Digital PCR-based GRHL2 methylation testing in acute myeloid leukemia: diagnosis, prognosis and monitoring.

Background: Acute myeloid leukemia (AML) is a challenging disease with high rates of recurrence. The role of the cancer-related gene GRHL2 in AML has not been widely studied. Methods: Peripheral blood samples were collected from 73 AML patients and 68 healthy controls. Droplet digital PCR was used to detect GRHL2 methylation levels to explore the value of GRHL2 methylation in the diagnosis, treatment response and prognosis of AML. Result: GRHL2 methylation was significantly increased in AML patients (p < 0.01), with high diagnostic accuracy (area under the curve: 0.848; p < 0.001). GRHL2 methylation was correlated with chemotherapy response (p < 0.05) and is an independent prognostic factor for AML (p < 0.05). Conclusion: GRHL2 methylation is expected to serve as a biomarker for diagnosing AML patients and predicting prognosis.

CircRNA CircEHBP1 Regulates the Maturation of MiR-129 to Increase the Chemoresistance of Cancer Cells to Adriamycin in Acute Myeloid Leukaemia.

Background: MicroRNA-129 (miR-129) is known to promote chemosensitivity of many types of cancer cells. However, the role of miR-129 in acute myeloid leukaemia (AML) is unclear. We predicted that premature miR-129 might interact with circEHBP1, a well-characterized oncogene in bladder cancer, and analyzed the interaction between circEHBP1 and miR-129 in AML. Methods: Expression of circEHBP1 and miR-129 in AML patients before and after adriamycin (ADR) treatment was determined by RT-qPCR. CircEHBP1 distribution in nuclear and cytoplasm fractions of AML cells was determined using a cellular fractionation assay. The direct interaction of circEHBP1 with premature miR-129 was explored with an RNA-RNA pull-down assay. Finally, the role of circEHBP1 in regulating miR-129 maturation was analyzed in overexpression cells by RT-qPCRs. Results: Compared to the controls, AML patients exhibited increased circEHBP1 and premature miR-129 levels but decreased mature miR-129 levels. Altered gene expression was more obvious in ADR resistant group than in ADR sensitive group. CircEHBP1 was detected in both nuclear and cytoplasm fractions of AML cells and directly interacted with premature miR-129. CircEHBP1 overexpression increased premature miR-129 level but decreased mature miR-129 level. In AML cells, circEHBP1 suppressed ADR-induced cell apoptosis and attenuated the enhancing effects of miR-129 on cell apoptosis. More importantly, the role of circEHBP1 in regulating cell apoptosis was more obvious in ADR resistance cells. Conclusion: CircEHBP1 may suppress miR-129 maturation to increase the chemoresistance of cancer cells to ADR in AML.

Abnormal GRHL2 Methylation Confers Malignant Progression to Acute Leukemia.

Purpose: Abnormal methylation of Grainyhead-like 2 (GRHL2) is associated with a substantial role in the malignant phenotype of tumor patients. Our present research is aimed at studying the abnormal expression of GRHL2 and the association of methylation in patients with acute leukemia and its relationship with prognosis. Materials and Methods: We used quantitative real-time polymerase chain reaction (qRT-PCR) for detecting the aberrant expression level of GRHL2 in 60 patients with acute leukemia and 60 normal controls. We analyzed the significant correlation between the expression level of GRHL2 with clinicopathological features and patients' prognosis in acute leukemia using the corresponding statistical methods. Secondly, we employed qRT-PCR and Western blotting to detect the mRNA and protein levels of GRHL2 in leukemia cell lines. Next, we used methylation-specific polymerase chain reaction (MSP) technology for detecting the methylation of GRHL2 in clinical samples with acute leukemia and cell lines. Then we investigated the demethylating effect of arsenic trioxide and 5-azacitidine on the mRNA and protein expression levels of GRHL2 in cell lines of acute leukemia. Finally, we studied the effects of arsenide trioxide and 5-azacitidine on the proliferation of leukemia cells and the TGF-ß signaling pathway. Results: We found a lower level of GRHL2 expression not only in acute leukemia patients but also in cell lines when compared with normal controls. At the same time, the expression level of GRHL2 in patients with acute leukemia was significantly correlated with leukocyte count, platelet count, and cytogenetic risk grouping. In addition, the lower GRHL2 expression group showed a significantly lower overall survival rate in acute leukemia patients than that of patients with a higher GRHL2 expression group. Univariate and multivariate analyses revealed that the expression of GRHL2 is an independent risk factor in acute leukemia patients. The methylation level of the GRHL2 promoter region in acute leukemia patients and cell lines was significantly higher than the normal control group, and we found the elevated mRNA and protein levels of GRHL2 in acute leukemia cell lines after the use of the demethylation drug arsenic trioxide and 5-azacitidine. At the same time, arsenide trioxide and 5-azacitidine are associated with the inhibition of cellular proliferation of acute leukemia cells and also promote the elevated expression of TGF-ß signaling pathway-linked proteins, including TGF-ß, Smad2, Smad3, and Smad4. Conclusion: Increased expression and methylation level of GRHL2 are closely associated with the prognosis and malignant phenotype of acute leukemia patients and play an irreplaceable role in the occurrence and development of patients with acute leukemia.

Direct infusion electrospray ionization-ion mobility-mass spectrometry for rapid metabolite marker discovery of medicinal Phellodendron Bark.

Ion-mobility mass spectrometry (IM-MS) currently serves as a powerful tool for the structural identification of numerous biological compounds and small molecules. In this work, rapid metabolomic analysis of closely-related herbal medicines by direct injection ion mobility-quadrupole time-of-flight mass spectrometry (DI-IM-QTOF MS) was established. Phellodendron chinense Bark (PC) and Phellodendron amurense Bark (PA) were studied as a case. Thirty-three batches of PC and twenty-two batches of PA have been directly injected in electrospray ionization-IM-QTOF MS in positive mode. Without chromatographic separation, each run was completed within 3 min. After data alignment and statistical analysis, a total of seven chemical markers were found (p-value < 0.05, VIP > 1.00). Among them, the ion m/z 342.17 and m/z 356.18 present a single peak in the drift spectrum, respectively, but their drift time has a certain deviation compared with the pure substance of known compounds. In addition, the MS/MS spectra also confirmed that the single peak includes two chemical isomers. To investigate the composition ratio of individual isomers, the calibration curves of relative drift time (rDT) based on the standard superposition method were established, which were found to fit the least square regression. The ion [M]+m/z 342.17 was recognized consisting of magnoflorine (MAG) and phellodendrine (PHE), and their composition ratio in PA and PC samples was calculated. The results were compared with those obtained by the HPLC quantitative method, which produced equivalent quantification results. Our DI-IM-QTOF MS methodology provides an additional methodology for the relative quantification of unresolved isomers in drift tube IM-MS and offers DI-IM-QTOF MS based metabolomics.

Dynamic trajectory of platelet counts after the first cycle of induction chemotherapy in AML patients.

BACKGROUND: Platelet counts varied over time after induction chemotherapy. We aimed to investigate the different trajectories of platelet counts after the first cycle of induction chemotherapy in patients newly diagnosed with acute myeloid leukemia. METHODS AND RESULTS: In total, 149 individuals were included in this study. We identified four distinct trajectories using a group-based trajectory model: low- stability group (n = 27, 18.12%), low-level decrease-medium elevation group (n = 42, 28.19%), low-level decrease-high elevation group (n = 60, 40.27%), and high-level decrease-medium elevation group (n = 20, 13.42%). The baseline characteristics of the high-level decrease-medium elevation group included higher platelet count, lower white blood cell count, lower percentage of bone marrow blasts, and lower rates of complete remission after the first cycle of induction chemotherapy. Compared with the low-stability group, the hazard ratios were 0.32 (95% confidence interval, 0.15-0.68) for the low-level decrease-medium elevation group, 0.31 (95% confidence interval, 0.15-0.63) for the low-level decrease-high elevation group, and 0.35 (95% confidence interval, 0.13-0.89) for the high-level decrease-medium elevation group after adjustment for age and gender by Cox proportional hazard regression. Compared with the low-stability group, the hazard ratios were 0.33 (95% confidence interval, 0.14-0.77) for the low-level decrease-medium elevation group and 0.31 (95% confidence interval, 0.14-0.67) for the low-level decrease-high elevation group after adjustment for age, gender, white blood cell count, and bone marrow blasts. These associations persisted after adjusting for age, gender, white blood cell count, bone marrow blasts, and platelet count. CONCLUSION: The dynamic trajectory of platelet counts after the first cycle of induction chemotherapy is a significant predictor of all-cause mortality in patients with acute myeloid leukemia. Timely intervention should be considered for the low-stability group. The low-level decrease-medium elevation and low-level decrease-high elevation groups were independent protective factors for all-cause mortality.

MiR-140 Targets lncRNA DNAJC3-AS1 to Suppress Cell Proliferation in Acute Myeloid Leukemia.

OBJECTIVES: MiR-140 and DNAJC3-AS1 have been demonstrated to play critical roles in cancer biology, while their participation in acute myeloid leukemia (AML) is unclear. This study aimed to explore the role of miR-140 and DNAJC3-AS1 in AML. METHODS: The expression of DNAJC3-AS1 and miR-140 were detected by RT-qPCR. Then, the role of DNAJC3-AS1 and miR-140 in regulating each other was explored by overexpression assay. Next, the direct interaction between DNAJC3-AS1 and miR-140 was analyzed using an RNA pull-down assay. Next, the subcellular location of DNAJC3-AS1 was explored using cellular, subcellular fractionation assay. Finally, cell proliferation analysis was evaluated with BrdU assay. RESULTS: Increased expression levels of DNAJC3-AS1 and decreased expression levels of miR-140 were observed in AML patients. DNAJC3-AS1 was detected in nuclear and cytoplasm samples and direct interaction between DNAJC3-AS1 and miR-140 was observed. DISCUSSION: Reduced expression levels of DNAJC3-AS1 were observed after overexpression of miR-140 in AML cells. DNAJC3-AS1 increased cell proliferation and inhibited the role of miR-140 in suppressing cell proliferation. CONCLUSION: In conclusion, miR-140 may target DNAJC3-AS1 to suppress cell proliferation in AML.

Detection of Imatinib Based on Electrochemical Sensor Constructed Using Biosynthesized Graphene-Silver Nanocomposite.

The establishment of a monitoring technique for imatinib is necessary in clinical and environmental toxicology. Leaf extracts of Lycoris longituba were used as reducing agent for the one-step synthesis of reduced graphene oxide-Ag nanocomposites. This nanocomposite was characterized by TEM, FTIR, XRD, and other instruments. Then, the graphene/Ag nanocomposite was used as a modifier to be cemented on the surface of the glassy carbon electrode. This electrode exhibited excellent electrochemical sensing performance. Under the optimal conditions, the proposed electrode could detect imatinib at 10 nM-0.28 mM with a low limit of detection. This electrochemical sensor also has excellent anti-interference performance and reproducibility.

CircRNA circ_POLA2 is Upregulated in Acute Myeloid Leukemia (AML) and Promotes Cell Proliferation by Suppressing the Production of Mature miR-34a.

PURPOSE: CircRNA circ_POLA2 has been reported as an oncogene in lung cancer, while its role in other malignancies is unknown. This study aimed to explore the role of circ_POLA2 in acute myeloid leukemia (AML). METHODS: The expression levels of circ_POLA2, mature miR-34a and miR-34a precursor in bone marrow mononuclear cells (BMMNCs) from AML patients (n = 50) and healthy controls (n = 50) were determined by RT-qPCR. Correlations among them were analyzed by Pearson's correlation coefficient. Overexpression of circ_POLA2 was achieved in AML cell lines, followed by the measurement of the expression levels of mature miR-34a and miR-34a precursor. The role of circ_POLA2 and miR-34a in regulating AML cell proliferation was assessed by CCK-8 assay. RESULTS: Circ_POLA2 was upregulated in AML and inversely correlated with mature miR-34a, but not miR-34a precursor. In AML cells, overexpression of circ_POLA2 decreased the expression levels of mature miR-34a, but not miR-34a precursor. Cell proliferation analysis showed that the overexpression of miR-34a attenuated the effects of overexpression of circ_POLA2 on cell proliferation. CONCLUSION: Circ_POLA2 is upregulated in AML and promotes cell proliferation by suppressing the production of mature miR-34a.

Arsenic trioxide increases expression of secreted frizzled-related protein 1 gene and inhibits the WNT/ß-catenin signaling pathway in Jurkat cells.

The aim of the present study was to investigate the demethylation effect of arsenic trioxide (As2O3) on the secreted frizzled-related protein 1 (SFRP1) gene and its ability to inhibit the Wingless-type MMTV integration site family (WNT) pathway in Jurkat cells. Methylation-specific polymerase chain reaction was used to examine the CpG island methylation status of the SFRP1 gene in leukemia cell lines. In addition, the effects on Jurkat cells of treatment with different concentrations of As2O3 for 48 h were investigated. Reverse transcription-quantitative polymerase chain reaction was employed to measure the expression of mRNAs, while western blot analysis was used to examine protein expression in cells. The SFRP1 gene was methylated in Jurkat cells. However, both methylated and unmethylated SFRP1 genes were detected in HL60 and K562 cells. In normal bone marrow mononuclear cells, the SFRP1 gene was unmethylated. Following treatment with As2O3 for 48 h, the SFRP1 gene was demethylated, and the mRNA and protein expression levels of the SFRP1 gene were increased. By contrast, the mRNA and protein expression levels of ß-catenin and cyclin Dl were downregulated. The protein expression of c-myc was also downregulated, but As2O3 exhibited no significant effect on the mRNA expression of c-myc. Abnormal methylation of the SFRP1 gene was detected in Jurkat cells. These results suggest that As2O3 activates SFRP1 gene expression at the mRNA and protein levels in Jurkat cells by demethylation of the SFRP1 gene. Furthermore, they indicate that As2O3 regulates WNT target genes and controls the growth of Jurkat cells through the WNT/ß-catenin signaling pathway.

Gene essentiality prediction based on fractal features and machine learning.

Essential genes are required for the viability of an organism. Accurate and rapid identification of new essential genes is of substantial theoretical interest to synthetic biology and has practical applications in biomedicine. Fractals provide facilitated access to genetic structure analysis on a different scale. In this study, machine learning-based methods using solely fractal features are presented and the problem of predicting essential genes in bacterial genomes is evaluated. Six fractal features were investigated to learn the parameters of five supervised classification methods for the binary classification task. The optimal parameters of these classifiers are determined via grid-based searching technique. All the currently available identified genes from the database of essential genes were utilized to build the classifiers. The fractal features were proven to be more robust and powerful in the prediction performance. In a statistical sense, the ELM method shows superiority in predicting the essential genes. Non-parameter tests of the average AUC and ACC showed that the fractal feature is much better than other five compared features sets. Our approach is promising and convenient to identify new bacterial essential genes.

A multicenter randomized open-label study of rituximab plus rhTPO vs rituximab in corticosteroid-resistant or relapsed ITP.

This study aimed to compare the efficacy and safety of rituximab (RTX) plus recombinant human thrombopoietin (rhTPO) with RTX alone in patients with immune thrombocytopenia (ITP) who had failed to respond to corticosteroids or relapsed. Recruited patients were randomized at a ratio of 2:1 into 2 groups: the combination group (RTX + rhTPO, n = 77) and the monotherapy group (RTX, n = 38). Overall response was achieved in 79.2% of patients in the combination group vs 71.1% in the monotherapy group (P = .36), and the complete response (CR) rate was 45.4% in the combination group compared with 23.7% in the monotherapy group (P = .026). The combination group had significantly shorter time to response (TTR; median and range, 7 and 4-28 days) compared with the monotherapy group (28 and 4-90 days) (P < .01). There was no difference between these 2 groups in terms of the long-term response (P = .12). Our findings demonstrated that the combination of RTX and rhTPO significantly increased the CR rate and shortened TTR compared with RTX monotherapy in the treatment of corticosteroid-resistant or relapsed ITP but failed to show a beneficial effect on the long-lasting response. This study is registered at www.clinicaltrials.gov as #NCT01525836.

Arsenic trioxide inhibits DNA methyltransferase and restores TMS1 gene expression in K562 cells.

BACKGROUND: Gene silencing associated with aberrant methylation of promoter region CpG islands is an acquired epigenetic alteration that serves as an alternative to genetic defects in the inactivation of tumor suppressor genes in human cancers. The demethylating, dose-dependent effect of arsenic trioxide (As2O3) on several tumor-related genes has already been postulated. However, whether such a demethylating effect also applies to the TMS1 gene in chronic myeloid leukemia cell line K562 cells has not been studied so far. The aim of the present study was to detect the methylation status of the TMS1 gene in K562 cells and the demethylation effect of As2O3 on TMS1 as well as TMS1 apoptosis-associated protein Bcl-2/Bax and DNA methyltransferase (DNMT) expression. METHODS: TMS1 mRNA expression in K562 cells and normal bone marrow was determined by reverse transcription (RT) polymerase chain reaction (PCR), and the DNA methylation status of the TMS1 promoter in K562 cells treated with different concentrations of As2O3 for 48 h was determined by methylation-specific PCR. RT-PCR and Western blot were used to detect TMS1 and DNMT expression. We also assessed TMS1-associated apoptosis protein Bcl-2/Bax expression by Western blot and apoptosis rates by flow cytometry using annexin V/propidium iodide double staining. RESULTS: In K562 cells, TMS1 was completely methylated and both TMS1 mRNA and protein showed a low expression, but 2 µmol/l As2O3 could significantly restore the expression of the TMS1 gene both at mRNA and protein level (p < 0.01) by fully reversing DNA methylation. As2O3 decreased mRNA and protein expression of DNMT1 (p < 0.05) in a dose-dependent manner. Flow cytometry showed that in the experimental group (2 µmol/l As2O3), cell apoptosis was significantly increased compared with the control group (no As2O3; p < 0.05). In the experimental group, Western blot showed that the expression of the anti-apoptotic protein Bcl-2 was significantly decreased; however, the proapoptotic protein Bax was markedly increased and the Bcl-2/Bax ratio was markedly reduced (p < 0.01). CONCLUSIONS: As2O3 could restore the expression of TMS1 by inhibiting DNMT to reverse the hypermethylation and induced apoptosis of K562 cells by downregulation of Bcl-2/Bax expression.

Essential thrombocytosis accompanied by coagulation factor XII deficiency: a case report.

Essential thrombocytosis (ET) is a type of myeloproliferative neoplasm with clinical manifestations of thrombosis and hemorrhage, the mechanisms of which remains unclear. Some researches indicated that ET is mainly related to the defect of platelet function and the abnormality of coagulation mechanism. A few reports showed that ET accompanied by acquired hemophilia. However, no evidence of ET with coagulation factor XII deficiency has been published. we here report a case of ET accompanied with coagulation factor XII deficiency, which had clinically significant bleeding tendency.

[Effects of arsenic trioxide on the methylation of TMS1 gene in K562 cells].

OBJECTIVE: To detect the methylation status of TMS1 gene and its demethylation by arsenic trioxide (As2O3) in K562 cells. METHODS: K562 cells were treated with different concentrations of As2O3 for 48 hours. Methylation-specific PCR (MSP) was used to determine the methylation status of TMS1. RT-PCR and Western blot were used to detect the levels of TMS1 mRNA and protein. TMS1 associated apoptosis proteins Bcl-2/Bax were also analyzed by Western blot. Apoptosis were evaluated by flow cytometry using Annexin V/propium iodide (PI) double staining. RESULTS: TMS1 gene was completely methylated in K562 cells and the levels of TMS1 mRNA and protein were low (0.01±0.01, 0.09±0.02), which could be reversed (mRNA: 0.72±0.04; protein: 1.30±0.06; P<0.01) by 2 µmol/L As2O3 via overt demethylation of TMS1 gene. Apoptosis in experiment group (12.24±1.06) was significantly higher than that in control group (2.05±0.16, P<0.05). In experiment group, the down-expression of antiapoptotic protein Bcl-2 and up-expression of pro-apoptotic protein Bax led to an obvious decline ratio of Bcl-2/Bax (0.56±0.12), as compared to the control group (1.94±0.14, P<0.01). CONCLUSION: As2O3 could up-regulate TMS1 gene expression by reversing its hypermethylation and induced apoptosis by down-regulation of Bcl-2/Bax ratio in K562 cells.

[Study of WIF-1 promoter methylation with expressions of ß-catenin in acute leukemia].

OBJECTIVE: To explore the significance of WIF-1 gene promoter methylation and the expression of ß-catenin in acute leukemia (AL) patients. METHODS: The method of methylation specific polymerase chain reaction was employed to detect the status of WIF-1 gene methylation in 55 acute leukemia patients and normal controls from January 2009 to June 2010 in our hospital. The expression of ß-catenin was measured by flow cytometry. RESULTS: The methylation of WIF-1 gene promoter was found in 32.7% (18/55) AL patients. And the percentage was significantly higher than that of the controls (0). The patients with the methylation of WIF-1 gene had a lower complete remission rate (38.9%, 7/18) for the first chemotherapy than those without (81.1%, 30/37) (P < 0.05). The expressions of ß-catenin in methylation AL patients and those with non-methylation were 17.5% ± 3.3% and 15.4% ± 3.6% respectively. And they were significantly higher than the controls (10.5% ± 1.5%, P < 0.05). The expression of ß-catenin was higher in positive methylation patients than those negative ones (P < 0.05). CONCLUSION: The methylation of WIF-1 gene promoter and ß-catenin may be involved in the abnormal activation of Wnt/ß-catenin signal in acute leukemia.

[A preliminary study on the implication of Apaf-1 promoter methylation and the expression of apoptosis inhibitor protein Apollon in adult acute leukemia].

OBJECTIVE: To investigate the role of Apaf-1 gene promoter methylation and apoptosis inhibitor protein Apollon in pathogenesis of acute leukemia (AL) and their clinical significance. METHODS: Methylation specific PCR (MSP) was used to detect the methylation status of Apaf-1 gene promoter in 53 AL patients (28 AML, 10 ALL and 15 relapsed) and 10 healthy or nonmalignant blood diseases patients as control. RT-PCR was used to detect the expression levels of Apaf-1 mRNA and immunocytochemistry to detect the expression levels of Apollon protein. RESULTS: The abnromal methylation of Apaf-1 gene promotor in AL was 18/53(33.9%). No Apaf-1 mRNA was detected in methylation positive patients. Only one case in healthy and nonmalignant individuals was deletion of Apaf-1 mRNA expression without abnormal methylation. The positive methylation rate in AL bone marrow mononuclear cells was significantly higher than that in controls (P < 0.05). The expressin levels of Apollon protein in AL patients was higher than that in control (P < 0.05). The positive methylation ratio and Apollon protein level were higher in white blood cell count > 10 × 10(9)/L than in ≤ 10 × 10(9)/L (P < 0.05). There is a positive correlaiton between positive methylation ratio and Apollon protein expression in AL patients. CONCLUSION: Abnormal methylation of Apaf-1 gene promotor and high expression of Apollon might involved in leukemogenesis.