Aging and comprehensive molecular profiling in acute myeloid leukemia.

Acute myeloid leukemia (AML) is an aging-related and heterogeneous hematopoietic malignancy. In this study, a total of 1,474 newly diagnosed AML patients with RNA sequencing data were enrolled, and targeted or whole exome sequencing data were obtained in 94% cases. The correlation of aging-related factors including age and clonal hematopoiesis (CH), gender, and genomic/transcriptomic profiles (gene fusions, genetic mutations, and gene expression networks or pathways) was systematically analyzed. Overall, AML patients aged 60 y and older showed an apparently dismal prognosis. Alongside age, the frequency of gene fusions defined in the World Health Organization classification decreased, while the positive rate of gene mutations, especially CH-related ones, increased. Additionally, the number of genetic mutations was higher in gene fusion-negative (GF-) patients than those with GF. Based on the status of CH- and myelodysplastic syndromes (MDS)-related mutations, three mutant subgroups were identified among the GF- AML cohort, namely, CH-AML, CH-MDS-AML, and other GF- AML. Notably, CH-MDS-AML demonstrated a predominance of elderly and male cases, cytopenia, and significantly adverse clinical outcomes. Besides, gene expression networks including HOXA/B, platelet factors, and inflammatory responses were most striking features associated with aging and poor prognosis in AML. Our work has thus unraveled the intricate regulatory circuitry of interactions among different age, gender, and molecular groups of AML.

The Ubiquitin-specific Protease USP36 Associates with the Microprocessor Complex and Regulates miRNA Biogenesis by SUMOylating DGCR8.

miRNA biogenesis is a cellular process that produces mature miRNAs from their primary transcripts, pri-miRNAs, via two RNAse III enzyme complexes: the Drosha-DGCR8 microprocessor complex in the nucleus and the Dicer-TRBP complex in the cytoplasm. Emerging evidence suggests that miRNA biogenesis is tightly regulated by posttranscriptional and posttranslational modifications and aberrant miRNA biogenesis is associated with various human diseases including cancer. DGCR8 has been shown to be modified by SUMOylation. Yet, the SUMO ligase mediating DGCR8 SUMOylation is currently unknown. Here, we report that USP36, a nucleolar ubiquitin-specific protease essential for ribosome biogenesis, is a novel regulator of DGCR8. USP36 interacts with the microprocessor complex and promotes DGCR8 SUMOylation, specifically modified by SUMO2. USP36-mediated SUMOylation does not affect the levels of DGCR8 and the formation of the Drosha-DGCR8 complex, but promotes the binding of DGCR8 to pri-miRNAs. Consistently, abolishing DGCR8 SUMOylation significantly attenuates its binding to pri-miRNAs and knockdown of USP36 attenuates pri-miRNA processing, resulting in marked reduction of tested mature miRNAs. Induced expression of a SUMOylation-defective mutant of DGCR8 inhibits cell proliferation. Together, these results suggest that USP36 plays an important role in regulating miRNA biogenesis by SUMOylating DGCR8. Significance: This study identifies that USP36 mediates DGCR8 SUMOylation by SUMO2 and is critical for miRNA biogenesis. As USP36 is frequently overexpressed in various human cancers, our study suggests that deregulated USP36-miRNA biogenesis pathway may contribute to tumorigenesis.

KIF18A knockdown reduces proliferation, migration, invasion and enhances radiosensitivity of esophageal cancer.

Kinesin family member 18A (KIF18A) is significantly overexpressed and is related to the poor prognosis of human cancers. However, the function of KIF18A in esophageal cancer (EC) is still unclear. Human EC cell lines were used in this study. KIF18A expression in human tissues was assessed using Gene Expression Profiling Interactive Analysis 2.0 (GEPIA2). The expressions of KIF18A or IGF2BP3 in EC cells were detected using qRT-PCR or WB. Cells were transfected using si-KIF18A, si-IGF2BP3, and plasmid IGF2BP3. The abilities of proliferation, migration, and invasion were detected by EdU, wound-healing, and transwell assay. The interaction between KIF18A and IGF2BP3 was predicted by starBase v3.0 and studied by RIP and RNA stability assay. Colony formation assay was used to reflect the changes of radiosensitivity in EC cells. KIF18A was upregulated in EC, and KIF18A knockdown inhibited EC cell proliferation, migration, invasion, and radioresistance. The prediction in starBase and RIP assay results showed that KIF18A mRNA could bind to IGF2BP3 protein in EC cells. RNA stability assay was performed to confirm that IGF2BP3 affects mRNA stability of KIF18A. Further studies also showed that IGF2BP3 could positively regulate KIF18A on proliferation, migration, invasion, and radioresistance. Our findings first revealed an oncogenic effect of KIF18A in human EC progression. KIF18A expression was associated with radioresistance of EC cells. The binding relationship between KIF18A and IGF2BP3 might influence the mRNA stability of KIF18A in EC cell lines.

Importance of monitoring arsenic methylation metabolism in acute promyelocytic leukemia patients receiving the treatment of arsenic trioxide.

BACKGROUND: Arsenic trioxide [ATO, inorganic arsenite (iAsIII) in solution] plays an important role in the treatment of acute promyelocytic leukemia (APL). However, the long-term adverse effects (AEs) and the retention of arsenic among APL patients are rarely reported. In this study, we focused on arsenic methylation metabolism and its relationship with chronic hepatic toxicity, as we previously reported, among APL patients who had finished the treatment of ATO. METHODS: A total of 112 de novo APL patients who had completed the ATO-containing treatment were enrolled in the study. Arsenic species [iAsIII, inorganic arsenate (iAsV), and their organic metabolites, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)] in patients' plasma, urine, hair and nails were detected by high-performance liquid chromatography combined with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Eighteen single nucleotide polymorphisms (SNPs) of the arsenic (+ 3 oxidative state) methylation transferase (AS3MT) gene, which was known as the main catalyzer for arsenic methylation, were tested with the polymerase chain reaction method. RESULTS: The study showed the metabolic pattern of arsenic in APL patients undergoing and after the treatment of ATO, in terms of total arsenic (TAs) and four species of arsenic. TAs decreased to normal after 6 months since cessation of ATO. But the arsenic speciation demonstrated significantly higher portion of iAsIII in patient's urine (40.08% vs. 1.94%, P < 0.001), hair (29.25% vs. 13.29%, P = 0.002) and nails (30.21% vs. 13.64%, P = 0.003) than the healthy controls', indicating a decreased capacity of arsenic methylation metabolism after the treatment of ATO. Urine primary methylation index (PMI) was significantly lower in patients with both chronic liver dysfunction (0.14 vs. 0.28, P = 0.047) and hepatic steatosis (0.19 vs. 0.3, P = 0.027), suggesting that insufficient methylation of arsenic might be related to chronic liver disorders. Two SNPs (A9749G and A27215G) of the AS3MT gene were associated with impaired urine secondary methylation index (SMI). CONCLUSIONS: The long-term follow-up of arsenic speciation indicated a decreased arsenic methylation metabolism and a probable relationship with chronic hepatic disorders among APL patients after the cessation of ATO. Urine PMI could be a monitoring index for chronic AEs of ATO, and the SNPs of AS3MT gene should be considered when determining the dosage of ATO.

Arsenic trioxide replacing or reducing chemotherapy in consolidation therapy for acute promyelocytic leukemia (APL2012 trial).

As all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) are widely accepted in treating acute promyelocytic leukemia (APL), deescalating toxicity becomes a research hotspot. Here, we evaluated whether chemotherapy could be replaced or reduced by ATO in APL patients at different risks. After achieving complete remission with ATRA-ATO-based induction therapy, patients were randomized (1:1) into ATO and non-ATO groups for consolidation: ATRA-ATO versus ATRA-anthracycline for low-/intermediate-risk patients, or ATRA-ATO-anthracycline versus ATRA-anthracycline-cytarabine for high-risk patients. The primary end point was to assess disease-free survival (DFS) at 3 y by a noninferiority margin of -5%; 855 patients were enrolled with a median follow-up of 54.9 mo, and 658 of 755 patients could be evaluated at 3 y. In the ATO group, 96.1% (319/332) achieved 3-y DFS, compared to 92.6% (302/326) in the non-ATO group. The difference was 3.45% (95% CI -0.07 to 6.97), confirming noninferiority (P < 0.001). Using the Kaplan-Meier method, the estimated 7-y DFS was 95.7% (95% CI 93.6 to 97.9) in ATO and 92.6% (95% CI 89.8 to 95.4) in non-ATO groups (P = 0.066). Concerning secondary end points, the 7-y cumulative incidence of relapse (CIR) was significantly lower in ATO (2.2% [95% CI 1.1 to 4.2]) than in non-ATO group (6.1% [95% CI 3.9 to 9.5], P = 0.011). In addition, grade 3 to 4 hematological toxicities were significantly reduced in the ATO group during consolidation. Hence, ATRA-ATO in both chemotherapy-replacing and -reducing settings in consolidation is not inferior to ATRA-chemotherapy (https://www.clinicaltrials.gov/, NCT01987297).

Predictive value of serum cystatin C for risk of mortality in severe and critically ill patients with COVID-19.

BACKGROUND: The outbreak of coronavirus disease 2019 (COVID-19) has rapidly evolved into a global pandemic. COVID-19 is clinically categorized into mild, moderate, severe, and critical illness. Acute kidney injury is an independent risk factor for poor prognosis in patients with. Serum cystatin C (sCys C) is considered a more sensitive biomarker for early renal insufficiency than conventional indicators of renal function. Early detection of risk factors that affect the prognosis of severe and critically ill patients while using active and effective treatment measures is very important and can effectively reduce the potential mortality rate. AIM: To determine the predictive value of sCys C for the prognosis of patients with COVID-19. METHODS: The clinical data of 101 severe and critically ill patients with COVID-19 at a designated hospital in Wuhan, Hubei Province, China were analyzed retrospectively. According to the clinical outcome, the patients were divided into a discharge group (64 cases) and a death group (37 cases). The general information, underlying diseases, and laboratory examination indexes of the two groups were compared. Multivariate Cox regression was used to explore the relationship between sCys C and prognosis. The receiver operating characteristic (ROC) curve was used to demonstrate the sensitivity and specificity of sCys C and its optimal cut-off value for predicting death. RESULTS: There were significant differences in age, sCys C, creatinine, C-reactive protein, serum albumin, creatine kinase-MB, alkaline phosphatase, lactate dehydrogenase, neutrophil count, and lymphocyte count between the two groups (P < 0.001). Multivariate logistic regression analysis showed that sCys C was an independent risk factor for death in patients with COVID-19 (Odds ratio = 1.812, 95% confidence interval [CI]: 1.300-2.527, P < 0.001). The area under the ROC curve was 0.755 (95%CI: 1.300-2.527), the cut-off value was 0.80, the specificity was 0.562, and the sensitivity was 0.865. CONCLUSION: sCys C is an independent risk factor for death in patients with COVID-19. Patients with a sCys C level of 0.80 mg/L or greater are at a high risk of death.

Epidemiological investigation of Helicobacter pylori infection in elderly people in Beijing.

BACKGROUND: The Helicobacter pylori (H. pylori) infection rate in China is approximately 50%. H. pylori is a pathogenic factor of peptic ulcer and chronic gastritis. In addition, H. pylori infection may also be associated with a variety of cardiovascular diseases in elderly people, such as arteriosclerosis, coronary heart disease, and cerebral infarction, having deleterious effect on their health. With the aging of the population, the disease characteristics of the elderly population have been increasingly valued by the whole society. We conducted an epidemiological survey of H. pylori infection among elderly people in Beijing to provide a basis for health management of H. pylori infection. AIM: To understand the epidemiological characteristics of H. pylori infection in elderly people in Beijing. METHODS: A total of 1090 elderly people aged more than 60 years from different parts of Beijing (urban and rural areas) were selected using the random cluster sampling method. Structured questionnaires were completed during home visits and the 13C-urea breath test was conducted for H. pylori detection. RESULTS: The prevalence of H. pylori infection was 46.5% (507/1090). The infection rate in men was 51.8%, which was significantly higher than that in women (42.5%; P < 0.05). The H. pylori infection rate in illiterate people was significantly higher than that in literate persons (53.5% vs 44.8%, P < 0.05). The total infection rate of H. pylori gradually increased with age and the difference was statistically significant (P < 0.01). The H. pylori infection rate in smokers was significantly higher than that in non-smokers and those who had quit smoking (P < 0.05). CONCLUSION: The prevalence of H. pylori infection among elderly people is 46.5% and the infection rate gradually increases with age. Sex, education level, age, and smoking were determined to be H. pylori infection risk factors. The relationship of H. pylori infection with region, occupation, drinking, and diet structure needs to be further studied.

Feedback loop in miR-449b-3p/ADAM17/NF-κB promotes metastasis in nasopharyngeal carcinoma.

An emerging body of evidence has promoted the understanding of the role of microRNAs (miRNAs) in tumorigenesis and progression, but the mediating function of miRNAs in nasopharyngeal carcinoma (NPC) development remains poorly elucidated. In this study, miR-449b-3p was downregulated in NPC specimens (P < .001) and cells (P < .05). Cytological and animal experiments provided evidence that miR-449b-3p inhibited NPC metastasis in vitro and in vivo. Disintegrin and metalloproteinase 17 (ADAM17) was revealed as a direct target of miR-449b-3p. Rescue experiments suggested that the downregulation of ADAM17 in the miR-449b-3p knockdown cells partially reversed the inhibition of cell invasion and migration. Luciferase reporter assay, chromatin immunoprecipitation assay, and Western blot analysis showed that ADAM17 could suppress the promoter activity and expression of miR-449b-3p by inducing NF-κB transcriptional activity. In conclusion, our study provided new insights into the underlying mechanism of the invasion and metastasis of NPC. The novel miR-449b-3p/ADAM17/NF-κB feedback loop could be a target for the clinical treatment of NPC.

Identification of key pathways and genes in nasopharyngeal carcinoma using bioinformatics analysis.

Nasopharyngeal carcinoma (NPC) is one of the most common malignancies in the head and neck. The aim of the current study was to identify the key pathways and genes involved in NPC through bioinformatics analysis and to identify potential molecular mechanisms underlying NPC proliferation and progression. Three gene expression profiles (GSE12452, GSE34573 and GSE64634) were downloaded from the Gene Expression Omnibus database. A total of 76 samples were analyzed, of which 59 were NPC samples and 17 were normal samples. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were subsequently conducted. The protein-protein interaction (PPI) network of the differentially expressed genes (DEGs) was constructed using Cytoscape software. Analysis of GSE12452, GSE34573 and GSE64634 datasets identified 1,301 (553 upregulated and 748 downregulated), 1,232 (348 upregulated and 884 downregulated) and 1,218 (555 upregulated and 663 downregulated) DEGs, respectively. Using Venn diagram analysis, 268 DEGs (59 upregulated and 209 downregulated) that intersected all three datasets, were selected for further analysis. The results of GO analysis revealed that upregulated DEGs were significantly enriched in biological processes, including 'cell adhesion', 'cell division', 'mitosis' and 'mitotic cell cycle'. The downregulated DEGs were mainly enriched in 'microtubule-based movement', 'cilium movement', 'cilium axoneme assembly' and 'epithelial cell differentiation'. The KEGG pathway analysis results revealed that the upregulated DEGs were highly associated with several pathways, including 'extracellular matrix-receptor interaction', 'human papillomavirus infection', 'arrhythmogenic right ventricular cardiomyopathy' and 'focal adhesion', whereas the downregulated DEGs were enriched in 'metabolic pathways', 'Huntington's disease', 'fluid shear stress and atherosclerosis' and 'chemical carcinogenesis'. On the basis of the PPI network of the DEGs, the following top 10 hub genes were identified: Dynein axonemal light intermediate chain 1, dynein axonemal intermediate chain 2, calmodulin 1, coiled-coil domain containing 114, dynein axonemal heavy chain 5, radial spoke head 9 homolog, radial spoke head component 4A, NDC80 kinetochore complex component, thymidylate synthetase and coiled-coil domain containing 39. In conclusion, by performing a comprehensive bioinformatics analysis of DEGs, putative targets that could be used to elucidate the molecular mechanisms underlying NPC were identified.

miR-184 Inhibits Tumor Invasion, Migration and Metastasis in Nasopharyngeal Carcinoma by Targeting Notch2.

BACKGROUND/AIMS: A recent study found that dysregulated microRNA-184 (miR-184) is involved in the proliferation and survival of nasopharyngeal carcinoma (NPC). This study aimed to evaluate the detailed mechanisms of invasion, migration and metastasis of NPC cells. METHODS: Quantitative reverse-transcription PCR (qRT-PCR) and Western blot were used to confirm the expression levels of miR-184 and Notch2. NPC cell invasion and migration were subsequently examined using in vitro cell invasion and wound-healing assays, respectively. MicroRNA (miRNA) target gene prediction databases and dual-luciferase reporter assay were adopted to validate the target genes of miR-184. RESULTS: MiR-184 was downregulated in the NPC cell lines. The miR-184 inhibitor increased the number of invading NPC cells, whereas miR-184 mimics inhibited the invasive ability of such cells. The protein level of E-cadherin decreased, whereas those of N-cadherin and vimentin increased in the anti-miR-184 group. This result showed that miR-184 inhibited NPC cell invasion and metastasis by regulating EMT progression. MiRNA target gene prediction databases indicated the potential of Notch2 as a direct target gene of miR-184. Such a notion was then validated by results of dual-luciferase reporter assay. Notably, shRNANotch2 restrained the EMT and partially abrogated the inhibitory effects of miR-184 on EMT progression in NPC cells. CONCLUSION: MiR-184 functions as a tumour-suppressive miRNA targeting Notch2 and inhibits the invasion, migration and metastasis of NPC.

MIIP gene expression is associated with radiosensitivity in human nasopharyngeal carcinoma cells.

The present study aims to investigate the radiosensitization effect of the migration and invasion inhibitory protein (MIIP) gene on nasopharyngeal carcinoma (NPC) cells. The MIIP gene was transfected into NPC 5-8F and CNE2 cells. The level of MIIP was analyzed by quantitative reverse transcription-polymerase chain reaction analysis and western blot. The changes in radiosensitivity of the cells were analyzed by colony formation assay. The changes in cell apoptosis and cycle distribution following irradiation were detected by flow cytometry. The expression of BCL2 associated X, apoptosis regulator/B-cell lymphoma 2 was evaluated using western blot. DNA damage was analyzed by counting γ-H2AX foci. The expression levels of γ-H2AX were evaluated by immunofluorescence and western blot. In a previous study by the authors, the results indicated that the expression of MIIP gene evidently increased in MIIP-transfected 5-8F (5-8F OE) and MIIP-transfected CNE2 (CNE2 OE) cells compared with the parental or negative control cells. In the present study, the survival rate of 5-8F OE and CNE2 OE cells markedly decreased following irradiation (0, 2, 4, 6 and 8 Gy) compared with the negative control (5-8F NC and CNE2 NC) and the untreated (5-8F and CNE2) groups. The expression of MIIP was able to increase apoptosis, which resulted in G2/M cell cycle arrest and DNA damage repair was attenuated in 5-8F and CNE2 cells following irradiation as measured by the accumulation of γ-H2AX. It was indicated that MIIP expression is associated with the radiosensitivity of NPC cells and has a significant role in regulating cell radiosensitivity.

MiR-152 functioning as a tumor suppressor that interacts with DNMT1 in nasopharyngeal carcinoma.

BACKGROUND: In recent years, miR-152 has been dysregulated in a variety of tumors and used as a tumor suppressor. Nevertheless, its role in nasopharyngeal carcinoma (NPC) remains unidentified. MATERIALS AND METHODS: Real-time quantitative PCR (polymerase chain reaction) was performed to analyze the expression of miR-152 in NPC cell lines. MiR-152 expression profiles in NPC tissues were obtained from Gene Expression Omnibus (GEO GSE36682). The effect of miR-152 on the invasion and proliferation of NPC cells was determined through cell invasion, wound healing, and cell viability assays. Apoptosis was examined by flow cytometry, and Western blot was performed to measure expression of the target gene. Pyrosequencing was used to detect the methylation level of NPC cells. RESULTS: In this study, miR-152 was downregulated in the NPC tissues and cell lines. When miR-152 was enhanced, the invasion and migration of NPC cells were inhibited. However, miR-152 had no effect on the proliferation of NPC cells. Luciferase reporter gene analysis was performed, and the results showed that DNMT1 (DNA (cytosine-5)-methyltransferase 1) is a direct target of miR-152 in NPC cells. DNMT1 downregulation and miR-152 overexpression both reversed the effects of miR-152 inhibition on the NPC cells. In addition, miR-152 expression increased as a result of the inhibition of the methylation level of miR-152 when DNMT1 expression was downregulated. CONCLUSION: The overexpression of miR-152 inhibited the migration and invasion of NPC cells by targeting DNMT1. Furthermore, DNMT1 regulated miR-152 expression through DNA methylation. Overall, the novel miR-152-DNMT1 regulatory circuit may provide better understanding of the pathogenesis of NPC and new epigenetic therapeutic target in NPC.

Prognostic significance of Epstein-Barr virus DNA in NK/T-cell lymphoma: a meta-analysis.

Extranodal NK/T-cell lymphoma is closely associated with Epstein-Barr virus (EBV) infection. However, the prognostic value of EBV-DNA in extranodal NK/T-cell lymphoma remains unclear. Thus, we conducted a meta-analysis to estimate its prognostic significance. PubMed, EMBASE, and Web of Science were used to search for studies conducted until June 12, 2017. The pooled hazard ratio (HR) and its 95% confidence interval (CI) were calculated to evaluate the prognostic value of pretreatment EBV-DNA on the overall survival of extranodal NK/T-cell lymphoma. Seven eligible studies on 356 patients with extranodal NK/T-cell lymphoma were pooled for this meta-analysis. Results suggested that the pretreatment EBV-DNA positivity was significantly correlated with the overall survival of extranodal NK/T-cell lymphoma (pooled HR =3.78, 95% CI: 1.52-9.40, p=0.004; heterogeneity test: I2=52%, p=0.05). Subgroup analyses stratified by sample type, survival analysis mode, and HR origin showed that patients with positive pretreatment EBV-DNA had poorer prognosis than those with negative pretreatment EBV-DNA. Moreover, the cut-off value (HR =1.66; 95% CI: 0.73-3.73; p=0.22) might account for the heterogeneity. No significant publication bias was observed. Pretreatment EBV-DNA positivity can predict poor prognosis for patients with extranodal NK/T-cell lymphoma. Future large-scale studies based on prognostic significance of EBV-DNA for patients with extranodal NK/T-cell lymphoma are necessary.

Arsenic trioxide at conventional dosage does not aggravate hemorrhage in the first-line treatment of adult acute promyelocytic leukemia.

OBJECTIVES: The arsenic trioxide (ATO) plus all-trans retinoic acid (ATRA) therapy has demonstrated a tremendous success in the first-line treatment of acute promyelocytic leukemia (APL). Actually, early death (ED) is currently thought as a major challenge in APL. ATO has been reported to inhibit platelet function in vitro, and whether it increases the ED rate by exacerbating the hemorrhagic symptoms remains to be investigated. METHODS: Effects of ATO on platelet aggregation and adhesion were evaluated in vitro and in thirty-two complete remission (CR) and four newly diagnosed APL patients. Furthermore, concentrations of plasma total arsenic were monitored in APL patients via ICP-MS. RESULTS: The inhibition of platelet function, either aggregation or adhesion, did occur in vitro when the concentration of ATO reached 2 µmol/L. However, in CR APL patients receiving ATO with normal platelet count, the platelets responded normally when being activated and so did those in the newly diagnosed patients with thrombocytopenia. Our data further showed that the conventional dosage of ATO reached a plasma concentration substantially below the required concentration to inhibit platelets. CONCLUSIONS: In the first-line treatment of APL, the use of ATO is safe and effective and does not compromise the hemostatic potential that may eventually increase ED rate.

Determination of Pb, Cr, Cd, and As in Aluminum-Plastic Packaging Materials via Inductively Coupled Plasma-Mass Spectrometry with Microwave Digestion.

Microwave digestion was performed to study the pretreatment methods of aluminum-plastic packaging materials (APPMs). Five different digestion reagent combinations and proportions were thoroughly considered. Digestion results indicated that the most suitable reagent combination was sulfuric and nitric acids with the optimal proportion of 1∶7 after the orthogonal experiment. Moreover, the possible reasons of the experimental phenomenon were analyzed. The contents of Pb, Cr, Cd, and As in APPMs were subsequently determined via inductively coupled plasma-mass spectrometry (ICP-MS). The satisfactory linearity of calibration curves was obtained with the linear correlation coefficients above 0.999 5, and the instrument detection limits of Pb, Cr, Cd, and As for the current method were 0.215, 0.067, 0.006 and 0.020 ng·mL-1, respectively. Furthermore, the recoveries of standard addition ranged from 83.8% to 111.6%, and the relative standard deviations ranged from 0.5% to 7.4%. Two independent parallel determination results of Pb, Cr, Cd, and As in APPMs were approaching, and the student's t-test (confidence level, α=0.05) showed that the determination results had no significant differences. In conclusion, the present method exhibited fine linearity, low detection limit, high recovery, and good precision, which can accurately be utilized to analyze Pb, Cr, Cd, and As elements in APPMs or other similar materials.

Mutations of Epigenetic Modifier Genes as a Poor Prognostic Factor in Acute Promyelocytic Leukemia Under Treatment With All-Trans Retinoic Acid and Arsenic Trioxide.

BACKGROUND: Acute promyelocytic leukemia (APL) is a model for synergistic target cancer therapy using all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), which yields a very high 5-year overall survival (OS) rate of 85 to 90%. Nevertheless, about 15% of APL patients still get early death or relapse. We performed this study to address the possible impact of additional gene mutations on the outcome of APL. METHODS: We included a consecutive series of 266 cases as training group, and then validated the results in a testing group of 269 patients to investigate the potential prognostic gene mutations, including FLT3-ITD or -TKD, N-RAS, C-KIT, NPM1, CEPBA, WT1, ASXL1, DNMT3A, MLL (fusions and PTD), IDH1, IDH2 and TET2. RESULTS: More high-risk patients (50.4%) carried additional mutations, as compared with intermediate- and low-risk ones. The mutations of epigenetic modifier genes were associated with poor prognosis in terms of disease-free survival in both training (HR = 6.761, 95% CI 2.179-20.984; P = 0.001) and validation (HR = 4.026, 95% CI 1.089-14.878; P = 0.037) groups. Sanz risk stratification was associated with CR induction and OS. CONCLUSION: In an era of ATRA/ATO treatment, both molecular markers and clinical parameter based stratification systems should be used as prognostic factors for APL.

Prognostic analysis and comparison of colon cancer in Han and Hui patients.

AIM: To investigate the relevant prognostic factors and their differences between colorectal cancer (CRC) patients of Chinese Han and Hui ethnicities in the Beijing region. METHODS: A retrospective analysis of 880 patients diagnosed with CRC at Xuanwu Hospital, Capital Medical University between September 2001 and September 2011 was performed. Among the 880 patients, 398 and 482 were Hui and Han, respectively. Characteristics including sex, age, diet, tumor size, primary tumor site, Dukes' stage and degree of differentiation were analyzed for their influence on prognosis. Data on dietary structures were recorded through a questionnaire survey conducted during the patient's first visit, return visit or follow-up checkups. RESULTS: Among patients with colon cancer, the 5-year survival rate for patients of Hui ethnicity was lower than that for Han patients (P = 0.025). Six risk factors (age of onset, dietary structure, tumor size, Dukes' stage, location of cancer and degree of differentiation) in both Han and Hui patients were identified as prognostic factors (P < 0.05). Multivariate analysis showed that age of onset (P = 0.002), diet (P = 0.000), Dukes' stage (P = 0.000) and degree of differentiation (P = 0.000) are prognostic factors affecting both ethnic groups. Comparison of prognostic factors between Han and Hui patients with CRC showed that dietary structure was a statistically significant factor, and diet varied significantly between the two ethnic groups. CONCLUSION: Dietary structure has a significant influence on colon cancer prognosis among Han and Hui patients with colon cancer in Beijing, which may cause a difference in their survival rates.

Hypoxia inhibits the spontaneous calcification of bone marrow-derived mesenchymal stem cells.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are the popular seed cells for regenerative medicine, and there has been a rapid increase in the number of BM-MSC-based clinical trials. However, the safety of these cells should also be closely studied. In this study, spontaneous calcification of BM-MSCs from rats was evaluated in normoxia (20% O(2)) without osteogenic medium after continuous culture for 21 days; obvious mineralized nodules were observed, which were positive for Alizarin Red, collagen-I (Col-I), osteocalcin (OC) and alkaline phosphatase (ALP), and mainly consisted of C, O and Ca elements. Interestingly, hypoxia (2% O(2)) significantly inhibited this spontaneous calcification. In addition, the ALP and calcium content of rBM-MSCs were sharply reduced. Based on RT-PCR results, the expression of osteogenic genes (Cbfa1/Runx2, Col-I, ALP, and OC) was reduced compared to that in normoxia. These results demonstrate a natural and unique characterization of rat BM-MSCs in normoxia after continuous culture and highlight the inhibiting effects of hypoxia. Finally, this study contributes to the information regarding the application of BM-MSCs in the regeneration of various tissues.

Sonic hedgehog enhances the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells.

MSCs (mesenchymal stem cells) may be promising seed cells for tissue regeneration because of their self-renewal and multi-differentiation potential. Shh (sonic hedgehog) is involved in the skeletal formation during embryo development and skeletal regeneration. However, how Shh regulates the biological characteristics of BM-MSCs (bone marrow-derived MSCs) is poorly understood. We have investigated the effect of rShh-N (recombinant N-terminal Shh) on the proliferation and osteogenic differentiation of rBM-MSCs (rat BM-MSCs) in vitro. rBM-MSCs were treated with rShh-N at concentrations up to 200 ng/ml. Proliferation and colony-forming ability of rBM-MSCs were increased in a dose-dependent manner. rShh-N increased the ratio of cells in S and G2/M phase, as well as the number of Ki-67+ cells. In addition, ALP (alkaline phosphatase) activity and matrix mineralization were enhanced by 200 ng/ml rShh-N. Real-time PCR showed that rShh-N (200 ng/ml) up-regulated the expression of genes encoding Cbfa-1 (core-binding factor α1), osteocalcin, ALP and collagen type I in rBM-MSCs. This information reveals some potential of rShh-N in the therapeutics of bone-related diseases.