American Association for Cancer Research
00085472can172690-sup-188568_2_supp_4460584_p17rqq.docx (29.66 kB)

Supplementary Materials and Methods from Role of Chromatin Damage and Chromatin Trapping of FACT in Mediating the Anticancer Cytotoxicity of DNA-Binding Small-Molecule Drugs

Download (29.66 kB)
journal contribution
posted on 2023-03-31, 02:22 authored by Elimelech Nesher, Alfiya Safina, Ieman Aljahdali, Scott Portwood, Eunice S. Wang, Igor Koman, Jianmin Wang, Katerina V. Gurova

File contains the list of all chemicals, reagents, antibodies and cells used with sources and catalogue numbers, as well as detailed description of all methods, mentioned in the in the main text, including cytotoxicity assays, imaging, cell-free experiments nascent RNA-seq, ChIP-seq. Includes Supplementary Table 1.



National Cancer Institute

Roswell Park Cancer

Komen Foundation



Precisely how DNA-targeting chemotherapeutic drugs trigger cancer cell death remains unclear, as it is difficult to separate direct DNA damage from other effects in cells. Recent work on curaxins, a class of small-molecule drugs with broad anticancer activity, shows that they interfere with histone–DNA interactions and destabilize nucleosomes without causing detectable DNA damage. Chromatin damage caused by curaxins is sensed by the histone chaperone FACT, which binds unfolded nucleosomes becoming trapped in chromatin. In this study, we investigated whether classical DNA-targeting chemotherapeutic drugs also similarly disturbed chromatin to cause chromatin trapping of FACT (c-trapping). Drugs that directly bound DNA induced both chromatin damage and c-trapping. However, chromatin damage occurred irrespective of direct DNA damage and was dependent on how a drug bound DNA, specifically, in the way it bound chromatinized DNA in cells. FACT was sensitive to a plethora of nucleosome perturbations induced by DNA-binding small molecules, including displacement of the linker histone, eviction of core histones, and accumulation of negative supercoiling. Strikingly, we found that the cytotoxicity of DNA-binding small molecules correlated with their ability to cause chromatin damage, not DNA damage. Our results suggest implications for the development of chromatin-damaging agents as selective anticancer drugs.Significance: These provocative results suggest that the anticancer efficacy of traditional DNA-targeting chemotherapeutic drugs may be based in large part on chromatin damage rather than direct DNA damage. Cancer Res; 78(6); 1431–43. ©2018 AACR.