Establishment and molecular characterization of decitabine-resistant K562 cells.

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.

Circular RNA of vimentin expression as a valuable predictor for acute myeloid leukemia development and prognosis.

The focus of this study was to investigate the expression status of Circ-vimentin (VIM) and further analyze its pathogenesis and clinical significance in acute myeloid leukemia (AML) patients. Real-time quantitative polymerase chain reaction was carried on Circ-VIM in 113 AML patients and 42 healthy controls. Circ-VIM was significantly upregulated in AML compared with control and was positively correlated with white blood cells (WBC) count. Receiver operating characteristic curve analysis indicated that the performance of Circ-VIM expression could serve as a promising biomarker for differentiating AML patients from controls. Significant correlations of Circ-VIM expression were found with WBC and French-American-British classifications. Survival analyses further showed that over-expressed Circ-VIM were associated with markedly shorter overall survival (OS) and leukemia-free survival (LFS) in whole-cohort AML, nonacute promyelocytic leukemia AML and cytogenetically normal-AML patients. Multivariate analysis also disclosed that Circ-VIM over-expression was an independent poor prognostic factor for OS and LFS in AML patients. Remarkably, Pearson correlation analysis evidenced that the expression of Circ-VIM was positively correlated with VIM expression in all AML patients. These results indicated that overexpression Circ-VIM could serve as a significant biomarker.

Hypermethylation of ITGBL1 is associated with poor prognosis in acute myeloid leukemia.

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.

Reduced protocadherin17 expression in leukemia stem cells: the clinical and biological effect in acute myeloid leukemia.

BACKGROUND: Leukemia stem cell (LSC)-enriched genes have been shown to be highly prognostic in acute myeloid leukemia (AML). However, the prognostic value of tumor suppressor genes (TSGs) that are repressed early in LSC remains largely unknown. METHODS: We compared the public available expression/methylation profiling data of LSCs with that of hematopoietic stem cells (HSCs), in order to identify potential tumor suppressor genes in LSC. The prognostic relevance of PCDH17 was analyzed on a cohort of 173 AML patients from The Cancer Genome Atlas (TCGA), and further validated in three independent cohorts (n = 339). RESULTS: We identified protocadherin17 (PCDH17) and demonstrated that it was significantly down-regulated and hypermethylated in LSCs compared with HSCs. Our analyses of primary AML patient samples also confirmed these deregulations. Clinically, low PCDH17 expression was associated with female sex (P = 0.01), higher WBC (P < 0.0001), higher percentages of blasts in bone marrow (BM) and peripheral blood (PB) (P = 0.04 and < 0.001, respectively), presence of FLT3-internal tandem duplications (P = 0.002), mutated NPM1 (P = 0.02), and wild-type TP53 (P = 0.005). Moreover, low PCDH17 expression predicted worse overall survival (OS) in four independent cohorts as well as in the molecularly defined subgroups of AML patients. In multivariable analyses, low PCDH17 expression retained independent prognostic value for OS. Biologically, PCDH17 expression-associated gene signatures were characterized by deregulations of EMT- and Wnt pathway-related genes. CONCLUSIONS: PCDH17 gene was silenced by DNA methylation in AML. Low PCDH17 expression is associated with distinct clinical and biological features and improves risk stratification in patients with AML.

Circ-Foxo3 is positively associated with the Foxo3 gene and leads to better prognosis of acute myeloid leukemia patients.

BACKGROUND: The Foxo3 gene, belonging to the forkhead family, is one of the classes of transcription factors characterized by a forkhead DNA-binding domain, which usually considered being a cancer suppressor gene. Circ-Foxo3 is a circular structure which connects the 3'end to the 5'end. Scholars detected that circ-Foxo3 could compete with Foxo3 for binding to some miRNAs. METHODS: In this study, we will test the expression of Foxo3 and circ-Foxo3 in de novo acute myeloid leukemia (AML) patients to explore the relationship between Foxo3 gene and circ-Foxo3. All the de novo AML samples and normal control samples was measured by real-time quantitative PCR. A receiver operating characteristic curve was conducted to differentiate AML patients from control people. Association of Foxo3 expression and overall survival was conducted by Kaplan-Meier survival analysis. RESULTS: We found that the expression of Foxo3 gene in de novo patients was significantly lower than control samples (P = 0.009). Meanwhile, circ-Foxo3 also expressed lower in de novo AML patients than in control samples (P = 0.040). In different classifications, this trend could be observed more remarkably. In non-M3 patients, the Foxo3 high patients' survival time was longer than Foxo3 low patients (P = 0.002). Besides, in non-favorable risk groups, patients with low expression of Foxo3 had longer survival time than Foxo3 high patients (P = 0.004). Furthermore, in normal Karyotypic patients, the overall survival time of patients with high-expressed Foxo3 was significantly longer than those with low expression (P = 0.034). Besides, Pearson analysis was also conducted between these two genes in AML patients. Results revealed that they were positively correlated (R = 0.63, P < 0.001). CONCLUSION: In conclusion, we found that low expression of circ-Foxo3 and Foxo3 were frequent in AML patients, and patients with high expression of Foxo3 often had a trend of better prognosis.

The Octamer-Binding Transcription Factor 4 (OCT4) Pseudogene, POU Domain Class 5 Transcription Factor 1B (POU5F1B), is Upregulated in Cervical Cancer and Down-Regulation Inhibits Cell Proliferation and Migration and Induces Apoptosis in Cervical Cancer Cell Lines.

BACKGROUND The POU domain class 5 transcription factor 1B (POU5F1B), is a pseudogene that is homologous to octamer-binding transcription factor 4 (OCT4), and is located adjacent to the MYC gene on human chromosome 8q24. POU5F1B has been reported to be transcribed in several types of cancer, but its role in cervical cancer remains unclear. This study aimed to investigate the expression and function of POU5F1B in tissue samples of human cervical cancer and in cervical cancer cell lines in vitro. MATERIAL AND METHODS Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to quantify POU5F1B expression in cervical cancer tissues and in SiHa, HeLa, CaSki, and C33A human cervical cancer cell lines. Functional in vitro studies included analysis of the effects of POU5F1B expression on cervical cancer cell proliferation, migration, and apoptosis using a Cell Counting Kit-8 (CCK-8) assay, cell migration assays, and flow cytometry. Luciferase activity assays, qRT-PCR, and Western blot were performed to confirm the expression of POU5F1B. RESULTS POU5F1B was significantly upregulated in cervical cancer tissues and cell lines. Interference with the expression of POU5F1B significantly inhibited cell proliferation, apoptosis, migration and invasion, and induced apoptosis in vitro. Western blot demonstrated that POU5F1B could modulate the expression of the OCT4 protein. CONCLUSIONS POU5F1B was upregulated in cervical cancer and down-regulation inhibited cell proliferation and migration and induced apoptosis in cervical cancer cell lines by modulating OCT4. Further studies are required to determine whether POU5F1B might be a diagnostic or prognostic biomarker or therapeutic target in cervical cancer.

Low Expression of Pseudogene POU5F1B Affects Diagnosis and Prognosis in Acute Myeloid Leukemia (AML).

BACKGROUND The transcription factor Oct-4 is necessary for maintaining pluripotency and self-renewal of embryonic stem cells, and POU5F1B is a processed pseudogene of Oct-4 with coding capacity. The purpose of this study is to evaluate the expression and clinical implication of POU5F1B in AML. MATERIAL AND METHODS The expression of the POU5F1B transcript was evaluated in 175 newly diagnosed AML patients and 39 healthy controls by use of real-time quantitative PCR (RQ-PCR). RESULTS POU5F1B was underexpressed in AML compared with controls (P<0.001). The receiver operating characteristic (ROC) curve revealed that the POU5F1B transcript level was able to differentiate AML patients from healthy individuals (AUC=0.682). In non-APL AML patients, the POU5F1Blow group had significantly higher WBC than the POU5F1Bhigh group (20.2×109 vs. 4.6×109 L⁻¹, P=0.021). Among whole-cohort AML, non-APL AML, and intermediate-risk AML, POU5F1Bhigh patients had obviously higher complete remission (CR) rates than POU5F1Blow patients (P=0.012, P=0.012 and P=0.027). In addition, Kaplan-Meier analysis demonstrated better overall survival (OS, P=0.019, P=0.007 and P=0.046, respectively) in POU5F1Bhigh patients compared with POU5F1Blow patients. Furthermore, in multivariate survival analysis, POU5F1B was independently associated with OS in non-APL AML patients and intermediate-risk AML as a favorable prognostic factor. CONCLUSIONS POU5F1B was frequently underexpressed in AML, and might contribute to the diagnosis and prognosis of AML.

Overexpression of miR-216b: Prognostic and predictive value in acute myeloid leukemia.

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 high BM 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.

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.

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.

Decreased SCIN expression, associated with promoter methylation, is a valuable predictor for prognosis in acute myeloid leukemia.

The present study was aimed to investigate SCIN expression as well as promoter methylation and further explore their clinical relevance in acute myeloid leukemia (AML) patients. Real-time quantitative PCR was carried out to detect the expression level of SCIN in 119 AML patients and 37 healthy controls. Real-time quantitative methylation-specific PCR and bisulfite sequencing PCR were carried out to detect SCIN promoter methylation levels in 103 AML patients and 29 controls. As compared with controls, the level of SCIN transcript was significantly down-regulated in AML patients (P = 0.001), and the level of methylated SCIN promoter was significantly higher in AML patients (P = 0.001). Moreover, the level of promoter methylation was weakly negatively correlated with SCIN expression in AML patients (R = -0.265, P = 0.027). Demethylation of SCIN promoter by 5-aza-2'-deoxycytidine could restore its expression in leukemic cell line THP1. The age of SCINlow patients was significantly higher and C/EBPA mutation was significantly less than SCINhigh patients (P = 0.039 and 0.038, respectively). Moreover, the rate of complete remission (CR) of SCINlow patients was significantly lower than SCINhigh patients (P = 0.009). Kaplan-Meier analysis showed that low SCIN expression was associated with shorter overall survival (P = 0.036). Cox regression analysis demonstrated low SCIN expression was an independent poor prognostic factor (P = 0.047). Furthermore, SCIN expression was restored in those patients who achieved CR after induction therapy (P = 0.003). These findings indicate that decreased SCIN expression associated with its promoter methylation is a valuable biomarker for predicting adverse prognosis in AML patients.

Low Expression of FUS1 Is Negatively Correlated with miR-378 and May Predict Adverse Prognoses in Acute Myeloid Leukemia.

FUS1 is a tumor suppressor gene that has been found to be frequently lost in a variety of solid tumors. In this study, we aimed to investigate the expression status of the FUS1 gene in acute myeloid leukemia (AML), as well as its clinical significance. We further explored the correlation between the expression of FUS1 and miR-378 in AML. We detected expression of the FUS1 transcript in bone marrow mononuclear cells from 23 controls and 158 newly diagnosed AML patients by real-time quantitative polymerase chain reaction. Downregulated FUS1 expression was found in 139 out of 158 (87.97%) AML cases; this rate was significantly lower than that in all 23 controls (p = 0.012). Receiver operating characteristic curve analysis revealed that the FUS1 transcript level could discriminate AML patients from controls effectively (area under the ROC curve = 0.663). Kaplan-Meier analysis demonstrated that non-M3-AML patients with a low FUS1 expression had a shorter overall survival (p = 0.049) and leukemia-free survival (p = 0.051) than those with a high FUS1 expression. Furthermore, we studied the correlation between the expression of FUS1 and miR-378 in 53 newly diagnosed AML patients. We found that the correlation coefficient was -0.346, which showed that FUS1 and miR-378 were negatively correlated in AML patients (p = 0.011). These results indicate that the low expression of FUS1 is a common molecular event in AML.

CDH1 (E-cadherin) expression independently affects clinical outcome in acute myeloid leukemia with normal cytogenetics.

BACKGROUND: Epithelial-mesenchymal transition (EMT) is a critical process which involves in tumor metastasis. As an important EMT marker gene, CDH1 (E-cadherin) expression and its clinical implication in acute myeloid leukemia (AML) remain largely elusive. METHODS: Real-time quantitative PCR (RQ-PCR) was carried out to examine CDH1 transcript level in 123 de novo AML patients and 34 controls. RESULTS: Compared with controls, CDH1 was significantly downregulated in AML (p<0.001). The median level of CDH1 expression divided total AML patients into CDH1 low-expressed (CDH11ow) and CDH1 high-expressed (CDH1high) groups. There were no significant differences between the two groups in age, peripheral blood cell counts, complete remission (CR) rate, and the distribution of FAB/WHO subtypes as well as karyotypes/karyotypic classifications (p>0.05). However, CDH11ow group tended to have a higher bone marrow (BM) blasts (p=0.093). The spearman correlation analysis further illustrated a trend towards a negative correlation between CDH1 expression level and BM blasts (r=-0.214, p=0.052). CDH1low group had a tendency towards a lower frequency of N/K-RAS mutations (p=0.094). Furthermore, CDH1low patients had markedly shorter overall survival (OS) time in cytogenetic normal AML (CN-AML) (p=0.019). Both univariate and multivariate analyses confirmed the prognostic value of CDH1 expression in CN-AML patients (p=0.027 and 0.033, respectively). CONCLUSIONS: CDH1 downregulation acted as an independent prognostic biomarker in CN-AML patients.

Let-7a-3 hypomethylation is associated with favorable/intermediate karyotypes but not with survival in acute myeloid leukemia.

Aberrant methylation of let-7a-3 promoter has been observed in various malignancies. However, the clinical relevance of let-7a-3 methylation remains poorly known in acute myeloid leukemia (AML). This study was to investigate the let-7a-3 methylation status and to explore its clinical significance in AML. let-7a-3 promoter was significantly hypomethylated in AML patients compared to controls (median 4.51 vs 0.49) (P = 0.0003). Receiver operating characteristic curve (ROC) analysis discriminated all patients or cytogenetically normal patients from controls with an areas under the ROC curve (AUC) of 0.737 or 0.783, respectively (P < 0.001). Patients with favorable/intermediate karyotypes had significantly higher let-7a-3 unmethylation than controls. Patients with DNMT3A mutations had a trend of high level of let-7a-3 unmethylation than did those with wild-type DNMT3A (median 6.76 vs 3.66, P = 0.096). There was no significant difference in overall survival between patients with and without hypomethylated let-7a-3 (median 12 vs 5 months, P = 0.103). No correlation was observed between the level of let-7a-3 expression and let-7a-3 unmethylation in AML samples (R = 0.197, P = 0.150). However, the level of let-7a-3 expression was increased in a dose-dependent manner in THP-1 line treated with 5-aza-dC, while the methylation density of let-7a-3 promoter decreased with 5-aza-dC dose. Our findings suggest that let-7a-3 hypomethylation is associated with favorable and intermediate karyotypes but not a prognostic predictor for AML patients. Let-7a-3 expression may be partially regulated by promoter methylation.

Reduced miR-215 expression predicts poor prognosis in patients with acute myeloid leukemia.

OBJECTIVE: Abnormal expression of microRNA-215 has been identified in a variety of solid cancers. However, little is known about the expression pattern of microRNA-215 in acute myeloid leukemia. This study was to investigate the status of microRNA-215 expression and further analyze its clinical significance in acute myeloid leukemia. METHODS: Real-time quantitative polymerase chain reaction assay was performed to evaluate the expression level of microRNA-215 in 113 patients with acute myeloid leukemia. Besides, the relationship between microRNA-215 levels and clinical and pathological factors was explored. RESULTS: Compared with the healthy individuals, microRNA-215 expression in acute myeloid leukemia patients was significantly down-regulated (P= 0.001). MicroRNA-215 low-expressed patients had higher white blood cells than microRNA-215 high-expressed patients (P= 0.014). The incidence of FLT3/ITD mutation in the patients with low microRNA-215 expression was significantly higher than those with high microRNA-215 expression (P= 0.025). MicroRNA-215 low-expressed patients had significantly shorter overall survival than microRNA-215 high-expressed patients in both non-M3 acute myeloid leukemia patients and cytogenetically normal patients (P= 0.017 and P= 0.044, respectively). Meanwhile, multivariate analysis confirmed the adverse prognostic value of microRNA-215 expression in acute myeloid leukemia patients with non-M3 subtypes. CONCLUSIONS: Our study demonstrates that reduced microRNA-215 expression is a common event and is associated with poor clinical outcome in acute myeloid leukemia.

Down-Regulation of miR-186 Correlates with Poor Survival in de novo Acute Myeloid Leukemia.

BACKGROUND: MicroRNA-186 (miR-186) plays an important role in the pathogenesis of several cancers. Our study was intended to investigate the expression status and the prognostic implication of miR-186 in acute myeloid leukemia (AML). METHODS: Real-time quantitative PCR was carried out in 112 de novo AML patients and 28 controls. RESULTS: The level of miR-186 expression in AML was significantly down-regulated compared to normal controls (p < 0.001). Patients with low miR-186 expression presented significantly older age than those with high miR-186 expression (p = 0.004). MiR-186high patients had a significantly higher frequency of CEBPA mutation than miR-186low patients (20% and 4%, respectively, p = 0.022). In addition, miR-186low patients had a significantly lower complete remission (CR) rate (30% vs. 53%, respectively, p = 0.028) than miR-186high patients. Moreover, miR-186low patients showed significantly shorter overall survival (OS) time than miR-186high patients in both whole AML and non-M3 patients (p = 0.023 and 0.026, respectively). Additionally, the adverse prognostic impact of miR-186 down-regulation was also shown in both whole AML and non-M3 patients without CEBPA mutation (p = 0.017 and 0.023, respectively). CONCLUSIONS: Our study suggests that miR-186 down-regulation is a frequent event and predicts poor prognosis in de novo AML patients.

High expression of OCT4 is frequent and may cause undesirable treatment outcomes in patients with acute myeloid leukemia.

In recent years, many researches have shown that OCT4 is overexpressed in both germ cell tumors and somatic cancers. Meanwhile, OCT4 has relationship with poor prognosis in a lot of solid tumors, such as hepatocellular carcinoma, gastric cancer, and esophageal cancer. In our study, we investigated the expression status of OCT4 and its clinical significance in patients with acute myeloid leukemia (AML) using real-time quantitative PCR. The receiver operating characteristic (ROC) curve reveals that the level of OCT4 expression could be available for a potential diagnostic biomarker for differentiating AML from controls with an area under the ROC curve (AUC) of 0.915 (95 % confidence interval (CI) 0.837-0.992; P < 0.001). At the cutoff value of 0.56, the sensitivity and the specificity are 75.9 and 81.2 %, respectively. The amount of white blood cell (WBC) of patients with high OCT4 expression is higher than that of patients with low OCT4 expression (18.2 × 10(9) versus 2.7 × 10(9) L(-1), P = 0.001). Among those patients who are less than 70 years old, patients with OCT4 high expression have significantly shorter overall survival (OS) than those without OCT4 high expression (P = 0.048). These findings suggest that OCT4 high expression is a common event and may have an adverse impact on prognosis in AML.

Aberrant hypermethylation of CTNNA1 gene is associated with higher IPSS risk in patients with myelodysplastic syndrome.

BACKGROUND: CTNNA1 gene is a putative tumor suppressor for its roles in inhibiting proliferation and promoting apoptosis. Aberrant expression of CTNNA1 is regulated by epigenetic mechanisms including both promoter methylation and histone deacetylation in hematopoietic malignancies. However, the clinical relevance of CTNNA1 methylation remains rarely known in myelodysplastic syndrome (MDS). METHODS: We investigated the methylation status of CTNNA1 promoter using methylation-specific PCR (MSP) and analyzed its clinical significance in Chinese MDS patients. RESULTS: Aberrant hypermethylation of CTNNA1 gene was identified in 22% (18/83) of the patients. CTNNA1 expression was significantly correlated with promoter methylation status (p<0.05). No significant differences were observed in the age, sex, and blood parameters between patients with and without CTNNA1 hypermethylation (p>0.05). The frequency of CTNNA1 hypermethylation was significantly higher in patients with isolated del(5q) (3/4, 75%) than those with other abnormal karyotypes (4/23, 17%) and also than those with normal karyotypes (11/54, 20%) (p=0.042 and 0.040, respectively). The patients with higher IPSS risks (Int-2/High) had significantly increased incidence of CTNNA1 methylation than those with lower risks (Low/Int-1) (36% vs. 15%, p=0.049). Although the estimated 50% survival time of the CTNNA1-methylated group [median 13 months, 95% confidence interval (CI) 3-22 months] was shorter than that of CTNNA1-unmethylated group (median 24 months, 95% CI 7-41 months), the difference was not statistically significant (p=0.330). CONCLUSIONS: Our data confirm that aberrant CTNNA1 methylation is a common event and is associated with higher IPSS risk in MDS.

Low SOX17 expression: prognostic significance in de novo acute myeloid leukemia with normal cytogenetics.

BACKGROUND: Aberrant expression of SRY-box containing gene 17 (SOX17) has been observed in several solid tumors. However, little is known about SOX17 expression in acute myeloid leukemia (AML). The purpose of this study was to investigate the alteration of SOX17 expression and to explore its clinical significance in AML. METHODS: Real-time quantitative PCR (RQ-PCR) was performed to analyze the status of SO1X17 expression in 103 patients with de novo AML and 26 normal controls. The clinical relevance of SOX17 expression was analyzed in AML. RESULTS: SOX17 level in AML was significantly down-regulated compared to controls (p<0.001). Receiver operating characteristic curve (ROC) curve analysis revealed that an area under the ROC curve (AUC) of 0.834 (95% CI 0.765-0.903; p<0.0001) or 0.789 (95% CI 0.690-0.888, p<0.001) in discriminating all patients or cytogenetically normal patients from controls, respectively. The cohort of AML patients was divided into two groups according to the cut-off value of 0.017 (60% sensitivity and 100% specificity, respectively). Cytogenetically normal patients with low SOX17 expression had significantly shorter OS than those with high SOX17 expression (median 4 vs. 25 months, respectively, p=0.035). Multivariate analysis confirmed low SOX17 expression as an independent risk factor. CONCLUSIONS: Our findings indicated that low SOX17 level may define an important risk factor in AML with normal cyotgenetics.

Circular RNA BMI1 Serves as a Potential Target for Diagnosis and Treatment in Esophageal Cancer.

AIMS: Previous studies have confirmed that BMI1 is elevated in esophageal cancer, which is a potential therapeutic target for esophageal cancer. However, the clinical significance of circular RNA BMI1 (circ-BMI1) in esophageal cancer is not yet clear. Herein, we revealed the clinical implication of circ-BMI1 in esophageal cancer, and provided a theoretical basis for molecular diagnosis and potential targeted therapy of esophageal cancer. METHODS: Firstly, 10 fresh paired esophageal cancer tissues and paracancer tissues, 49 esophageal cancer serum samples and 28 healthy control serum samples were involved in our study. Differential expression and clinical significance of circ-BMI1 in esophageal cancer patients and healthy controls were evaluated by quantitative Real-time RT-PCR (RT-qPCR). Secondly, effects of circ-BMI1 differential expression on biological function of esophageal cancer cell line Eca109 were analyzed. Effects of circ-BMI1 on cell proliferation, migration and colony forming ability were evaluated by CCK-8, wound healing, and colony-forming assay. Cell apoptosis, drug sensitivity tests were also be conducted. Finally, influence of Eca109 cells differentially expressed by circ-BMI1 on tumorigenicity in nude mice was studied. RESULTS: Expression of circ-BMI1 in serum and tissues of esophageal cancer patients was significantly decreased compared to controls (P < 0.001 and P = 0.003, respectively). Area under the receiver operating characteristic curve (ROC) was 0.726. Cell proliferation, migration and colony forming ability of circBMI1-Eca109 cells were obviously decreased than that of NC-Eca109 cells (P < 0.05). circBMI1-Eca109 cells were more sensitive to 5-fluorouracil and cisplatin, and tumor volume of nude mice in circBMI1-Eca109 group was smaller (P < 0.05). CONCLUSIONS: The study indicated that expression of circ-BMI1 was significantly down-regulated in esophageal cancer. Overexpression of circ-BMI1 inhibited proliferation, migration, colony formation of Eca109 cells, and tumor growth of Eca109 cells in nude mice. circ-BMI1 may be a potential target for diagnosis and treatment in esophageal cancer.