Project description:Transcriptional profiling of primary human malignant B cells from patients with chronic lymphocytic leukaemia (CLL), comparing untreated CLL cells with CLL cells that have been treated 24h with 200nM mithramycin. Mithramycin intercalates into GC-rich regions of DNA to inhibit binding of the transcription factor SP1. The goal of this experiment is to gain understanding of the genes regulated by SP1 in primary CLL cells.
Project description:Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in developed countries. Ibrutinib (PCI-32765), a specific and irreversible inhibitor of Bruton's Tyrosine Kinase (BTK) represents a major step forward in the treatment of CLL. We have undertaken a detailed analysis of the changes happening to the chromatin structure in CLL cells from patients continuously receiving oral doses of ibrutinib. ChIP-seq has been performed for H3K4me3, H3K27ac, H3K27me3 and EZH2 up to 56 days following the beginning of the treatment. We observed that Ibrutinib-dependent lymphocytosis correlates with a global and transient recruitment of EZH2 to active cis-regulatory elements and increased H3K27me3.
Project description:Series of Chronic Lymphocytic Leukaemia (mix of U-CLL and M-CLL) with and without anti-IgM stimulation of the B cell receptor. RNA acquired at 6hrs and 24hrs post stimulation.
Project description:<TO BE UPDATED> Chronic lymphocytic leukaemia (CLL) is a common, adult B-cell leukaemia that has challenges in prognosis and treatment. It is characterised by a heterogeneous clinical course with multiple distinct phenotypes currently defined genetically or with target-specific monoclonal antibodies. While many studies have examined specific protein targets or global mRNA expression in CLL, few have attempted to characterise expression across the whole proteome. To achieve a non-biased, global proteomics characterisation, 14 CLL samples representing the genetic mutant subgroups NOTCH1, SF3B1 and WT, were subjected to quantitative mass spectrometry and compared with normal B cells using two isobaric tag experiments (TMT 10-plex). 6150 proteins were fully quantitated revealing a strong correlation between the regulated proteins across the CLL samples, independent of subtype. >800 proteins demonstrated significant upregulation (p<0.05) across the CLL samples. In addition to several novel cell surface markers, overexpressed proteins were strongly indicative of dysregulation to mRNA processing, spliceosome activity, transcriptional control by RNA pol II and epigenetic mechanisms (all p<10-10). A strong enrichment was observed for proteins coded by chromosome 12, often observed with trisomy in CLL (p<0.001). Downregulated proteins included cell adhesion molecules such as integrins and suggested a reduced capacity for endothelial transmigration (both p<10-10). These findings confirm many previous observations of CLL-specific protein overexpression (eg. CD5, ROR1, matriptase) and identify several novel surface targets for investigation. They also suggest that strong patterns of protein expression exist across CLL subtypes. Together, these results demonstrate the potential of proteomics and advocate the characterisation of further cancer samples by such methods.
Project description:NOTCH1 is mutationally activated in ~15% of cases of chronic lymphocytic leukaemia (CLL), but its role in B-cell development and leukemogenesis is not known. Here, we report that the active intracellular portion of NOTCH1 (ICN1) is detectable in ~50% of peripheral blood CLL cases lacking gene mutations. We identify a ‘NOTCH1 CLL gene expression signature’ in CLL cells, and show that this signature is significantly enriched in primary CLL cases expressing ICN1, independent of NOTCH1 mutation. NOTCH1 target genes include key regulators of B-cell proliferation, survival and signal transduction physiology. In particular, we show that MYC is a direct target of NOTCH1 via B-cell specific distal regulatory elements, thus implicating this oncogene in the pathogenesis of the disease.
Project description:Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in developed countries. Ibrutinib (PCI-32765), a specific and irreversible inhibitor of Bruton's Tyrosine Kinase (BTK) represents a major step forward in the treatment of CLL, but cases of resistance are emerging. We have undertaken a detailed analysis of the changes happening to the chromatin structure in CLL cells from two patients on ibrutinib and showing disease progression. ChIP-seq has been performed for H3K4me3, H3K27ac and H3K27me3. We observed chromatin alterations independent of the disease progression. Raw data is available in EGA under controlled access with accession EGAD00001005220
Project description:Mithramycin A in known to bind DNA but its exact cellular mechanism of action is still unclear. We used Affymatrix GenFlex_Tag_16K_V2 microarrays to profile sensitivity of genetically barcoded S. cerevisiae gene deletion strains to mithramycin A
Project description:The study aims to define gene expression changes associated with mithramycin treatment of Ewing Sarcoma cell lines. The data consist of 12 arrays. Two cell lines, TC71 and TC32, were treated with solvent control or with mithramycin, and RNA was extracted at 6 hours. Three biological replicates per cell line/treatment.
Project description:we evaluated the capacity of different types of antigen/BCR interactions to induce leukemia in a transgenic mouse model of CLL Key words; B-cell antigen receptor (BCR), chronic lymphocytic leukaemia (CLL), T-cell leukemia (TCL)
Project description:We performed single-molecule telomere length and telomere fusion analysis in patients at different stages of chronic lymphocytic leukaemia (CLL). Our work identified the shortest telomeres ever recorded in primary human tissue reinforcing the concept that there is significant cell division in CLL. Furthermore, we provide direct evidence that critical telomere shortening, dysfunction and fusion contribute to disease progression. The frequency of short telomeres and fusion events increased with advanced disease, but importantly these were also found in a subset of early-stage patient samples indicating that these events can precede disease progression. Sequence analysis of fusion events isolated from individuals with the shortest telomeres revealed limited numbers of repeats at the breakpoint, sub-telomeric deletion and microhomology. Array-CGH analysis of individuals displaying evidence of telomere dysfunction revealed large-scale genomic rearrangements that were concentrated in the telomeric regions; this was not observed in samples with longer telomeres.