Project description:This analysis focused on identifying factors that protect pre-B cells against DNA double strand break (DSB)-mediated DNA damage stress during pre-B cell differentiation. Differentiation of pre-B cells including immunoglobulin light chain gene recombination were performed by withdrawal of interleukin-7 (IL-7) from IL-7-dependent murine pre-B cells or by inhibition of the BCR-ABL1 kinase activity in BCR-ABL1-transformed pre-B cells. The BCR-ABL1 kinase inhibitor STI571 (Imatinib) was used for the inhibition of BCR-ABL1.
Project description:This analysis focused on identifying factors that protect pre-B cells against DNA double strand break (DSB)-mediated DNA damage stress during pre-B cell differentiation. Differentiation of pre-B cells including immunoglobulin light chain gene recombination were performed by withdrawal of interleukin-7 (IL-7) from IL-7-dependent murine pre-B cells or by inhibition of the BCR-ABL1 kinase activity in BCR-ABL1-transformed pre-B cells. The BCR-ABL1 kinase inhibitor STI571 (Imatinib) was used for the inhibition of BCR-ABL1. IL-7-dependent murine pre-B cells were either cultured in IL-7 (10 ng/ml) or induced to differentiate by withdrawal of IL-7. BCR-ABL1-transformed pre-B cells were either treated with 10 µM STI571 (in absence or presence of 10 ng/ml IL-7) for 16 hours or cultured without STI571. Three samples for each condition were processed.
Project description:BCR-ABL1-targeting tyrosine kinase inhibitors (TKIs) have revolutionized treatment of Philadelphia chromosome-positive (Ph+) hematologic neoplasms. Nevertheless, acquired TKI resistance remains a major problem in chronic myeloid leukemia (CML), and TKIs are less effective against Ph+ B-cell acute lymphoblastic leukemia (B-ALL). GAB2, a scaffolding adaptor that binds and activates SHP2, is essential for leukemogenesis by BCR-ABL1, and a GAB2 mutant lacking SHP2 binding cannot mediate leukemogenesis. Using a genetic loss-of-function approach and bone marrow transplantation (BMT) models for CML and BCR-ABL1+ B-ALL, we show that SHP2 is required for BCR-ABL1-evoked myeloid and lymphoid neoplasia. Ptpn11 deletion impairs initiation and maintenance of CML-like myeloproliferative neoplasm, and compromises induction of BCR-ABL1+ B-ALL. SHP2, and specifically, its SH2 domains, PTP activity and C-terminal tyrosines, is essential for BCR-ABL1+, but not WT, pre-B cell proliferation. The MEK/ERK pathway is regulated by SHP2 in WT and BCR-ABL1+ pre-B cells, but is only required for the proliferation of BCR-ABL1+ cells. SHP2 is required for SRC family kinase (SFK) activation only in BCR-ABL1+ pre-B cells. RNAseq reveals distinct SHP2-dependent transcriptional programs in BCR-ABL1+ and WT pre-B cells. Our results suggest that SHP2, via SFKs and ERK, represses MXD3/4 to facilitate a MYC-dependent proliferation program in BCR-ABL1-transformed pre-B cells.
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:In order to investigate the function of pre-B cell receptor in ALL, we isolated bone marrow cells from Ighm KO mice and transformed them with BCR-ABL1. In a second transduction the BCR-ABL1 driven pre-B cells were transformed either with uchain-CD8 or empty vector control (CD8) and subjected to gene expression analysis.
Project description:In order to investigate the function of MYC in ALL, we isolated bone marrow cells from conditional MYC knockout mice and transformed them with BCR-ABL1. In a second transduction the BCR-ABL1 driven pre-B cells were transformed either with CRE or empty vector control.
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:In order to investigate the function of PAX5 in ALL, we isolated bone marrow cells from C57Bl6 mice and transformed them with BCR-ABL1. In a second transduction the BCR-ABL1 driven pre-B cells were transformed either with PAX5-GFP or empty vector control (GFP) and subjected to gene expression analysis.
Project description:In order to investigate the function of IKZF1 in ALL, we isolated bone marrow cells from C57Bl6 mice and transformed them with BCR-ABL1. In a second transduction the BCR-ABL1 driven pre-B cells were transformed either with IKZF1-GFP or empty vector control (GFP) and subjected to gene expression analysis.