Clinical and biological implications of IDH1/2 in acute myeloid leukemia with DNMT3Amut

Recent advances in understanding DNA methylation of prostate cancer

Epigenetic modifications, such as DNA methylation, is widely studied in cancer. DNA methylation patterns have been shown to distinguish between benign and malignant tumors in various cancers, including prostate cancer. It may also contribute to oncogenesis, as it is frequently associated with downregulation of tumor suppressor genes. Aberrant patterns of DNA methylation, in particular the CpG island hypermethylator phenotype (CIMP), have shown associative evidence with distinct clinical features and outcomes, such as aggressive subtypes, higher Gleason score, prostate-specific antigen (PSA), and overall tumor stage, overall worse prognosis, as well as reduced survival. In prostate cancer, hypermethylation of specific genes is significantly different between tumor and normal tissues. Methylation patterns could distinguish between aggressive subtypes of prostate cancer, including neuroendocrine prostate cancer (NEPC) and castration resistant prostate adenocarcinoma. Further, DNA methylation is detectable in cell-free DNA (cfDNA) and is reflective of clinical outcome, making it a potential biomarker for prostate cancer. This review summarizes recent advances in understanding DNA methylation alterations in cancers with the focus on prostate cancer. We discuss the advanced methodology used for evaluating DNA methylation changes and the molecular regulators behind these changes. We also explore the clinical potential of DNA methylation as prostate cancer biomarkers and its potential for developing targeted treatment of CIMP subtype of prostate cancer.

Clinical characteristics and prognostic significance of DNA methylation regulatory gene mutations in acute myeloid leukemia

BACKGROUND

DNA methylation is a form of epigenetic modification that regulates gene expression. However, there are limited data on the comprehensive analysis of DNA methylation regulated gene mutations (DMRGM) in acute myeloid leukemia (AML) mainly referring to DNA methyltransferase 3α (DNMT3A), isocitrate dehydrogenase 1 (IDH1), isocitrate dehydrogenase 2 (IDH2), and Tet methylcytidine dioxygenase 2 (TET2).

RESULTS

A retrospective study of the clinical characteristics and gene mutations in 843 newly diagnosed non-M3 AML patients was conducted between January 2016 and August 2019. 29.7% (250/843) of patients presented with DMRGM. It was characterized by older age, higher white blood cell count, and higher platelet count (P < 0.05). DMRGM frequently coexisted with FLT3-ITD, NPM1, FLT3-TKD, and RUNX1 mutations (P < 0.05). The CR/CRi rate was only 60.3% in DMRGM patients, significantly lower than in non-DMRGM patients (71.0%, P = 0.014). In addition to being associated with poor overall survival (OS), DMRGM was also an independent risk factor for relapse-free survival (RFS) (HR: 1.467, 95% CI: 1.030-2.090, P = 0.034). Furthermore, OS worsened with an increasing burden of DMRGM. Patients with DMRGM may be benefit from hypomethylating drugs, and the unfavorable prognosis of DMRGM can be overcome by hematopoietic stem cell transplantation (HSCT). For external validation, the BeatAML database was downloaded, and a significant association between DMRGM and OS was confirmed (P < 0.05).

CONCLUSION

Our study provides an overview of DMRGM in AML patients, which was identified as a risk factor for poor prognosis.

Epigenetic regulation in hematopoiesis and its implications in the targeted therapy of hematologic malignancies

Hematologic malignancies are one of the most common cancers, and the incidence has been rising in recent decades. The clinical and molecular features of hematologic malignancies are highly heterogenous, and some hematologic malignancies are incurable, challenging the treatment, and prognosis of the patients. However, hematopoiesis and oncogenesis of hematologic malignancies are profoundly affected by epigenetic regulation. Studies have found that methylation-related mutations, abnormal methylation profiles of DNA, and abnormal histone deacetylase expression are recurrent in leukemia and lymphoma. Furthermore, the hypomethylating agents and histone deacetylase inhibitors are effective to treat acute myeloid leukemia and T-cell lymphomas, indicating that epigenetic regulation is indispensable to hematologic oncogenesis. Epigenetic regulation mainly includes DNA modifications, histone modifications, and noncoding RNA-mediated targeting, and regulates various DNA-based processes. This review presents the role of writers, readers, and erasers of DNA methylation and histone methylation, and acetylation in hematologic malignancies. In addition, this review provides the influence of microRNAs and long noncoding RNAs on hematologic malignancies. Furthermore, the implication of epigenetic regulation in targeted treatment is discussed. This review comprehensively presents the change and function of each epigenetic regulator in normal and oncogenic hematopoiesis and provides innovative epigenetic-targeted treatment in clinical practice.

Mutation profile of acute myeloid leukaemia in a Chinese cohort by targeted next-generation sequencing

Background

Acute myeloid leukaemia (AML) results from the clonal expansion of blast cells of myeloid origin driven by genomic defects. The advances in next‐generation sequencing (NGS) have allowed the identification of many mutated genes important in the pathogenesis of AML.

Aims

In this study, we aimed to assess the mutation types and frequency in a Chinese cohort presenting with de novo AML cohort using a targeted NGS strategy.

Methods

In total, we studied samples from 87 adult patients with de novo AML who had no prior history of cytotoxic chemotherapy. Samples were evaluated using a 120‐gene targeted NGS panel to assess the mutation profile.

Results

Of the 87 AML patients, there were 60 (69%) with a normal karyotype. 89.7% of patients had variants, with an average of 1.9 mutations per patient (range: 0–5 mutations per patient). DNMT3A variants were the most common, being detected in 33 patients (37.9%). NPM1 (34.5%), IDH1/2 (24.1%) and FLT3‐ITD (20.7%) mutations was the next most common. Of the patients with DNMT3A mutations, 24.2% also had mutations NPM1 and FLT3‐ITD and 6.1% NPM1, FLT3‐ITD and IDH mutations.

Conclusion

Both DNMT3A and NPM1 mutations were more common than in other Chinese and Western AML cohorts that have been studied. DNMT3A mutations tended to co‐occur with NPM1 and FLT3‐ITD mutations and were most commonly seen with a normal karyotype.

Additional mutations in IDH1/2-mutated patients with acute myeloid leukemia

OBJECTIVE

Somatic mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) frequently emerge in acute myeloid leukemia (AML), but the clinical features and molecular characteristics of IDH mutational status and other coexisting mutations have not been investigated in a large extensively characterized AML series. The aim of this study was to gain insight into the mutational profile of IDH-mutated patients, such as the frequency and clinical characteristics of coexisting mutated genes.

MATERIALS AND METHODS

We investigated 485 newly diagnosed AML patients (range 18-81 years). DNA was extracted from bone marrow samples at the time of diagnosis. All samples were investigated with a panel of 49 mutational genes using next-generation sequencing (NGS). FLT3-ITD, NPM1, and CEBPA mutations were detected by Sanger PCR sequencing.

RESULTS

We found 84 patients (17.3%) with IDH1 or IDH2 mutations. There were 40 IDH1^R132 , 15 IDH2^R140Q , 17 IDH2^R172K , and 12 uncommon mutations. No patient was found to have both IDH1 and IDH2 mutations. Patients with IDH2^R140Q mutations were more frequently older and presented with significantly lower average platelet counts, while IDH2^R172K -mutated patients had significantly lower white blood cell (WBC) counts. On the background of IDH mutations, the presence of a normal karyotype showed a balanced distribution. The four most frequently coexisting mutated genes were NPM1, DNMT3A, TET2, and FLT3-ITD. The majority of coexisting mutated genes were involved in regulating transcription and DNA methylation. IDH mutation status had no effect on the CR rate, regardless of other molecular abnormalities.

CONCLUSION

Isocitrate dehydrogenases mutations are associated with a complex coexisting mutation cluster in AML. Future investigation is needed to reveal the association between IDH mutations and other genetic abnormalities, which may have an impact on the progression and prognosis of disease.

Prognostic role of ACTL10 in Cytogenetic Normal Acute Myeloid Leukemia

ACTL10 is a member of the actin family; however, despite previous studies suggesting that certain proteins in this family may be related to the pathogenesis of leukemia, to the best of our knowledge, no studies to date have demonstrated any association between ACTAL10 and leukemia. Thus, the present study aimed to determine the association between ACTL10 expression levels, DNA methylation levels and the clinical prognosis in cytogenic normal acute myeloid leukemia (CN-AML). Data from seventy-five patients with CN-AML and patients with AML treated with chemotherapy or allogeneic hematopoietic stem cell transplantation were obtained from The Cancer Genome Atlas (TCGA) dataset and were used to analyze the clinical prognosis of ACTL10 RNA expression levels and DNA methylation levels. In addition, the study also investigated the combined clinical prognosis of ACTL10 RNA expression levels and ACTL10 DNA methylation levels in 74 patients with CN-AML from the TCGA dataset. ACTL10 RNA expression levels were observed to be highly expressed in patients with CD34⁺/CD38⁺ AML (P<0.01). Both ACTL10 RNA expression levels and DNA methylation were found to be independent prognostic factors for patients with CN-AML; patients with CN-AML in the ACTL10 RNA-high expression group had an increased EFS (P=0.0016) and OS (P=0.014) and patients in ACTL10 DNA methylation-low group also demonstrated a long EFS (P<0.0001) and OS (P=0.004). Notably, integrating ACTL10 RNA expression levels and ACTL10 DNA methylation levels could more accurately predict the prognosis of patients with CN-AML (EFS and OS, P<0.0001). In conclusion, the findings of the present study suggested that the high RNA expression levels and low DNA methylation levels of ACTL10 may predict a good prognosis in patients with CN-AML.