ABSTRACT: Identification of expresion patterns after treatment with GC/RA and combination with AZA/SAHA in MYC amplified and BRG1 mutant lung cancer cell lines
Project description:Comprehensive characterization of the DNA methylome regulated by the treatment with glucocorticoids (GC) and retinoic acid (RA) alone and combined with AZA/SAHA and the relationship of these features with the status of BRG1 and MYC in lung cancer cell lines. MYC amplified cell lines and BRG1 mutant cell lines were treated with glucocorticoids (GC) and retinoic acid (RA) alone and combined with AZA/SAHA and their methylation was then measured
Project description:To development our gene expression approach , we have employed whole genome microarray expression profiling as a discovery platform to identify genes potentialy regulated by the treatment with glucocorticoids (GC) and retinoic acid (RA) alone and combined with AZA/SAHA and the relationship of these features with the status of BRG1 and MYC in lung cancer cell lines. MYC amplified cell lines and BRG1 mutant cell lines were treated with glucocorticoids (GC) and retinoic acid (RA) alone and combined with AZA/SAHA and their expression was then measured
Project description:Comprehensive characterization of the DNA methylome regulated by the treatment with glucocorticoids (GC) and retinoic acid (RA) alone and combined with AZA/SAHA and the relationship of these features with the status of BRG1 and MYC in lung cancer cell lines.
Project description:To development our gene expression approach , we have employed whole genome microarray expression profiling as a discovery platform to identify genes potentialy regulated by the treatment with glucocorticoids (GC) and retinoic acid (RA) alone and combined with AZA/SAHA and the relationship of these features with the status of BRG1 and MYC in lung cancer cell lines.
Project description:Patterns of changes in DNA global methylation following the treatment with GC/RA and with GC/RA plus AZA/SAHA in MYC amplified and BRG1 mutant lung cancer cell lines
Project description:Combination therapies targeting malignancies aim to increase treatment efficacy and reduce toxicity. Hypomethylating drug 5-Aza-2’-deoxycytidine (5-Aza-2’) enhances transcription of tumor suppressor genes and induces replication errors via entrapment of DNMT1. Post-translational modification by SUMO plays major roles in the DNA damage response and is required for degradation of entrapped DNMT1. Here, we combine SUMOylation inhibitor TAK981 and DNA-hypomethylating agent 5-Aza-2’ to improve treatment of MYC driven hematopoietic malignancies, since MYC overexpressing tumors are sensitive to SUMOylation inhibition. We studied the classical MYC driven malignancy Burkitt lymphoma, as well as diffuse large B-cell lymphoma (DLBCL) with and without MYC translocation. SUMO inhibition prolonged the entrapment of DNMT1 to DNA, resulting in DNA damage. An increase in DNA damage was observed in cells co-treated with TAK981 and 5-Aza-2’. Both drugs synergized to reduce cell proliferation in vitro in a B cell lymphoma cell panel, including Burkitt lymphoma and DLBCL. In vivo experiments combining TAK981 (25 mg/kg) and 5-Aza-2’ (2.5 mg/kg) showed a significant reduction in outgrowth of Burkitt lymphoma in an orthotopic xenograft model. In contrast, single dosing of TAK981 was ineffective and single dosing of 5-Aza-2’ only led to a modest outgrowth reduction. TAK981 and 5-Aza-2’ synergize to reduce B cell Lymphoma outgrowth in vitro and in vivo. SUMOylation is a key-player in the repair of DNA damage, hence upon TAK981 treatment the repair of DNA damage induced by 5-Aza-2’ treatment is impaired. Our results demonstrate the potential of tailored combination of drugs, based on insight in molecular mechanisms, to improve the efficacy of cancer therapies.
Project description:Combination therapies targeting malignancies aim to increase treatment efficacy and reduce toxicity. Hypomethylating drug 5-Aza-2’-deoxycytidine (5-Aza-2’) enhances transcription of tumor suppressor genes and induces replication errors via entrapment of DNMT1. Post-translational modification by SUMO plays major roles in the DNA damage response and is required for degradation of entrapped DNMT1. Here, we combine SUMOylation inhibitor TAK981 and DNA-hypomethylating agent 5-Aza-2’ to improve treatment of MYC driven hematopoietic malignancies, since MYC overexpressing tumors are sensitive to SUMOylation inhibition. We studied the classical MYC driven malignancy Burkitt lymphoma, as well as diffuse large B-cell lymphoma (DLBCL) with and without MYC translocation. SUMO inhibition prolonged the entrapment of DNMT1 to DNA, resulting in DNA damage. An increase in DNA damage was observed in cells co-treated with TAK981 and 5-Aza-2’. Both drugs synergized to reduce cell proliferation in vitro in a B cell lymphoma cell panel, including Burkitt lymphoma and DLBCL. In vivo experiments combining TAK981 (25 mg/kg) and 5-Aza-2’ (2.5 mg/kg) showed a significant reduction in outgrowth of Burkitt lymphoma in an orthotopic xenograft model. In contrast, single dosing of TAK981 was ineffective and single dosing of 5-Aza-2’ only led to a modest outgrowth reduction. TAK981 and 5-Aza-2’ synergize to reduce B cell Lymphoma outgrowth in vitro and in vivo. SUMOylation is a key-player in the repair of DNA damage, hence upon TAK981 treatment the repair of DNA damage induced by 5-Aza-2’ treatment is impaired. Our results demonstrate the potential of tailored combination of drugs, based on insight in molecular mechanisms, to improve the efficacy of cancer therapies.
Project description:Analysis of steady-state mRNA levels in induced pluripotent stem cells (iPSCs) differentiated for 5 days with retinoic acid (RA) and treated for final 48 hrs with GSK343 (EZH2 inhibitor), 5-azacytidine (5-aza, DNA methyltransferase inhibitor), or their combination (Combo).
Project description:Cancer cells frequently depend on chromatin regulatory activities to maintain a malignant phenotype. Here, we show that leukemia cells require the mammalian SWI/SNF chromatin remodeling complex for their survival and aberrant self-renewal potential. While Brg1, an ATPase subunit of SWI/SNF, is known to suppress tumor formation in several cancer types, we found that leukemia cells instead rely on Brg1 to support their oncogenic transcriptional program, which includes Myc as one of its key targets. To account for this context-specific function, we identify a cluster of lineage-specific enhancers located 1.7 megabases downstream of Myc that are occupied by SWI/SNF, as well as the BET protein Brd4. Brg1 is required at these distal elements to maintain transcription factor occupancy and for long-range chromatin looping interactions with the Myc promoter. Notably, these distal Myc enhancers coincide with a region that is focally amplified in 3% of acute myeloid leukemia. Together, these findings define a leukemia maintenance function for SWI/SNF that is linked to enhancer-mediated gene regulation, providing general insights into how cancer cells exploit transcriptional coactivators to maintain oncogenic gene expression programs In order to understanding the transcription regulation network downstream of Brg1 in murine AML, we performed microarray in murine MLL-AF9/NrasG12D cell line under the condition that Brg1 was suppressed by three independent shRNAs for 96h.
