EGAS00001001963-sc-20180314 - samples
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ABSTRACT:
PROVIDER: EGAD00001004037 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Aim to characterise cancer gene landscape in CLL, particularly in cases with mutated POT1 gene. Treatment-naïve CLL cases will be interrogated by targeted exome sequencing using a cancer gene panel.
| EGAS00001001963 | EGA
Project description:Chronic lymphocytic leukemia (CLL) stereotyped subsets #6 and #8 include cases expressing unmutated B cell receptor immunoglobulin (BcR IG) (U-CLL). Yet, subset #6 (IGHV1-69/IGKV3-20) is less aggressive compared to subset #8 (IGHV4-39/IGKV1(D)-39) which has the highest risk for Richter’s transformation among all CLL. The underlying reasons for this divergent clinical behavior are not fully elucidated. To gain insight into this issue, here we focused on epigenomic signatures and their links with gene expression, particularly investigating genome-wide DNA methylation profiles in subsets #6 and #8 as well as other U-CLL cases not expressing stereotyped BcR IG using the Illumina 450k methylation arrays. Additionally we analysed the methylation profiles of naive and memory B cell subsets from healthy donors and compared them with those of the CLL cases.
2019-04-04 | E-MTAB-6955 | biostudies-arrayexpress
Project description:Telomere protection 1 (POT1) is an important subunit in the shelterin complex, considered the telomere protector. POT1 dysfunction may lead to telomere length dysregulation and genomic instability. Both germline and somatic POT1 mutations have been identified in CLL patients, suggesting the development of the disease. This study aimedto evaluate the occurrence of POT1 mutations throughout CLL's progression and determine their prognostic significance.
2025-03-14 | GSE261569 | GEO
Project description:We investigated at two time points a longitudinal cohort of 27 untreated Chronic Lymphocytic Leukemia (CLL) patients with either stable or progressive disease. The sequenced genes included BCOR, EGR2, HIST1H1E, ITPKB, KRAS, MED12, NRAS, RIPK1, SAMHD1, ATM, BIRC3, BRAF, CHD2, DDX3X, DDX3Y, FBXW7, KIT, KLHL6, MAPK1, MYD88, NOTCH1, PIK3CA, POT1, SF3B1, TP53, XPO1 and ZMYM3, which were previously identified as mutated in CLL studies.
2019-11-05 | E-MTAB-8020 | biostudies-arrayexpress
Project description:Approximately 1% of chronic lymphocytic leukemia (CLL) cases harbor a translocation juxtaposing the immunoglobulin heavy chain (IGH) and B-cell lymphoma 3 (BCL3) loci. Aiming at comprehensive molecular characterization of IGH::BCL3-positive B-cell neoplasms we here investigated samples from 84 patients using FISH, whole genome and targeted sequencing and DNA methylation analyses. Junctional sequences obtained in 27 patients showed breakpoints upstream of BCL3 in all CLL cases. IGH breaks were presumably driven by aberrant class-switch recombination in 26/27 cases, frequently involving IGHA (12/26). Notably, 95% (78/82) of patients carried an unmutated IGHV with significant CLL stereotype subset #8 enrichment. Trisomy 12 (61%, 51/83) and mutations affecting NOTCH1 (32%, 25/79), BRAF (14%, 11/79) and FBXW7 (14%, 11/79) were frequent aberrations. DNA methylation analysis assigned 77% (51/66) of patients with IGH::BCL3-translocation with at least 60% tumor cell content to the naive B-cell-like group but unraveled a distinct and during follow-up stable signature resembling in part plasma cell-like epigenetic features. A binary DNA methylation classifier using 20 CpGs could distinguish IGH::BCL3-translocated CLL samples from other CLL subtypes. In an efficacy cohort of 3832 previously untreated patients from GCLLSG trials, IGH::BCL3 was associated with shorter progression-free survival (PFS) and overall survival (OS) in 28 patients when treated with chemoimmunotherapy, but not in those receiving venetoclax. Our findings highlight the genetic and epigenetic homogeneity of IGH::BCL3-translocated CLL samples and their differences from other types of CLL suggesting IGH::BCL3 leukemic B-cell neoplasms to be a biological distinct subtype of CLL.
2026-05-12 | GSE295456 | GEO
Project description:Chronic Lymphocytic Leukemia (CLL) is clinically divided into IGHV mutated (M-CLL) and IGHV unmutated (U-CLL) subtypes, which are thought to arise from distinct cells of origin along the B-cell differentiation pathway. We measured genome-scale DNA methylation in purified CLL samples (n=89) and utilized reference-based cell deconvolution techniques to develop a continuous metric of epigenetic similarity across a B-naive-like to B-memory-like scale (B-Index). B-Index accurately classifies CLL into clinical subtypes (98.8%), has a stronger epigenetic signal than IGHV gene percent identity, and demonstrates additional epigenetic signal within the M-CLL subgroup. We demonstrate that U-CLL is epigenetically more similar to B-memory than B-naive cells and reconcile previous reports of a B-naive-like epigenetic signal. The B-memory-like program of U-CLL is enriched for binding sites of transcription factors related to the germinal center activation pathway. Our findings provide epigenetic evidence for discerning CLL mechanisms of initiation and cell of origin. We also identified an epigenetic signal associated with tumor burden, which may have some relation to viral infections such as Epstein-Barr-Virus. Our cell-type deconvolution-based approach to developing a continuous metric for CLL epigenetic differentiation state can be applied to other tumors with multiple subtypes across differentiation stages.
2026-05-21 | GSE307998 | GEO
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.
2017-03-24 | GSE92701 | GEO
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.
2017-03-24 | GSE92626 | GEO
Project description:To identify genomic alterations contributing to the pathogenesis of high‑risk chronic lymphocytic leukemia (CLL) beyond the well‑established role of TP53 aberrations, we comprehensively analyzed 146 high‑risk CLL cases by single‑nucleotide polymorphism (SNP)‑arrays and targeted next‑generation sequencing including 75 relapsed/refractory and 71 treatment‑naïve high‑risk cases from prospective clinical trials. Increased genomic complexity was a hallmark of relapsed/refractory and treatment‑naïve high‑risk CLL, and was associated with TP53 and ATM dysfunction. In relapsed/refractory cases previously exposed to the selective pressure of chemo(immuno)therapy, gain(8)(q24.21) and del(9)(p21.3) were found particularly enriched. Both of these copy number alterations (CNAs) affected key regulators of cell cycle progression, namely c‑MYC and CDKN2A/B. Gains in 8q24.21 were either focal gains in a c‑MYC enhancer region or larger gains directly affecting the c‑MYC locus, but only the latter type was highly enriched in relapsed/refractory CLL (17%). Loss of CDKN2A/B was found frequently to co‑occur with gain of c‑MYC and in this combination it was likely associated with Richter transformation. In addition to a high frequency of NOTCH1 mutations (23%), we found recurrent genetic alterations in SPEN (4% mutated), RBPJ (8% deleted) and SNW1 (8% deleted), all affecting a protein complex that represses transcription of NOTCH1 target genes. We investigated the functional impact of these alterations on HES1, DTX1 and c‑MYC gene transcription and found de‑repression of these NOTCH1 target genes particularly with SPEN mutations. In summary, we provide new insights into the pathogenesis of high‑risk CLL by defining novel recurrent CNAs and identifying alterations that likely contribute to disease refractoriness.
2020-05-06 | GSE131114 | GEO
Project description:CD38 and CD49d are associated negative prognosticators in chronic lymphocytic leukemia (CLL). Despite evidence that both molecules are involved in interactions occurring between CLL and normal cells in the context of CLL-involved tissues, a functional link is still missing. Using gene expression profiles comparing CD38+CD49d+ vs. CD38-CD49d- CLL cells, we demonstrated overexpression of the CCL3 and CCL4 chemokines in cells from the former group. These chemokines were also upregulated by CD38 signals in CLL; moreover, CCL3 was expressed by CLL cells from bone marrow biopsies (BMB) of CD38+CD49d+ but not CD38-CD49d- cases. High levels of CCR1 and, to a lesser extent, CCR5, the receptors for CCL3 and CCL4, were found in CLL-derived monocyte-macrophages. Consistently, CCL3 increased monocyte migration, and CD68+ macrophage infiltration was particularly high in BMB from CD38+CD49d+ CLL. Conditioned media from CCL3-stimulated macrophages induced endothelial cells to express VCAM-1, the CD49d ligand, likely through TNFα over-production. These effects were apparent in BMB from CD38+CD49d+CLL, where lymphoid infiltrates were characterized by a prominent meshwork of VCAM-1+ stromal/endothelial cells. Lastly, CD49d engagement by VCAM-1-transfectants increased viability of CD38+CD49d+ CLL cells. Altogether, CD38 and CD49d can be thought of as a part of a consecutive chain of events ultimately leading to improved survival of CLL cells.
2009-03-03 | GSE14560 | GEO