Upregulation of microRNA-375 is associated with poor prognosis in pediatric acute myeloid leukemia

A genome-wide serum miRNA expression analysis previously showed the upregulation of microRNA-375 (miR-375) in acute myeloid leukemia (AML) patients compared with healthy controls. The aim of this study was to investigate the expression patterns and the prognostic relevance of miR-375 in pediatric AML. Expression levels of miR-375 in bone marrow mononuclear cells were detected by real-time quantitative PCR in a cohort of 106 patients with newly diagnosed pediatric AML. Expression levels of miR-375 in the bone marrow of pediatric AML patients were significantly higher than those in normal controls (P < 0.001). Then, miR-375 upregulation occurred more frequently in French–American–British classification subtype M7 than in other subtypes (P < 0.001). Regarding to cytogenetic risk, the expression levels of miR-375 in pediatric AML patients with unfavorable karyotypes were dramatically higher than those in intermediate and favorable groups (P = 0.002). Moreover, high miR-375 expression was significantly associated with shorter relapse-free survival (P < 0.001) and overall survival (P < 0.001) in pediatric AML patients. Multivariate analysis further identified miR-375 expression and cytogenetics risk as independent prognostic factors for both relapse-free survival and overall survival. In particular, the prognostic relevance of miR-375 expression was more obvious in the subgroup of patients with intermediate-risk cytogenetics. Our findings suggest for the first time that the upregulation of miR-375 may be one of the molecular mechanisms involved in the development and progression of pediatric AML. Since its correlation with poor relapse-free survival and overall survival, miR-375 may be a novel biomarker to improve the management of pediatric AML patients.     

Association of the plasma riboflavin levels and riboflavin transporter (C20orf54) gene statuses in Kazak esophageal squamous cell carcinoma patients

To evaluate the association of the plasma riboflavin level in Kazak esophageal cancer patients and their riboflavin transporter (C20orf54) gene statuses. Plasma riboflavin levels were detected by high performance liquid chromatography in Kazak patients with esophageal squamous cell carcinoma (ESCC) and healthy controls. C20orf54 mRNA and protein expression were analyzed by real-time fluorogenic quantitative polymerase chain reaction and immunohistochemistry in samples from 61 ESCC patients consisting of both tumor and normal tissue, respectively. C20orf54 mRNA expression was decreased in ESCC (0.279 ± 0.102) than in normal counterpart tissue (0.479 ± 0.287; P = 0.049) significantly. Tumors exhibited low C20orf54 protein expression (42.6, 26.2, 18.0 and 13.1 % for no C20orf54 staining, weak staining, medium staining and strong staining, respectively), which was significantly lower than that in the normal mucous membrane (13.1, 26.2, 41.0 and 19.7 % for no C20orf54 staining, weak staining, medium staining and strong staining, respectively). Defective expression of C20orf54 in tumor cells was significantly associated with poor differentiation. However, other parameters such as depth of invasion and lymph node metastasis had no significant relationship with C20orf54 expression. The average blood concentration of riboflavin was 2.6468 ± 1.3474 ng/ml in ESCC patients lower than control group (4.2960 ± 3.2293 ng/ml, P = 0.015). A positive correlation of plasma riboflavin levels with defective expression of C20orf54 protein was found in ESCC patients (F = 8.626; P = 0.038). Defective expression of C20orf54 is associated with the development of Kazak esophageal squamous cell carcinoma and this may represent a mechanism underlying the decreased plasma riboflavin levels in ESCC.     

T cells from indolent CLL patients prevent apoptosis of leukemic B cells in vitro and have altered gene expression profile

T cells may have a role in sustaining the leukemic clone in chronic lymphocytic leukemia (CLL). In this study, we have examined the ability of T cells from CLL patients to support the survival of the leukemic B cells in vitro. Additionally, we compared global gene expression of T cells from indolent CLL patients with healthy individuals and multiple myeloma (MM) patients. Apoptosis of purified leukemic B cells was inhibited in vitro when co-cultured with increasing numbers of autologous T cells (p < 0.01) but not autologous B and T cells of normal donors. The anti-apoptotic effect exceeded that of the anti-apoptotic cytokine IL-4 (p = 0.002) and was greater with CD8+ cells (p = 0.02) than with CD4+ cells (p = 0.05). The effect was depended mainly on cell–cell contact although a significant effect was also observed in transwell experiments (p = 0.05). About 356 genes involved in different cellular pathways were deregulated in T cells of CLL patients compared to healthy individuals and MM patients. The results of gene expression profiling were verified for 6 genes (CCL4, CCL5 (RANTES), XCL1, XCL2, KLF6, and TRAF1) using qRT–PCR and immunoblotting. Our results demonstrate that CLL-derived T cells can prevent apoptosis of leukemic B cells and have altered expression of genes that may facilitate the survival of the leukemic clone.     

Association Study Between Macrophage Migration Inhibitory Factor-173 Polymorphism and Acute Myeloid Leukemia in Taiwan

Acute myeloid leukemia (AML) is the most common acute leukemia diagnosed in adults. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that plays a significant role in pathogenesis and autoimmune diseases. The major function of MIF is to promote the cell proliferation, migration, and invasion. The aim of the present study is to identify the association between MIF-173 (rs755662) single nucleotide polymorphism (SNP) and AML in Taiwanese population. DNA samples extracted from 256 AML patients and 256 healthy controls were investigated using polymerase chain reaction followed by restriction fragment length polymorphism analysis. The association between MIF-173 SNP genotype and AML patients were assessed with SPSS software. The results show that the GC genotype of MIF-173 SNP is significantly higher in AML patients than in the healthy controls (OR 1.58, 95 % CI 1.06, P = 0.034). Carrier genotypes GC and CC may be a causative factor for AML cancer (OR 1.39, 95 % CI 0.95, P = 0.085). White blood cell count (10³/µl) were significantly associated with AML MIF-173 polymorphism patients (P = 0.002). Our results in this study provide the first evidence that the MIF-173 polymorphism is associated with AML. MIF is a potential biomarker for development of AML cancer in male adult in Taiwanese population. Further validations in other populations are warranted.     

Up-regulation of Slc39A2(Zip2) mRNA in peripheral blood mononuclear cells from patients with pulmonary tuberculosis

Zinc is the most common trace mineral after iron in the human body. In organisms, zinc transporters help zinc influx and efflux from cells. A previous study has reported that Zip2 was up-regulated over 27-fold in human monocytic THP-1 cells, when intracellular zinc was depleted by TPEN. Our study found Zip2 was over-expressed in leukocytes of asthmatic infants, especially those in which the serum zinc level was lower than those in healthy infants. Pulmonary tuberculosis (PTB) patients have significantly low serum zinc levels. Here we investigated whether Zip2 level was changed in the patients with PTB. Zip2 mRNA and protein levels in peripheral blood mononuclear cells (PBMC) from PTB (n ₁ = 23) and healthy controls (n ₂ = 42) were detected by quantitative real-time PCR and western blot, respectively. mRNA expression levels of another four zinc transporters, Zip1, Zip6, Zip8 and ZnT1, were detected by quantitative real-time PCR. Zip2 mRNA level was significantly up-regulated in PTB patients (P = 0.001), and Zip8 mRNA level was significantly down-regulated compared with control individuals (P < 0.001). In contrast, there were no significant changes in mRNA levels of Zip1, Zip6 and ZnT1 in either group (P > 0.05). Zip2 protein expression levels increased in PTB patients compared with control individuals. Our study found that knockdown of ZIP2 with siRNA caused a decrease in Zip2 levels in PBMC of PTB patients, while reducing the expression of INF-γ (P < 0.01) and increasing the expression of IL-6(P < 0.01). These data provide evidence that increased expression of Zip2 gene is closely associated with immunity of PTB patients, suggesting that the Zip2 gene may play a key role in the initial infection control of the human body, by promoting and maintaining the immune response of adaptive T cells.     

Selenium and Glutathione Peroxidase Status in Adult Egyptian Patients with Acute Myeloid Leukemia

This study was undertaken to evaluate selenium (Se) and glutathione peroxidase (GPX) status in patients with newly diagnosed acute myeloid leukemia (AML) before and after induction therapy. Twenty-five patients with newly diagnosed AML and 15 healthy age- and sex-matched control subjects were included in this study. Serum Se level by the graphite furnace atomic absorption spectrometric technique and GPX activity by an adaptation of Beutler method was performed for the patients before and after receiving the induction therapy. Serum Se level was significantly lower in patients with AML versus control subjects (63.1?±?8.8 versus 77?±?8.8 µg/L before therapy with a P value <0.01 and 69?±?6.8 versus 77?±?8.8 µg/L after therapy with a P value <0.01).GPX activity was significantly lower in patients with AML versus control subjects (1.6?±?0.4 versus 3.4?±?0.7 µ/g protein pretreatment with a P value <0.01and 1.9?±?0.6 versus 3.4?±?0.7 µ/g protein post induction treatment with P value <0.01).Se level and GPX activity significantly increased in AML patients after treatment. Patients who accomplished complete remission after induction harbored significantly higher Se levels than resistant patients before and after treatment. There was no significant correlation between serum Se level and GPX activity. Decreased Se level and reduced GPX activity in AML patients support the association of carcinogenesis and subnormal Se states.     

Comprehensive analysis of the long noncoding RNA HOXA11-AS gene interaction regulatory network in NSCLC cells

Background

Long noncoding RNAs (lncRNAs) are related to different biological processes in non-small cell lung cancer (NSCLC). However, the possible molecular mechanisms underlying the effects of the long noncoding RNA HOXA11-AS (HOXA11 antisense RNA) in NSCLC are unknown.

Methods

HOXA11-AS was knocked down in the NSCLC A549 cell line and a high throughput microarray assay was applied to detect changes in the gene profiles of the A549 cells. Bioinformatics analyses (gene ontology (GO), pathway, Kyoto Encyclopedia of Genes and Genomes (KEGG), and network analyses) were performed to investigate the potential pathways and networks of the differentially expressed genes. The molecular signatures database (MSigDB) was used to display the expression profiles of these differentially expressed genes. Furthermore, the relationships between the HOXA11-AS, de-regulated genes and clinical NSCLC parameters were verified by using NSCLC patient information from The Cancer Genome Atlas (TCGA) database. In addition, the relationship between HOXA11-AS expression and clinical diagnostic value was analyzed by receiver operating characteristic (ROC) curve.

Results

Among the differentially expressed genes, 277 and 80 genes were upregulated and downregulated in NSCLC, respectively (fold change ≥2.0, P < 0.05 and false discovery rate (FDR) < 0.05). According to the degree of the fold change, six upregulated and three downregulated genes were selected for further investigation. Only four genes (RSPO3, ADAMTS8, DMBT1, and DOCK8) were reported to be related with the development or progression of NSCLC based on a PubMed search. Among all possible pathways, three pathways (the PI3K-Akt, TGF-beta and Hippo signaling pathways) were the most likely to be involved in NSCLC development and progression. Furthermore, we found that HOXA11-AS was highly expressed in both lung adenocarcinoma and squamous cell carcinoma based on TCGA database. The ROC curve showed that the area under curve (AUC) of HOXA11-AS was 0.727 (95% CI 0.663–0.790) for lung adenocarcinoma and 0.933 (95% CI 0.906–0.960) for squamous cell carcinoma patients. Additionally, the original data from TCGA verified that ADAMTS8, DMBT1 and DOCK8 were downregulated in both lung adenocarcinoma and squamous cell carcinoma, whereas RSPO3 expression was upregulated in lung adenocarcinoma and downregulated in lung squamous cell carcinoma. For the other five genes (STMN2, SPINK6, TUSC3, LOC100128054, and C8orf22), we found that STMN2, TUSC3 and C8orf22 were upregulated in squamous cell carcinoma and that STMN2 and USC3 were upregulated in lung adenocarcinoma. Furthermore, we compared the correlation between HOXA11-AS and de-regulated genes in NSCLC based on TCGA. The results showed that the HOXA11-AS expression was negatively correlated with DOCK8 in squamous cell carcinoma (r = ?0.124, P = 0.048) and lung adenocarcinoma (r = ?0.176, P = 0.005). In addition, RSPO3, ADAMTS8 and DOCK8 were related to overall survival and disease-free survival (all P < 0.05) of lung adenocarcinoma patients in TCGA.

Conclusions

Our results showed that the gene profiles were significantly changed after HOXA11-AS knock-down in NSCLC cells. We speculated that HOXA11-AS may play an important role in NSCLC development and progression by regulating the expression of various pathways and genes, especially DOCK8 and TGF-beta pathway. However, the exact mechanism should be verified by functional experiments.

     

NBS1 rs1805794G>C polymorphism is associated with decreased risk of acute myeloid leukemia in a Chinese population

As a key encoding protein gene of MRN (MRE11-RAD50-NBS1) complex, NBS1 plays a crucial role in maintaining genomic stability and preventing cell apoptosis, inflammation and tumorgenesis. Single nucleotide polymorphisms (rs2735383 and rs1805794) in NBS1 have been frequently studied in some cancers with discordant results in previous case–control studies. However, the relationship between these two functional polymorphisms and the susceptibility to acute myeloid leukemia (AML) in Chinese population has not been investigated. We performed a case–control study with 428 patients and 600 controls to detect the association between the two polymorphisms of NBS1 and the risk of AML in a Chinese population. The polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) method was carried out to determine the genotypes of potential functional SNPs in NBS1 gene. The results showed that compared with the homozygous carriers rs1805794CC, rs1805794GC genotype was significantly associated with decreased risk of AML in total subjects (adjusted odds ratio (OR) = 0.50; 95 % CI = 0.37–0.67), the risk decreased even further in those carrying rs1805794GG genotype (OR = 0.23; 95 % CI = 0.16–0.34). No significant association was found between rs2735383C>G polymorphism and the risk of AML (OR = 0.93; 95 % CI = 0.71–1.22 for GC; OR = 0.78; 95 % CI = 0.53–1.13 for CC, P = 0.152). These findings indicated that rs1805794G/C polymorphism in NBS1 may play a protective role in mediating the risk of AML.