Normalization of Illumina Infinium whole-genome SNP data improves copy number estimates and allelic intensity ratios [Omni2.5]
Ontology highlight
ABSTRACT: Recurring genetic abnormalities have been identified in Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). Among them, IKZF1 deletion was associated with poor prognosis in patients treated with imatinib-based or dasatinib-based regimens. However, the molecular determinants for clinical outcomes in ponatinib-treated patients remain unknown. We systematically analyzed genetic alterations in adults with Ph-positive ALL uniformly treated in clinical trials with dasatinib-based regimens or a ponatinib-based regimen and investigated the molecular determinants for treatment outcomes using pretreatment specimens collected from adults with Ph-positive ALL treated with Hyper-CVAD plus dasatinib or ponatinib. DNA sequencing and SNP microarray were performed and recurrent genetic abnormalities were found in 84% of the patients, among whom IKZF1 deletion was most frequently detected (60%). IKZF1 deletion frequently co-occurred with other copy-number abnormalities (IKZF1plus, 46%) and was significantly associated with unfavorable overall survival (OS) (false discovery rate < 0.1) and increased cumulative incidence of relapse (p = 0.01). In a multivariate analysis, dasatinib therapy, lack of achievement of 3-month complete molecular response, and the presence of IKZF1plus status were significantly associated with poor OS. The differential impact of IKZF1plus was largely restricted to patients given Hyper-CVAD plus ponatinib; dasatinib-based regimens had unfavorable outcomes regardless of the molecular abnormalities.
Project description:Recurring genetic abnormalities have been identified in Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). Among them, IKZF1 deletion was associated with poor prognosis in patients treated with imatinib-based or dasatinib-based regimens. However, the molecular determinants for clinical outcomes in ponatinib-treated patients remain unknown. We systematically analyzed genetic alterations in adults with Ph-positive ALL uniformly treated in clinical trials with dasatinib-based regimens or a ponatinib-based regimen and investigated the molecular determinants for treatment outcomes using pretreatment specimens collected from adults with Ph-positive ALL treated with Hyper-CVAD plus dasatinib or ponatinib. DNA sequencing and SNP microarray were performed and recurrent genetic abnormalities were found in 84% of the patients, among whom IKZF1 deletion was most frequently detected (60%). IKZF1 deletion frequently co-occurred with other copy-number abnormalities (IKZF1plus, 46%) and was significantly associated with unfavorable overall survival (OS) (false discovery rate < 0.1) and increased cumulative incidence of relapse (p = 0.01). In a multivariate analysis, dasatinib therapy, lack of achievement of 3-month complete molecular response, and the presence of IKZF1plus status were significantly associated with poor OS. The differential impact of IKZF1plus was largely restricted to patients given Hyper-CVAD plus ponatinib; dasatinib-based regimens had unfavorable outcomes regardless of the molecular abnormalities.
Project description:Recurring genetic abnormalities have been identified in Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). Among them, IKZF1 deletion was associated with poor prognosis in patients treated with imatinib-based or dasatinib-based regimens. However, the molecular determinants for clinical outcomes in ponatinib-treated patients remain unknown. We systematically analyzed genetic alterations in adults with Ph-positive ALL uniformly treated in clinical trials with dasatinib-based regimens or a ponatinib-based regimen and investigated the molecular determinants for treatment outcomes using pretreatment specimens collected from adults with Ph-positive ALL treated with Hyper-CVAD plus dasatinib or ponatinib. DNA sequencing and SNP microarray were performed and recurrent genetic abnormalities were found in 84% of the patients, among whom IKZF1 deletion was most frequently detected (60%). IKZF1 deletion frequently co-occurred with other copy-number abnormalities (IKZF1plus, 46%) and was significantly associated with unfavorable overall survival (OS) (false discovery rate < 0.1) and increased cumulative incidence of relapse (p = 0.01). In a multivariate analysis, dasatinib therapy, lack of achievement of 3-month complete molecular response, and the presence of IKZF1plus status were significantly associated with poor OS. The differential impact of IKZF1plus was largely restricted to patients given Hyper-CVAD plus ponatinib; dasatinib-based regimens had unfavorable outcomes regardless of the molecular abnormalities.
Project description:Genetic correlates in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia treated with Hyper-CVAD plus dasatinib or ponatinib
Project description:Background Children with Down Syndrome have an augmented risk for B-cell acute lymphoblastic leukaemia (DS-ALL), which is associated with a survival lower than in non-DS ALL, due to increased chemotherapy-related toxicity and a higher relapse rate, thus demanding new tailored therapeutic strategies. Cytogenetic abnormalities common in childhood ALL are less frequent in DS-ALL, while alterations in CRLF2 and IKZF1 genes are increased. Aim of the study was to evaluate in DS-ALL children the incidence and prognostic value of the Philadelphia Chromosome-Like (Ph-like) status and the “IKZF1plus” profile, both associated with poor outcome in non-DS ALL and therefore introduced in current therapeutic protocols for BCP-ALL. Method Seventy DS-ALL patients at diagnosis treated in Italian centres from 2000 to 2014 were evaluated for their cytogenetic status, including the Ph-like ALL profile, while the IKZF1plus feature was investigated in a larger cohort of 134 patients treated in Italian and German centres from 2000 to 2011. Findings Forty-six out of 70 (65•7%) AIEOP DS-ALL patients displayed the Ph-like ALL gene expression signature, mostly characterized by CRLF2 (n=33) and IKZF1 (n=16) alterations (13 had both alterations); only one case was positive for an ABL-class and one for a PAX5 fusion gene. In the Italian and German joint cohort, we observed 35•6% patients positive for P2RY8::CRLF2 fusion, 24•8% for IKZF1 deletion and 18% for IKZF1plus feature. Unexpectedly, a higher IKZF1 expression and activity were observed in IKZF1plus than IKZF1 wt DS-ALL patients. Ph-like signature and IKZF1 deletion were associated with poor outcome, which further worsens when IKZF1 deletion was co-occurring with P2RY8::CRLF2, qualifying for the IKZF1plus definition. Interpretation These subgroups, which for the most part are not associated with other high risk features, need new and tailored therapeutic strategies, not only focussed on the use of drugs that restore IKZF1 function.
Project description:Alterations of IKZF1, encoding the lymphoid transcription factor IKAROS, are a hallmark of high risk acute lymphoblastic leukemia (ALL), however the role of IKZF1 alterations in ALL pathogenesis is poorly understood. Here we show that in mouse models of BCR-ABL1 leukemia, Ikzf1 and Arf alterations synergistically promote the development of an aggressive lymphoid leukemia. Ikzf1 alterations were associated with acquisition of stem cell-like features, including self-renewal and increased bone marrow stromal adhesion. Rexinoid receptor agonists reversed this phenotype, in part by inducing expression of IKZF1, resulting in abrogation of adhesion and self-renewal, cell cycle arrest and attenuation of proliferation without direct cytotoxicity. Retinoids potentiated the activity of dasatinib in mouse and human BCR-ABL1 ALL, providing a new therapeutic option in IKZF1-mutated ALL. Significance: The outcome of therapy for high-risk acute lymphoblastic leukemia remains suboptimal despite contemporary chemotherapy and the advent of targeted therapeutic approaches. Recent genomic studies have identified deletions or mutations of IKZF1 as a hallmark of high-risk ALL, but an understanding of how IKZF1 alteration contribute to leukemia development are lacking. Here we show that IKZF1 alterations drive lymphoid lineage, a stem cell-like phenotype, abnormal bone marrow adhesion, and poor responsiveness to tyrosine kinase inhibitor (TKI) therapy. Using a high-content screen, we show that retinoids reverse this phenotype in part by inducing expression of wild type IKZF1, and increase responsiveness to TKIs. These findings provide new insight into the pathogenesis of high-risk ALL and potential new therapeutic approaches. Pre-B mRNA profiles of p185 MIG and IK6 cells, DMSO or drug treated, in 3 or 4 replicates, using Illumina HiSeq 2500.
Project description:The Philadelphia chromosome (Ph) encoding the oncogenic BCR-ABL1 kinase defines a subset of ALL with a particularly unfavorable prognosis. Acute lymphoblastic leukemia (ALL) cells are derived from B cell precursors in most cases and typically carry rearranged immunglobulin heavy chain (IGH) variable (V) region genes devoid of somatic mutations. Somatic hypermutation is restricted to mature germinal center B cells and depends on activation-induced cytidine deaminase (AID). Studying AID expression in 108 cases of ALL, we detected AID mRNA in 24 of 28 Ph-positive ALLs as compared to 6 of 80 Ph-negative ALLs. Forced expression of BCR-ABL1 in Ph-negative ALL cells and inhibition of the BCR-ABL1-kinase showed that aberrant expression of AID depends on BCR-ABL1 kinase activity. Consistent with aberrant AID expression in Ph-positive ALL, IGH V region genes and BCL6 were mutated in many Ph-positive but unmutated in most Ph-negative cases. In addition, AID introduced DNA-single-strand breaks within the tumor suppressor gene CDKN2B in Ph-positive ALL cells, which was sensitive to BCR-ABL1 kinase inhibition and silencing of AID expression by RNA interference. These findings identify AID as a BCR-ABL1-induced mutator in Ph-positive ALL cells, which may be relevant with respect to the particularly unfavorable prognosis of this leukemia subset. Keywords: gene expression array-based (RNA / in situ oligonucleotide)
Project description:Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a distinct subtype of B-ALL with a poor prognosis. Rearrangement of LYN is a recurrent genetic abnormality in Ph-like ALL, but functional analysis of LYN-related fusion genes identified in ALL has not been reported. In this study, we performed functional analysis of the NCOR1-LYN fusion gene identified in a pediatric Ph-like ALL patient to establish its potential for molecular targeted therapy. Retroviral transduction of interleukin (IL)-3-dependent Ba/F3 cells with NCOR1-LYN enabled IL-3-independent proliferation, with constitutive phosphorylation of the tyrosine residues of the LYN kinase domain in the fusion protein. Replacing tyrosine residues with phenylalanine in the LYN kinase domain abolished IL-3 independence. Tyrosine kinase inhibitor dasatinib killed Ba/F3 cells expressing NCOR1-LYN in vitro accompanied by dephosphorylation of the tyrosine residues of the LYN kinase domain in the fusion protein. In a patient-derived xenograft (PDX) mouse model, generated using leukemic cells from the NCOR1-LYN positive Ph-like ALL patient, dasatinib controlled the growth of leukemic cells in vivo and significantly extended the survival time of the PDX mice (p=0.03). Our data demonstrate that, like other kinase fusions identified in Ph-like ALL, the NCOR1-LYN rearrangement has proliferative activity, and that tyrosine phosphorylation of the LYN kinase domain is critical for IL-3 independent growth. Furthermore, in a preclinical model we demonstrate the efficacy in vivo of dasatinib as therapy for Ph-like ALL with a LYN rearrangement.
Project description:Alterations of IKZF1, encoding the lymphoid transcription factor IKAROS, are a hallmark of high risk acute lymphoblastic leukemia (ALL), however the role of IKZF1 alterations in ALL pathogenesis is poorly understood. Here we show that in mouse models of BCR-ABL1 leukemia, Ikzf1 and Arf alterations synergistically promote the development of an aggressive lymphoid leukemia. Ikzf1 alterations were associated with acquisition of stem cell-like features, including self-renewal and increased bone marrow stromal adhesion. Rexinoid receptor agonists reversed this phenotype, in part by inducing expression of IKZF1, resulting in abrogation of adhesion and self-renewal, cell cycle arrest and attenuation of proliferation without direct cytotoxicity. Retinoids potentiated the activity of dasatinib in mouse and human BCR-ABL1 ALL, providing a new therapeutic option in IKZF1-mutated ALL. Significance: The outcome of therapy for high-risk acute lymphoblastic leukemia remains suboptimal despite contemporary chemotherapy and the advent of targeted therapeutic approaches. Recent genomic studies have identified deletions or mutations of IKZF1 as a hallmark of high-risk ALL, but an understanding of how IKZF1 alteration contribute to leukemia development are lacking. Here we show that IKZF1 alterations drive lymphoid lineage, a stem cell-like phenotype, abnormal bone marrow adhesion, and poor responsiveness to tyrosine kinase inhibitor (TKI) therapy. Using a high-content screen, we show that retinoids reverse this phenotype in part by inducing expression of wild type IKZF1, and increase responsiveness to TKIs. These findings provide new insight into the pathogenesis of high-risk ALL and potential new therapeutic approaches.
Project description:Alterations of IKZF1, encoding the lymphoid transcription factor IKAROS, are a hallmark of high risk acute lymphoblastic leukemia (ALL), however the role of IKZF1 alterations in ALL pathogenesis is poorly understood. Here we show that in mouse models of BCR-ABL1 leukemia, Ikzf1 and Arf alterations synergistically promote the development of an aggressive lymphoid leukemia. Ikzf1 alterations were associated with acquisition of stem cell-like features, including self-renewal and increased bone marrow stromal adhesion. Rexinoid receptor agonists reversed this phenotype, in part by inducing expression of IKZF1, resulting in abrogation of adhesion and self-renewal, cell cycle arrest and attenuation of proliferation without direct cytotoxicity. Retinoids potentiated the activity of dasatinib in mouse and human BCR-ABL1 ALL, providing a new therapeutic option in IKZF1-mutated ALL. Significance: The outcome of therapy for high-risk acute lymphoblastic leukemia remains suboptimal despite contemporary chemotherapy and the advent of targeted therapeutic approaches. Recent genomic studies have identified deletions or mutations of IKZF1 as a hallmark of high-risk ALL, but an understanding of how IKZF1 alteration contribute to leukemia development are lacking. Here we show that IKZF1 alterations drive lymphoid lineage, a stem cell-like phenotype, abnormal bone marrow adhesion, and poor responsiveness to tyrosine kinase inhibitor (TKI) therapy. Using a high-content screen, we show that retinoids reverse this phenotype in part by inducing expression of wild type IKZF1, and increase responsiveness to TKIs. These findings provide new insight into the pathogenesis of high-risk ALL and potential new therapeutic approaches.
Project description:A phase I trial of a SRC kinase Inhibitor, dasatinib, in combination with paclitaxel and carboplatin in patients with advanced or recurrent ovarian cancer. Background: We conducted a phase I study of dasatinib, an oral SRC tyrosine kinase inhibitor, in combination with paclitaxel and carboplatin in advanced and recurrent epithelial ovarian cancer (EOC). Methods: The primary objective was to determine the maximum tolerated dose (MTD). Secondary objectives included toxicity, response rate (RR), pharmacokinetics and pharmacodynamics. Based on the 3+3 design, cohorts of 3-6 pts received paclitaxel 175 mg/m2 and carboplatin AUC 6 every three weeks with escalating doses of dasatinib (100, 120, 150 mg daily), followed by an 8 patient expansion cohort. Results: Twenty patients were enrolled between 06/07 and 12/09. The median age was 61 yrs (42-82) with a median of 2 prior regimens (0-6), and 71% had platinum-sensitive disease. There were 3-6 pts in each cohort, and 8 in the expansion cohort. Pharmacokinetics were observed over the first 2 cycles of therapy. One DLT was observed in the 100 mg dasatinib cohort (grade 3 myalgia. Other toxicities in all cycles included neutropenia (95% grade 3-4), thrombocytopenia (35% grade 3-4), and fatigue (10% grade 3). The RR was 45% (complete responses, 3/18(17%); partial responses, 5/18(28%)) and 56% (10/18) had stable disease. The PFS6-month actuarial estimate was 86%. The median PFS and OS were 7.8 and 16.2 months, respectively. Conclusions: Due to the high incidence of myelosuppression with subsequent cycles the recommended phase II dose is 150 mg daily of dasatinib in combination with paclitaxel and carboplatin. The combination was safe with evidence of clinical activity in advanced EOC. Global profiles of expression were characterized using unsupervised clustering methods and gene- and pathway-analyses of differential expression.