Project description:Background & Aims: The contribution of genetics to the pathogenesis of inflammatory bowel disease (IBD) has been established by twin studies, targeted sequencing and genome-wide association studies (GWASs). This has yielded a plethora of risk loci with an aim to identify causal variants. Research on the genetic components of IBD has mainly focused on protein coding genes, thereby omitting other functional elements in the human genome i.e. the regulatory regions. Methods: Using acetylated histone 3 lysine 27 (H3K27ac) chromatin immunoprecipitation and sequencing (ChIP-seq), we identified tens of thousands of potential regulatory regions that are active in intestinal epithelium and immune cells, the main cell types involved in IBD. We correlated these regions with susceptibility loci for IBD. Results: We show that 45 out of 163 single nucleotide polymorphisms (SNPs) associated with IBD co-localize with active regulatory elements. In addition, another 47 IBD associated SNPs co-localize with active regulatory element via other SNP in strong linkage disequilibrium. Altogether 92 out of 163 IBD-associated SNPs can be connected with distinct regulatory element. This is 2.5 to 3.5 times more frequent than expected from random sampling. The genomic variation in these SNPs often creates or disrupts known binding motifs - thereby possibly affecting the binding affinity of transcriptional regulators and altering the expression of regulated genes. Conclusions: We show that in addition to protein coding genes, non-coding DNA regulatory regions, active in immune cells and in intestinal epithelium, are involved in IBD. H3K27ac ChIP-seq (ab4729, Abcam) profile of 7 intestinal epithelial samples
Project description:Administration of azithromycin after allogeneic hematopoietic stem cell transplantation for hematological malignancies has been associated with relapse in a randomized phase 3 controlled clinical trial. Studying 240 samples from patients randomized in this trial is a unique opportunity to better understand the mechanisms underlying relapse, the first cause of mortality after transplantation. We used multi-omics on patients' samples to decipher immune alterations associated with azithromycin intake and post-transplant relapsed malignancies. Azithromycin was associated with a network of altered energy metabolism pathways and immune subsets, including T cells biased toward immunomodulatory and exhausted profiles. In vitro, azithromycin exposure inhibited T cells cytotoxicity against tumor cells and impaired T cells metabolism through glycolysis inhibition, mitochondrial genes downregulation, and immunomodulatory genes upregulation, notably SOCS1. These results highlight that azithromycin directly affects immune cells that favor relapse, which raises caution about long-term use of azithromycin treatment in patients at high risk of malignancies.
Project description:Ezh2 and EZH1 are histone H3 lysine 27 (H3K27)-specific methyltransferases. Their hyperactive mutations and overexpression were found in cancer including various hematological malignancies. UNC1999 is a highly selective inhibitor for both enzymes. It suppresses H3K27 tri- and di-methylation globally and inhibits growth of MLL-rearranged acute leukemia. Here we performed ChIP-Seq to profile how UNC1999 affects distribution of H3K27me3 and its antagonizing H3K27ac in MLL-AF9-immortalized leukemia cells. We also performed ChIP-seq of SUZ12, an essential common cofactor of EZH2 and EZH1 following compound treatments. We treated MLL-AF9 transformed murine leukemia cells with DMSO, UNC1999 or UNC2400 (an inactive analog compound of UNC1999). Cells were then collected and used for ChIP-Sequencing of Input, H3K27me3, SUZ12, and H3K27ac.
Project description:Immunosuppression caused by cancer itself and cytotoxic treatment may pose a challenge to coronavirus disease 2019 (COVID-19) patients with hematological malignancies. Here, we use multidimensional flow cytometry (MFC) to analyze immune profiles in peripheral blood samples of 515 COVID-19 patients at presentation. In 14 cases, deep immunophenotyping of B- and T-cells was performed and six myeloid- and dendritic-cell subsets were FACSorted for transcriptome analysis using RNAseq. Of the 515 patients, 15 and 10 had solid and hematological tumors, respectively. Those with hematological cancer showed significantly higher rates of intensive care (50%) and death (30%) from COVID-19 vs cases with solid cancer and no tumor. Patients with hematological malignancies displayed altered immune profiles with significantly decreased absolute numbers of several subsets of myeloid and lymphoid cells. Myeloid- and dendritic-cell types from hematological cases showed differentially expression of genes coding transcription factors, toll-like receptors and proinflammatory interleukin receptors implicated in response to coronaviruses. The relative distribution of the B-cell compartment was notoriously altered in COVID-19 patients with hematological cancer, and progressively lower numbers of B- and T-cell subsets were observed in deceased cases. Altogether, our results suggest an association between impaired immune responses and poorer outcomes in COVID-19 patients with hematological malignancies.
Project description:Background: Causative genes are mostly unknown for the mismatch repair-proficient category of familial colorectal cancers designated as FCCTX. Recent evidence suggests shared susceptibility factors between colorectal and hematological malignancies. Study design: We investigated 28 FCCTX families by exome sequencing, supplemented with whole genome sequencing, RNA-sequencing, and tumor studies to identify the predisposing genes. Guided by the findings, germline and somatic exomes of ~400 patients with acute leukemia, myelodysplastic syndrome, and myeloma were subsequently examined. Results: A family with hematological and solid malignancies revealed a truncating variant in the DEAH-box RNA helicase gene DHX40 co-segregating with disease in seven family members. Neoplastic tissues revealed no apparent “second hit”, implying a haploinsufficiency model of tumorigenesis. DHX40 siRNA-treated cell lines exhibited a 13% increase in aberrantly spliced transcripts vs. GAPDH-siRNA or non-target siRNA-treated cells. Two additional families showed truncating germline variants in the TDRD9 and TDRD5 genes encoding Tudor domain-containing RNA-binding proteins. In the hospital-based hematological series, 18% of germline and 28% of somatic exomes revealed possibly pathogenic DEAD/H box gene variants, including somatic variants of DHX40 in four. Conclusions: This study identifies DHX40, TDRD9, and TDRD5 as novel candidate genes for FCCTX predisposition. In the family segregating the truncating DHX40 variant, two carriers had hematological neoplasia, suggesting possible analogy to DDX41, a DEAD-box RNA helicase gene previously linked to myeloid malignancies. Our findings emphasize aberrant RNA metabolism behind FCCTX and hematological neoplasia.
Project description:TET1/2/3 are methylcytosine dioxygenases regulating cytosine hydroxymethylation in the genome. Tet1 and Tet2 are abundantly expressed in HSC/HPCs and implicated in the pathogenesis of hematological malignancies. Tet2-deletion in mice causes myeloid malignancies, while Tet1-null mice develop B-cell lymphoma after an extended period of latency. Interestingly, TET1 and TET2 were often concomitantly down-regulated in acute B-lymphocytic leukemia. Here, we investigated the overlapping and non-redundant functions of Tet1/Tet2 in HSC maintenance and development of hematological malignancies using Tet1/2 double knockout (DKO) mice. DKO and Tet2-/- HSC/HPCs had overlapping and unique 5hmC and 5mC profiles and behaved differently. DKO mice exhibited strikingly decreased incidence and delayed onset of myeloid malignancies compared to Tet2-/- mice and in contrast developed lethal B-cell malignancies. Transcriptome analysis of DKO tumors revealed expression changes in many genes dysregulated in human B-cell malignancies, such as LMO2, BCL6 and MYC. These results highlight the critical roles of TET1 or TET2 individually and their cross-talks in the pathogenesis of hematological malignancies. Given the role of Tet proteins in 5mC oxidation, we employed a previously established chemical labeling and affinity purification method coupled with high-throughput sequencing (hMe-Seal) to profile the genome-wide distribution of 5hmC, as well as methylated DNA immunoprecipitation (MeDIP) coupled with high-throughput sequencing (MeDIP-seq) to profile 5mC using BM LK cells purified from young WT, Tet2-/- and DKO mice (6-10 wks old).
Project description:Investigation of whole genome gene expression level changes in patients treated with cyclophosphamide We have studied the gene expression profile for 11 patients with different types of hematological malignancies but all of them have been treated with CP i.v.
Project description:Antibody-based therapy for cancer is now one of the most successful and important strategies for treating patients with hematological malignancies. However, the lack of efficient tumor-associated antigens restricts the targeting therapy of myeloid leukemia. Analysis of the gene expression proï¬les of primary bone marrow samples from human acute myeloid leukemia (AML) patients or healthy donors was to identify and expand novel targets for the treatment of myeloid leukemias. we found that epithelial cell adhesion molecule (EpCAM) is overexpressed in patients with AML. we analyzed the gene expression proï¬les of bone marrow mononuclear cells from 2 human acute myeloid leukemia (AML) patients and 2 healthy donors using an oligonucleotide microarray, to identify up-regulated genes in AML samples comparing with healthy tissues.