ABL Tyrosine Kinase Phosphorylates DGCR8 to Stimulate MicroRNA Processing in DNA Damage Response
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE59028 | GEO | 2015/07/01
SECONDARY ACCESSION(S): PRJNA254155
REPOSITORIES: GEO
Similar Datasets
Project description:miR-seq to find miRs that are induced by DNA damage and whose induction requires ABL kinase activity Use p53-inactive HEK293T cells. Use doxorubicin to induce DNA damage. Use imatinib co-treatment to inhibit ABL kinase activity
2015-07-01 | E-GEOD-59028 | biostudies-arrayexpress
Project description:The DNA damage response network stimulates microRNA (miRNA) biogenesis to coordinate repair, cell cycle checkpoints, and apoptosis. The multistep process of miRNA biogenesis involves the cleavage of primary miRNAs by the microprocessor complex composed of the ribonuclease Drosha and the RNA binding protein DGCR8. We found that the tyrosine kinase ABL phosphorylated DGCR8, a modification that was required for the induction of a subset of miRNAs after DNA damage. Focusing on the miR-34 family, ABL stimulated the production of miR-34c, but not miR-34a, through Drosha/DGCR8-dependent processing of primary miR-34c (pri-miR-34c). This miRNA-selective effect of ABL required the sequences flanking the precursor miR-34c (pre-miR-34c) stem-loop. In pri-miRNA processing, DGCR8 binds the pre-miR stem-loop and recruits Drosha to the miRNA. RNA cross-linking assays showed that DGCR8 and Drosha interacted with pri-miR-34c, but we found an inverse correlation between ABL-stimulated processing and DGCR8 association with pri-miR-34c. When coexpressed in HEK293T cells, ABL phosphorylated DGCR8 at Tyr(267). Ectopic expression of a Y267F-DGCR8 mutant reduced the recruitment of Drosha to pri-miR-34c and prevented ABL or Drosha from stimulating the processing of pri-miR-34c. In mice engineered to express a nuclear import-defective mutant of ABL, miR-34c, but not miR-34a, expression was reduced in the kidney, and apoptosis of the renal epithelial cells was impaired in response to cisplatin. These results reveal a new pathway in the DNA damage response wherein ABL-dependent tyrosine phosphorylation of DGCR8 stimulates the processing of selective primary miRNAs.
| S-EPMC4499470 | biostudies-literature
Project description:Tyrosine kinase activity is the crucial enzymatic activity driving all known functions of the BCR-ABL protein and is required for protection from apoptosis by BCR-ABL, therefore, targeting this enzyme is an effective approach for therapeutic strategies. Recently, a novel structural entity, imatinib (STI571; Novartis, Basel, Switzerland), a potent and selective inhibitor of the tyrosine kinase activity of BCR-ABL, has shown promise against Ph-positive leukemia in human clinical trials. However, the emergence of imatinib resistance in patients with acute forms of Ph-positive leukemia has highlighted the need for overriding chemotherapy to eradicate this disease. AMN107 and BMS-354825 are clinically active “next-generation” BCR-ABL inhibitors. One potentially powerful approach is to use these compounds in combination with imatinib. The rationale for such approaches is that an inhibitor cocktail may target the widest range of resistant clones and thereby delay the onset of acquired drug resistance. More potent BCR-ABL inhibitors would be to target residual leukemia that persists in patients in whom imatinib induces durable remission but failed to eradicate the disease. From these points, our studies are performed to determine (1) the differences of molecular signaling pathways between BMS-354825 and imatinib (2) the mechanisms by which drug resistance of BMS-354825 and imatinib occur except for point mutation of BCR-ABL kinase domain. Keywords: drug sensitivity
2006-03-31 | GSE2810 | GEO
Project description:Background In the ongoing battle against BCR-ABL+ leukemia, despite significant advances with tyrosine kinase inhibitors (TKIs), the persistent challenges of drug resistance and the enduring presence of leukemic stem cells (LSCs) remain formidable barriers to achieving a cure. Methods In this study, we demonstrated that Disulfiram (DSF) induces ferroptosis to synergize with TKIs in inhibiting BCR-ABL+ cells, particularly targeting resistant cells and LSCs, using cell models, mouse models, and primary cells from patients. We elucidated the mechanism by which DSF promotes GPX4 degradation to induce ferroptosis through immunofluorescence, co-immunoprecipitation (CO-IP), RNA sequencing, lipid peroxidation assays, and rescue experiments. Results Here, we present compelling evidence elucidating the sensitivity of DSF, an FDA-approved drug for alcohol dependence, towards BCR-ABL+ cells. Our findings underscore DSF's ability to selectively induce a potent cytotoxic effect on BCR-ABL+ cell lines and effectively inhibit primary BCR-ABL+ leukemia cells. Crucially, the combined treatment of DSF with TKIs selectively eradicates TKI-insensitive stem cells and resistant cells. Of particular note is DSF's capacity to disrupt GPX4 stability, elevate the labile iron pool, and intensify lipid peroxidation, ultimately leading to ferroptotic cell death. Our investigation shows that BCR-ABL expression induces alterations in cellular iron metabolism and increases GPX4 expression. Additionally, we demonstrate the indispensability of GPX4 for LSC development and the initiation/maintenance of BCR-ABL+ leukemia. Mechanical analysis further elucidates DSF's ability to circumvent resistance by reducing GPX4 levels through the disruption of its binding with HSPA8, thereby promoting GPX4 ubiquitination and subsequent degradation. Furthermore, the combined treatment of DSF with TKIs effectively targets both BCR-ABL+ blast cells and drug-insensitive LSCs, conferring a significant survival advantage in mouse models. Conclusion In summary, the dual inhibition of GPX4 and BCR-ABL presents a promising therapeutic strategy to synergistically target blast cells and drug-insensitive LSCs in patients, offering potential avenues for advancing leukemia treatment.
2024-09-05 | GSE276122 | GEO
Project description:Nonmuscle myosin light chain kinase (nmMLCK), a multi-functional cytoskeletal protein critical to vascular homeostasis, is highly regulated by tyrosine phosphorylation. We identified multiple novel c-Abl-mediated nmMLCK phosphorylation sites by mass spectroscopy analysis (including Y231, Y464, Y556, Y846) and examined their influence on nmMLCK function and human lung endothelial cell (EC) barrier regulation. Tyrosine phosphorylation of nmMLCK increased kinase activity, reversed nmMLCK-mediated inhibition of Arp2/3-mediated actin polymerization, and enhanced binding to the critical actin-binding phosphotyrosine protein, cortactin. EC challenge with sphingosine 1-phosphate (S1P), a potent barrier-enhancing agonist, resulted in c-Abl and phosphorylated nmMLCK recruitment into caveolin-enriched microdomains, rapid increases in Abl kinase activity, and spatial targeting of c-Abl to barrier-promoting cortical actin structures. Conversely, reduced c-Abl expression in EC (siRNA) markedly attenuated S1P-mediated cortical actin formation, reduced the EC modulus of elasticity (assessed by atomic force microscopy), reduced nmMLCK and cortactin tyrosine phosphorylation, and attenuated S1P-mediated barrier enhancement. These studies indicate an essential role for Abl kinase in vascular barrier regulation via posttranslational modification of nmMLCK and strongly support c-Abl-cortactin-nmMLCK interaction as a novel determinant of cortical actin-based cytoskeletal rearrangement critical to S1P-mediated EC barrier enhancement.
| S-EPMC2982111 | biostudies-literature
Project description:Gene expression profile variation between 4 BCR-Abl transduced cell lines: <br> 1-Mouse DA1-3b cell line as reference, <br> 2-DR1 imatinib resistant clone with E255K BCR-abl mutation<br> 3-DRBMSR 2 dasatinib resistant clone with E255K and T315I BCR-Abl mutation.<br> 4-DRBMSR 7 dasatinib resistant clone with E255K and T315I and V299L BCR-Abl mutation<br> <br> BCR-ABL is an oncogenic tyrosine kinase involved in the development of chronic myelogenous leukaemia (CML).
2007-08-01 | E-MEXP-772 | biostudies-arrayexpress
Project description:In this study, we have prepared a mouse embryonic fibrobalst (MEF) cell line stably expressing R367A mutant human Abl in which the native mouse Abl1 and Abl2 were genetically deleted. We have used these R367A mutant Abl cells in combination with mass spectrometry to identify phosphorylation targets of Abl. Below, we describe these findings and their potential biological significance.
2018-03-16 | PXD007118 | Pride
Project description:Combined targeting of GPX4 and BCR-ABL tyrosine kinase selectively compromises BCR-ABL+ leukemia stem cells
| PRJNA1154942 | ENA
Project description:The Hippo pathway is an evolutionarily conserved pathway that controls cell proliferation, organ size, tissue regeneration and stem cell self-renewal. Here we show that it also regulates the DNA damage response. At high cell density, when the Hippo pathway is active, DNA damage-induced apoptosis and the activation of the tyrosine kinase c-Abl were suppressed. At low cell density, overexpression of the Hippo pathway kinase large tumor suppressor 2 (Lats2) inhibited c-Abl activity. This led to reduced phosphorylation of downstream c-Abl substrates, the transcription coactivator Yes-associated protein (Yap) and the tumor suppressor p73. Inhibition of c-Abl by Lats2 was mediated through Lats2 interaction with and phosphorylation of c-Abl. Lats2 knockdown, or expression of c-Abl mutants that escape inhibition by Lats2, enabled DNA damage-induced apoptosis of densely plated cells, while Lats2 overexpression inhibited apoptosis in sparse cells. These findings explain a long-standing enigma of why densely plated cells are radioresistant. Furthermore, they demonstrate that the Hippo pathway regulates cell fate decisions in response to DNA damage.
| S-EPMC3770326 | biostudies-literature
Project description:We used massively parallel DNA sequencing of paired-end ditags (DNA-PET) to identify structural genetic factors associated with disease progression and drug-resistance in representative samples from four CML patients and one CML cell line. The functional consequences of our genetic findings were evaluated in primary CML cells and cell lines, and validated in a larger CML cohort. We discovered a novel intronic deletion that correlated with imatinib-resistance, and was subsequently confirmed to be a polymorphism in normal East-Asian, but not African or Caucasian, populations. We found that the polymorphism favored expression of transcripts lacking a pro-apoptotic domain, which is critical for imatinib-induced cell death. A CML cell line containing the polymorphism also exhibited BCR-ABL-independent imatinib-resistance.
2012-02-27 | GSE28303 | GEO