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Doehner, K.

Publications and source records attributed to Doehner, K..

4 recordsLinked to original sources

Menin-Inhibition Sensitizes Acute Myeloid Leukemia to CLEC12A-Directed CAR Cell Therapy

Menin inhibitors targeting the Menin-KMT2A chromatin complex have emerged as highly selective therapies for KMT2A-rearranged (KMT2A-r) and NPM1-mutated (NPM1mut) acute myeloid leukemia (AML), with recent regulatory approval and increasing interest in combination strategies. In contrast, CAR cell therapies have not yet been successfully established for AML. Here, we show that menin-inhibition primes KMT2A-r and NPM1mut AML for CAR-based targeting by inducing robust and uniform expression of the myeloid antigen CLEC12A (CLL-1). Menin inhibitors did not impair T or NK cell viability, phenotype, or effector function. We engineered second-generation CLEC12A-directed CAR T cells that efficiently eliminated CLEC12A-positive AML. Across in vitro systems and xenograft models, the combination therapy consistently outperformed either monotherapy, resulting in profound disease control and significantly prolonged survival, with evidence of near-complete leukemia eradication in vivo. These findings support epigenetic priming with menin inhibitors to enhance CLEC12A-directed CAR cell-therapy in these AML subtypes. SignificanceMenin inhibitors, now approved for AML treatment, induce the immune target CLEC12A in NPM1mut and KMT2A-r AML subtypes and sensitize AML cells to CLEC12A-directed CAR T cells without compromising immune function. As CLEC12A-CARs are already in clinical testing, this combination is immediately actionable for clinical investigation.

cancer biology↗

Acute Myeloid Leukemia with deletion 5q is an epigenetically distinct subgroup defined by heterozygous loss of KDM3B

Acute myeloid leukemia (AML) is a hematological malignancy characterized by a block in differentiation and accelerated proliferation of myeloid progenitor cells. Genes encoding for epigenetic regulators are among the most frequent targets for mutations and structural variations in AML, giving rise to profound epigenetic heterogeneity between and within tumors. Deletions of chromosome 5q [del(5q)] are among the most common copy number alterations in AML and are associated with extremely poor clinical outcome and therapy resistance, however the mechanisms linking del(5q) to leukemic progression are not understood. Analyzing DNA methylation profiles from 477 elderly AML patients using DNA methylome deconvolution, we discovered that del(5q) AML is an epigenetically distinct subgroup characterized by a signature of DNA hypermethylation, which we propose may be linked to dysregulation of H3K9me1/2 and overexpression of the leukemic stem cell marker, DNMT3B. Interrogation of the minimally deleted 5q region highlighted the H3K9me1/2 demethylase KDM3B as a likely target for haploinsufficiency in this subgroup. Our data suggest that del(5q) AML should be reconsidered as an epigenetically dysregulated subgroup, driven by heterozygous loss of KDM3B, and that the resulting imbalance of H3K9me1/2 may contribute to the progression of these aggressive leukemias.

cancer biology↗

A base-line cellular antiviral state is maintained by cGAS and its most frequent naturally occurring variant rs610913

Upon recognition of aberrantly located DNA, the innate immune sensor cGAS activates STING/IRF-3-driven antiviral responses. Here we characterized the ability of a specific variant of the cGAS-encoding gene MB21D1, rs610913, to alter cGAS-mediated DNA sensing and viral infection. rs610913 is a frequent G>T polymorphism resulting in a P261H exchange in the cGAS protein. Data from the International Collaboration for the Genomics of HIV suggested that rs610913 nominally associates with HIV-1 acquisition in vivo. Molecular modeling of cGAS(P261H) hinted towards the possibility for an additional binding site for a potential cellular co-factor in cGAS dimers. However, cGAS(WT) or cGAS(P261H)-reconstituted THP-1 cGAS KO cells shared steady-state expression of interferon-stimulated genes (ISGs), as opposed to cells expressing the enzymatically inactive cGAS(G212A/S213A). Accordingly, cGAS(WT) and cGAS(P261H) cells were less susceptible to lentiviral transduction and infection with HIV-1, HSV-1, and Chikungunya virus as compared to cGAS KO- or cGAS(G212A/S213A) cells. Upon DNA challenge, innate immune activation appeared to be mildly reduced upon expression of cGAS(P261H) compared to cGAS(WT). Finally, DNA challenge of PBMCs from donors homozygously expressing rs610913 provoked a trend towards a slightly reduced type I IFN response as compared to PBMCs from GG donors. Taken together, the steady-state activity of cGAS maintains a base-line antiviral state rendering cells more refractory to ISG-sensitive viral infections. Even though rs610913 failed to grossly differ phenotypically from the wild-type gene, its expression potentially results in a slightly altered susceptibility to viral infections in vivo.

immunology↗

Acute myeloid leukemia cells are targeted by the naturally occurring CXCR4 antagonist EPI-X4

This manuscript has been withdrawn by the authors as no consent could be achieved with regard to data contribution. Based on this no agreement on authorship and/or listing in the acknowledgement section was reached. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

cancer biology↗