DNMT3A R882

Our biochemical, cellular, and genomic DNA methylation analyses demonstrate that introducing the DNMT3B-converting mutations inhibits the R882H-/R882C-triggered DNMT3A polymerization and enhances substrate access, thereby eliminating the dominant-negative effect of the DNMT3A R882 mutations in cells. Together, this study provides mechanistic insights into DNMT3A R882 mutations-triggered aberrant oligomerization and DNA hypomethylation in AML, with important implications in cancer therapy.

In conclusion, our work reveals that selinexor displays anti-leukemia efficacy against DNMT3AR882H AML via downregulating glutathione pathway. Combination of selinexor and BSO provides novel therapeutic strategy for AML treatment.

MOLM13 cells were exposed to stepwise increasing concentrations of cytarabine (Ara-C) to generate MOLM13/Ara-C cells...Furthermore, CALCRL knockdown restricted tumor growth and the chemoresistance of AML in vivo, as well as inducing cell apoptosis in tumor tissues. Together, these data reveal that CALCRL is a vital regulator of leukemia cell survival and resistance to chemotherapy, suggesting CALCRL as a promising therapeutic target for the treatment of FTL3-ITD and DNMT3A-R882 double-mutated AML.

Overexpression of DNMT3L (which is minimally expressed in AML cells) also corrects the hypomethylation phenotype of Dnmt3a marrow, probably by augmenting the activity of WT DNMT3A encoded by the residual WT allele. DNMT3L reactivation may represent a previously unidentified approach for restoring DNMT3A activity in hematopoietic cells with reduced DNMT3A function.

DNMT3A was mutated in 18% (2903/16,565) of all MN which included primary acute myeloid leukemia (pAML, n=1910), secondary (sAML, n=531), myeloproliferative neoplasms (MPN, n=100), myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN, n=57), myelodysplastic syndrome (MDS, n=305) in the whole cohort. We analyzed 2903 DNMT3AMT MN and further classified them; 41%(n=1191/2903) had single R882, 48%(n=1407/2903) with single non-R882, 8%(n=226/2903) had double mutations at non-R882 locus, 1%(n=39/2903) was homozygous for R882 and 1% (n=40/2903) with mutations at R882 and non-R882 positions. Among non-R882 mutations, missense was more common [38%(85/226)] than nonsense [4%(9/226)], frameshift [1%(2/226)], and all others [57%(130/226)] (including splice-site, insertions, deletions, and other combinations in double non-R882 mutations).

Surprisingly, the clonal mutations were not well mixed in the BM with regions of high clonal diversity millimeters away from regions with a paucity of these mutated clones. Future work will expand this platform to describe BM clonal architecture in a larger set of bone marrow specimens and a wide variety clinical scenarios to help further explain the role of the BM niche in CH, MPNs and leukemia.

In this trial, pts were assigned to intensive chemotherapy plus all-trans retinoic acid with or without gemtuzumab ozogamicin; none of the pts received midostaurin. Our study provides comprehensive data on the genomic landscape and its clinical impact in pts with NPM1mut AML fit for intensive chemotherapy. The co-mutational pattern clearly differs between younger and older NPM1mut AML pts. Using this large dataset allowed the identification of secondary and tertiary gene-gene interactions with significant impact on outcome.

Mutational profiling of children with AML identified DNMT3A mutations in adolescents and young adults and is enriched in those with NPMc+ mutations. As NPMc+ patients are considered to be favorable risk, knowledge of DNMT3A mutations would provide additional information for more precise risk stratification in childhood AML. Children with de novo AML and dual DNMT3A/NPM1 mutations remain at high risk of relapse and adverse outcome regardless of FLT3-ITD status.

In Cox proportional hazards models controlling for basic demographics (N = 451K) or demographics plus cardiovascular-relevant covariates (N = 390K), we found that R882H but not R882C was associated with significantly greater incidence of heart failure and of a composite measure consisting of death or coronary artery disease (Figure 1B). In conclusion, our study found evidence in experimental models and patient data that DNMT3A R882H may pose a greater risk for inflammatory phenotypes than R882C.

DNMT3A mutations promote resistance to anthracyclines (including daunorubicin, the component of standard "7+3" induction therapy), interferon alpha, and ABL1 kinase inhibitor imatinib...The combination of Polθis + quizartinib and Polθis + etoposide completely eradicated clonogenic activity of these cells while Polθis + cytarabine and Polθis + azacytidine exerted modest and weak effects, respectively, when compared to individual compound treatments...Median survival time of the mice will be recorded. Altogether, we discovered that Polθ protects OTK-positive DNMT3A-deficient myeloid malignant cells from the toxic effects of DSBs and identified Polθ as a novel therapeutic target.

In summary, our work demonstrates a novel CRISPR/Cas9 approach to dissect the contribution of individual somatic lesions in human leukemia. The precise correction of single lesions while leaving co-occurring mutations intact allows us to perform controlled, functional genetic experiments on primary human AML. Here, we employ this approach to dissect the contribution of DNMT3A mutations to leukemia initiation and maintenance.

Copy number variation analysis at the single-cell level indicated that the cell type that possesses DNMT3A mutations is an important factor in AML relapse and that GMP and LMPP cells can affect relapse in patients with AML. This study advances our understanding of the role of DNMT3A in AML relapse and our approach can be applied to predict treatment outcomes.

Notably, these mutations are still activating in the context of a heterozygous R882H mutation. Altogether, we showcase the utility of base editor scanning for discovering functional regions of target proteins.

There is a great diversity of possible genetic alterations in DNMT3A, TET2, and ASXL1 genes, which requires detailed investigation. Further studies in dynamics will evaluate their prognostic impacts in AML patients.

We comprehensively evaluated the clinical and genetic characteristics, and expression profiles of AML patients with common mutations, and found that AML patients with triple mutations might be a distinct AML subtype, which should be redefined.

Taken together, our data showed that DNMT3A mutation caused NAMPT overexpression to induce the reprogramming of NAM-NAD metabolism and contribute to abnormal proliferation, which provided a potential direction for targeted therapy at the metabolic level in AML with DNMT3A mutation.

Overall survival analysis showed a statistically significant difference when ELN 2022 risk groups were compared to ELN2017, as well as among WHO 2022 AML classes, confirming an improvement of the new classification and risk stratification systems.TP53 variants occurred in the absence of other gene mutations and were associated with a shorter OS, as expected. The triple mutation pattern of FLT3 ITD- NPM1 mut - DNMT3A mut was the most frequent combination both in young and older patients without impact on outcomes. DTAS mutations did not affect OS in our setting.

This study presented DNMT3A mutation patterns of Korean AML patients. Results of this study suggest that higher allele frequency of DNMT3A methyltransferase domain mutations might be suggested as an adverse prognostic factor for survival and a predictable factor for initial HMA therapy in elderly AML patients.Overall survival according to VAF of MTD mutation in DNMT3A mutant Korean patients. Cases with unknown mutation loci were excluded.

We showed that DNMT3A mutations are an independent factor for poor prognosis; moreover, when confounding factors that include DNMT3A mutations were excluded, NPM1 mutations were a favorable prognostic factor. This revealed that ethnological prognostic discrepancies in NPM1 mutations might be corrected through prognostic stratification based on the DNMT3A status.

Taken together, these results suggest a novel mechanism by which a DNMT3A R882H mutation promotes glycolysis via activation of NRF2/NQO1 pathway. A parallel glycolysis inhibition adds to the anticancer effects of daunorubicin which might lead to a novel therapeutic approach for the treatment of AML patients carrying a DNMT3A R882H mutation.

TSPO gene may be used as an indicator of efficacy in FLT3-ITD /DNMT3A R882 double-mutated AML.

He received a reduced dose of idarubicin and cytarabine therapy. Even 9 months after starting VEN+AZA, the patient is still alive and healthy without AML recurrence. Thus, VEN+AZA therapy may be highly effective for treating IDH2- and DNMT3A-mutated AML in elderly patients.

Recognizing and referring patients with possible germline mutations for appropriate genetic evaluation and testing provides insight into best patient care strategies along with education and testing opportunities for family members. Leukemia based NGS panels may aid as screening tools for detecting potential pathogenic germline variants.

Validation of this assay in larger cohorts promises to yield a tool to identify patients who may benefit from early post-transplant interventions to forestall relapse. We also demonstrate how this assay can reveal novel insights into human disease HSC biology.

We targeted only patients aged 70 years or younger who were diagnosed after 2010 and who received standard induction therapy consisting of 7 days of standard-dose cytarabine (100–200 mg/m2 continuous infusion) and 3 days of an anthracycline antibiotic infusion (idarubicin 12 mg/m2 or daunorubicin 60–90 mg/m2). Our study showed that the addition of DNMT3AR882 mutations to existing prognostic models allowed for further stratification of NPM1-mutated AML. This new prognostic model might provide important clinical guidance.

Taken together, our in vivo and transcriptomic studies show that Sf3b1 point mutations are a stronger driver of stem cell self-renewal and gene expression than Dnmt3a mutations in Sf3b1/Dnmt3a mutant HSPCs. These findings suggest that agents that interfere with the DNA damage response, cell cycle regulation, or spliceosome function may more effectively target SF3B1 and SF3B1/DNMT3A mutant HSCs in patients with MDS.

These findings suggest that bone marrow biopsy from a small section of bone marrow may not accurately describe disease state and clonal mutation burden in myeloid neoplasms. Future applications of these tools will help describe the extrinsic factors and local microenvironment that drive clonal evolution over time in the bone marrow.

Our findings identified NRF2 as an important player in the regulation of cell apoptosis through which helps mediate chemoresistance to daunorubicin in AML cells with DNMT3A R882H mutation. Targeting NRF2 might be a novel therapeutic approach to treat AML patients with a DNMT3A R882H mutation. Video abstract.