A clickable melphalan for monitoring DNA interstrand crosslink accumulation and detecting ICL repair defects in Fanconi anemia patient cells
Résumé
Fanconi anemia (FA) is a genetic disorder associated with developmental defects, bone marrow failure and cancer. The FA pathway is crucial for the repair of DNA interstrand crosslinks (ICLs). In this study, we have developed and characterized a new tool to investigate ICL repair: a c lic kable version of the crosslinking agent melphalan which we name c lic k-melphalan. Our results demonstrate that c lic k-melphalan is as effective as its unmodified counterpart in generating ICLs and associated toxicity. The lesions induced by clickmelphalan can be detected in cells by post-labelling with a fluorescent reporter and quantified using flow cytometry. Since c lic k-melphalan induces both ICLs and monoadducts, we generated c lic k-monomelphalan, which only induces monoadducts, in order to distinguish between the two types of DNA repair. By using both molecules, we show that FANCD2 knockout cells are deficient in removing c lic k-melphalan-induced lesions. We also found that these cells display a delay in repairing c lic kmono-melphalan-induced monoadducts. Our data further revealed that the presence of unrepaired ICLs inhibits monoadduct repair. Finally, our study demonstrates that these c lic kable molecules can differentiate intrinsic DNA repair deficiencies in primary FA patient cells from those in primary xeroderma pigmentosum patient cells. As such, these molecules may have potential for developing diagnostic tests.
Domaines
Sciences du Vivant [q-bio]
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