Similar Datasets
Project description:Mutant p53 alters gene expression in human acute myeloid leukemia cells [patients]
| PRJNA1089568 | ENA
Project description:TP53, encoding for the tumor suppressor p53, is the most frequently mutated gene in human cancer. The selective pressures shaping its mutational spectrum, dominated by missense mutations, have remained enigmatic, and neomorphic gain-of-function (GOF) activities have been implicated. We generated isogenic human leukemia cell lines of the most common TP53 missense mutations using CRISPR/Cas9. Functional, DNA binding, and transcriptional analyses revealed loss-of-function (LOF) without GOF effects of missense mutations. Comprehensive mutational scanning of p53 single amino acid variants demonstrated that DNA-binding domain missense variants exert dominant-negative effects (DNE). In mice, DNE of p53 missense variants confer a selective advantage on hematopoietic cells upon DNA damage in vivo. Clinical outcomes in acute myeloid leukemia patients showed no evidence of GOF for TP53 missense mutations. These findings establish dominant-negativity as the primary unit of selection for TP53 missense mutations in myeloid malignancies.
2019-08-30 | GSE131592 | GEO
Project description:TP53, encoding for the tumor suppressor p53, is the most frequently mutated gene in human cancer. The selective pressures shaping its mutational spectrum, dominated by missense mutations, have remained enigmatic, and neomorphic gain-of-function (GOF) activities have been implicated. We generated isogenic human leukemia cell lines of the most common TP53 missense mutations using CRISPR/Cas9. Functional, DNA binding, and transcriptional analyses revealed loss-of-function (LOF) without GOF effects of missense mutations. Comprehensive mutational scanning of p53 single amino acid variants demonstrated that DNA-binding domain missense variants exert dominant-negative effects (DNE). In mice, DNE of p53 missense variants confer a selective advantage on hematopoietic cells upon DNA damage in vivo. Clinical outcomes in acute myeloid leukemia patients showed no evidence of GOF for TP53 missense mutations. These findings establish dominant-negativity as the primary unit of selection for TP53 missense mutations in myeloid malignancies.
2019-08-30 | GSE131484 | GEO
Project description:Eliminating mutant p53 (mt p53) protein could be a useful strategy to treat mt p53 tumors and potentially improve the prognosis of cancer patients. In this study, we unveil different mechanisms that eliminate p53-R248Q, one of the most frequent mutants found in human cancers. We show that the Hsp90 inhibitor 17-AAG eliminates R248Q by stimulating macroautophagy under normal growth conditions. Metabolic stress induced by the pyruvate dehydrogenase kinase-1 (PDK1) inhibitor dichloroacetate (DCA) inhibits the macroautophagy pathway. This induces the accumulation of R248Q, which in addition further inhibits macroautophagy. Combination of DCA and 17-AAG further decreases the autophagy flux compared to DCA alone. Despite this, this co-treatment strongly decreases R248Q levels. In this situation of metabolic stress, 17-AAG induces the binding of p53-R248Q to Hsc70 and the activation of Chaperone-Mediated Autophagy (CMA), leading to higher R248Q degradation than in non-stress conditions. Thus, different metabolic contexts induce diverse autophagy mechanisms that degrade p53-R248Q, and under metabolic stress, its degradation is CMA-mediated. Hence, we present different strategies to eliminate this mutant and provide new evidence of the crosstalk between macroautophagy and CMA and their potential use to target mutant p53.
| S-EPMC6449403 | biostudies-literature
Project description:We previously demonstrated that a subset of acute myeloid leukemia (AML) patients with concurrent RAS pathway and TP53 mutations have extremely poor prognosis, and most of these TP53 mutations are missense mutations. Here, we report that in contrast to mixed AML and T-cell malignancy developed in NrasG12D/+; p53-/- (NP-/-) mice, NrasG12D/+; p53R172H/+ (NPmut) mice rapidly developed an inflammation-associated AML. Under the inflammatory conditions, NPmut hematopoietic stem and progenitor cells (HSPCs) displayed imbalanced myelopoiesis and lymphopoiesis and largely normal cell proliferation despite MEK/ERK hyperactivation. RNA-Seq analysis revealed that NrasG12D signaling and p53mut synergize to establish an NPmut-AML transcriptome distinct from that of NA-/- cells. The NPmut-AML transcriptome showed GATA2 downregulation and elevated expression of inflammatory genes, including those linked to NFΚB signaling. NFΚB was also upregulated in human NRAS;TP53 AML. Exogenous expression of GATA2 in human NPmut KY821 AML cells downregulated inflammatory gene expression. Mouse and human NPmut AML cells were sensitive to MEK and NFΚB inhibition in vitro. The proteasome inhibitor bortezomib stabilized NFΚB inhibitory protein IΚBɑ mitigated inflammatory gene expression, and potentiated the survival benefit of a MEK inhibitor in NPmut mice. Our study demonstrates that a p53 structural mutant synergizes with NrasG12D to promote AML through mechanisms distinct from p53 loss.
2023-09-25 | GSE243642 | GEO
Project description:UTX Loss Alters Therapeutic Responses in KMT2A-rearranged Acute Myeloid Leukemia
| PRJNA884687 | ENA
Project description:Acute myeloid leukemia (AML) is a hematologic malignancy for which several epigenetic regulators have been identified as therapeutic targets. Here we report the development of cereblon-dependent degraders of IKZF2 and casein kinase 1 alpha (CK1α) termed DEG-35 and DEG-77. We utilized a structure-guided approach to develop DEG-35 as a nanomolar degrader of IKZF2, a hematopoietic specific transcription factor that contributes to myeloid leukemogenesis. DEG-35 possesses additional substrate specificity for the therapeutically relevant target CK1α which was identified through unbiased proteomics and a PRISM screen assay. Degradation of IKZF2 and CK1α blocks cell growth and induces myeloid differentiation in AML cell lines through CK1α–p53- and IKZF2-dependent pathways. Target degradation by DEG-35 or the analog DEG-77 delays leukemia progression in murine and human AML mice models. Overall, we provide a strategy for multi-targeted degradation of IKZF2/CK1α to enhance efficacy against AML that may be expanded to additional targets and indications.
2023-03-08 | PXD039474 | Pride
Project description:Tumor protein p53 is a key regulator of several cellular pathways, including DNA repair, cell cycle and angiogenesis. Kevetrin exhibits p53-dependent as well as independent activity in solid tumors, while its effects on leukemic cells remain unknown. We analyzed the response of acute myeloid leukemia (AML) cell lines (TP53 wild-type: OCI-AML3 and MOLM-13; and TP53-mutant: KASUMI-1 and NOMO-1) to kevetrin at a concentration range of 85-340 μM. Kevetrin induced cell growth arrest and apoptosis in all cell lines and in primary cells, with TP53-mutant models displaying a higher sensitivity and p53 induction. Gene expression profiling revealed a common core transcriptional program altered by drug exposure and the downregulation of glycolysis, DNA repair and unfolded protein response signatures. These findings suggest that kevetrin may be a promising therapeutic option for patients with both wild-type and TP53-mutant AML.
2020-09-03 | GSE137574 | GEO
Project description:Internal tandem duplication (ITD) mutations within the FMS-like receptor tyrosine kinase-3 (FLT3) can be found in up to 25~30% of acute myeloid leukemia (AML) patients and confer a poor prognosis. Although FLT3 tyrosine kinase inhibitors (TKIs) have shown clinical responses, the overall outcome of FLT3-ITD+ AML patients remains poor, and most of them would relapse very shortly. TKIs can not eliminate primitive FLT3-ITD+ AML cells, which are potential sources of relapse. Therefore, elucidating the mechanisms underlying FLT3-ITD+ AML maintenance and drug resistance is essential to develop novel, effective treatment strategies. Here, we demonstrate that FLT3 inhibition induces histone deacetylase 8 (HDAC8) upregulation through FOXO1 and FOXO3-mediated transactivation in FLT3-ITD+ AML cells. Upregulated HDAC8 deacetylates and inactivates p53, leading to leukemia maintenance and drug resistance upon TKIs treatment. Genetic or pharmacological inhibition of HDAC8 re-activates p53, abrogates leukemia maintenance and significantly enhances TKI-mediated elimination of FLT3-ITD+ AML cells. Importantly, in FLT3-ITD+ AML patient-derived xenograft models, the combination of FLT3 TKI (AC220) with a HDAC8 inhibitor (22d) significantly inhibits leukemia progression and effectively reduces primitive FLT3-ITD+ AML cells. Moreover, we extend these findings to an AML subtype harboring another tyrosine kinase activating mutation. In conclusion, our study demonstrates that HDAC8 upregulation as an important mechanism to resist TKIs and promote leukemia maintenance, and suggests that combining HDAC8 inhibition with TKI treatment could be a promising strategy to treat FLT3-ITD+ AML and other tyrosine kinase mutation-harboring leukemias.
2020-02-13 | GSE138057 | GEO
Project description:Mutant p53 alters chromatin accessibility in hematopoietic stem and progenitor cells.
| PRJNA1088138 | ENA