ABSTRACT: Gene expression data of BCR-ABL1 transformed myeloid cells from BCL6 wild-type and BCL6 knockout mice treated with and without Imatinib and RI-BPI
Project description:To identify differences in the gene regulation between BCL6+/+ and BCL6-/- CML cells a gene expression analysis has been performed. We investigated the gene expression pattern in BCL6+/+ cells in the presence or absence of Imatinib and a combination of Imatinib and RI-BPI (a novel retro-inverso BCL6 peptide inhibitor). In BCL6-/- CML cells, we investigated the gene expression pattern in the presence or absence of Imatinib. BCR-ABL1 transformed myeloid cells from BCL6+/+ mice were cultured in the presence or absence of 10µM Imatinib or 10µM Imatinib and 20µM RI-BPI for 16 hours. BCR-ABL1 transformed myeloid cells from BCL6-/- mice were cultured in the presence or absence of 10µM Imatinib. Two samples for each condition were processed.
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: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:To elucidate the mechanism of BCL6-mediated pre-B cell survival signaling, we investigated the gene expression pattern in BCR-ABL1-transformed BCL6+/+ and BCL6-/- B cell precursors. Pharmacological inhibition of BCR-ABL1 was performed with the BCR-ABL1 kinase inhibitor STI571 (Imatinib). BCR-ABL1 transformed B cell precursors of BCL6 wildtype and BCL6 knockout mice were either treated with 10µM STI571 (Imatinib) for 16 hours or cultured in absence of STI571. Three samples for each condition were processed.
Project description:To elucidate the mechanism of BCL6-mediated pre-B cell survival signaling, we investigated the gene expression pattern in BCR-ABL1-transformed BCL6+/+ and BCL6-/- B cell precursors. Pharmacological inhibition of BCR-ABL1 was performed with the BCR-ABL1 kinase inhibitor STI571 (Imatinib).
Project description:To identify differences in the gene regulation between BCL6+/+ and BCL6-/- CML cells a gene expression analysis has been performed. We investigated the gene expression pattern in BCL6+/+ cells in the presence or absence of Imatinib and a combination of Imatinib and RI-BPI (a novel retro-inverso BCL6 peptide inhibitor). In BCL6-/- CML cells, we investigated the gene expression pattern in the presence or absence of Imatinib.
Project description:This comparative genomic hybridization (CGH) study investigated the effect of BCL6 on clonal evolution in BCR-ABL1-driven acute lymphoblastic leukemia (ALL). The frequencies of copy number alterations in BCR-ABL1-transformed BCL6+/+ and BCL6-/- leukemias were determined. Three BCR-ABL1-transformed BCL6+/+ and BCL6-/- ALL samples derived from mice were maintained for 4 month in cell culture and were subjected to CGH analysis. As control samples, normal untransformed splenoytes were used.
Project description:In order to investigate the function of Bach2 in pre-B ALL, we isolated bone marrow cells from wildtype and Bach2 knockout mice of C57Bl6 background and transformed them with BCR-ABL1. We compared the gene expression profiles of Bach2 wildtype and knockout pre-B ALL cells, both with and without imatinib treatment (2uM for 16h).
Project description:This comparative genomic hybridization (CGH) study investigated the effect of BCL6 on clonal evolution in BCR-ABL1-driven acute lymphoblastic leukemia (ALL). The frequencies of copy number alterations in BCR-ABL1-transformed BCL6+/+ and BCL6-/- leukemias were determined.
Project description:The BCL6 transcriptional repressor is a critical oncogene in diffuse large B-cell lymphomas (DLBCL). The specific BCL6 inhibitor RI-BPI potently kills DLBCL cells. We find that RI-BPI induces a particular gene expression signature in DLBCL. In order to identify classes of drugs that might synergize with RIBPI we examined the connectivity of this signature and found a strong association with HDAC and Hsp90 inhibitors. This was explained by the discovery that BCL6 directly represses the p300 lysine acetyltransferase and its co-factor BAT3. RI-BPI induced expression of p300 and BAT3, and p300 acetyltransferase activity, resulting in acetylation of p300 targets like p53 and Hsp90. As a consequence, RI-BPI could attenuate Hsp90 chaperone function, similar to the effect of Hsp90 and HDAC inhibitors. Induction of p300 and BAT3 was required for the anti-lymphoma effects of RI-BPI since specific blockade of either protein rescued DLBCL cells from the BCL6 inhibitor. RI-BPI synergistically killed DLBCL cells in combination with HDAC inhibitors (SAHA, TSA and VPA) and Hsp90 inhibitors (17-DMAG and PUH71). The combination of RI-BPI and SAHA, or RI-BPI and PU-H71 potently suppressed or even eradicated human DLBCL in mice. BCL6 repression of EP300 thus provides a basis for rational targeted combinatorial therapy for patients with DLBCL.