Project description:Background. B-Acute lymphoblastic leukemia (B-ALL) represents a hematologic malignancy with poor clinical outcome and low survival rates in adult patients. Only 61% of Colombian adult patients with ALL achieve complete remission and a median overall survival of less than 11.3 months and event-free survival of 7.34 months. Identification of prognostic factors is crucial for proper treatment strategies and optimal results of therapy. The goal of our study was to determine if gene expression signatures correlate with response to therapy and to evaluate the utility of these as prognostic tools for survival to better predict patient risk prior to therapy. Methods and findings. This study included 43 adult patients newly diagnosed with B-cell precursor or common B-ALL. Through microarray gene expression profiles, we identified 442 genes differentially expressed between 27 leukemia patients who responded or not to induction chemotherapeutic treatment. Hierarchical analysis with the 99 most differentially expressed genes between the two groups revealed 3 sets of patients that differed in their clinical characteristics, giving these genes high prognostic clinical outcome impact. We validated the expression of 7 genes by RT-PCR in 43 patients, and in addition to finding a correlation with gene expression profiles, we established correlations with good and poor prognosis from the time of diagnosis. Conclusions. Our study suggests that the response to induction treatment and clinical outcome of patients can be predicted from the onset of the disease and that gene expression profiles can be used to stratify patient risk adequately and accurately. The present study represents the first that shows that gene expression profiling could become a clinically relevant tool for stratification in the early course of disease of Colombian adults B-ALL. Stem cells from bone marrow samples from B-acute lymphoblastic leukemia (B-ALL) patients responding or not to the inductive therapy were isolated by sorting, and the gene expression was compared between the two groups. This submission includes samples from 27 B-ALL patients and 3 healthy individuals.
Project description:Background. B-Acute lymphoblastic leukemia (B-ALL) represents a hematologic malignancy with poor clinical outcome and low survival rates in adult patients. Only 61% of Colombian adult patients with ALL achieve complete remission and a median overall survival of less than 11.3 months and event-free survival of 7.34 months. Identification of prognostic factors is crucial for proper treatment strategies and optimal results of therapy. The goal of our study was to determine if gene expression signatures correlate with response to therapy and to evaluate the utility of these as prognostic tools for survival to better predict patient risk prior to therapy. Methods and findings. This study included 43 adult patients newly diagnosed with B-cell precursor or common B-ALL. Through microarray gene expression profiles, we identified 442 genes differentially expressed between 27 leukemia patients who responded or not to induction chemotherapeutic treatment. Hierarchical analysis with the 99 most differentially expressed genes between the two groups revealed 3 sets of patients that differed in their clinical characteristics, giving these genes high prognostic clinical outcome impact. We validated the expression of 7 genes by RT-PCR in 43 patients, and in addition to finding a correlation with gene expression profiles, we established correlations with good and poor prognosis from the time of diagnosis. Conclusions. Our study suggests that the response to induction treatment and clinical outcome of patients can be predicted from the onset of the disease and that gene expression profiles can be used to stratify patient risk adequately and accurately. The present study represents the first that shows that gene expression profiling could become a clinically relevant tool for stratification in the early course of disease of Colombian adults B-ALL.
Project description:Genome-Wide DNA Copy Number Analysis of Acute Lymphoblastic Leukemia Identifies New Genetic Markers Associated with Clinical Outcome
Project description:RNA was extracted from the diagnostic bone marrow specimens of 50 T-cell acute lymphoblastic leukemia pediatric patients and analysed by Affymetrix microarray to model gene classifiers predictive of clinical outcome
Project description:Acute myeloid leukemia (AML) is a heterogeneous disease in respect of molecular aberrations and prognosis. We used gene expression profiling of 562 patients treated in the German AMLCG 1999 trial to develop a gene signature that predicts survival in AML. Analysis of 562 samples (140 HGU-133plus2; 422 HGU-133A; 422 HGU-133B) from adult patients with acute myeloid leukemia (AML).
Project description:Gene expression profiling in leukemia cases may predict the clinical outcome of the patients and may improve the treatment for specific leukemia subtypes. The goal is to compare the differences in gene expression pattern between T-ALL and B-ALL subtypes in Malaysian childhood acute lymphoblastic leukemia patients.
Project description:The development of a clinically relevant xenograft model of pediatric acute lymphoblastic leukemia, using a 4-drug treatment regimen designed to mimic pediatric remission induction therapy. Relapse and acquired drug resistance in T-cell acute lymphoblastic leukemia (T-ALL) remains a significant clinical problem. This study was designed to establish a preclinical model of resistance to induction therapy in childhood T-ALL to examine the emergence of drug resistance and identify novel therapies. We performed transcription profiling by array of human CD45-positive human lymphocytes from patients with acute pediatric lymphoblastic leukemia, and from xenografted NOD/SCID mice treated with vincristine, daunorubicin, dexamethasone and L-asparagine. Several different treatment regimes were used in this study (VLXD, VLXDR, VLXD2, VXL and VLXD2-ALL31) and are summarised in the protocols associated with this submission.
Project description:Acute myeloid leukemia with normal karyotype (NK-AML) represents a cytogenetic grouping with intermediate prognosis but substantial molecular and clinical heterogeneity. Within this subgroup, presence of FLT3 (FMS-like tyrosine kinase 3) internal tandem duplication (ITD) mutation predicts less favorable outcome. The goal of our study was to discover gene-expression patterns correlated with FLT3-ITD mutation, and to evaluate the utility of a FLT3 signature for prognostication. The dataset comprises gene-expression profiles of 137 normal karyotype acute myeloid leukemia (NK-AML) specimens carried out using Stanford cDNA microarrays, to accompany the study of L Bullinger et al. For each array, Channel 2 represents Cy5-labeled NK-AML RNA, and Channel 1 Cy3-labeled universal reference RNA. Keywords: Logical Set