Project description:Following the discovery of BRD4 as a non-oncogene addiction target in acute myeloid leukemia (AML), BET inhibitors are being explored as promising therapeutic avenue in numerous cancers. While clinical trials have reported single-agent activity in advanced hematologic malignancies, mechanisms determining the response to BET inhibition remain poorly understood. To identify factors involved in primary and acquired BET resistance in leukemia, we performed a chromatin-focused shRNAmir screen in a sensitive MLL/AF9; NrasG12D‑driven AML model, and investigated dynamic transcriptional profiles in sensitive and resistant murine and human leukemias. Our screen reveals that suppression of the PRC2 complex, contrary to effects in other contexts, promotes BET resistance in AML. PRC2 suppression does not directly affect the regulation of Brd4-dependent transcripts, but facilitates the remodeling of regulatory pathways that restore the transcription of key targets such as Myc. Similarly, while BET inhibition triggers acute MYC repression in human leukemias regardless of their sensitivity, resistant leukemias are uniformly characterized by their ability to rapidly restore MYC transcription. This process involves the activation and recruitment of WNT signaling components, which compensate for the loss of BRD4 and drive resistance in various cancer models. Dynamic ChIP- and STARR-seq enhancer profiles reveal that BET-resistant states are characterized by remodeled regulatory landscapes, involving the activation of a focal MYC enhancer that recruits WNT machinery in response to BET inhibition. Together, our results identify and validate WNT signaling as a driver and candidate biomarker of primary and acquired BET resistance in leukemia, and implicate the rewiring of transcriptional programs as an important mechanism promoting resistance to BET inhibitors and, potentially, other chromatin-targeted therapies. RNA-Seq of DMSO- or JQ1-treated cancer cell lines; ChIP-seq for H3K36me3 and H3K27me3 in a leukemia cell line treated either with DMSO or JQ1, ChIP-seq for H3K27ac in resistant and sensitive mouse and human leukemia. Functional enhancer mapping (STARR-seq) in K-562 treated either with DMSO or JQ1.
Project description:Objective of the study is to determine global changes in gene expression after HDAC inhibitor Trichostatin (TSA) treatment in H69 cell line
Project description:Histone deacetylase (HDAC) inibitors suppress cell proliferation of prostate cancer, but the detailed mechanisms are unknown. Moreover, HDAC includes 18 family members, namely HDAC1-11 and SIRT1-7, and differences of effects on prostate cancer proliferation among these enzymes are also unknown. Thus, we clarified differences of gene expression between prostate cancer cell line (LNCaP) treated with pan-HDAC inhibitors (TSA and OBP-801) or selective HDAC inhibitor (NCC-149, HDAC8-specific inhibitor)using cDNA microarray. LNCaP treated with TSA (1μM), NCC149 (2μM), OBP-801 (200nM) or DMSO for 24hrs, RNA was extracted from cells, and cDNA array was performed.
Project description:Knockdown of the oncogene, BRD4-NUT, in a rare cancer, termed NUTmidline carcinoma (NMC), results in morphologic features consistent with squamous differentiation. Treatment with the HDAC-inhibitor, TSA, appears to cause the same phenotype. Here, we use gene expression profiling to compare the changes in gene expression following BRD4-NUT knockdown and TSA treatment.
Project description:Genome wide expression changes following treatment with the HDACs (Histone Deacetylase Inhibitor) CG-1521 (7.5uM) or TSA (Trichostatin A) were investigated to determine regulatory targets and patterns of the HDAC Inhibitors. Keywords: Expression response to treatment, data was used for a comparison of gene expression and regulation between CG-1521 and TSA in LNCaP Cells
Project description:Two human acute lymphoblastic leukemia cell lines were treated with a BET bromodomain inhibitor that blocks BET association with chromatin. These cell lines, MHH-CALL4 and MUTZ-5, each carry translocation of the CRLF2 gene into the IgH locus, and their growth was found to be susceptible to BET inhibition. Gene expression changes were analyzed in each cell line versus vehicle control. Cell were treated for 8 hours with either DMSO or 500nM of the BET bromodomain inhbitor JQ1. Three samples for each treatment were taken and analyzed for each cell line. CEL files were analyzed at both the core and extended gene level by RMA with the Affymetrix Expression Console software.
Project description:Histone deacetylase (HDAC) inibitors suppress cell proliferation of prostate cancer, but the detailed mechanisms are unknown. Moreover, HDAC includes 18 family members, namely HDAC1-11 and SIRT1-7, and differences of effects on prostate cancer proliferation among these enzymes are also unknown. Thus, we clarified differences of gene expression between prostate cancer cell line (LNCaP) treated with pan-HDAC inhibitors (TSA and OBP-801) or selective HDAC inhibitor (NCC-149, HDAC8-specific inhibitor)using cDNA microarray.