HA117 endows HL60 cells with a stem-like signature by inhibiting the degradation of DNMT1 via its ability to down-regulate expression of the GGL domain of RGS6

Potential Prognostic Markers for Relapsed/Refractory vs. Responsive Acute Myeloid Leukemia

Simple Summary

Acute myeloid leukemia (AML) is the most common blood cancer in the elderly, which progresses rapidly and is often fatal. The prognosis for AML remains poor in most older patients: only about 15% of patients over 60 years of age can recover. Our aim is to determine new potential AML clinical treatment prognosis markers. We analyzed certain genes, proteins and the epigenome profile in therapy-resistant and responsive AML patients at diagnosis stage and after clinical treatment. We determined that MYC, WT1, IDH1, CDKN1A, HDAC2, TET1, KAT6A and GATAD2A gene expression changes might characterize refractory AML. Therefore, these genes could have an impact for AML prognosis.

Abstract

Acute myeloid leukemia (AML) is a heterogeneous disease. A significant proportion of AML patients is refractory to clinical treatment or relapses. Our aim is to determine new potential AML clinical treatment prognosis markers. We investigated various cell fate and epigenetic regulation important gene level differences between refractory and responsive AML patient groups at diagnosis stage and after clinical treatment using RT-qPCR. We demonstrated that oncogenic MYC and WT1 and metabolic IDH1 gene expression was significantly higher and cell cycle inhibitor CDKN1A (p21) gene expression was significantly lower in refractory patients’ bone marrow cells compared to treatment responsive patients both at diagnosis and after clinical treatment. Moreover, we determined that, compared to clinical treatment responsive patients, refractory patients possess a significantly higher gene expression of histone deacetylase 2 (HDAC2) and epigenetic DNA modulator TET1 and a significantly lower gene expression of lysine acetyltransferase 6A (KAT6A) and nucleosome remodeling and deacetylase (NuRD) complex component GATAD2A. We suggest that MYC, WT1, IDH1, CDKN1A, HDAC2, TET1, KAT6A and GATAD2A gene expression changes might characterize refractory AML. Thus, they might be useful for AML prognosis. Additionally, we suggest that epigenetic modulation might be beneficial in combination with standard treatment.

Oncogenic Roles and Inhibitors of DNMT1, DNMT3A, and DNMT3B in Acute Myeloid Leukaemia

Epigenetic alteration has been proposed to give rise to numerous classic hallmarks of cancer. Impaired DNA methylation plays a central role in the onset and progression of several types of malignancies, and DNA methylation is mediated by DNA methyltransferases (DNMTs) consisting of DNMT1, DNMT3A, and DNMT3B. DNMTs are frequently implicated in the pathogenesis and aggressiveness of acute myeloid leukaemia (AML) patients. In this review, we describe and discuss the oncogenic roles of DNMT1, DNMT3A, and DNMT3B in AML. The clinical response predictive roles of DNMTs in clinical trials utilising hypomethylating agents (azacitidine and decitabine) in AML patients are presented. Novel hypomethylating agent (guadecitabine) and experimental DNMT inhibitors in AML are also discussed. In summary, hypermethylation of tumour suppressors mediated by DNMT1 or DNMT3B contributes to the progression and severity of AML (except MLL-AF9 and inv(16)(p13;q22) AML for DNMT3B), while mutation affecting DNMT3A represents an early genetic lesion in the pathogenesis of AML. In clinical trials of AML patients, expression of DNMTs is downregulated by hypomethylating agents while the clinical response predictive roles of DNMT biomarkers remain unresolved. Finally, nucleoside hypomethylating agents have continued to show enhanced responses in clinical trials of AML patients, and novel non-nucleoside DNMT inhibitors have demonstrated cytotoxicity against AML cells in pre-clinical settings.

Potential association of long noncoding RNA HA117 with tetralogy of Fallot

Tetralogy of Fallot (TOF) is a congenital heart disease characterized by abnormal cardiomyocyte differentiation in the right ventricular outflow tract (RVOT), and HA117 is a novel long noncoding RNA (lncRNA) with anti-differentiation roles. To investigate the potential association of HA117 with TOF, we collected 84 RVOT tissues from patients with TOF. We determined the expression of HA117 in RVOT samples from TOF patients and collected clinical data to conduct a cross-sectional and short-term follow-up study. McGoon ratio, Nakata index, and left ventricular end-diastolic volume index (LVEDVI) were negatively correlated with the expression of HA117 based on subgroup analysis, correlation analysis and logistic regression analysis. Additionally, cardiopulmonary bypass (CPB) time and ICU stay were longer in patients with higher expression of HA117 than in patients with lower expression of HA117. Furthermore, percentage improvement in SPO₂ was significantly reduced in patients with increased HA117 expression at 6 months after surgery. Our results suggested that the increased expression of the novel lncRNA HA117 is a risk factor for unfavorable McGoon ratio, Nakata index and LVEDVI in TOF patients. Additionally, an increased expression of HA117 might lead to adverse short-term outcomes in TOF patients.