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It was previously reported that PRR34‐AS1 was overexpressed in some solid tumors. PRR34‐AS1 promoter was shown to have a differential methylation region (DMR), and was hypomethylated in acute myeloid leukemia (AML). Therefore, the present study used real‐time quantitative PCR (RQ‐PCR) to explore the expression characteristics of PRR34‐AS1 in AML. In addition, the correlation between the expression of PRR34‐AS1 and clinical prognosis of AML was determined. The findings of this study indicated that high PRR34‐AS1 expression was bound up with shorter overall survival (OS) in AML patients (p = 0.002). Moreover, patients with high expression of PRR34‐AS1 had significantly lower complete remission (CR) rate compared with those with low expression of PRR34‐AS1 after induction chemotherapy. Furthermore, multivariate analysis confirmed that PRR34‐AS1 expression was an independent factor affecting CR in whole‐AML, non‐APL‐AML, and CN‐AML patients (p = 0.032, 0.039, and 0.036, respectively). Methylation‐specific PCR (MSP) and bisulfite sequencing PCR (BSP) were used to explore the methylation status of PRR34‐AS1. PRR34‐AS1 promoter showed a pattern of hypomethylation in AML patients compared with normal controls (p = 0.122). Notably, of whole‐AML and non‐APL‐AML patients, PRR34‐AS1 hypomethylated patients presented a significantly shorter OS than those with a hypermethylated PRR34‐AS1 (p = 0.010 and 0.037, respectively). Multivariate analysis confirmed that the hypomethylation of PRR34‐AS1 served as an independent prognostic indicator in both whole‐cohort AML and non‐APL‐AML categories (p = 0.057 and 0.018, respectively). In summary, the findings of this study showed that abnormalities in PRR34‐AS1 are associated with poor prognosis in AML. Therefore, monitoring this index may be important in the prognosis of AML and can provide information on effective chemotherapy against the disease. [ABSTRACT FROM AUTHOR]

The deregulated DLX gene family members DLX1/2/3/4/5/6 (DLXs) caused by DNA methylation has been demonstrated in various cancers with therapeutic target value. However, the potential role of DLXs methylation in myeloid neoplasms such as acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) remains to be elucidated. Clinical significance of DLXs methylation/expression was analyzed in patient with AML and MDS. The functional roles of DLXs were determined in vitro. In the identification stage, we found that lower DLX5 expression was correlated with prognosis in AML among all DLXs analyzed by The Cancer Genome Atlas datasets. In the validation stage, we revealed that reduced DLX5 expression was frequently occurred, and was also correlated with promoter hypermethylation in AML evaluated by targeted bisulfite sequencing. Epigenetic studies also showed that DLX5 promoter DNA methylation was associated with its expression. By quantitative polymerase chain reaction, we also validated that DLX5 hypermethylation was frequent event in both AML and MDS, and also correlated with MDS transformation to leukemia. Moreover, DLX5 hypermethylation was associated with lower rate of complete remission and shorter time of leukemia‐free/overall survival, and was also confirmed by Logistic/Cox regression analysis. Functional studies revealed the antiproliferative and pro‐apoptotic effects of DLX5 in MDS‐derived AML cell‐line SKM‐1. Finally, bioinformatics analysis demonstrated that DLX5 functioned in leukemogenesis may be through the association with PI3K/Akt signaling pathway. Collectively, our findings demonstrated that DLX5 methylation, negatively correlated DLX5 expression, was a potential prognostic and predictive indicator in patients with AML and MDS, which could also act as an epigenetic driver in myeloid neoplasms. [ABSTRACT FROM AUTHOR]

Accumulating studies have proved EZH2 dysregulation mediated by mutation and expression in diverse human cancers including AML. However, the expression pattern of EZH2 remains controversial in acute myeloid leukaemia (AML). EZH1/2 expression and mutation were analysed in 200 patients with AML. EZH2 expression was significantly decreased in AML patients compared with normal controls but not for EZH1 expression. EZH2 mutation was identified three of the 200 AML patients (1.5%, 3/200), whereas none of the patients harboured EZH1 mutation (0%, 0/200). EZH2 expression and mutation were significantly associated with −7/del(7) karyotypes. Moreover, lower EZH2 expression was associated with older age, higher white blood cells, NPM1 mutation, CEBPA wild‐type and WT1 wild‐type. Patients with EZH2 mutation showed shorter overall survival (OS) and leukaemia‐free survival (LFS) than patients without EHZ2 mutation after receiving autologous or allogeneic haematopoietic stem cell transplantation (HSCT). However, EZH2 expression has no effect on OS and LFS of AML patients. Notably, in EZH2 low group, patients undergone HSCT had significantly better OS and LFS compared with patients only received chemotherapy, whereas no significant difference was found in OS and LFS between chemotherapy and HSCT patients in EZH2 high group. Collectively, EZH2 dysregulation caused by mutation and under‐expression identifies specific subtypes of AML EZH2 dysregulation may be acted as potential biomarkers predicting prognosis and guiding the treatment choice between transplantation and chemotherapy. [ABSTRACT FROM AUTHOR]

Background: Downstream of tyrosine kinase 6 (DOK6), which is specifically expressed in the nervous system, was previously recognized as an adapter only in neurite outgrowth. Recent studies also demonstrated the potential role of DOK6 in solid tumors such as gastric cancer and breast cancer. However, previous studies of DOK6 have not dealt with its roles in myeloid malignancies. Herein, we verified the promoter methylation status of DOK6 and further explored its clinical implication in de novo acute myeloid leukemia (AML). Methods: A total of 100 newly diagnosed adult AML patients were involved in the current study. DOK6 expression and methylation were detected by real‐time qPCR and methylation‐specific PCR (MSP), respectively. Bisulfite sequencing PCR (BSP) was performed to assess the methylation density of the DOK6 promoter. Results: Downstream of tyrosine kinase 6 promoter methylation was significantly increased in AML patients compared to controls (P = .037), whereas DOK6 expression significantly decreased in AML patients (P < .001). The expression of DOK6 was markedly up‐regulated after treated by 5‐aza‐2′‐deoxycytidine (5‐aza‐dC) in THP‐1 cell lines. The methylation status of the DOK6 promoter was associated with French‐American‐British classifications (P = .037). There was no significant correlation existed between DOK6 expression and its promoter methylation (R = .077, P = .635). Interestingly, of whole‐AML and non‐APL AML patients, both have a tendency pertaining to the DOK6 methylation group and a significantly longer overall survival (OS) than the DOK6 unmethylation group (P = .042 and.036, respectively). Conclusion: Our study suggested that DOK6 promoter hypermethylation was a common molecular event in de novo AML patients. Remarkably, DOK6 promoter methylation could serve as an independent and integrated prognostic biomarker not only in non‐APL AML patients but also in AML patients who are less than 60 years old. [ABSTRACT FROM AUTHOR]

The current study was aimed to investigate integrin beta‐like 1 (ITGBL1) methylation pattern and its clinical relevance in patients with acute myeloid leukemia (AML). Real‐time methylation‐specific polymerase chain reaction (PCR; RQ‐MSP) and bisulfite sequencing PCR (BSP) were performed to detect the methylation of ITGBL1 promoter. Real‐time quantitative PCR (RT‐qPCR) was performed to analyze ITGBL1 transcript level. The results showed that ITGBL1 methylation level in 131 patients with AML was significantly higher than 29 controls (p < 0.001). The ITGBL1‐hypermethylated group tended to have a higher bone marrow (BM) blasts (p = 0.076). Meanwhile, ITGBL1‐hypermethylated patients tended to have a lower complete remission (CR) rate (p = 0.102). ITGBL1‐hypermethylated patients had significantly shorter overall survival (OS) and leukemia‐free survival (LFS) than ITGBL1 hypomethylated patients in whole AML cohort (p = 0.009 and 0.043, respectively) and patients with nonacute promyelocytic leukemia (APL ; p = 0.023 and 0.039, respectively). Multivariate analysis confirmed that the ITGBL1 methylation served as an independent prognostic factor in both patients with whole‐cohort AML (p = 0.030) and patients with non‐APL (p = 0.020). Furthermore, the ITGBL1 methylation level was significantly decreased in follow‐up AML patients who achieved complete remission after induction therapy (P = 0.001). ITGBL1 methylation negatively correlated with ITGBL1 expression in patients with AML (R = −0.328, p = 0.008). Moreover, demethylation of ITGBL1 could increase the ITGBL1 expression in the K562 leukemic cell line (p < 0.05). In conclusion, the ITGBL1 hypermethylation is a potential biomarker for predicting prognosis and monitoring disease status in patients with AML. The results showed that ITGBL1 methylation level in patients with AML was significantly higher than controls. ITGBL1‐hypermethylated patients had significantly shorter overall survival (OS) and leukemia‐free survival (LFS) than ITGBL1 hypomethylated patients in patients with whole AML cohort and nonacute promyelocytic leukemia (APL). Multivariate analysis confirmed that ITGBL1 methylation served as an independent prognostic factor in both patients with whole‐cohort AML and patients with non‐APL. [ABSTRACT FROM AUTHOR]

The clinical activity of decitabine (5‐aza‐2‐deoxycytidine, DAC), a hypomethylating agent, has been demonstrated in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients. However, secondary resistance to this agent often occurs during treatment and leads to treatment failure. It is important to clarify the mechanisms underlying the resistance for improving the efficacy. In this study, by gradually increasing concentration after a continuous induction of DAC, we established the DAC‐resistant K562 cell line (K562/DAC) from its parental cell line K562. The proliferation and survival rate of K562/DAC was significantly increased, whereas the apoptosis rate was remarkably decreased than that of K562 after DAC treatment. In K562/DAC, a total of 108 genes were upregulated and 118 genes were downregulated by RNA‐Seq. In addition, we also observed aberrant expression of DDX43/H19/miR‐186 axis (increased DDX43/H19 and decreased miR‐186) in K562/DAC cells. Ectopic expression of DDX43 in parental K562 cells rendered cells resistant to the DAC. Taken together, we successfully established DAC‐resistant K562 cell line which can serve as a good model for investigating DAC resistance mechanisms, and DDX43/H19/miR‐186 may be involved in DAC resistance in K562. [ABSTRACT FROM AUTHOR]

Previous studies have been indicated that integrin α2 (ITGA2) may be important in cell migration, invasion, survival, and angiogenesis. However, the correlation between ITGA2 expression and acute myeloid leukemia (AML) is still unclear. Real‐time quantitative polymerase chain reaction was carried out to analyze ITGA2 messenger RNA level. Methylation‐specific polymerase chain reaction (PCR) and bisulfite sequencing PCR were performed to detect the methylation of ITGA2 promoter. ITGA2 expression was significantly upregulated in 134 de novo AML patients compared with 33 controls (p = 0.007). ITGA2high group had markedly lower complete remission (CR) rate than ITGA2low group (p = 0.011). Furthermore, the overall survival in ITGA2high patients was significantly shorter than ITGA2low patients throughout AML cohort, non–acute promyelocytic leukemia (APL) and cytogenetic normal‐AML (p = 0.001, 0.002, and 0.044, respectively). Multivariate analysis confirmed that ITGA2 overexpression served as an independent prognostic factor in both whole‐cohort AML patients (p = 0.018) and non‐APL AML patients (p = 0.021). Besides, ITGA2 expression level was significantly decreased in AML patients after CR (p = 0.011), and was returned at the time of relapse phase (p = 0.021). Moreover, unmethylated ITGA2 promoter was identified in normal controls, leukemia cell lines, and primary leukemia cells with low or high ITGA2 expression. In conclusions, methylation‐independent ITGA2 overexpression is associated with poor prognosis in AML. Integrin α2 (ITGA2) expression was significantly upregulated in 134 de novo acute myeloid leukemia (AML) patients compared with 33 controls (p = 0.007). Furthermore, the overall survival in high ITGA2 expression patients was significantly shorter than low ITGA2 expression patients throughout AML cohort, non–acute promyelocytic leukemia (APL), and cytogenetic normal‐AML (p = 0.001, 0.002, and 0.044, respectively). Multivariate analysis confirmed that ITGA2 overexpression served as an independent prognostic factor in both whole‐cohort AML patients (p = 0.018) and non‐APL AML patients (p = 0.021). [ABSTRACT FROM AUTHOR]

DOK-1 and DOK-2 (DOK1/2) are closely related members of downstream of tyrosine kinase (DOK) family genes, which are found to be frequently rearranged in several hematopoietic cancers. However, the clinical implications of DOK1/2 in acute myeloid leukemia (AML) remain largely unknown. To investigate the clinical significance, real-time quantitative PCR (RQ-PCR)was carried out to detectDOK1/2 expressions in 125 de novo AML patients and 28 healthy controls. Real-time quantitative methylation-specific PCR (RQ-MSP) andbisulfite sequencingPCR(BSP)wereapplied todetectDOK1/2methylation level anddensity.DOK1/2expressionsweresignificantlydown-regulated inAMLpatients. The promoters of DOK1/2 were highly hypermethylated and negatively correlated with DOK1/2 expressions in AML patients. In addition, we also confirmed that DOK1/2 expressions could be restored by DOK1/2 demethylation using 5-aza-2′-deoxycytidine in leukemia cell line THP-1. Survival analyses showed that low-expressed DOK1/2 were associated withmarkedly shorter overall survival and leukemia free survival in both wholecohort AML and non-M3 AML patients. Multivariate analyses further revealed that DOK1/2 were act as independent prognostic factors in AML patients. These findings indicate that decreased DOK1/2 expressions associated with their promoter hypermethylations predict adverse prognosis in AML. [ABSTRACT FROM AUTHOR]

TET2 (Ten‐Eleven Translocation 2) gene is a member of TET family that can modify DNA through catalyzing the conversion of 5‐methylcytosine (5‐mC) into 5‐hydroxymethylcytosine (5‐hmC). Although TET2 mutation has been disclosed in a variety of hematopoietic malignancies, the prognostic implication of TET2 expression in acute myeloid leukemia (AML) remains largely elusive. In this study, real‐time quantitative PCR was carried out to detect the level of TET2 transcript in 134 de novo AML patients and 35 healthy donors. TET2 mRNA level was significantly down‐regulated in AML patients compared with controls (p = 0.010). Among the French–American–British (FAB) subtypes, the incidence of TET2 under‐expression in M0/M1 subtypes was significantly higher than in the other subtypes M2/M3/M4/M5/M6 (p = 0.017), and also markedly higher than in the other granulocyte subtypes M2/M3 (p = 0.005). TET2 low‐expressed patients showed a significantly higher frequency of NPM1 mutations than TET2 high‐expressed patients. Although there was no significant difference in complete remission rate between two groups (low and high TET2 expression), patients with low TET2 expression had markedly shorter overall survival (OS) in both non‐M3 and cytogenetically normal AML (CN‐AML) (p = 0.016 and 0.044, respectively). Furthermore, multivariate analysis confirmed the prognostic value of TET2 expression on OS among CN‐AML patients (p = 0.049). Importantly, TET2 expression in complete remission (CR) time was significantly higher than newly diagnosis time (p = 0.001), and was returned to lower level when in relapse time (p < 0.001). These findings indicated that down‐regulation of TET2 expression was a common event and acted as a prognostic and predictive biomarker in CN‐AML patients. [ABSTRACT FROM AUTHOR]

CHFR acts as a tumor suppressor gene, which is frequently inactivated caused by its promoter hypermethylation in various solid tumors. Although a recent study showed that CHFR hypermethylation was a frequent event in acute myeloid leukemia (AML) and correlated with adverse clinical outcome, herein, we found that CHFR methylation was a rare event in patients with myeloid malignancies (including AML, chronic myeloid leukemia, and myelodysplastic syndromes), but its expression may serve as an independent prognostic biomarker in AML. CHFR expression was assessed by real‐time quantitative PCR, whereas CHFR methylation was detected by methylation‐specific PCR and bisulfite sequencing PCR. In AML patients, lower CHFR expression was associated with lower complete remission (CR) rate, and CHFR expression was significantly increased in CR after chemotherapy. Moreover, patients with lower CHFR expression showed shorter overall survival and leukemia‐free survival, and multivariate analysis confirmed that lower CHFR expression was an independent risk factor in AML. Importantly, the prognostic value of CHFR expression was validated using the published Gene Expression Omnibus datasets. Notably, CHFR promoter was nearly unmethylated in patients with myeloid malignancies. Our findings revealed that lower CHFR expression was independently associated with unfavorable prognosis in AML. Moreover, aberrant CHFR promoter methylation was a rare event in myeloid malignances. [ABSTRACT FROM AUTHOR]

Accumulating studies have shown that miR-216b acted as a tumor suppressor and was down-regulated in solid tumors. However, little studies revealed the role or clinical implication of miR-216b in blood cancers. Herein, we reported miR-216b expression and its clinical significance in patients with acute myeloid leukemia (AML). In the current study, we analyzed bone marrow (BM) miR-216b expression in 115 de novo AML patients examined by real-time quantitative PCR. Notably, BM miR-216b expression was significantly up-regulated in AML patients, and could serve as a potential biomarker distinguishing AML from controls. No significant correlations of BM miR-216 expression were found with sex, age, white blood cells, hemoglobin, platelets, BM blasts, French-American-British classifications, and karyotypes. Significantly, patients with high miR-216b expression tended to have a lower frequency of FLT3-ITD mutation and higher incidence of U2AF1 and IDH1/2 mutations. Moreover, complete remission (CR) rate and overall survival were negatively affected by BM miR-216b overexpression among cytogenetically normal AML (CN-AML). Cox regression analyses showed that highBM miR-216b expression may act as an independent risk factor in CN-AML patients. Among the follow-up patients, BM miR-216b level in CR phase was markedly lower than in diagnosis time, and was returned in relapse phase. Collectively, our findings indicated that miR-216b overexpression was a frequent event in de novo AML, and independently conferred a poor prognosis in CN-AML. Moreover, miR-216b expression was a valuable biomarker correlated with disease recurrence in AML. [ABSTRACT FROM AUTHOR]

Previous study has revealed that H19 expression is required for efficient tumor growth induced by BCR-ABL in chronic myeloid leukemia (CML). Herein, we further determined H19 expression and its clinical implication in patients with CML. H19 expression and methylation were detected by real-time quantitative PCR and real-time quantitative methylation-specific PCR, and then clinical implication of H19 expression was further analyzed. H19 expression was significantly up-regulated in CML patients ( p < 0.001). H19 expression with an area under receiver operating characteristic curve value of 0.824 might serve as a promising biomarker in distinguishing CML patients from controls. The patients with high H19 expression had a tendency of higher white blood cells and BCR-ABL transcript than those with low H19 expression. H19 overexpression occurred with the higher frequency in blast crisis stage (11/11, 100%), lower in accelerated phase (3/5, 60%), and chronic phase (42/62, 66%) stages. Moreover, paired patients during disease progression with increased BCR-ABL transcript also showed a significant upregulation of H19 expression. Meanwhile, H19 expression was decreased in follow-up patients who achieved complete molecular remission after tyrosine kinase inhibitors-based therapy. Epigenetic studies showed that H19 differentially methylated region/imprinting control region (DMR/ICR) was hypomethylated and associated with H19 expression in CML patients. Moreover, demethylation of H19 DMR/ICR reactivated H19 expression in K562 cells. Collectively, H19 overexpression, a frequent event in CML, was associated with higher BCR-ABL transcript involving in disease progression. Moreover, H19 DMR/ICR hypomethylation in CML may be one of the mechanisms mediating H19 overexpression. [ABSTRACT FROM AUTHOR]

Promoter hypermethylation-mediated inactivation of ID4 plays a crucial role in the development of solid tumours. This study aimed to investigate ID4 methylation and its clinical relevance in myeloid malignancies. ID4 hypermethylation was associated with higher IPSS scores, but was not an independent prognostic biomarker affecting overall survival (OS) in myelodysplastic syndrome (MDS). However, ID4 hypermethylation correlated with shorter OS and leukaemia-free survival (LFS) time and acted as an independent risk factor affecting OS in acute myeloid leukaemia (AML). Moreover, ID4 methylation was significantly decreased in the follow-up paired AML patients who achieved complete remission (CR) after induction therapy. Importantly, ID4 methylation was increased during MDS progression to AML and chronic phase (CP) progression to blast crisis (BC) in chronic myeloid leukaemia (CML). Epigenetic studies showed that ID4 methylation might be one of the mechanisms silencing ID4 expression in myeloid leukaemia. Functional studies in vitro showed that restoration of ID4 expression could inhibit cell proliferation and promote apoptosis in both K562 and HL60 cells. These findings indicate that ID4 acts as a tumour suppressor in myeloid malignancies, and ID4 methylation is a potential biomarker in predicting disease progression and treatment outcome. [ABSTRACT FROM AUTHOR]

Epigenetic inactivation of GPX3 has been identified in various cancers including leukemia. Moreover, aberrant DNA methylation was also found as a dominant mechanism of disease progression in myelodysplastic syndrome ( MDS). This study intended to explore GPX3 promoter methylation and its clinical relevance in 110 patients with MDS. GPX3 methylation was examined by real-time quantitative methylation-specific PCR ( RQ- MSP) and bisulfite sequencing PCR ( BSP). GPX3 methylation was identified in 15% (17/110) MDS patients, and significantly higher than controls, and lower than acute myeloid leukemia ( AML) patients ( P = 0.024 and 0.041). GPX3 methylated patients had older age and higher frequency of DNMT3A mutation ( P = 0.015 and 0.066). Cases with GPX3 methylation showed significantly shorter overall survival ( OS) time than those with GPX3 unmethylation analyzed with Kaplan-Meier analysis ( P = 0.012). Moreover, Cox regression analysis revealed that GPX3 methylation might act as an independent prognostic indicator in MDS ( HR = 1.847, P = 0.072). GPX3 methylation density was significantly increased during the progression from MDS to secondary acute myeloid leukemia ( sAML) in three follow-up paired patients. Our study concludes that GPX3 methylation in bone marrow is associated with adverse prognosis and leukemia transformation in MDS. [ABSTRACT FROM AUTHOR]

Background: Previous studies have disclosed up‐regulation of MIR‐378 in acute myeloid leukemia (AML), and might consequently affect the outcome of the patients. Correspondingly, hypomethylation of MIR‐378 was also identified in AML, particularly for FAB‐M2 subtype with t(8;21) chromosomal translocation. Nevertheless, the methylation status of MIR‐378 has not been illustrated in myelodysplastic syndrome (MDS). Herein we designed to understand the methylation pattern of MIR‐378 involved in MDS and clinical interrelation thereof. Methods: Real‐time quantitative methylation‐specific PCR (RQ‐MSP) was performed to evaluate the methylation degree of MIR‐378 5'‐flanking region on bone marrow mononuclear cells collected from 95 de novo MDS patients. Five gene mutations (IDH1, IDH2, DNMT3A, U2AF1, and SF3B1) were detected by high‐resolution melting analysis to further evaluate the clinical relevance of hypomethylation of MIR‐378. Results: Unmethylated level of MIR‐378 5'‐flanking region was significantly higher in MDS patients than that in controls (p =.034). Hypomethylated MIR‐378 was identified in 20 of 95 (21%) cases with MDS. Male patients appeared to be more frequent to harbor MIR‐378 hypomethylation compared to female patients (15/55, 27.3% vs. 4/40, 10.0%, p =.04). There was no significant difference in age, white blood cell counts, platelet counts, hemoglobin concentration, and karyotypes between the patients with and without MIR‐378‐hypomethylation. Distinct distribution of five gene mutations was not observed in the two groups as well. However, MIR‐378‐hypomethylated patients had significantly shorter overall survival than those without MIR‐378 hypomethylation (p =.036). Moreover, among patients <60 years, hypomethylation of MIR‐378 was confirmed to be an independent adverse prognostic factor by both Kaplan–Meier and Multivariate Cox analyses. Conclusion: Hypomethylation of MIR‐378 5'‐flanking region is an adverse prognosticator in MDS, particularly in patients <60 years. [ABSTRACT FROM AUTHOR]