Project description:This SuperSeries is composed of the following subset Series:; GSE11940: Topoisomerase II inhibition involves characteristic chromosomal expression patterns: Doxorubicin study; GSE11941: Topoisomerase II inhibition involves characteristic chromosomal expression patterns: Trovafloxacin study Experiment Overall Design: Refer to individual Series
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:A variety of important anticancer drugs kill cells by increasing cellular levels of topoisomerase II-DNA cleavage complex. The anthracycline anticancer drug doxorubicin forms a stable ternary complex with DNA and topoisomerase IIa, thereby inhibiting the normal function of the enzyme. In this study we found genes regulated by doxorubicin - induced and repressed - to be located much closer to each other than genes distributed randomly all over the genome (< 100 kbp). Keywords: Doxorubicin-treated human hepatocytes versus non-treated human hepatocytes
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.
Project description:A variety of important anticancer drugs kill cells by increasing cellular levels of topoisomerase II-DNA cleavage complex. The anthracycline anticancer drug doxorubicin forms a stable ternary complex with DNA and topoisomerase IIa, thereby inhibiting the normal function of the enzyme. In this study we found genes regulated by doxorubicin - induced and repressed - to be located much closer to each other than genes distributed randomly all over the genome (< 100 kbp). Experiment Overall Design: We calculated specifically the probability by which particular genes which were deregulated by the treatment of human hepatocytes with doxorubicin will occur within DNA windows of different sizes as compared to the probability of all known mapped genes (RefSeq transcripts) of the human genome (NCBI RefSeq 19,360; build 36.2) to occur within the same DNA windows.
Project description:Doxorubicin is a widely used chemotherapeutic drug that intercalates between DNA base-pairs and posions Topoisomerase II, although the mechanistic basis for cell killing remains speculative. Here we show that both anthracyclines and Topoisomerase II poison cause enhanced DNA double-strand breaks around CpG island promoters of active genes genome-wide. We propose that torsion-based enhancement of nucleosome turnover exposes promoter DNA, ultimately causing DNA breaks around promoters that contributes to cell killing. We have analyzed mouse squamous cell carcinoma cells treated with doxorubicin, aclarubicin and etoposide. The direct in situ Breaks Labeling, Enrichment on Streptavidin (BLESS, PMID 23503052) method was used for mapping DNA double-strand breaks genome-wide.
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. As a result, the epigenome and the transcriptome are strongly affected. Tissue culture cells were treated with doxorubicin, aclarubicin or etoposide for 2 hours. Then drugs were removed by extensive washing. cells were further cultured for indicated days before total RNA were extracted and compared to un-treated control.