Zi-jun Xu

Hypomethylation-mediated H19 overexpression increases the risk of disease evolution through the association with BCR-ABL transcript in chronic myeloid leukemia†

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.

Efficacy and safety of decitabine in treatment of elderly patients with acute myeloid leukemia: A systematic review and meta-analysis

Elderly patients with acute myeloid leukemia (AML) have limited treatment options concerned about their overall fitness and potential treatment related mortality. Although a number of clinical trials demonstrated benefits of decitabine treatment in elderly AML patients, the results remains controversial. A meta-analysis was performed to evaluate efficacy and safety of decitabine in treatment of elderly AML patients. Eligible studies were identified from PubMed, Web of Science, Embase and Cochrane Library. Nine published studies were included in the meta-analysis, enrolling 718 elderly AML patients. The efficacy outcomes were complete remission (CR), overall response rate (ORR) and overall survival (OS). Safety was evaluated based on treatment related grades 3–4 adverse events (AEs) and early death (ED) rate. Pooled estimates with 95% confidence interval (CI) for CR, ORR and OS were 27% (95% CI 19%–36%), 37% (95% CI 28%–47%) and 8.09 months (95% CI 5.77–10.41), respectively. The estimated treatment related early death (ED) incidences were within 30-days 7% (95% CI 2%–11%) and 60-days 17% (95% CI 11%–22%), respectively. Thrombocytopenia was the most common grades 3–4 AEs. Subgroup analyses of age, cytogenetics risk, AML type and bone marrow blast percentage showed no significant differences of treatment response to decitabine. In conclusion, decitabine is an effective and well-tolerated therapeutic alternative with acceptable side effects in elderly AML patients.

High bone marrow miR-19b level predicts poor prognosis and disease recurrence in de novo acute myeloid leukemia

Oncogenic role of miR-19 family has been identified in human cancers especially in lymphoid malignancies. However, to date, little studies investigated the role of miR-19 family in myeloid malignancies. Herein, we examined miR-19a/b expression and explored its clinical significance in de novo acute myeloid leukemia (AML). The detection of miR-19a/b expression was performed by real-time quantitative PCR in bone marrow mononuclear cells of 113 patients and 42 healthy donors. Both miR-19a/b levels were significantly increased in AML patients in contrast to controls. Patients with miR-19a/b overexpression were more frequently occurred in female, and had an older age. Moreover, cases with miR-19a overexpression had a higher frequency of U2AF1, C-KIT and CEBPA mutations, whereas miR-19b overexpressed cases harbored U2AF1 and IDH1/2 mutations. There was no significant association of miR-19a overexpression with complete remission (CR) rate and overall survival (OS) among whole-cohort AML, non-M3 AML, and cytogenetically normal AML (CN-AML). However, although miR-19b overexpression was not correlated with CR rate, patients with miR-19b overexpression presented significantly shorter OS in whole-cohort AML and a trend in non-M3 AML and CN-AML patients. Importantly, our data also showed that miR-19a/b expression level at CR phase was lower than diagnosis time, and was returned to primary level even higher when at relapse phase. Our findings revealed that miR-19a/b overexpression were frequent events in de novo AML patients. Moreover, up-regulation of miR-19b expression was associated with poor prognosis and disease recurrence in AML.

H19 overexpression promotes leukemogenesis and predicts unfavorable prognosis in acute myeloid leukemia

BackgroundThe long non-coding RNA H19 plays a crucial role in solid tumor initiation and progression. However, the potential role of H19 and its clinical significance in acute myeloid leukemia (AML) remain largely elusive.MethodsH19 expression was detected by qPCR, and clinical significance in AML patients was further analyzed. The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) data for AML were used as validation cohorts. The roles of H19 in cell proliferation and apoptosis were determined by cell proliferation assay and flow cytometry analysis.ResultsH19 expression was significantly increased in AML patients but not associated with embedded miR-675 expression. Moreover, H19 overexpression was not dependent on the methylation pattern in H19 differentially methylated region/imprinting control region. Strong association was observed between H19 overexpression and patients’ characteristics including sex, higher white blood cells, older age, and intermediate karyotype, FLT3-ITD, and DNMT3A mutations. In addition, H19 overexpression correlated with lower complete remission (CR) rate and shorter overall survival, and further confirmed by multivariate analyses. Importantly, the prognostic effect of H19 expression was validated by TCGA and GEO data. In the follow-up of patients, H19 expression in CR phase was lower than diagnosis time and returned at relapse time. Loss-of-function experiments showed that H19 exhibited anti-proliferative and pro-apoptotic effects in leukemic cell HL60. Furthermore, H19 expression was positively correlated with potential downstream gene ID2 in AML.ConclusionsOur findings revealed that methylation-independent H19 was a prognostic and predictive biomarker in AML, and H19/ID2 played crucial roles in leukemogenesis with potential therapeutic target value.

Methylation-associated DOK1 and DOK2 down-regulation: potential biomarkers for predicting adverse prognosis in acute myeloid leukemia†

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 detect DOK1/2 expressions in 125 de novo AML patients and 28 healthy controls. Real‐time quantitative methylation‐specific PCR (RQ‐MSP) and bisulfite sequencing PCR (BSP) were applied to detect DOK1/2 methylation level and density. DOK1/2 expressions were significantly down‐regulated in AML patients. 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 with markedly shorter overall survival and leukemia free survival in both whole‐cohort 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.

High bone marrow ID2 expression predicts poor chemotherapy response and prognosis in acute myeloid leukemia

Dysregulation of ID proteins is a frequent event in various human cancers and has a direct role in cancer initiation, maintenance, progression and drug resistance. Our previous study has revealed ID1 expression and its prognostic value in acute myeloid leukemia (AML). Herein, we further reported ID2 expression and its clinical significance in AML. Real-time quantitative PCR was performed to detect ID2 transcript level in bone marrow mononuclear cells of 145 de novo AML patients. ID2 expression was significantly up-regulated in AML patients compared with controls. ID2 overexpression occurred with the highest frequency in poor karyotype (10/17, 59%), lower in intermediate karyotype (35/83, 42%), and the lowest in favorable karyotype (7/40, 18%). Moreover, high ID2 expression correlated with lower complete remission (CR) rate, shorter overall survival, and acted as an independent prognostic biomarker in whole-cohort AML and non-M3-AML patients. Importantly, the prognostic value of ID2 expression in AML was validated by The Cancer Genome Atlas (TCGA) data. In the follow-up of patients, ID2 expression at CR phase was decreased than at the time of diagnosis, and was increased again at the time of relapse. These findings demonstrated that bone marrow ID2 overexpression was a frequent event in AML patients, and predicts poor chemotherapy response and prognosis.

Hypermethylation of secreted frizzled-related proteins predicts poor prognosis in non-M3 acute myeloid leukemia

Objective Secreted frizzled-related proteins (SFRPs) as Wnt signaling antagonists have been found to be dysregulated by promoter hypermethylation in several cancers including acute myeloid leukemia (AML). This study aimed to investigate the methylated status of SFRPs promoter region and its clinical relevance in Chinese non-M3 AML patients. Methods SFRPs methylation in 139 primary non-M3 AML patients was determined using methylation-specific real-time quantitative polymerase chain reaction. Results The frequency of aberrant methylation was as follows: 30.2% for SFRP1, 27.3% for SFRP2, 5.0% for SFRP4, and 1.4% for SFRP5. Hypermethylation of at least one SFRP gene occurred in 51.8% (72/139) of non-M3 AML patient samples, which was significantly higher compared to normal control (0/21) (P<0.001). Hypermethylation of SFRP1 was potentially associated with N/K-RAS mutations (P=0.043), and the frequency of SFRPs methylation was higher in patients ≥50 years compared to those <50 years, especially for SFRP2 (P<0.05). Furthermore, both whole cohort and cytogenetically normal (CN) patients with high SFRPs-methylated group showed a shorter overall survival (OS) compared to those with low group (P=0.036 and P=0.035, respectively). Moreover, Cox regression multivariate analysis revealed that SFRPs hypermethylation acts as an independent prognostic biomarker among both whole cohort (hazard ratio =1.804, P=0.026) and CN (hazard ratio =2.477, P=0.023) patients. In leukemic cell line HL60 treated with 5-aza-2′-deoxycytidine, the alteration of SFRP1/2 expression inversely correlated with change in SFRP1/2 methylation (r=−0.975, P=0.005 and r=−0.975, P=0.005, respectively). A tendency of negative correlation was observed between SFRP1 expression and its promoter methylation in AML patients (r=−0.334, P=0.038). Conclusion These findings suggested that hypermethylation of SFRP1/2 was a frequent event and silenced SFRP1/2 expression in AML. Moreover, hypermethylation of SFRPs promoter was an adverse risk factor for OS in Chinese non-M3 AML patients.

Efficacy and Safety of Lenalidomide for Treatment of Low-/Intermediate-1-Risk Myelodysplastic Syndromes with or without 5q Deletion: A Systematic Review and Meta-Analysis.

Background Lenalidomide could effectively induce red blood cell (RBC) transfusion independence (TI) in patients with lower-risk (Low/Intermediate-1) myelodysplastic syndrome (MDS) with or without 5q deletion. However whether lenalidomide ultimately improves the overall survival (OS) of lower-risk MDS patients and reduces the progression to AML remains controversial. Method A meta-analysis was conducted to examine the efficacy and safety of lenalidomide in the treatment of lower-risk MDS. Efficacy was assessed according to erythroid hematologic response (HI-E), cytogenetic response (CyR), OS and AML progression. Safety was evaluated based on the occurrence rates of grades 3–4 adverse events (AEs). Results Seventeen studies were included consisting of a total of 2160 patients. The analysis indicated that the overall rate of HI-E was 58% with 95% confidence interval (CI) of 43–74%. The pooled estimates for the rates of CyR, complete CyR, and partial CyR were 44% (95% CI 19–68%), 21% (95% CI 13–30%) and 23% (95% CI 15–32%), respectively. The patients with 5q deletion had significantly higher rate of HI-E and CyR than those without 5q deletion (P = 0.002 and 0.001, respectively). The incidences of grades 3–4 neutropenia, thrombocytopenia, leukopenia, anemia, deep vein thrombosis, diarrhea, fatigue and rash were 51% (95% CI 30–73%), 31% (95% CI 20–42%), 9% (95% CI 5–13%), 7% (95% CI 2–12%), 3% (95% CI 2–5%), 3% (95% CI 1–5%), 2% (95% CI 1–4%) and 2% (95% CI 1–3%), respectively. Lenalidomide significantly improved OS (HR: 0.62, 95% CI 0.47–0.83, P = 0.001) and lowered the risk of AML progression in del(5q) patients (RR: 0.61, 95% CI 0.41–0.91, P = 0.014). Conclusions In spite of the AEs, lenalidomide could be effectively and safely used for the treatment of lower-risk MDS patients with or without 5q deletion.

Lower expression of bone marrow miR-122 is an independent risk factor for overall survival in cytogenetically normal acute myeloid leukemia

BACKGROUND The liver-enriched microRNA-122 (miR-122) plays a crucial role in pathogenesis of hepatocellular carcinoma (HCC) with prognostic value. Recently, miR-122 was also found to be related to many other cancers besides HCC. However, less study determined miR-122 expression and its clinical significance in acute myeloid leukemia (AML). METHODS Real-time quantitative PCR was performed to detect the level of bone marrow (BM) miR-122 in de novo AML patients. The clinical significance of miR-122 expression in AML was further investigated. RESULTS Among whole-cohort AML, lower expression of BM miR-122 was associated with male patients, higher hemoglobin and favorable-karyotypes (P = 0.038, 0.006, and 0.038, respectively). Among cytogenetically normal AML (CN-AML), lower expression of BM miR-122 was correlated with DNMT3A wild type (P = 0.043). Moreover, patients with lower expression of BM miR-122 presented lower complete remission (CR) rate and shorter overall survival (OS) than those with higher expression of BM miR-122 in CN-AML (P = 0.025 and 0.013, respectively). Cox regression analyses further confirmed the prognostic value of BM miR-122 expression in CN-AML (P = 0.024). In follow-up patients, BM miR-122 expression level in CR time was increased compared to diagnosis time, and was returned to primary level when in relapse time again (P = 0.062 and 0.049, respectively). CONCLUSIONS Our findings indicated that lower expression of BM miR-122 acted as an independent risk factor for OS in CN-AML.

SETBP1 mutations in Chinese patients with acute myeloid leukemia and myelodysplastic syndrome

BACKGROUND Somatic mutations in SETBP1 gene have recently been detected in hematologic malignancies. The present study aimed to explore the frequency and clinical correlations of SETBP1 mutations in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). METHODS In this study, we used high-resolution melting analysis (HRMA) to detect the SETBP1 mutations in a cohort of 363 patients with AML or MDS. RESULTS A total of 1.2% (3/249) of AML and 1.8% (2/114) of MDS patients were found with heterozygous SETBP1 mutations. In AML, patients with SETBP1 mutations showed higher hemoglobin (P = 0.004) and were more frequently recurrent in AML-M4 subtype (P = 0.034). All five SETBP1 mutated patients had normal karyotypes. The patients with SETBP1 mutations had significantly higher incidences of concurrent SRSF2 mutations (P = 0.002). HRMA could detect SETBP1 mutations with 5% sensitivity, obviously higher than 25% of Sanger sequencing. CONCLUSIONS We established a rapid, inexpensive, high-throughput and sensitive method to screen SETBP1 mutations. SETBP1 mutations were a rare molecular event in AML and MDS patients.