Correlation of TET2 SNP rs2454206 with improved survival in children with acute myeloid leukemia featuring intermediate-risk cytogenetics

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.

[Analysis of clinical significance and prognostic impact of TET2 single nucleotide polymorphism I1762V in patients with acute myeloid leukemia]

Objective: This study aimed to investigate the clinical and prognostic significance of TET2 single nucleotide polymorphism I1762V in patients with acute myeloid leukemia (AML) . Methods: The high-throughput sequencing method was used to sequence 58 hematological tumor-related genes in bone marrow samples from 413 patients with AML. TET2 I1762V and other somatic mutations were annotated and compared with patients' clinical information and prognosis. Results: I1762V was found in 154 patients with AML, which was significantly different from the general population in NyuWa Chinese Population Variant Database (χ(2)=72.4, P<0.001) . I1762V was not related to sex, age, and karyotype of patients with AML (P>0.05) . Patients with I1762V had a significantly higher proportion of NPM1 and KIT gene mutations than others (P<0.001) . NPM1 and KIT mutations were mutually exclusive. The survival analysis results revealed that the overall survival (OS) and progression-free survival (PFS) of patients with AML with I1762V were significantly greater than those of wild-type patients (HR=0.57, P=0.030; HR=0.55, P=0.020) , whereas the OS and PFS in patients with AML with DNMT3A mutation (with or without I1762V mutation) were lower than those of wild-type patients (HR=1.79, P=0.030; HR=1.74, P=0.040) . Conclusion: TET2 SNP I1762V has been linked to AML. I1762V is a prognostic factor of patients with AML, which can be used to guide the treatment and evaluate the prognosis of AML.

GATA2 rs2335052 and GATA2 rs78245253 single-nucleotide polymorphisms in Chinese patients with acute myelocytic leukemia

INTRODUCTION

GATA binding protein 2 (GATA2) gene, involved in progression of hematologic malignancies and various solid tumors, is a susceptibility gene for inherited acute myeloid leukemia (AML). However, the influence of its single-nucleotide polymorphisms (SNPs) on AML remains unknown.

METHODS

We used allele-specific PCR to genotype GATA2 rs2335052 and rs78245253 in 159 newly diagnosed AML (non-M3) patients and 300 healthy volunteers, and all of participants came from China. And 34 common hematological tumor gene mutations in 159 AML patients were detected by next-generation sequencing. Kaplan-Meier survival analysis and Cox proportional hazard regression were used to analyze the association between the two SNPs and the prognosis of AML.

RESULTS

We found GATA2 rs2335052 C/T genotype, rs2335052 T/T genotype and rs78245253 G/C genotype in 51.6%, 13.8% and 11.3% AML patients. Our results demonstrated that GATA2 rs2335052 and rs78245253 were associated with certain laboratory features in AML patients, which had no effect on the pathogeny, chemotherapy response and recurrence of patients. Nevertheless, Kaplan-Meier survival analysis showed that, compared with rs78245253 G/G genotype, rs78245253 G/C genotype was significantly related to a decrease in overall survival (OS) (P = .020). Additionally, multivariate cox regression analysis showed that GATA2 rs78245253 was an independent risk factor for OS of AML patients in China.

CONCLUSION

GATA2 rs78245253 was an independent predictor for prognosis of AML patients in China and may be used as a potential indicator to predict the survival of AML patients in China. Further studies are needed to validate these findings and clarify the underlying mechanism.

A rare case of acute promyelocytic leukemia with ider(17)(q10)t(15;17)(q22;q21) and favorable outcome

Background

Chromosomal rearrangements in addition to t(15;17) have been reported in 25-40% of APL patients, with a large predominance of trisomy 8. Other abnormalities are far less frequent, particularly as ider(17), and the prognostic significance is still unclear.

Case presentation

We present the case of a patient with t(15;17)(q22;q21), der(15)t(15;17) and ider(17)(q10)t(15;17)(q22;q21). In particular, the RT-PCR result for PML-RARA of this patient was a false negative and mutational analysis of AML-related genes showed SNP rs2454206 in the TET2 gene and yielded negative findings in other genes including AML1, ASXL1, CEBPA, DNMT3A, FLT3, KIT, NPM1, TP53, and U2AF1. After the early usage of arsenic trioxide combinated with ATRA and vigorous supportive treatment to maintain PLT ≥30×10⁹/L and FIB >1500 mg/L, this patient was under MMR and HCR without any clinical symptoms or signs until now.

Conclusion

False negative reslults of RT-PCR analysis for PML-RARA are rare in APL and ider(17) is even more infrequent. To our knowledge, this is the first reported case of APL with ider(17) and false negative RT-PCR analysis results. The role of ider(17) in APL is still an ongoing investigation and limited by the small number of published cases. The patient reported here benefited from vigorous supportive treatment during the combination of ATRA and arsenic trioxide in induction chemotherapy and the clinical outcome was favorable.

The Role of Forkhead Box Proteins in Acute Myeloid Leukemia

Forkhead box (FOX) proteins are a group of transcriptional factors implicated in different cellular functions such as differentiation, proliferation and senescence. A growing number of studies have focused on the relationship between FOX proteins and cancers, particularly hematological neoplasms such as acute myeloid leukemia (AML). FOX proteins are widely involved in AML biology, including leukemogenesis, relapse and drug sensitivity. Here we explore the role of FOX transcription factors in the major AML entities, according to "The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia", and in the context of the most recurrent gene mutations identified in this heterogeneous disease. Moreover, we report the new evidences about the role of FOX proteins in drug sensitivity, mechanisms of chemoresistance, and possible targeting for personalized therapies.

Silencing long non-coding RNA HOTAIR exerts anti-oncogenic effect on human acute myeloid leukemia via demethylation of HOXA5 by inhibiting Dnmt3b

Background

As an aggressive hematological malignancy, acute myeloid leukemia (AML) remains a dismal disease with poor prognosis. Long non-coding RNAs (lncRNAs) have been widely reported to be involved in tumorigenesis of AML. Here, we define an important role of lncRNA HOTAIR in AML in relation to HOXA5 methylation.

Methods

Firstly, the expression of HOTAIR was examined in AML samples and cells collected. Next, gain- or loss-of function experiments were conducted in AML cells to explore the effect of HOTAIR on AML. Then, relationship among HOXA5 promoter methylation, HOTAIR and Dnmt3b was measured. Expression of HOXA5 and cell proliferation/apoptosis-related genes was also detected. A last, in vivo assay was performed to assess the tumor formation in nude mice in order to explore the roles of HOTAIR and HOXA5 in cell apoptosis and proliferation.

Results

LncRNA HOTAIR was found to be upregulated in AML cells and tissues. With silencing of HOTAIR and overexpression of HOXA5, AML cell proliferation was decreased while the apoptosis was induced. Furthermore, HOTAIR was observed to recruit Dnmt3b and to increase HOXA5 promoter methylation. Moreover, silencing HOTAIR and upregulating HOXA5 were found to induce apoptosis and reduce proliferation of AML cells in vivo.

Conclusion

Our findings highlight the anti-tumor ability of HOTAIR silencing in AML, suggesting that silencing HOTAIR was able to inhibit AML progression through HOXA5 promoter demethylation by decreasing Dnmt3b.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0808-z) contains supplementary material, which is available to authorized users.