PTBP1 Regulates DNMT3B Alternative Splicing by Interacting With RALY to Enhance the Radioresistance of Prostate Cancer.

Radiotherapy is a curative arsenal for prostate cancer (PCa), but radioresistance seriously compromises its effectiveness. Dysregulated RNA splicing factors are extensively involved in tumor progression. Nonetheless, the role of splicing factors in radioresistance remains largely unexplored in PCa. Here, 23 splicing factors that are differentially expressed between PCa and adjacent normal tissues across multiple public PCa databases are identified. Among those genes, polypyrimidine tract binding protein 1 (PTBP1) is significantly upregulated in PCa and is positively associated with advanced clinicopathological features and poor prognosis. Gain- and loss-of-function experiments demonstrate that PTBP1 markedly reinforces genomic DNA stability to desensitize PCa cells to irradiation in vitro and in vivo. Mechanistically, PTBP1 interacts with the heterogeneous nuclear ribonucleoproteins (hnRNP) associated with lethal yellow protein homolog (RALY) and regulates exon 5 splicing of DNA methyltransferase 3b (DNMT3B) from DNMT3B-S to DNMT3B-L. Furthermore, upregulation of DNMT3B-L induces promoter methylation of dual-specificity phosphatase-2 (DUSP2) and subsequently inhibits DUSP2 expression, thereby increasing radioresistance in PCa. The findings highlight the role of splicing factors in inducing aberrant splicing events in response to radiotherapy and the potential role of PTBP1 and DNMT3B-L in reversing radioresistance in PCa.

Only FLT3-ITD co-mutation did not have a deleterious effect on acute myeloid leukemia patients with NPM1 mutation, but concomitant with DNMT3A co-mutation or a < 3log reduction of MRD2 predicted poor survival.

Co-occurring mutations are frequently observed in acute myeloid leukemia (AML) with NPM1 mutation, and NPM1 measurable residual disease (MRD) is an effective prognostic biomarker. This retrospective study investigated the impact of gene co-mutations and NPM1 MRD on outcomes in these patients. Among 234 patients, 11.5% carried the rare type NPM1 mutation (NPM1RT). The median age was 49 years (IQR 36-58), with a median follow-up of 30.4 months (IQR 12.1-55.7). Nine genes were mutated in > 10%, with DNMT3A (53.8%) and FLT3-ITD (44.4%) being most prevalent. Univariable analysis in 137 patients showed FLT3-ITD, DNMT3A co-mutations, and MRD2 < 3 log reduction predicted poorer survival. FLT3-ITD and DNMT3A co-mutations correlated with the lowest event-free (EFS) and overall survival (OS) (3-year EFS 30.0%; 3-year OS 34.4%; both p < 0.001). FLT3-ITD alone did not worsen survival compared to patients without FLT3-ITD. Multivariable analysis identified DNMT3A co-mutation [EFS, HR = 1.9, p = 0.021; OS, HR = 2.2, p = 0.023] and MRD2 ≥ 3 log reduction (EFS, HR = 0.2; OS, HR = 0.1, both p < 0.001) as independent survival predictors. Patients with FLT3-ITD and DNMT3A co-mutations or a MRD2 < 3 log reduction were identified as high risk, but allogeneic hematopoietic stem cell transplantation (allo-HSCT) improved survival significantly compared to chemotherapy only (3-year EFS, 57.9% vs. 30.0%, p = 0.012; 3-year OS, 72.9% vs. 34.4%, p = 0.001). In AML patients with NPM1 mutation, the detrimental impact of FLT3-ITD mutation was exacerbated by DNMT3A co-mutation. Poor-risk younger patients identified by FLT3-ITD and DNMT3A co-mutations or MRD2 < 3 log reduction benefit from allo-HSCT.

Bmi-1 Epigenetically Orchestrates Osteogenic and Adipogenic Differentiation of Bone Marrow Mesenchymal Stem Cells to Delay Bone Aging.

With the increase in the aging population, senile osteoporosis (SOP) has become a major global public health concern. Here, it is found that Prx1 and Bmi-1 co-localized in trabecular bone, bone marrow cavity, endosteum, and periosteum. Prx1-driven Bmi-1 knockout in bone-marrow mesenchymal stem cells (BMSCs) reduced bone mass and increased bone marrow adiposity by inhibiting osteoblastic bone formation, promoting osteoclastic bone resorption, downregulating the proliferation and osteogenic differentiation of BMSCs, and upregulating the adipogenic differentiation of BMSCs. However, Prx1-driven Bmi-1 overexpression showed a contrasting phenotype to Prx1-driven Bmi-1 knockout in BMSCs. Regarding mechanism, Bmi-1-RING1B bound to DNMT3A and promoted its ubiquitination and inhibited DNA methylation of Runx2 at the region from 45047012 to 45047313 bp, thus promoting the osteogenic differentiation of BMSCs. Moreover, Bmi-1-EZH2 repressed the transcription of Cebpa by promoting H3K27 trimethylation at the promoter region -1605 to -1596 bp, thus inhibiting the adipogenic differentiation of BMSCs. It is also found that Prx1-driven Bmi-1 overexpression rescued the SOP induced by Prx1-driven Bmi-1 knockout in BMSCs. Thus, Bmi-1 functioned as a hub protein in the epigenetic regulation of BMSCs differentiation to delay bone aging. The Prx1-driven Bmi-1 overexpression in BMSCs can be used as an approach for the translational therapy of SOP.

Effective Treatment with Venetoclax and Hypomethylating Agents for the Coexistence of Multiple Myeloma and Acute Myeloid Leukemia: A Case Report and Literature Review.

OBJECTIVE: Multiple myeloma (MM) and Acute myeloid leukemia (AML) are distinct hematologic malignancies originating from different cell lineages. Their coexistence is extremely rare, and current treatment approaches are even more so. Therefore, exploring the clinical features of their coexistence and the promising treatment strategy is worthwhile. CASE REPORT: We described three cases involving the coexistence of MM and DNMT3A-mutant AML, two of which presented simultaneous occurrences, while Case 3 had secondary AML about 70 months after the MM. DISCUSSION: All cases exhibited DNMT3A mutations, which characterized by one missense mutation and two frameshift mutations; all were likely loss of function mutations. Among them, two patients were treated with Venetoclax-based regimens and achieved favorable effects. The patients were alive for 62,38 and 103 months. CONCLUSIONS: Clonal hematopoiesis of DNMT3A may have a crucial role in the coexistence of MM and AML and Venetoclax-based regimens reveal favorable treatment responses. However, drug resistance still needs to be considered, and further research is required to elucidate the underlying mechanisms and treatment strategies.

Landscape of biallelic DNMT3A mutant myeloid neoplasms.

DNA methyltransferase 3 A mutations (DNMT3AMT) are frequent in myeloid neoplasia (MN) and mostly heterozygous. However, cases with multiple DNMT3AMT can be also encountered but their clinical and genetic landscape remains unexplored. We retrospectively analyzed 533 cases with DNMT3AMT identified out of 5,603 consecutive MNs, of whom 8.4% had multiple DNMT3AMT hits. They were most frequent in acute myeloid leukemia (AML) with R882 variant accounting for 13.3% of the multi-hits. Multiple DNMT3AMT more likely coincided with IDH2 (P = 0.005) and ETV6 (P = 0.044) mutations compared to patients with single DNMT3AMT. When the sum of variant allele frequencies (VAFs) for multiple DNMT3AMT exceeded 60%, we found a significant positive clonal burden correlation of the two DNMT3A variants (P < 0.0001) suggesting that they occurred in biallelic configuration. AML patients with biallelic DNMT3A inactivation (n = 52) presented with older age (P = 0.029), higher leukocytes (P < 0.0001) and peripheral blast counts (P = 0.0001) and significantly poorer survival rate (5.6% vs. 47.6% at 2 years; P = 0.002) than monoallelic DNMT3AMT. Multivariate analysis identified biallelic DNMT3AMT (HR 2.65; P = 0.001), male gender (HR 2.05; P = 0.014) and adverse genetic alteration according to the European LeukemiaNet 2022 classification (HR 1.84; P = 0.028) as independent adverse factors for survival, whereas intensive chemotherapy (HR 0.47; P = 0.011) favorably influenced outcomes. Longitudinal molecular analysis of 12 cases with biallelic DNMT3AMT demonstrated that such clones persisted or expanded in 9 relapsed or transformed cases (75%) suggesting the early origin of biallelic hits with strong leukemogenic potential. Our study describes the likelihood that biallelic DNMT3AMT, while rare, are indeed compatible with clonal expansion and thus questions the applicability of synthetic lethality strategies.

The profile and prognostic significance of bone marrow T-cell differentiation subsets in adult AML at diagnosis.

Background: T lymphocytes in tumor microenvironment play a pivotal role in the anti-tumor immunity, and the memory of T cells contributes to the long-term protection against tumor antigens. Compared to solid tumors, studies focusing on the T-cell differentiation in the acute myeloid leukemia (AML) bone marrow (BM) microenvironment remain limited. Patients and methods: Fresh BM specimens collected from 103 adult AML patients at diagnosis and 12 healthy donors (HDs) were tested T-cell differentiation subsets by multi-parameter flow cytometry. Results: CD4 and CD8 T-cell compartments had different constituted profiles of T-cell differentiated subsets, which was similar between AML patients and HDs. Compared to HDs, AML patients as a whole had a significantly higher proportion of CD8 effector T cells (Teff, P = 0.048). Moreover, the T-cell compartment of AML patients with no DNMT3A mutations skewed toward terminal differentiation at the expense of memory T cells (CD4 Teff: P = 0.034; CD8 Teff: P = 0.030; CD8 memory T: P = 0.017), whereas those with mutated DNMT3A had a decrease in CD8 naïve T (Tn) and CD4 effector memory T cells (Tem) as well as an increase in CD4 central memory T cells (Tcm) (P = 0.037, 0.053 and 0.053). Adverse ELN genetic risk correlated with a lower proportion of CD8 Tn. In addition, the low proportions of CD4 Tem and CD8 Tn independently predicted poorer relapse-free survival (RFS, HR [95%CI]: 5.7 (1.4-22.2), P = 0.017 and 4.8 [1.3-17.4], P = 0.013) and event-free survival (EFS, HR [95% CI]: 3.3 (1.1-9.5), P = 0.029; 4.0 (1.4-11.5), P = 0.010), respectively. Conclusions: AML patients had abnormal profiles of BM T-cell differentiation subsets at diagnosis, which was related to DNMT3A mutations. The low proportions of CD4 Tem and CD8 Tn predicted poor outcomes.

Telomerase and mitochondria inhibition promote apoptosis and TET2 and ANMT3a expression in triple negative breast cancer cell lines.

Introduction: High metastasis, resistance to common treatments, and high mortality rate, has made triple-negative breast cancer (TNBC) to be the most invasive type of breast cancer. High telomerase activity and mitochondrial biogenesis are involved in breast cancer tumorigenesis. The catalytic subunit of telomerase, telomerase reverse transcriptase (hTERT), plays a role in telomere lengthening and extra-biological functions such as gene expression, mitochondria function, and apoptosis. In this study, it has been aimed to evaluate intrinsic-, extrinsic-apoptosis and DNMT3a and TET2 expression following the inhibition of telomerase and mitochondria respiration in TNBC cell lines. Methods: TNBC cells were treated with IC50 levels of BIBR1532, tigecycline, and also their combination. Then, telomere length, and DNMT3a, TET2, and hTERT expression were evaluated. Finally, apoptosis rate, apoptosis-related proteins, and genes were analyzed. Results: The present results showed that IC50 level of telomerase and inhibition of mitochondria respiration induced apoptosis but did not leave any significant effect on telomere length. The results also indicated that telomerase inhibition induced extrinsic-apoptosis in MDA-MB-231 and caused intrinsic- apoptosis in MDA-MB-468 cells. Furthermore, it was found that the expression of p53 decreased and was ineffective in cell apoptosis. The expressions of DNMT3a and TET2 increased in cells. In addition, combination treatment was better than BIBR1532 and tigecycline alone. Conclusion: The inhibition of telomerase and mitochondria respiration caused intrinsic- and extrinsic- apoptosis and increased DNMT3a and TET2 expression and it could be utilized in breast cancer treatment.

Methyltransferase DNMT3B promotes colorectal cancer cell proliferation by inhibiting PLCG2.

Aberrant DNA methylation patterns in the promoter region of PLCG2 are associated with dysregulated signaling pathways and cellular functions. Its role in colorectal cancer cells is still unknown. In this study, qRT-PCR is used to measure DNMT3B expression in colorectal cancer. Western blot analysis and immunohistochemistry are used to analyze DNMT3B and PLCG2 protein levels in colorectal tissues and cell lines. Cell Counting Kit-8 (CCK-8) and colony formation assays are used to assess the proliferation of colorectal cancer cells. Methylation-specific PCR (MSP) and bisulfite-sequencing PCR (BSP) are used to measure DNA methylation level. Our results show that DNMT3B is overexpressed in colorectal cells in the TCGA datasets according to Kaplan-Meier plots. DNMT3B is significantly overexpressed in tumor tissues compared to that in adjacent nontumor tissues. Western blot analysis results demonstrate high expression of DNMT3B in tumor tissues. Compared to normal colonic epithelial cells, colorectal cancer cell lines exhibit elevated level of PLCG2 methylation. Overexpression of PLCG2 effectively prevents the growth of colorectal cancer xenograft tumors in vivo. PLCG2 is identified as a key downstream regulatory protein of DNMT3B in colorectal cancer. DNMT3B inhibits PLCG2 transcription through methylation of the PLCG2 promoter region. DNMT3B controls colorectal cancer cell proliferation through PLCG2, which is useful for developing therapeutic approaches that target PLCG2 expression for the treatment of colorectal cancer.

[Appropriate use of the ELN guidelines based on results of real-world genetic analysis in Japanese patients with AML].

Researchers in the field of acute myeloid leukemia have long sought to establish a prognostic stratification system for clinical use that combines multiple genetic mutations. In 2022, the European LeukemiaNet (ELN) proposed a new prognostic model incorporating new genetic mutations. However, Japanese National Health insurance only recently began covering clinical genetic analysis for AML. We established the Multi-center Collaborative Program for Gene Sequencing of Japanese AML (GS-JAML) to contribute to clinical practice by providing rapid genetic analysis results. Retrospective analysis of this research program revealed (1) the clinical significance of CEBPA-bZIP mutations, and (2) the clinical significance of DNMT3A mutations in NPM1 mutated AML.

Decoding Clonal Hematopoiesis: Emerging Themes and Novel Mechanistic Insights.

Clonal hematopoiesis (CH), the relative expansion of mutant clones, is derived from hematopoietic stem cells (HSCs) with acquired somatic or cytogenetic alterations that improve cellular fitness. Individuals with CH have a higher risk for hematological and non-hematological diseases, such as cardiovascular disease, and have an overall higher mortality rate. Originally thought to be restricted to a small fraction of elderly people, recent advances in single-cell sequencing and bioinformatics have revealed that CH with multiple expanded mutant clones is universal in the elderly population. Just a few years ago, phylogenetic reconstruction across the human lifespan and novel sensitive sequencing techniques showed that CH can start earlier in life, decades before it was thought possible. These studies also suggest that environmental factors acting through aberrant inflammation might be a common theme promoting clonal expansion and disease progression. However, numerous aspects of this phenomenon remain to be elucidated and the precise mechanisms, context-specific drivers, and pathways of clonal expansion remain to be established. Here, we review our current understanding of the cellular mechanisms driving CH and specifically focus on how pro-inflammatory factors affect normal and mutant HSC fates to promote clonal selection.

WT1 And DNMT3A Mutations in Prognostic Significance of Acute Myeloid Leukemia: A Meta-Analysis.

Background: Adult acute leukemia most commonly manifests as acute myeloid leukemia (AML), a highly heterogeneous malignant tumor of the blood system. The application of genetic diagnostic technology is currently prevalent in numerous clinical sectors. According to recent research, the presence of specific gene mutations or rearrangements in leukemia cells is the primary cause of the disease. As different types of leukemia are caused by atypical mutated genes, testing for these mutations or rearrangements can help diagnose leukemia and identify the disease's molecular targets for treatment. Methods: Using the search fields "WT1," "DNMT3A," "Acute myeloid leukemia," and "survival," the CBM, Cochrane Library, Scopus, EMBASE, and PUBMED databases were separately reviewed. The methodology for evaluating the risk of bias developed by the Cochrane Collaboration was used in conjunction with a methodical evaluation of pertinent literature. Excluded studies with the following characteristics: (1) incomplete and repetitive publications, (2) unable to retrieve or convert data, (3) non-English or Chinese articles. Results: This analysis included 13 studies covering a total of 3478 subjects. The frequency of Wilms' Tumor 1 (WT1) mutations is 6.7%-35.73%, and the frequency of DNMT3A mutations is 12.06%-51.1%. The remission rate of patients with WT1 mutations was less than that of patients without WT1 mutations (OR = 0.22; 95% confidence interval [CI]: 0.14, 0.36; p < 0.00001; I2 = 55%). The DNMT3A mutation has no statistical significance for the prognosis of AML (OR = 1.21; 95% CI: 0.93, 1.58; p = 0.16; I2 = 80%). After removing one study, the heterogeneity of the indicator (mitigation rate) among other studies of DNMT3A mutation was dramatically reduced (OR = 0.63; 95% CI: 0.43, 0.93; p = 0.02; I2 = 0%). Conclusions: Our meta-analysis shows that WT1 mutations hurt the remission rate of AML. Moreover, the impact of DNMT3A mutations on AML needs to be treated with caution. Gene diagnosis is critical for the prognosis and clinical management of AML.

Recurrent carotid paragangliomas in a syndromic patient with a heterozygous missense variant in DNA Methyltransferase 3 Alpha.

We report a 40-year-old African American female with a novel variant in exon 8 of DNA methyltransferase 3 alpha (DNMT3A), (NM_022552.4: c.905G>C, p.G302A) who presented with a history of recurrent carotid paragangliomas, mediastinal mass, intellectual disability, dysarthria, cholelithiasis, diabetes mellitus, hypertension, and dysmorphic features. We interpret this novel variant as likely pathogenic and causative for the patient's syndromic features of Heyn-Sproul-Jackson syndrome. Heyn-Sproul-Jackson syndrome is a condition caused by gain-of-function genetic changes in DNMT3A. Paragangliomas have also been observed in non-syndromic patients with genetic alterations in DNMT3A. We describe a patient with clinical features of Heyn-Sproul-Jackson syndrome such as intellectual disability, dysarthria, brachydactyly, and lack of brain MRI findings to add evidence to associate paragangliomas with DNMT3A and draw particular attention to the potential involvement of the proline-tryptophan-tryptophan-proline domain of DNMT3A.

Therapeutic potential of tLyp-1-EV-shCTCF in inhibiting liver cancer stem cell self-renewal and immune escape via SALL3 modulation in hepatocellular carcinoma.

The progression of hepatocellular carcinoma (HCC) is influenced by disrupted metabolic processes, presenting challenges in prognostic outcomes. Hepatocellular carcinoma (HCC), a leading cause of cancer-related mortality, is closely associated with metabolic reprogramming and stem cell-like properties in liver cancer stem cells (LCSCs). This study explored the potential molecular mechanisms by which tLyP-1-modified extracellular vesicles (EVs) delivering CTCF shRNA (tLyp-1-EV-shCTCF) regulate mitochondrial DNA methylation-induced glycolytic metabolic reprogramming and LCSC self-renewal. Through a series of methods, including Western blot, nanoparticle tracking analysis, and immunofluorescence, we demonstrated the successful delivery and internalization of tLyp-1-EV in HCC cells. Our results identified SALL3 as a critical factor underexpressed in HCC and LCSCs, while CTCF was overexpressed. Overexpression of SALL3 inhibited LCSC self-renewal and immune evasion by blocking the CTCF-DNMT3A interaction, thus repressing DNMT3A methyltransferase activity and subsequent mitochondrial DNA methylation-mediated glycolytic metabolic reprogramming. In vivo experiments further supported these findings, showing that tLyp-1-EV-shCTCF treatment significantly reduced tumor growth by upregulating SALL3 expression, thereby inhibiting glycolytic metabolic reprogramming and enhancing the immune response against HCC cells. This study provides novel insights into the role of SALL3 and mitochondrial DNA methylation in HCC progression, offering potential therapeutic targets for combating HCC and its stem cell-like properties.

Andrographolide suppresses the malignancy of pancreatic cancer via alleviating DNMT3B-dependent repression of tumor suppressor gene ZNF382.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer type that urgently requires effective therapeutic strategies. Andrographolide, a labdane diterpenoid compound abundant in Andrographis paniculata, has anticancer effects against various cancer types, but its anticancer activity and mechanism against PDAC remain largely uncharacterized. PURPOSE: This study explores novel drug target(s) and underlying molecular mechanism of andrographolide against PDAC. STUDY DESIGN AND METHODS: The malignant phenotypes of PDAC cells, PANC-1 and MIA PaCa-2 cells, were measured using MTT, clonogenic assays, and Transwell migration assays. A PDAC xenograft animal model was used to evaluate tumor growth in vivo. Western blot, immunofluorescence and immunohistochemistry were used for measuring protein expression. The TCGA database was analyzed to evaluate promoter methylation status, gene expression, and their relationship with patient survival rates. RT-qPCR was used for detecting mRNA expression. Reporter assays were used for detecting signal transduction pathways. Promoter DNA methylation was determined by sodium bisulfite treatment and methylation-specific PCR (MSP). The biological function and role of specific genes involved in drug effects were measured through gene overexpression. RESULTS: Andrographolide treatment suppressed the proliferation and migration of PDAC cells and impaired tumor growth in vivo. Furthermore, andrographolide induced the mRNA and protein expression of zinc finger protein 382 (ZNF382) in PDAC cells. Overexpression of ZNF382 inhibited malignant phenotypes and cancer-associated signaling pathways (AP-1, NF-κB and ß-catenin) and oncogenes (ZEB-1, STAT-3, STAT-5, and HIF-1α). Overexpression of ZNF382 delayed growth of PANC-1 cells in vivo. ZNF382 mRNA and protein expression was lower in tumor tissues than in adjacent normal tissues of pancreatic cancer patients. Analysis of the TCGA database found the ZNF382 promoter is hypermethylated in primary pancreatic tumors which correlates with its low expression. Furthermore, andrographolide inhibited the expression of DNA methyltransferase 3 beta (DNMT3B) and increased the demethylation of the ZNF382 promoter in PDAC cells. Overexpression of DNMT3B attenuated the andrographolide-suppressed proliferation and migration of PDAC cells. CONCLUSION: Our finding revealed that ZNF382 acts as a tumor suppressor gene in pancreatic cancer and andrographolide restores ZNF382 expression to suppress pancreatic cancer, providing a novel molecular target and a promising therapeutic approach for treating pancreatic cancer.

DNMT3A-R882: a mutation with many paradoxes.

Understanding the underlying mechanism of acute myeloid leukemia (AML) has led to the discovery of novel biomarkers to help predict, treat and monitor leukemia. DNA (cytosine-5)-methyltransferase 3 A (DNMT3A) is considered a prognostic and therapeutic epigenetic target in AML patients with a hotspot mutation of R882. R882 mutation is associated with impaired differentiation of Hematopoietic stem cells in the bone marrow and disease progression. The prevalence of R882 mutation varied in different ethnicities and countries, and similarly, its prognostic impact differed among numerous studies. Nevertheless, the co-occurrence of mutations in R882 with NPM1 and FLT3 has been reported more frequently and is associated with a worse prognosis. These studies also suggest diverse results regarding bone marrow transplantation response as a treatment, while chemoresistance is reached as a conclusive outcome These findings highlight the crucial need for an in-depth discussion on the significance of the R882 mutation in AML patients. Understanding its impact on leukemic transformation, prognosis, and treatment is vital for advancing clinical implications.

Significance of targeting DNMT3A mutations in AML.

Acute myeloid leukemia (AML) is the most prevalent form of leukemia among adults, characterized by aggressive behavior and significant genetic diversity. Despite decades of reliance on conventional chemotherapy as the mainstay treatment, patients often struggle with achieving remission, experience rapid relapses, and have limited survival prospects. While intensified induction chemotherapy and allogeneic stem cell transplantation have enhanced patient outcomes, these benefits are largely confined to younger AML patients capable of tolerating intensive treatments. DNMT3A, a crucial enzyme responsible for establishing de novo DNA methylation, plays a pivotal role in maintaining the delicate balance between hematopoietic stem cell differentiation and self-renewal, thereby influencing gene expression programs through epigenetic regulation. DNMT3A mutations are the most frequently observed genetic abnormalities in AML, predominantly in older patients, occurring in approximately 20-30% of adult AML cases and over 30% of AML with a normal karyotype. Consequently, the molecular underpinnings and potential therapeutic targets of DNMT3A mutations in AML are currently being thoroughly investigated. This article provides a comprehensive summary and the latest insights into the structure and function of DNMT3A, examines the impact of DNMT3A mutations on the progression and prognosis of AML, and explores potential therapeutic approaches for AML patients harboring DNMT3A mutations.

Different mutational profiles of subcutaneous panniculitis-like T-cell lymphoma and lupus panniculitis: an additional case series.

BACKGROUND AND OBJECTIVE: subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare cytotoxic T-cell lymphoma with indolent behavior, mostly present in women and associated with immunological diseases whose pathogenic background is still poorly understood. SPTCL is associated with lupus erythematosus panniculitis (LEP) and histologically misdiagnosed. OBJECTIVES: the aim of our study was to identify mutations affecting the pathogenesis of both SPTCL and LEP. MATERIALS AND METHODS: we studied a total of 10 SPTCL and 10 LEP patients using targeted Next Generation Sequencing and pyrosequencing. Differences in gene expression between molecular subgroups were investigated using NanoString technology. Clinical data were collected, and correlations sought with the molecular data obtained. RESULTS: the mutational profile of SPTCL and LEP is different. We identified fewer pathogenic mutations than previously reported in SPTCL, noting a single HAVCR2-mutated SPTCL case. Interestingly, 40% of our SPTCL cases showed the pathogenic TP53 (p.Pro72Arg) (P72R) variant. Although cases showing HAVCR2 mutations or the TP53 (P72R) variant had more severe symptomatic disease, none developed hemophagocytic syndrome (HPS). Furthermore, TP53 (P72R)-positive cases were characterized by a lower metabolic signaling pathway and higher levels of CD28 expression and Treg signaling genes. In addition, 30% of our cases featured the same mutation (T735C) of the epigenetic modificatory gene DNMT3A. None of the LEP cases showed mutations in any of the studied genes. CONCLUSIONS: the mutational landscape of SPTCL is broader than previously anticipated. We describe, for the first time, the involvement of the TP53 (P72R) pathogenic variant in this subgroup of tumors, consider the possible role of different genetic backgrounds in the development of SPTCL, and conclude that LEP does not follow the same pathogenic pathway as SPTCL.

Symptomatic Heart Failure and Clonal Hematopoiesis-Related Mutations in Patients With Acute Myeloid Leukemia.

Clonal hematopoiesis of indeterminate potential (CHIP) is a common risk factor for hematologic malignancies and cardiovascular diseases. This study aimed to investigate the association between CHIP-related mutations and symptomatic heart failure (HF) in patients diagnosed with acute myeloid leukemia (AML). A total of 563 patients with newly diagnosed AML who underwent DNA sequencing of bone marrow before treatment were retrospectively investigated. Cox proportional hazard regression models and Fine and Gray's subdistribution hazard regression models were used to assess the association between CHIP-related mutations and symptomatic HF. A total of 79.0% patients had at least 1 CHIP-related mutation; the most frequent mutations were DNMT3A, ASXL1, and TET2. A total of 51 patients (9.1%) developed symptomatic HF. The incidence of symptomatic HF was more frequent in patients with DNMT3A mutations (p <0.01), with a 1-year cumulative incidence of symptomatic HF in patients with DNMT3A mutations of 11.4%, compared with 3.9% in patients with wild-type DNMT3A (p <0.01). After adjustment for age and anthracyclines dose, DNMT3A mutations remained independently correlated with HF (hazard ratio 2.32, 95% confidence interval 1.26 to 4.29, p = 0.01). In conclusion, in patients with AML, the presence of DNMT3A mutations was associated with a twofold increased risk for symptomatic HF, irrespective of age and anthracyclines use.

Non-nucleoside inhibitors of DNMT1 and DNMT3 for targeted cancer therapy.

DNA methylation can deactivate tumor suppressor genes thus causing cancers. Two DNA methylation inhibitors have been approved by the Food and Drug Administration (FDA) and have entered clinical use. However, these inhibitors are nucleoside analogues that can be incorporated into DNA or RNA and induce significant side effects. DNMT1 and DNMT3 are key enzymes involved in DNA methylation. In the acute myeloid leukemia model, a non-nucleoside DNMT1-specific inhibitor has shown lower toxicity and improved pharmacokinetics compared to traditional nucleoside drugs. DNMT3 is also implicated in certain specific cancers. Thus, developing non-nucleoside inhibitors for DNMT1 or DNMT3 can help in understanding their roles in carcinogenesis and provide targeted treatment options in certain cancers. Although no non-nucleoside inhibitors have yet entered clinical trials, in this review, we focus on DNMT1 or DNMT3 selective inhibitors. For DNMT1 selective inhibitors, we have compiled information on the repurposed drugs, derivative compounds and selective inhibitors identified through virtual screening. Additionally, we have outlined potential targets for DNMT1, including protein-protein complex, RNA mimics and aptamers. Compared to DNMT1, research on DNMT3-specific inhibitors has been less extensive. In this context, our exploration has identified a limited number of molecular inhibitors, and we have proposed specific long non-coding RNAs (lncRNAs) as potential contributors to the selective inhibition of DNMT3. This collective effort aims to offer valuable insights into the development of non-nucleoside inhibitors that selectively target DNMT1 or DNMT3.

Pirfenidone Reverts Global DNA Hypomethylation, Promoting DNMT1/UHRF/PCNA Coupling Complex in Experimental Hepatocarcinoma.

Hepatocellular carcinoma (HCC) development is associated with altered modifications in DNA methylation, changing transcriptional regulation. Emerging evidence indicates that DNA methyltransferase 1 (DNMT1) plays a key role in the carcinogenesis process. This study aimed to investigate how pirfenidone (PFD) modifies this pathway and the effect generated by the association between c-Myc expression and DNMT1 activation. Rats F344 were used for HCC development using 50 mg/kg of diethylnitrosamine (DEN) and 25 mg/kg of 2-Acetylaminofluorene (2-AAF). The HCC/PFD group received simultaneous doses of 300 mg/kg of PFD. All treatments lasted 12 weeks. On the other hand, HepG2 cells were used to evaluate the effects of PFD in restoring DNA methylation in the presence of the inhibitor 5-Aza. Histopathological, biochemical, immunohistochemical, and western blot analysis were carried out and our findings showed that PFD treatment reduced the amount and size of tumors along with decreased Glipican-3, ß-catenin, and c-Myc expression in nuclear fractions. Also, this treatment improved lipid metabolism by modulating PPARγ and SREBP1 signaling. Interestingly, PFD augmented DNMT1 and DNMT3a protein expression, which restores global methylation, both in our in vivo and in vitro models. In conclusion, our results suggest that PFD could slow down HCC development by controlling DNA methylation.