Project description:The anthracycline doxorubicin is a highly effective anti-cancer drug associated with severe side effects, including secondary tumors and cardiotoxicity. Doxorubicin induces DNA damage through double-strand breaks (DSBs) and epigenetic or chromatin damage through histone eviction. We examined whether separation of these activities can help to detoxify doxorubicin, while maintaining its chemotherapeutic efficacy. We show that anthracycline variants harboring the histone eviction activity alone remain potent anti-cancer drugs, while greatly alleviating cardiotoxicity and secondary tumor formation. We thus demonstrate that treatment-limited side effects of doxorubicin can be synthesized away, yielding effective chemotherapeutics towards improved and prolonged treatment responses and higher patient quality of life.
Project description:The anthracycline doxorubicin (Doxo) is one of the most effective and commonly used anti-cancer drugs. However, its clinical application is limited by severe side effects, such as cardiotoxicity, therapy-related tumors and infertility. Doxo induces both DNA damage through double-strand breaks and chromatin damage through histone eviction. We examined whether separating these activities would detoxify Doxo, while maintaining its chemotherapeutic efficacy. Here we present anthracycline variants harboring the histone eviction activity alone which remain potent anti-cancer drugs, while greatly alleviating cardiotoxicity and therapy-related tumor formation. This suggests that the treatment-limited side effects of Doxo in mice can be strongly reduced by modifying the chemical structure. The modified anthracycline anti-cancer drugs may provide effective chemotherapeutics allowing prolonged treatment and a higher quality of life post-treatment.
Project description:Doxorubicin is a widely used and effective anthracycline chemotherapy drug, which use is limited due to its cardiotoxic side effects. We show that gene therapy with AAV-VEGF-B can inhibit the doxorubicin-induced cardiac atrophy and whole body cachexia.
Project description:Although chemotherapy induces complete remission in the majority of acute myeloid leukemia (AML) patients, many face a relapse. This relapse is caused by survival of chemotherapy-resistant leukemia (stem) cells, called measurable residual disease (MRD). Here, we demonstrate that the anthracycline doxorubicin epigenetically reprograms leukemia cells by inducing tri-methylation of histone 3 lysine 27 (H3K27) and H3K4. Moreover, within a doxorubicin-sensitive leukemia cell population, we identified a subpopulation of reversible anthracycline-tolerant cells (ATCs) with leukemic stem cell (LSC) features lacking upregulation of doxorubicin-induced H3K27me3 or H3K4me3. These ATCs have a distinct transcriptional landscape than the leukemia bulk and could be eradicated by inhibition of KDM6. In primary AML, reprogramming the transcriptional state by targeting KDM6 reduced MRD load and survival of LSCs residing within MRD, and enhanced the response to chemotherapy in vivo. Together, our results reveal plasticity of anthracycline resistance in AML cells and highlight the potential of transcriptional reprogramming by epigenetic-based therapeutics to target chemotherapy-resistant AML cells.
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:The anthracycline doxorubicin is a commonly used chemotherapeutic drug that induces cardiomyopathy in almost 10% of patients. The aim of this study was to examine the role of the leukocyte-derived enzyme Myeloperoxidase (MPO) in pathogenesis of anthracycline-induced Cardiomyopathy (AICM). We performed proteomics on whole heart tissue of MPO-deficient mice on C57BL/6J background and wildtype (WT) littermates seven days after intravenous injection of the anthracycline Doxorubicin (20 mg/kg bodyweight, dissolved in saline) or saline (NaCl).
Project description:Anthracyclines act by disrupting the interface of TopoII and DNA and by evicting histones. The anthracycline-specific redistribution of TopoII and its association with histone eviction were addressed in K562 cells. Chromatin immunoprecipitation, followed by deep sequencing (ChIP-seq) against endogenously tagged TopoIIα, and transposase-accessible chromatin with sequencing (ATAC-seq) was performed 4 hours after anthracycline exposure.
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.
Project description:Doxorubicin as a commonly used anthracycline has become the cornerstone of chemotherapy in a wide range of cancers owing to its high efficacy. However, clinical applications of doxorubicin are limited mainly due to its toxic effects on myocardium but the pathogenic mechanism of doxorubicin-induced cardiomyopathy are poorly understood. ADAM17 is known as tumor necrosis factor α converting enzyme (TACE), and the cleavage of TNF-α by ADAM17 is a prerequisite for pro-inflammatory TNF-α activity, which raises a possibility that inhibition of ADAM17 may exert a beneficial effect on disease processes where TNF-α plays an essential role. Our previous research has shown that cardiomyocyte specific knockout of ADAM17 improves diabetic cardiomyopathy by modulating cardiomyocyte apoptosis. However, the relationship between ADAM17 and doxorubicin-induced cardiomyopathy is unclear.Through RNA sequencing analysis, we observed significant changes in the TNF signaling pathway genes in the heart tissue of mice with or without cardiomyocyte ADAM17 knockout.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.