Project description:To investigate transcriptome properties of hiPSC-derived endothelial cells compared to primary endotheilal cells and other hiPSC differentiation protocols
Project description:Nilotinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor for the first-line treatment of Philadelphia chromosome-positive chronic myeloid leukemia. However, its nephrotoxicity has become prominent with the increase of clinical use, which greatly limits its long-term application. So far, the mechanism of nilotinib’s nephrotoxicity is still unknown leading to a lack of clinical intervention strategies. Here, we found that nilotinib could promote intrinsic apoptosis of both vascular endothelial cells and renal tubular epithelial cells, which was mediated by the excessive ubiquitin-proteasome degradation of anti-apoptotic protein BCL-XL. Moreover, we confirmed that Chloroquine (CQ) could intervene nilotinib-induced apoptosis by reversing the decreased BCL-XL whose mechanism was not relied on autophagy inhibition. Furthermore, RNA-seq analysis was applied to identify the potential target of CQ and the result suggested that CQ could alleviate nilotinib-induced ANKRD1 reduction. Further, we found ANKRD1 abrogated cell apoptosis by preventing ubiquitination of BCL-XL and hence inhibiting BCL-XL degradation. In conclusion, our research reveals the molecular mechanism of nilotinib’s nephrotoxicity, wherein the excessive degradation of BCL-XL via ubiquitin-proteasome pathway promotes kidney cells apoptosis, and provides CQ analogs as the clinical intervention strategy of nilotinib’s nephrotoxicity whose pharmacological effect is dependent on ANKRD1 instead of autophagy inhibition.
Project description:Human T-cell leukemia virus type 1 (HTLV-1) causes incurable adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Patients with HAM/TSP have increased levels of HTLV-1-infected cells compared with asymptomatic HTLV-1 carriers. However, the roles played by cellular genes in HTLV-1-infected CD4+ T cells await discovery. We combined microarray data and pathway analysis, and found that the ABL1 tyrosine kinase gene is a critical gene in HAM/TSP. ABL1 is a known survival factor for T- and B-lymphocytes. ABL1 is also part of the fused gene (BCR-ABL) known to be responsible for chronic myelogenous leukemia (CML), and tyrosine kinase inhibitors (TKI), including imatinib, nilotinib, and dasatinib, are in safe clinical use for treating CML. To evaluate whether ABL1 is indeed critical for the pathogenesis of HAM/TSP, we investigated the effect of ABL1 inhibitors on HTLV-1-infected cells. We developed a propidium monoazide-HTLV-1 viability quantitative PCR assay, which distinguishes DNA from live cells and DNA from dead cells. Using this method, we were able to measure the HTLV-1 proviral load (PVL) in live cells alone when peripheral blood mononuclear cells (PBMCs) from HAM/TSP cases were treated with TKI. Treating the PBMCs with nilotinib or dasatinib produced significant reductions in the PVL (21.0% and 17.5%, respectively) in live cells. Furthermore, a retrospective survey based on our clinical records found a rare case of HAM/TSP, where the patient also suffered from CML. The patient showed an 84.2% PVL reduction after CML treatment with imatinib. We conclude that inhibiting the ABL1 tyrosine kinase specifically reduced the PVL in PBMCs from patients with HAM/TSP, suggesting that ABL1 is a significant gene for the survival of HTLV-1-infected cells and that TKI may be a potential therapeutic agent for HAM/TSP.
Project description:Purpose: We identified a rare instance of the SFPQ-ABL1 in a child with Ph-like ALL. The overall purpose of this study was to compare the structure and function of the SFPQ-ABL1 fusion to the well characterised BCR-ABL1 fusion. We used phosphoproteomics, transcriptomics and functional assays to determine the transforming capacity, subcellular localisation, and signalling networks of these two fusions. Given the known function of SFPQ in mRNA splicing, transcriptomic analysis was performed to analyse the effect of BCR-ABL1 or SFPQ-ABL1 expression on gene splicing. Methods: mRNA profiles of Ba/F3 cells expressing BCR-ABL1, SFPQ-ABL1, and empty vector control (MSCV) were generated by deep sequencing, in four biologically independent cell lines, using Illumina GAIIx. The sequences were aligned by subread and quantified by featureCounts. Results: In contrast to BCR-ABL1, SFPQ-ABL1 localised to the nuclear compartment and was a weaker driver of cellular proliferation. Phosphoproteomics analysis showed upregulation of cell cycle, DNA replication and spliceosome pathways, and downregulation of signal transduction pathways, including ErbB, NF-kappa B, VEGF, and MAPK signalling in SFPQ-ABL1-, compared to BCR-ABL1-expressing cells. SFPQ-ABL1 expression did not activate PI3K/AKT signalling and was associated with phosphorylation of G2/M cell cycle proteins. We identified no difference in overall splicing between cells expressing BCR-ABL1 and SFPQ-ABL1. Conclusions: SFPQ-ABL1 has functionally distinct mechanisms by which it drives ALL, including subcellular localisation, proliferative capacity, and activation of cellular pathways, highlighting the role that fusion partners have in mediating the function of ABL1 fusions.
Project description:BCR-ABL positive acute lymphoblastic leukemia (ALL) cell survival is strongly dependent on the IRE1α-XBP1 branch of the Unfolded Protein Response (UPR). In the study at hand, we have focused on exploring the link between BCR-ABL1 and IRE1α to better understand whether a simultaneous pharmacological inhibition of both pathways could represent a beneficial therapeutic strategy in Philadelphia positive (Ph+) ALL. Therefore, the effect on the phosphoproteome of two inhibitors (MKC-8866 and Nilotinib) as well as a combination of both compounds was analysed in this study.
Project description:Objectives: Treatment with the second and third generation BCR-ABL1 tyrosine kinase inhibitors (TKIs) increases cardiovascular risk in chronic myeloid leukemia (CML) patients. We investigated the multifactorial process of TKI-induced vascular adverse effects in a translational model for atherosclerosis, the APOE3*Leiden.CETP mouse. Approach and results: Mice were treated for sixteen weeks with imatinib (150 mg/kg BID), nilotinib (10 and 30 mg/kg QD) or ponatinib (3 and 10 mg/kg QD), giving similar drug exposures as in CML-patients. Cardiovascular risk factors were analyzed throughout the study, and histopathological analysis of atherosclerosis and transcriptome analysis of the liver was performed. Imatinib and ponatinib decreased plasma cholesterol (imatinib, -69%, :<0.001; ponatinib 3mg/kg, -37%, P<0.001; ponatinib 10 mg/kg -44%, P<0.001) and atherosclerotic lesion area (imatinib, -78%, P<0.001; ponatinib 3 mg/kg, -52%, P=0.014; ponatinib 10 mg/kg, -48%, P=0.001), which were not affected by nilotinib. In addition, imatinib increased plaque stability. Gene expression and pathway analysis predicted that ponatinib may lead to a pro-coagulant state by adversely affecting coagulation factors of both the contact activation (intrinsic) and tissue factor (extrinsic) pathways. The coagulation factor VII in plasma was increased by ponatinib, whereas nilotinib increased FVIIa. Conclusion: Imatinib showed a beneficial cardiovascular risk profile, whereas nilotinib and ponatinib increase the cardiovascular risk through induction of a pro-thrombotic state.
Project description:Coordinated BCR-ABL1 kinase-dependent and -independent mechanisms convert p27 from a nuclear tumor suppressor to a cytoplasmic oncogene. Persistence of oncogenic p27 functions despite effective inhibition of BCR-ABL1 may contribute to resistance to tyrosine kinase inhibitors.
Project description:Philadelphia-like (Ph-like) acute lymphoblastic leukaemia (ALL) is a high-risk subtype of B-cell ALL characterised by a gene expression profile resembling Philadelphia Chromosome positive ALL (Ph+ ALL) in the absence of BCR-ABL1. Tyrosine kinase activating fusions, some involving ABL1, are recurrent drivers of Ph-like ALL and are targetable with tyrosine kinase inhibitors (TKIs). We identified a rare instance of SFPQ-ABL1 in a child with Ph-like ALL. SFPQ-ABL1 expressed in cytokine-dependent cell lines was sufficient to transform cells which were sensitive to ABL1-targeting TKIs. In contrast to BCR-ABL1, SFPQ-ABL1 localised to the nuclear compartment and was a weaker driver of cellular proliferation. Phosphoproteomics analysis showed upregulation of cell cycle, DNA replication and spliceosome pathways, and downregulation of signal transduction pathways, including ErbB, NF-kappa B, VEGF, and MAPK signalling in SFPQ-ABL1-, compared to BCR-ABL1-expressing cells. SFPQ-ABL1 expression did not activate PI3K/AKT signalling and was associated with phosphorylation of G2/M cell cycle proteins. SFPQ-ABL1 was sensitive to navitoclax and S-63845 and promotes cell survival through upregulation of Mcl-1 and Bcl-xL. SFPQ-ABL1 has functionally distinct mechanisms by which it drives ALL, including subcellular localisation, proliferative capacity, and activation of cellular pathways, highlighting the role that fusion partners have in mediating the function of ABL1 fusions.
Project description:Coordinated BCR-ABL1 kinase-dependent and -independent mechanisms convert p27 from a nuclear tumor suppressor to a cytoplasmic oncogene. Persistence of oncogenic p27 functions despite effective inhibition of BCR-ABL1 may contribute to resistance to tyrosine kinase inhibitors. BCR-ABL1 induced p27 versus knockout, controlling with Empty vector p27 versus knock out
Project description:The clinical management of metastatic colorectal cancer (mCRC) faces major challenges. For instance, patients harbouring oncogenic mutations in RAS signalling do not respond to anti-EGFR targeted treatment. Therefore, RAS-independent therapies are needed. Interestingly nilotinib, a clinically approved drug for chronic myeloid leukaemia, inhibits human CRC cell invasion in vitro and reduces their metastatic potential in intrasplenic tumour mouse models. Nilotinib acts by inhibiting the kinase activity of DDR1, a receptor tyrosine kinase for collagens, which we identified as a RAS-independent inducer of CRC metastasis. Using quantitative phosphoproteomics, we identified BCR as a new DDR1 substrate and demonstrated that nilotinib prevents DDR1-mediated BCR phosphorylation on Tyr177, which is important for maintaining -catenin transcriptional activity necessary for tumour cell invasion. DDR1 kinase inhibition also reduced the invasion of patient-derived metastatic and circulating CRC cell lines.