Project description:The Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which defines a subset of acute lymphoblastic leukemia (ALL) with a particularly unfavorable prognosis. In this study, the tyrosine kinase inhibitor imatinib was used for pharmacological inhibition of BCR-ABL1. Gene expression profiles of Ph+ ALL cell lines were analyzed in response to imatinib treatment.
Project description:The Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which defines a subset of acute lymphoblastic leukemia (ALL) with a particularly unfavorable prognosis. In this study, the tyrosine kinase inhibitor imatinib was used for pharmacological inhibition of BCR-ABL1. Gene expression profiles of Ph+ ALL cell lines were analyzed in response to imatinib treatment. Four Ph+ ALL cell lines (BV-173, NALM-1, SUP-B15, and TOM1) were either treated with 10µM STI571 (Imatinib) for 16 hours or cultured in absence of STI571.
Project description:The Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which defines a subset of acute lymphoblastic leukemia (ALL) with a particularly unfavorable prognosis. Tyrosine kinase inhibitors (TKI) are widely used to treat patients with leukemia driven by BCR-ABL1 and other oncogenic tyrosine kinases. In response to TKI-treatment, BCR-ABL1 ALL cells upregulate BCL6 protein levels by ~90-fold, i.e. to similar levels as in diffuse large B cell lymphoma (DLBCL) with BCL6 translocations. In this study, we used genome tiling arrays to identify BCL6 target genes with specific recruitment of BCL6. Three Ph+ ALL cell lines (BV-173, NALM-1 and TOM-1) in duplicate were either treated with 10µM STI571 (Imatinib) for 24 hours or cultured in absence of STI571.
Project description:The Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which defines a subset of acute lymphoblastic leukemia (ALL) with a particularly unfavorable prognosis. Tyrosine kinase inhibitors (TKI) are widely used to treat patients with leukemia driven by BCR-ABL1 and other oncogenic tyrosine kinases. In response to TKI-treatment, BCR-ABL1 ALL cells upregulate BCL6 protein levels by ~90-fold, i.e. to similar levels as in diffuse large B cell lymphoma (DLBCL) with BCL6 translocations. In this study, we analyzed the gene expression changes after treatment with Imatinib or Imatinib + RI-BPI.
Project description:The Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which defines a subset of acute lymphoblastic leukemia (ALL) with a particularly unfavorable prognosis. Tyrosine kinase inhibitors (TKI) are widely used to treat patients with leukemia driven by BCR-ABL1 and other oncogenic tyrosine kinases. In response to TKI-treatment, BCR-ABL1 ALL cells upregulate BCL6 protein levels by ~90-fold, i.e. to similar levels as in diffuse large B cell lymphoma (DLBCL) with BCL6 translocations. In this study, we used genome tiling arrays to identify BCL6 target genes with specific recruitment of BCL6.
Project description:The Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which defines a subset of acute lymphoblastic leukemia (ALL) with a particularly unfavorable prognosis. Tyrosine kinase inhibitors (TKI) are widely used to treat patients with leukemia driven by BCR-ABL1 and other oncogenic tyrosine kinases. In response to TKI-treatment, BCR-ABL1 ALL cells upregulate BCL6 protein levels by ~90-fold, i.e. to similar levels as in diffuse large B cell lymphoma (DLBCL) with BCL6 translocations. In this study, we analyzed the gene expression changes after treatment with Imatinib or Imatinib + RI-BPI. Three Ph+ ALL cell lines (BV-173, SUP-B15 and TOM-1) were treated in the presence or absence of 10 μM STI571 (Imatinib) or in the presence of both 10 μM STI571 and 20 μM RI-BPI for 24 hours.
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:Ph+ acute lymphoblastic leukemia (ALL) is characterized by the expression of an oncogenic fusion kinase termed BCR-ABL1. Here, we show that interleukin 7 receptor (IL7R) interacts with the chemokine receptor CXCR4 to recruit BCR-ABL1 and JAK kinases in close proximity. Treatment with BCR-ABL1 kinase inhibitors result in elevated expression of IL7R which enable the survival of transformed cells when IL7 was added together with the kinase inhibitors. Importantly, treatment with anti-IL7R antibodies prevents leukemia development in xenotransplantation models using patient-derived Ph+ ALL cells. Our results suggest that the association between IL7R and CXCR4 serves as molecular platform for BCR-ABL1 induced transformation and development of Ph+ ALL. Targeting this platform with anti-IL7R antibody eliminates Ph+ ALL cells including those with resistance to commonly used ABL1 kinase inhibitors. Thus, anti-IL7R antibodies may provide alternative treatment options for ALL in general and may suppress incurable drug-resistant leukemia forms.