Rituximab plus chlorambucil as initial treatment for elderly patients with chronic lymphocytic leukemia: effect of pretreatment biologic characteristics and gene expression patterns on response to treatment
ABSTRACT: Evaluation of pretreatment gene expression profiling features in elderly CLL patients; correlation with clinical outcome Evaluation of pretreatment gene expression profiling features in elderly CLL patients enrolled in a clinical trial; correlation with clinical outcome
Project description:Genomic aberrations are of predominant importance to the biology and clinical outcome of patients with chronic lymphocytic leukemia (CLL), and FISH-based genomic risk classifications are routinely used in clinical decision making in CLL. One of the known limitations of CLL FISH is the inability to comprehensively interrogate the CLL genome for genomic changes. In an effort at overcoming the existing limitations in CLL genome analysis, we have analyzed high-purity DNA isolated from FACS-sorted CD19+ cells and paired CD3+ or buccal cells from 255 CLL patients for acquired genomic copy number aberrations (aCNA) using ultra-high-density Affymetrix SNP 6.0 arrays. Overall, two or more subchromosomal aCNA were found in 39% (100/255) of all cases analyzed, while ≥3 subchromosomal aCNA were detected in 20% (50/255) of cases. Subsequently, we have correlated genomic lesion loads (genomic complexity) with the clinical outcome measures time to first therapy (TTFT) and overall survival (OS). Using multivariate analyses incorporating the most important prognostic factors in CLL together with SNP 6.0 array-based genomic lesion loads at various thresholds, we identify elevated CLL genomic complexity as an independent and powerful marker for the identification of CLL patients with aggressive disease and short survival. we have analyzed high-purity DNA isolated from FACS-sorted CD19+ cells and paired CD3+ or buccal cells from 255 CLL patients for acquired genomic copy number aberrations (aCNA) using ultra-high-density Affymetrix SNP 6.0 arrays
Project description:We assessed genome-wide expression of available pretreatment specimens from CLL patients enrolled in REACH, a study of fludarabine and cyclophosphamide FC or R-FC (addition of rituximab to FC) in relapsed CLL, to understand the disease heterogeneity and explore genes that may be prognostic or predictive of benefit from R-FC treatment. REACH (NCT00090051) was registered at www.clinicaltrials.gov. This dataset supports the manuscript "PTK2 expression and immunochemotherapy outcome in chronic lymphocytic leukemia" by Weisser et al. 300 available pretreatment specimens from patients enrolled in REACH trial were analyzed. Additional contributers: REACH study investigators and patients
Project description:Three different cell populations (6 healthy B-lymphocytes, 6 leukemic CLL B-lymphocyte of indolent form and 5 leukemic CLL B-lymphocyte of aggressive form) were stimulated in vitro with an anti-IgM antibody, activating the B-cell receptor (BCR). We analyzed the gene expression at 4 time points (60, 90, 210 and 390 minutes). Each gene expression measurement is performed both in stimulated cells and in control unstimulated cells. For one aggressive CLL case, we silenced expression of DUSP1 by transfecting DUSP1-specific RNAi and, as a control, transfected cells with a non-targeting RNAi. We then stimulated the BCR of these cells and analyzed the gene expression at the same time points in stimulated cells and in control unstimulated cells. B-cells were negatively selected from healthy donors and previously untreated CLL patients. BCR stimulated and unstimulated control B-cells were treated at four time points after stimulation for total RNA extraction and hybridization on Affymetrix microarrays.
Project description:We examined the microRNAs (miRNAs) expressed in chronic lymphocytic leukemia (CLL) and identified miR-150 as the most abundant, but with leukemia-cell-expression levels that varied among patients. CLL cells that expressed ZAP-70 or that used unmutated IGHV each had a median expression-level of miR-150 that was significantly lower than that of ZAP-70-negative CLL cells or those that used mutated IGHV. In samples stratified for expression of miR-150, CLL cells with low-level miR-150 expressed relatively higher levels of forkhead box P1 (FOXP1) and GRB2-associated binding protein 1 (GAB1), genes with 3’ UTRs having evolutionary-conserved binding sites for miR-150. High-level expression of miR-150 could repress expression of these genes, which encode proteins that may enhance B-cell receptor (BCR) signaling, a putative CLL-growth/survival signal. Also, high-level expression of miR-150 levels was a significant independent predictor of longer treatment-free-survival (TFS) or overall survival (OS), whereas an inverse association was observed for high-level expression of GAB1 or FOXP1 for OS. This study demonstrates that expression of miR-150 can influence the relative expression of GAB1 and FOXP1 and the signaling potential of the B-cell receptor (BCR), thereby possibly accounting for the noted association of expression of miR-150 and disease outcome. We performed gene expression analysis on isolated leukemia cells from 100 CLL patients using the Affymetrix HG-U133 Plus 2 platform. Array data was processed by dChip software (http://www.dchip.org). No techinical replicates were performed.
Project description:In the present study, the gene expression profiling was carried out in 21 early stage CLL patients. A gene expression signature was generated for CLL patients as compared to normal controls; CLL patients were further seggregated into IGHV unmutated (n=10) and IGHV mutated (n=11) subgroups. The expression pattern was confirmed using real time quantitative PCR and the results were correlated with clinical outcome. Overall design: Gene expression profiling was carried out in 21 CLL samples and pooled samples (n=2) from 10 healthy subjects. The CLL cases were further divided into unmutated (n=11) and mutated subgroup (n=10) on the basis of IGHV mutation status.
Project description:Purpose: The chromosomal deletion 11q affects biology and clinical outcome in CLL but del11q-deregulated genes remain incompletely characterized. Results: We have identified differential expression of the insulin receptor (INSR) in CLL, including high-level INSR expression in the majority of CLL with del11q. High INSR mRNA expression in 11q CLL (~10-fold higher mean levels than other genomic categories) was confirmed by Q-PCR in 247 CLL cases. INSR protein measurements in 257 CLL cases through FACS, compared with measurements in normal CD19+ B-cells and monocytes, confirmed that a subset of CLL aberrantly expresses high INSR levels. Overall design: We have employed integrated genomic profiling approaches upon CLL cases with and without del11q to identify 11q-relevant genes. Included are 10 primary human cases with del11q and 9 cases without del11q
Project description:Purpose: The chromosomal deletion 11q affects biology and clinical outcome in CLL but del11q-deregulated genes remain incompletely characterized. Results: We have identified differential expression of the insulin receptor (INSR) in CLL, including high-level INSR expression in the majority of CLL with del11q. High INSR mRNA expression in 11q CLL (~10-fold higher mean levels than other genomic categories) was confirmed by Q-PCR in 247 CLL cases. INSR protein measurements in 257 CLL cases through FACS, compared with measurements in normal CD19+ B-cells and monocytes, confirmed that a subset of CLL aberrantly expresses high INSR levels. We have employed integrated genomic profiling approaches upon CLL cases with and without del11q to identify 11q-relevant genes. Included are 10 primary human cases with del11q and 9 cases without del11q
Project description:The aims of this study were to assess the feasibility of prospective pharmacogenomics research in multicenter international clinical trials of bortezomib in multiple myeloma and to develop predictive classifiers of response and survival with bortezomib. Patients with relapsed myeloma enrolled in phase 2 and phase 3 clinical trials of bortezomib and consented to genomic analyses of pretreatment tumor samples. Bone marrow aspirates were subject to a negative-selection procedure to enrich for tumor cells, and these samples were used for gene expression profiling using DNA microarrays. Data quality and correlations with trial outcomes were assessed by multiple groups. Gene expression in this dataset was consistent with data published from a single-center study of newly diagnosed multiple myeloma. Response and survival classifiers were developed and shown to be significantly associated with outcome via testing on independent data. The survival classifier improved on the risk stratification provided by the International Staging System. Predictive models and biologic correlates of response show some specificity for bortezomib rather than dexamethasone. Informative gene expression data and genomic classifiers that predict clinical outcome can be derived from prospective clinical trials of new anticancer agents. Keywords: Gene expression profiling; correlation with outcome in clinical trials of the proteasome inhibitor bortezomib Overall design: Purified myeloma samples were collected prior to enrolment in clinical trials of bortezomib (PS-341). Samples were subject to replicate gene expression profiling using the Affymetrix 133A/B microarray. Data was normalized in MAS5.0 and the median of replicates is reported. Data was normalized to a Ttimmed mean of 15o and is NOT log transformed. Various patient parameters are reported as well as response, TTP and survival upon treatment with bortezomib or dexamethasone.
Project description:In the present study, the methylation profiling (MeDIP) was carried out in 14 treatment-naive, early stage (Rai stage 0-2) CLL patients and pooled 19+ normal controls. To find an association of methylation with IGHV mutation status, CLL patients were further segregated into IGHV unmutated (n=9) and IGHV mutated (n=5) subgroups. The methylation signature obtained for CLL versus nornal controls and; unmutated versus mutated CLL was integrated with gene expression profile of these patients and the results were correlated with clinical outcome. Overall design: Methylation profiling was carried out in 14 treatment naïve early stage CLL samples and pooled samples (n=3) from 10 healthy subjects. The CLL patients were further seggregated into unmutated (n=9) and mutated (n=5) on the basis of IGHV mutation status and methylation profile of these two groups were also compared.
Project description:CD38 expression is an important prognostic marker in CLL with high levels of CD38 associated with shorter overall survival. In this study, we used gene expression profiling and protein analysis of highly purified cell-sorted CD38+ and CD38- chronic lymphocytic leukemia cells to elucidate a molecular basis for the association between CD38 expression and inferior clinical outcome. Paired CD38+ and CD38- CLL cells derived from the same patient were shown to be monoclonal by VH gene sequencing but despite this, CD38+ CLL cells possessed a distinct gene expression profile when compared with their CD38- sub-clones. Keywords: Sub-clonal analysis of CLL cells derived from the same leukemia sample Overall design: These experiments compared the gene expression profile of CD38+ and CD38- sub-clones derived from 6 individual CLL patients.