoto-induced telomeric DNA damage in human cancer cells.PMC9709782Gillard MLe Berre GEpiskopou HDejeu JWeynand JElias BDecottignies ADefrancq EfalsePhoto-induced telomeric DNA damage in human cancer cells.Herein we report on the study of novel dinuclear ruthenium(ii) complexes designed to target and to photo-react with G-quadruplex telomeric DNA. Upon irradiation, complexes efficiently generate guanine radical cation sites as photo-oxidation products. The compounds also display efficient cell penetration with localization to the nucleus and show strong photocytotoxicity toward osteosarcoma cells. Thanks to a microscopic-based telomere dysfunction assay, which allows the direct visualization of DNA damage in cells, we brought the first evidence of forming photo-oxidative damage at telomeres in cellulo. This emphasizes interesting prospects for the development of future cancer phototherapies.2022-01-01T00:00:00Z2022 Nov2025-04-18T17:13:45.931Z2025-04-07T04:46:38.806ZS-EPMC97097823654457510.1039/d2cb00192f