The hematological malignancies classified as Mixed Lineage leukemias (MLL) harbor fusions of the MLL1 gene to partners that are members of transcriptional elongation complexes. MLL-rearranged leukemias are associated with extremely poor prognosis and response to conventional therapies and efforts to identify molecular targets are urgently needed. Using mouse models of MLL-rearranged acute myeloid leukemia (AML), here we show that genetic inactivation or small molecule inhibition of the protein arginine methyltransferase PRMT5 exhibit anti-tumoral activity in MLL-fusion protein driven transformation. Genome wide transcriptional analysis revealed that inhibition of PRMT5 methyltransferase activity overrides the differentiation block in leukemia cells without affecting the expression of MLL-fusion direct oncogenic targets. Furthermore, we find that this differentiation block is mediated by transcriptional silencing of the cyclin-dependent kinase inhibitor p21 (CDKN1a) gene in leukemia cells. Our study provides pre-clinical rationale for targeting PRMT5 using small molecule inhibitors in the treatment of leukemias harboring MLL-rearrangements. Overall design: RNA-seq data from 72h-treated DMSO and EPZ 015666 (PRMT5i) MLL-ENL/NrasG12D leukemia cells, three independent replicates.
Genetic deletion or small-molecule inhibition of the arginine methyltransferase PRMT5 exhibit anti-tumoral activity in mouse models of MLL-rearranged AML.
Specimen part, Treatment, Subject
View SamplesTranscriptional regulatory networks (TRNs) provide insight into cellular behavior by describing interactions between transcription factors (TFs) and their gene targets. The Assay for Transposase Accessible Chromatin (ATAC)-seq, coupled with transcription-factor motif analysis, provides indirect evidence of chromatin binding for hundreds of TFs genome-wide. Here, we propose methods for TRN inference in a mammalian setting, using ATAC-seq data to influence gene expression modeling. We rigorously test our methods in the context of T Helper Cell Type 17 (Th17) differentiation, generating new ATAC-seq data to complement existing Th17 genomic resources (plentiful gene expression data, TF knock-outs and ChIP-seq experiments). In this resource-rich mammalian setting our extensive benchmarking provides quantitative, genome-scale evaluation of TRN inference combining ATAC-seq and RNA-seq data. We refine and extend our previous Th17 TRN, using our new TRN inference methods to integrate all Th17 data (gene expression, ATAC-seq, TF KO, ChIP-seq). We highlight new roles for individual TFs and groups of TFs (“TF-TF modules”) in Th17 gene regulation. Given the popularity of ATAC-seq (a widely adapted protocol with high resolution and low sample input requirements), we anticipate that application of our methods will improve TRN inference in new mammalian systems and be of particular use for rare, uncharacterized cell types. Overall design: Gene expression (RNA-seq) of naive and Th17- and Th0-polarized CD4 T Cells
Leveraging chromatin accessibility for transcriptional regulatory network inference in T Helper 17 Cells.
Specimen part, Cell line, Subject
View SamplesWe performed microarray analysis to derive gene signatures down-stream of soluble CD40 ligand stimulation in human naive B cells. Nave B cells were purified from healthy donor PBMC using negative selection beads (Miltenyi) and cultured with sCD40L at 2.5ug/ml for 6hr before microarray analysis. In the same study, cells were also harvested at day 5 post-stimulation to confirm sCD40L-induced B cell activation and proliferation. FACS analysis confirmed soluble CD40L induced up-regulation of CD86 and CD69 at 24hr. B cell proliferation was measured at day 4 post-stimulation by EdU incorporation.
CD40L-Dependent Pathway Is Active at Various Stages of Rheumatoid Arthritis Disease Progression.
Specimen part, Treatment, Subject
View SamplesWe performed microarray analysis of sCD40L-stimulated iDC to derive a signature of CD40 activation. Human monocytes from normal healthy donors were differentiated to iDCs with GM-CSF and IL4. FACS analysis demonstrated the immature status of these cells, illustrated by low expression of CD80, CD40, and CD86. We confirmed that sCD40L induces the maturation of DCs, characterized by higher expression of CD80, HLA-DR, CD86, CD83 and CD40 and secretion of pro-inflammatory cytokines at 24hr post-stimulation. Cells were harvested at 1, 3 and 24hr post-stimulation for microarray analysis.
CD40L-Dependent Pathway Is Active at Various Stages of Rheumatoid Arthritis Disease Progression.
Specimen part, Treatment, Subject
View Samples