Project description:Newly diagnosed chronic phase chronic myeloid leukemia (CML) patients with a major cytogenetic response (MCyR) after 12 months of imatinib therapy have an excellent long-term outcome, while patients without MCyR have a high progression risk. Since patients with primary cytogenetic resistance may benefit from more intensive therapy up-front, we sought to identify biomarkers to predict MCyR. Keywords: Two group comparison to identify trasncriptomic signature that predicts response to therapy
Project description:Newly diagnosed chronic phase chronic myeloid leukemia (CML) patients with a major cytogenetic response (MCyR) after 12 months of imatinib therapy have an excellent long-term outcome, while patients without MCyR have a high progression risk. Since patients with primary cytogenetic resistance may benefit from more intensive therapy up-front, we sought to identify biomarkers to predict MCyR. Keywords: Two group comparison to identify trasncriptomic signature that predicts response to therapy CD34+ cells were isolated from cryopreserved mononuclear cells of chronic phase CML patients with a complete cytogenetic response (CCyR) or >65% Ph-positive metaphases after 12 months of imatinib therapy (training set N=36). Gene expression profiles generated on amplified RNA using Affymetrix HG-U133 Plus 2.0 arrays were compared between responders and non-responders, using the criteria ANOVA p<0.1 and fold difference >I1.5I. A minimal response classifier derived from the comparison was used to predict response in a prospectively collected validation set using same criteria for responders/nonresponders (N=23).
Project description:Chronic myeloid leukemia (CML) epitomizes successful targeted therapy, with 86% of patients in the chronic phase treated with tyrosine kinase inhibitors (TKIs) attaining remission. However, resistance to TKIs occurs during treatment, and patients with resistance to TKIs progress to the acute phase called Blast Crisis (BC), wherein the survival is restricted to 7-11 months. About 80 % of patients in BC are unresponsive to TKIs. This issue can be addressed by identifying a molecular signature which can predict resistance in CML-CP prior to treatment as well as by delineating the molecular mechanism underlying resistance. Herein, we report genomic analysis of CML patients and imatinib-resistant K562 cell line to achieve the same. WGS was performed on imatinib-sensitive and -resistant K562 cells. Library preparation was done by 30x WGS KAPA PCR-Free v2.1 kit, and Illumina HiSeq X sequencer was used for 2 x 150 bp paired-end sequencing. Our study identified accumulation of aberrations on chromosomes 1, 3, 7, 16 and 22 as predictive of occurrence of resistance. Further, recurrent amplification in chromosomal region 8q11.2-12.1 was detected in highly resistant K562 cells as well as CML patients. The genes present in this region were analyzed to understand molecular mechanism of imatinib resistance.
Project description:Chronic myeloid leukemia (CML) epitomizes successful targeted therapy, with 86% of patients in the chronic phase treated with tyrosine kinase inhibitors (TKIs) attaining remission. However, resistance to TKIs occurs during treatment, and patients with resistance to TKIs progress to the acute phase called Blast Crisis (BC), wherein the survival is restricted to 7-11 months. About 80 % of patients in BC are unresponsive to TKIs. This issue can be addressed by identifying a molecular signature which can predict resistance in CML-CP prior to treatment as well as by delineating the molecular mechanism underlying resistance. Herein, we report genomic analysis of CML patients and imatinib-resistant K562 cell line to achieve the same. Thirteen CML patients (sensitive and resistant to TKIs) and 2 BMT donors (as control) were recruited for the study. DNA was isolated from an enriched CD34+ fraction for each sample as well as from K562 cells made resistant to imatinib which provided a model system for further molecular investigations. DNA was subjected to Cytoscan HD array (Affymatrix) analysis from patient samples and cell lines. Affymetrix CytoScan™ HD array (Applied Biosystems™, Cat# 901835) chip consists of 2.6 M oligonucleotide probes across the genome, including 1953K unique non-polymorphic probes and 750K bi-allelic SNP (single nucleotide polymorphism) probes. Our study identified accumulation of aberrations on chromosomes 1, 3, 7, 16 and 22 as predictive of occurrence of resistance. Further, recurrent amplification in chromosomal region 8q11.2-12.1 was detected in highly resistant K562 cells as well as CML patients. The genes present in this region were analyzed to understand molecular mechanism of imatinib resistance.
Project description:Tyrosine kinase inhibitor (TKI) treatment of chronic myeloid leukemia (CML) is guided by the pre-defined European Leukemia Net (ELN) or other response criteria. This allows patient stratification only during but not prior to treatment initiation. Gene expression profiling (GEP)-based response prediction might become a valuable tool for patient stratification in CML, but so far published data for response prediction are conflicting. We generated an imatinib response predicting gene signature by GEP from peripheral blood samples of pre-treated CML patients in late chronic phase.
Project description:Identification of genes in CML patients with predictive value for their primary cytogenetic outcome to imatinib. All samples analyzed were taken just before the start of imatinib treatment. Leukemic patients were treated second-line with imatinib after failure of an interferon-alpha based therapy (first-line regimen).
Project description:This is a class prediction experiment, where the class is the response status to imatinib (also called Gleevec), a drug used to treat patients with chronic myelogenous leukemia (CML). There are two data sets, a training set (from Leipzig, 8 Responders and 5 Non-Responders) and a validation set (from Mannheim, 8 Responders and 7 Non-Responders). The objective is to identify differentially regulated genes between CML patients who respond and those who do not respond to imatinib and confirm the results in the validation data set. The samples from blood or bone marrow of CML patients were hybridized to Affymetrix HG-U95Av2 chip and RMA was used to generate the normalized signal values. Keywords = chronic myelogenous leukemia Keywords = imatinib Keywords = cytogenetic responses Keywords = Gleevec Keywords = Affymetrix Keywords: other
Project description:An approximately 60% of chronic myeloid leukemia (CML) patients who achieved a deep molecular response for more than 2 years maintained a major molecular response after discontinuation of imatinib. These findings indicate the possibility that a portion of CML patients treated with Tyrosine kinase inhibitors (TKIs) could discontinue TKI therapy, although long-term prognosis and/or adverse events after TKIs cessation remain unclear. Recent reports showed that transient musculoskeletal pain occurs in approximately 30% of CML patients after stopping imatinib. To ascertain the factors underlying musculoskeletal events after TKI cessation, we investigated exosomal miRNA in five CML patients who did not experience musculoskeletal events and five patients with musculoskeletal pain after stopping TKIs.
Project description:We analysed the impact of single nucleotide polymorphisms (SNPs) in drug transporter genes on the molecular response to imatinib, using 857 SNPs covering 94 drug transporter genes on 355 chronic phase chronic myeloid leukemia (CP-CML) patients.
Project description:We analysed the impact of single nucleotide polymorphisms (SNPs) in drug transporter genes on the molecular response to imatinib, using 857 SNPs covering 94 drug transporter genes on 355 chronic phase chronic myeloid leukemia (CP-CML) patients.
