Project description:Many anti-cancer drugs induce DNA breaks to eliminate tumor cells. The anthracycline topoisomerase II inhibitors can also evict histones. We performed a genome-wide high-resolution mapping of chemotherapeutic effects of various topoisomerase I and II inhibitors. We show that different drugs target different types of chromatin for induction of DNA damage and histone eviction. Topoisomerase inhibitors topotecan and etoposide similarly target transcriptionally active chromatin for DNA damage. Daunorubicin induces DNA breaks and evicts histones in active chromatin, thus quenching local DNA damage response. The analog aclarubicin evicts histones in H3K27me3-marked heterochromatin. These results can guide rational treatment decisions regarding these genome manipulating anti-cancer drugs. FAIRE-seq and g-H2AX ChIP-seq were performed on K562 cells after drug exposure
Project description:Many anti-cancer drugs induce DNA breaks to eliminate tumor cells. The anthracycline topoisomerase II inhibitors can also evict histones. We performed a genome-wide high-resolution mapping of chemotherapeutic effects of various topoisomerase I and II inhibitors. We show that different drugs target different types of chromatin for induction of DNA damage and histone eviction. Topoisomerase inhibitors topotecan and etoposide similarly target transcriptionally active chromatin for DNA damage. Daunorubicin induces DNA breaks and evicts histones in active chromatin, thus quenching local DNA damage response. The analog aclarubicin evicts histones in H3K27me3-marked heterochromatin. These results can guide rational treatment decisions regarding these genome manipulating anti-cancer drugs.
Project description:A major class of chemotherapeutics targets topoisomerase II for DNA double-strand breaks and cancer cell elimination. We compare four members of this class?the anthracyclines doxorubicin, daunorubicin and aclarubicin that does not induce DNA breaks?and a different compound, etoposide. We define a novel activity for anthracyclines: histone eviction from open chromosomal areas. Since histone variant H2AX is also evicted, DNA damage response is attenuated when compared to etoposide. Histone eviction also affects the epigenetic code and deregulates the transcriptome in cancer cells and organs such as the heart. Histone eviction by anthracyclines can drive apoptosis of topoisomerase-negative acute myeloid leukemia blasts in patients. Doxo- and daunorubicin combine the activities of two anti-cancer drugs: etoposide for DNA damage and aclarubicin for histone eviction. We define a novel mechanism of action of anti-cancer drugs doxo- and daunorubicin on chromatin biology with profound consequences on DNA damage responses, epigenetics, transcription, side effects and anti-cancer activities. Comparison of histone occupancy of cells or tissues treated with topoisomerase II inhibitors to un-treated ones by FAIRE-seq.
Project description:One major class of anti-cancer drugs targets topoisomerase II to induce DNA double-strand breaks and cell death of fast growing cells. Here, we compare three members of this class - the antracyclines doxorubicin and aclarubicin, and a chemically unrelated compound, etoposide. Aclarubicin does not induce DNA breaks. We define a new activity for the antracyclines: unsupported histone eviction from ´open´ or loosely packed chromosomal areas reflecting exon and promoter regions. Comparison of histone H3K4me3 of cells post topoisomerase II inhibitors treatment to un-treated ones by ChIP-seq. Comparison of phosphorylated histone H2AX of cells post topoisomerase II inhibitors doxorubicin and etoposide treatment to un-treated ones by ChIP-seq.
Project description:The effects of several compounds on the MCF7 human adenocarcinoma mammary cell line were analysed by gene expression profiling. Tested compounds: HSP90 inhibitors: 17AAG (Tanespimycin), NVP-AUY922, NMS-E973 (cpd developed at NMS). CDK inhibitors: CDK-887 (cpd developed at NMS). Topoisomerase inhibitors: Doxorubicin, SN38 (active metabolite of Irinotecan). The MCF7 cell line was treated with the different compounds for 6 hours at a dose equal to 5 times the IC50. Untreated MCF7 cells were used as a control. Two replicates per treatment.
Project description:Glucocorticoids (GCs) and topoisomerase II inhibitors are used in the treatment of acute lymphoblastic leukaemia (ALL) due to their ability to induce cell death in lymphoid cells. GC-induced apoptosis is mediated by the glucocorticoid receptor (GR), whereas topoisomerase II inhibitors cause DNA damage and activate sensors of DNA damage including the tumour suppressor p53. In order to shed light on the role of the microenvironment in cell death and identify determinants of drug sensitivity we performed transcriptomic analysis in ALL cells treated with the synthetic glucocorticoid dexamethasone, and the topoisomerase II inhibitor etoposide combined with bone marrow-derived conditioned media (CM).