Mutant DNA methylation regulators endow hematopoietic stem cells with the preleukemic stem cell property, a requisite of leukemia initiation and relapse

Emerging molecular subtypes and therapeutic targets in B-cell precursor acute lymphoblastic leukemia

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is characterized by genetic alterations with high heterogeneity. Precise subtypes with distinct genomic and/or gene expression patterns have been recently revealed using high-throughput sequencing technology. Most of these profiles are associated with recurrent non-overlapping rearrangements or hotspot point mutations that are analogous to the established subtypes, such as DUX4 rearrangements, MEF2D rearrangements, ZNF384/ZNF362 rearrangements, NUTM1 rearrangements, BCL2/MYC and/or BCL6 rearrangements, ETV6-RUNX1-like gene expression, PAX5alt (diverse PAX5 alterations, including rearrangements, intragenic amplifications, or mutations), and hotspot mutations PAX5 (p.Pro80Arg) with biallelic PAX5 alterations, IKZF1 (p.Asn159Tyr), and ZEB2 (p.His1038Arg). These molecular subtypes could be classified by gene expression patterns with RNA-seq technology. Refined molecular classification greatly improved the treatment strategy. Multiagent therapy regimens, including target inhibitors (e.g., imatinib), immunomodulators, monoclonal antibodies, and chimeric antigen receptor T-cell (CAR-T) therapy, are transforming the clinical practice from chemotherapy drugs to personalized medicine in the field of risk-directed disease management. We provide an update on our knowledge of emerging molecular subtypes and therapeutic targets in BCP-ALL.

Clinical efficacy of decitabine‑containing induction chemotherapy in de novo non‑elderly acute myeloid leukemia

To improve the complete response rate (CRR) and reduce the recurrence rate of newly diagnosed non‑elderly acute myeloid leukemia (AML), the present study compared the clinical efficacy of decitabine with cytarabine (A) and daunorubicin (D)‑based remission induction therapy with D + A‑based remission induction therapy. A total of 81 patients with newly diagnosed non‑elderly AML (non‑M3) were enrolled in the present study, and divided into the observation group [decitabine with D + A, demethoxydaunorubicin (I) + A or homoharringtonine (H) + A] and the control group (D + A, I + A or H + A). The observation group displayed a 91.4% CRR [95% confidence interval (CI), 81.7‑100%] and the control group displayed a 69.6% CRR (95% CI, 55.8‑83.4%). The 2‑year overall survival (OS) rate was improved in the observation group compared with the control group (P=0.008). Patients aged <60 years displayed a 92.9% CRR in the observational group and a 71.1% CRR in the control group (P<0.05). Patients with undetected methylation gene mutations displayed an improved CRR in the observation group compared with the control group (92.9 vs. 71.4%; P=0.028). Furthermore, relapse‑free survival (P=0.041) and OS (P=0.007) were significantly extended in the observation group compared with the control group. The present study suggested that the administration of decitabine with DA, IA or HA as an induction therapy improved the clinical efficacy and reduced the recurrence rate in patients with AML.

Altering chromatin methylation patterns and the transcriptional network involved in regulation of hematopoietic stem cell fate

Hematopoietic stem cells (HSCs) are quiescent cells with self-renewal capacity and potential multilineage development. Various molecular regulatory mechanisms such as epigenetic modifications and transcription factor (TF) networks play crucial roles in establishing a balance between self-renewal and differentiation of HSCs. Histone/DNA methylations are important epigenetic modifications involved in transcriptional regulation of specific lineage HSCs via controlling chromatin structure and accessibility of DNA. Also, TFs contribute to either facilitation or inhibition of gene expression through binding to enhancer or promoter regions of DNA. As a result, epigenetic factors and TFs regulate the activation or repression of HSCs genes, playing a central role in normal hematopoiesis. Given the importance of histone/DNA methylation and TFs in gene expression regulation, their aberrations, including changes in HSCs-related methylation of histone/DNA and TFs (e.g., CCAAT-enhancer-binding protein α, phosphatase and tensin homolog deleted on the chromosome 10, Runt-related transcription factor 1, signal transducers and activators of transcription, and RAS family proteins) could disrupt HSCs fate. Herewith, we summarize how dysregulations in the expression of genes related to self-renewal, proliferation, and differentiation of HSCs caused by changes in epigenetic modifications and transcriptional networks lead to clonal expansion and leukemic transformation.

Molecular landscape and targeted therapy of acute myeloid leukemia

For decades, genetic aberrations including chromosome and molecular abnormalities are important diagnostic and prognostic factors in acute myeloid leukemia (AML). ATRA and imatinib have been successfully used in AML and chronic myelogenous leukemia, which proved that targeted therapy by identifying molecular lesions could improve leukemia outcomes. Recent advances in next generation sequencing have revealed molecular landscape of AML, presenting us with many molecular abnormalities. The individual prognostic information derived from a specific mutation could be modified by other molecular lesions. Therefore, the genomic complexity in AML poses a huge challenge to successful translation into more accurate risk stratification and targeted therapy. Herein, a summary of these mutations and targeted therapies are described. We focus on the prognostic information of recent identified molecular lesions and emerging targeted therapy.

Preleukemic Hematopoietic Stem Cells in Human Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive malignancy of the bone marrow characterized by an uncontrolled proliferation of undifferentiated myeloid lineage cells. Decades of research have demonstrated that AML evolves from the sequential acquisition of genetic alterations within a single lineage of hematopoietic cells. More recently, the advent of high-throughput sequencing has enabled the identification of a premalignant phase of AML termed preleukemia. Multiple studies have demonstrated that AML can arise from the accumulation of mutations within hematopoietic stem cells (HSCs). These HSCs have been termed "preleukemic HSCs" as they represent the evolutionary ancestors of the leukemia. Through examination of the biological and clinical characteristics of these preleukemic HSCs, this review aims to shed light on some of the unexplored questions in the field. We note that some of the material discussed is speculative in nature and is presented in order to motivate future work.

An integrated analysis of cancer genes in clear cell renal cell carcinoma

AIM

This study was performed to detect driver genes and implement integrated analyses on these drivers in clear cell renal cell carcinoma (ccRCC).

METHODS

Driver genes and pathways were predicted by OncodriveFM and Dendrix using 39,636 somatic mutations from The Cancer Genome Atlas, followed by DNA methylation, copy number variation, differential expression and survival analyses.

RESULTS

Overall, 342 driver genes and 106 pathways were determined by OncodriveFM, two driver genes by Dendrix. 28 driver genes were found hypomethylated, overexpressed and associated to a poor prognosis. By contrast, 17 driver genes showed decreased expression, hypermethylation and indicated a better outcome in ccRCC.

CONCLUSION

The set of new cancer genes and pathways opens the avenue for developing potential therapeutic targets and prognostic biomarkers in ccRCC.

Das Tumorepigenom – von der Genregulation über die Tumorklassifikation zum Therapietarget

Epigenetische Regulationsmechanismen sind essenziell für den koordinierten Ablauf zahlreicher zellulärer Prozesse wie die Differenzierung und Entwicklung oder auch die Anpassung der Genaktivität an die herrschenden Umweltbedingungen. Insbesondere Tumorerkrankungen gehen mit oftmals umfangreichen Alterationen im Epigenom einher. Diese Veränderungen sind dabei vielfach charakteristisch entweder für die Tumorentität, das Stadium der Erkrankung oder aber das klinische Ansprechen des Tumors auf eine Therapie und damit die individuelle Prognose des Patienten. Nach einer kurzen Darstellung epigenetischer Marker und ihrer Bedeutung bei malignen Erkrankungen werden in diesem Artikel Alterationen im Tumorepigenom und ihre Nutzbarkeit im Rahmen einer individualisierten Medizin exemplarisch vorgestellt.

Evaluation of DNMT3A genetic polymorphisms as outcome predictors in AML patients

DNMT3A mutation is known as a recurrent event in acute myelogenous leukemia (AML) patients. However, association between DNMT3A genetic polymorphisms and AML patients' outcomes is unknown. DNMT3A 11 SNPs (rs11695471, rs2289195, rs734693, rs2276598, rs1465825, rs7590760, rs13401241, rs7581217, rs749131, rs41284843 and rs7560488) were genotyped in 344 diagnostic non-FAB-M3 AML patients from southern China. Patients underwent combined chemotherapy with cytarabine and anthracyclines. DNMT3A mRNA expression was analyzed in PBMCs from randomly selected AML patients. Multivariate analysis and combined genotype analysis showed that rs2276598 was associated with increased while rs11695471 and rs734693 were associated with decreased chemosensitivity (P<0.05), while rs11695471 (worse for OS), rs2289195 (favorable for OS and DFS) and rs2276598 (favorable for DFS) were significantly associated with disease prognosis (P<0.05). In conclusion, DNMT3A polymorphisms may be potential predictive markers for AML patients' outcomes, which might improve prognostic stratification of AML.

Health: a dream from reality to the future

This paper argues that health is a realistic productive force that may enhance the index of happiness. As the basis of all developments and the source of a person's and his/her family's happiness, health requires not only primary and secondary prevention, but also policy prevention, that is to say, grade-zero prevention. Therefore, people should pay more attention to Health in All Policies. As a new preventive strategy, the policy prevention will help improve people's health significantly and promote the concepts of "Healthy China" and "the Chinese Dream" or "the World Dream" to realize a dream from reality to the future.