Low expression of microRNA-340 confers adverse clinical outcome in patients with acute myeloid leukemia

MicroRNA-340 (miR-340) was considered as a tumor suppressor by affecting cancer cell proliferation, apoptosis, invasion, and migration, and was downregulated in diverse cancers. Moreover, dysregulation of miR-340 was also found to be associated with drug resistance and predicted patients’ survival in various cancers. Herein, we investigated miR-340 expression and its clinical significance in acute myeloid leukemia (AML). Real-time quantitative polymerase chain reaction was performed to detect miR-340 expression in bone marrow (BM) from 99 newly diagnosed AML patients except for acute promyelocytic leukemia (APL), 19 AML patients achieved complete remission (CR), and 29 healthy donors. BM miR-340 expression was significantly underexpressed in newly diagnosed AML patients as compared with controls (p = 0.031) and AML patients achieved CR (p = 0.025). No significant differences were observed between miR-340 expression and most of the clinicopathologic features (p > 0.05). However, low miR-340 expression was found to be associated with lower CR rate in both non-APL-AML and cytogenetically normal AML (CN-AML; p = 0.001 and 0.031, respectively), and acted as an independent risk factor for CR by logistic regression analysis (p = 0.001 and 0.021, respectively). More important, among both non-APL-AML and CN-AML, low expression of miR-340 was also associated with shorter overall survival (OS; p = 0.013 and 0.005, respectively), and was further validated by Cox regression (p = 0.031 and 0.039, respectively). Collectively, our study showed that BM miR-340 expression was downregulated in AML, and low expression of miR-340 correlated with adverse prognosis.     

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.     

HMP19 is a new metastasis suppressor in epithelial ovarian cancer

HMP19 is a neuron-specific gene; its expression product belongs to a family of neuronal proteins which can be found in numerous kinds of human cancers. However, the clinicopathological significance of HMP19 expression in epithelial ovarian cancer (EOC) is as yet unknown. In this study, protein expression levels of HMP19 in cancerous tissues were determined by tissue microarray immunohistochemistry analysis (TMA-IHC) (n = 117). HMP19 protein levels in cancer tissues were associated with clinical characteristics and overall survival rates of patients with EOC. It was found that both mRNA and protein levels of HMP19 were significantly lower in EOC than those in normal ovary or fallopian tube tissues (P<0.05). The protein expression level of HMP19 was significantly associated with a lower FIGO stage, a lower level of CA-125 and a lower presence of metastasis. Consistent with related adverse clinical pathological features, the overall survival (OS) rate of patients with low or non HMP19-expressing tumors was inferior compared to those with high HMP19-expressing tumors. This is in accordance with further studies that found high HMP19 protein level to be an independent prognostic factor for OS in EOC. Multivariate analysis demonstrated that tumor patients with low HMP19 expression had an exceedingly poor OS. HMP19 plays a role in metastasis/tumor suppression and offers a prognostic value for EOC. HMP19, as a new inhibitor, strongly inhibits metastasis and partially attenuates tumor growth in EOC.     

EZH2 dysregulation: Potential biomarkers predicting prognosis and guiding treatment choice in acute myeloid leukaemia

Accumulating studies have proved EZH2 dysregulation mediated by mutation and expression in diverse human cancers including AML. However, the expression pattern of EZH2 remains controversial in acute myeloid leukaemia (AML). EZH1/2 expression and mutation were analysed in 200 patients with AML. EZH2 expression was significantly decreased in AML patients compared with normal controls but not for EZH1 expression. EZH2 mutation was identified three of the 200 AML patients (1.5%, 3/200), whereas none of the patients harboured EZH1 mutation (0%, 0/200). EZH2 expression and mutation were significantly associated with ?7/del(7) karyotypes. Moreover, lower EZH2 expression was associated with older age, higher white blood cells, NPM1 mutation, CEBPA wild‐type and WT1 wild‐type. Patients with EZH2 mutation showed shorter overall survival (OS) and leukaemia‐free survival (LFS) than patients without EHZ2 mutation after receiving autologous or allogeneic haematopoietic stem cell transplantation (HSCT). However, EZH2 expression has no effect on OS and LFS of AML patients. Notably, in EZH2 low group, patients undergone HSCT had significantly better OS and LFS compared with patients only received chemotherapy, whereas no significant difference was found in OS and LFS between chemotherapy and HSCT patients in EZH2 high group. Collectively, EZH2 dysregulation caused by mutation and under‐expression identifies specific subtypes of AML EZH2 dysregulation may be acted as potential biomarkers predicting prognosis and guiding the treatment choice between transplantation and chemotherapy.     

Epigenetic dysregulation of ID4 predicts disease progression and treatment outcome in myeloid malignancies

Promoter hypermethylation‐mediated inactivation of ID4 plays a crucial role in the development of solid tumours. This study aimed to investigate ID4 methylation and its clinical relevance in myeloid malignancies. ID4 hypermethylation was associated with higher IPSS scores, but was not an independent prognostic biomarker affecting overall survival (OS) in myelodysplastic syndrome (MDS). However, ID4 hypermethylation correlated with shorter OS and leukaemia‐free survival (LFS) time and acted as an independent risk factor affecting OS in acute myeloid leukaemia (AML). Moreover, ID4 methylation was significantly decreased in the follow‐up paired AML patients who achieved complete remission (CR) after induction therapy. Importantly, ID4 methylation was increased during MDS progression to AML and chronic phase (CP) progression to blast crisis (BC) in chronic myeloid leukaemia (CML). Epigenetic studies showed that ID4 methylation might be one of the mechanisms silencing ID4 expression in myeloid leukaemia. Functional studies in vitro showed that restoration of ID4 expression could inhibit cell proliferation and promote apoptosis in both K562 and HL60 cells. These findings indicate that ID4 acts as a tumour suppressor in myeloid malignancies, and ID4 methylation is a potential biomarker in predicting disease progression and treatment outcome.     

Potential CD34 signaling through phosphorylated-BAD in chemotherapy-resistant acute myeloid leukemia

Abstract

Acute myeloid leukemia (AML) constitutively express growth factors and cytokines for survival. Chemotherapy alters these signals to induce cell death. However, drug resistance in AML remains a major hindrance to successful treatment and early warning is unavailable. Modulation of signaling pathways during chemotherapy may provide a window to detect response and predict treatment outcome. Blood samples collected from AML patients before and at day-3 of induction therapy were compared for changes in expression of CD117, CD34, pro-inflammatory cytokines and mediators of Akt and MAPK pathways, using multi-color flow cytometry. Nine patients were diagnosed as drug-resistant and seven sensitive to chemotherapy. Twelve were paired. Average percentages of CD34 (66.8?±?11.7% vs. 26.2?±?5.8%, p?=?0.033) and pBAD (66.9?±?8.2% vs. 28.9?±?8.2%, p?=?0.016) were significantly increased in chemo-resistant (N?=?9) compared to chemo-sensitive (N?=?5) samples. Percentages of CD34 were strongly correlated with pBAD (R?=?0.785; p?=?0.001; N?=?14) and pFKHR (R?=?0.755; p?=?0.002; N?=?14) at day-3 induction. Chemo-sensitive cases expressed significantly higher percentages of IL-18Rα (71.9?±?9.6% vs. 29.8?±?5.8%, p?=?0.016). Though not significantly different in the outcome, IL-1β was strongly associated with activated Akt-S473, IL-6 with phosphorylated JNK and FKHR while TNF-α appeared to trigger Bim, in treated samples. These preliminary results suggested AML cells resistant to chemotherapy increased expression of CD34 and may signal through pBAD while cells sensitive to chemotherapy-induced IL18Rα expression. These were observed early during induction therapy. Identifying CD34 is interesting as it is a convenient marker to monitor drug-resistance in AML patients. Inhibition of CD34 and pBAD signaling may be important in treating drug-resistant AML.     

MUC1‐C drives myeloid leukaemogenesis and resistance to treatment by a survivin‐mediated mechanism

Acute myeloid leukaemia (AML) is an aggressive haematological malignancy with an unmet need for improved therapies. Responses to standard cytotoxic therapy in AML are often transient because of the emergence of chemotherapy‐resistant disease. The MUC1‐C oncoprotein governs critical pathways of tumorigenesis, including self‐renewal and survival, and is aberrantly expressed in AML blasts and leukaemia stem cells (LSCs). However, a role for MUC1‐C in linking leukaemogenesis and resistance to treatment has not been described. In this study, we demonstrate that MUC1‐C overexpression is associated with increased leukaemia initiating capacity in an NSG mouse model. In concert with those results, MUC1‐C silencing in multiple AML cell lines significantly reduced the establishment of AML in vivo. In addition, targeting MUC1‐C with silencing or pharmacologic inhibition with GO‐203 led to a decrease in active β‐catenin levels and, in‐turn, down‐regulation of survivin, a critical mediator of leukaemia cell survival. Targeting MUC1‐C was also associated with increased sensitivity of AML cells to Cytarabine (Ara‐C) treatment by a survivin‐dependent mechanism. Notably, low MUC1 and survivin gene expression were associated with better clinical outcomes in patients with AML. These findings emphasize the importance of MUC1‐C to myeloid leukaemogenesis and resistance to treatment by driving survivin expression. Our findings also highlight the potential translational relevance of combining GO‐203 with Ara‐C for the treatment of patients with AML.     

Difference in larval type explains patterns of nonsynonymous substitutions in two ancient paralogs of the histone H3 gene in sea stars

SUMMARY Paralogous genes frequently show differences in patterns and rates of substitution that are typically attributed to different selection regimes, mutation rates, or local recombination rates. Here, two anciently diverged paralogous copies of the histone H3 gene in sea stars, the tandem‐repetitive early‐stage gene and a newly isolated gene with lower copy number that was termed the “putative late‐stage histone H3 gene” were analyzed in 69 species with varying mode of larval development. The two genes showed differences in relative copy number, overall substitution rates, nucleotide composition, and codon usage, but similar patterns of relative nonsynonymous substitution rates, when analyzed by the d_N/d_S ratio. Sea stars with a nonpelagic and nonfeeding larval type (i.e., brooding lineages) were observed to have d_N/d_S ratios that were larger than for nonbrooders but equal between the two paralogs. This finding suggested that demographic differences between brooding and nonbrooding lineages were responsible for the elevated d_N/d_S ratios observed for brooders and refuted a suggestion from a previous analysis of the early‐stage gene that the excess nonsynonymous substitutions were due to either (1) gene expression differences at the larval stage between brooders and nonbrooders or (2) the highly repetitive structure of the early‐stage histone H3 gene.     

Tarsal contact chemoreceptor for the host marking pheromone of the cherry fruit fly, Rhagoletis cerasi: responses to natural and synthetic compounds

Abstract. The European cherry fruit fly (Rhagoletis cerasi L.; Diptera, Tephritidae) marks cherries (Prunus avium L.) after oviposition with a host marking pheromone (HMP). The marking trail prevents additional oviposition by the same or other females into the same fruit. On the ventral side of the tarsi of both sexes, contact-chemoreceptor sensilla were identified which contain a receptor cell selectively sensitive to HMP. The HMP receptors of males were slightly more sensitive than those of females, suggesting that the more general term ‘host-marking pheromone’ is more appropriate than the previously used ‘oviposition deterring pheromone (ODP)’. The four structural isomers of the HMP, N(15R, S(β-glucopyranosyl)-oxy-8RS-hydroxypalmitoyl)-taurine, and various derivatives were synthesized and tested in an electrophysiological bioassay. Both the 8R,15R and the 8S,15RS isomers of the HMP were equally active with a threshold of about 2 times 10^-10M, and were shown to be present in the female faeces in similar proportions. The two 15S HMP isomers were about 13 times less active. Testing synthetic derivatives of the HMP molecule revealed that the presence of the four moieties of the molecule are important for the activity: taurine, palmitic acid, C₍₈₎ hydroxyl group, and glucose (C₍₁₅₎). The chain length of the fatty acid, the hydroxyl group at C₍₈₎ and the position of glucose at C₍₁₅₎ also influenced the activity. Only minor loss of activity (factor 2) relative to the natural molecule was observed when the methyl group in the C₍₁₅₎ position was removed. The removal of the β-glycosidically linked glucose (replaced by a hydroxyl group) resulted in about a 4-fold loss of activity. The cation of the HMP molecule seemed to have no effect on its activity, whereas both low and high pH reduced it significantly. Based on these results, field experiments have been initiated to control oviposition by cherry fruit flies on cherries applying the 15-desmethyl-HMP derivative.     

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.     

Up‐regulation of SPINT2/HAI‐2 by Azacytidine in bone marrow mesenchymal stromal cells affects leukemic stem cell survival and adhesion

The role of tumour microenvironment in neoplasm initiation and malignant evolution has been increasingly recognized. However, the bone marrow mesenchymal stromal cell (BMMSC) contribution to disease progression remains poorly explored. We previously reported that the expression of serine protease inhibitor kunitz‐type2 (SPINT2/HAI‐2), an inhibitor of hepatocyte growth factor (HGF) activation, is significantly lower in BMMSC from myelodysplastic syndromes (MDS) patients compared to healthy donors (HD). Thus, to investigate whether this loss of expression was due to SPINT2/HAI‐2 methylation, BMMSC from MDS and de novo acute myeloid leukaemia (de novo AML) patients were treated with 5‐Azacitidine (Aza), a DNA methyltransferase inhibitor. In MDS‐ and de novo AML‐BMMSC, Aza treatment resulted in a pronounced SPINT2/HAI‐2 levels up‐regulation. Moreover, Aza treatment of HD‐BMMSC did not improve SPINT2/HAI‐2 levels. To understand the role of SPINT2/HAI‐2 down‐regulation in BMMSC physiology, SPINT2/HAI‐2 expression was inhibited by lentivirus. SPINT2 underexpression resulted in an increased production of HGF by HS‐5 stromal cells and improved survival of CD34⁺ de novo AML cells. We also observed an increased adhesion of de novo AML hematopoietic cells to SPINT2/HAI‐2 silenced cells. Interestingly, BMMSC isolated from MDS and de novo AML patients had increased expression of the integrins CD49b, CD49d, and CD49e. Thus, SPINT2/HAI‐2 may contribute to functional and morphological abnormalities of the microenvironment niche and to stem/progenitor cancer cell progression. Hence, down‐regulation in SPINT2/HAI‐2 gene expression, due to methylation in MDS‐BMMSC and de novo AML‐BMMSC, provides novel insights into the pathogenic role of the leukemic bone marrow microenvironment.     

Expression of PD‐L1 on regulatory B cells in patients with acute myeloid leukaemia and its effect on prognosis

Programmed death‐ligand 1 (PD‐L1) is involved in immunosuppression in variety of tumours. Regulatory B cells (Bregs) are critical immune regulatory cells, and it has been demonstrated that the number of regulatory B cells in patients with acute myeloid leukaemia (AML) is much higher than that in healthy donors (HDs), which is linked to a poor prognosis. This study aimed to determine whether increased expression of PD‐L1, including in Bregs, is associated with a worse prognosis in individuals with AML. The proportion of Bregs, PD‐L1 expression in Bregs and PD‐1 expression in T cells were determined using flow cytometry using patient samples from 21 newly diagnosed AML patients at different stages of treatment and 25 HDs. We confirmed PD‐L1 expression in Bregs, and PD‐1 expression in CD3⁺CD4⁺T cells in bone marrow and peripheral blood samples from AML patients was higher than that in samples from HDs. The complete remission (CR) and progression‐free survival (PFS) of Bregs with high PD‐L1 expression were significantly decreased following induction chemotherapy. PD‐L1 expression is indeed increased in Bregs from individuals with AML, and high PD‐L1 expression is related to a poor prognosis.     

Microarray-based analysis and clinical validation identify ubiquitin-conjugating enzyme E2E1 (<Emphasis Type="Italic">UBE2E1</Emphasis>) as a prognostic factor in acute myeloid leukemia

Background

Previous research suggested that single gene expression might be correlated with acute myeloid leukemia (AML) survival. Therefore, we conducted a systematical analysis for AML prognostic gene expressions.

Methods

We performed a microarray-based analysis for correlations between gene expression and adult AML overall survival (OS) using datasets GSE12417 and GSE8970. Positive findings were validated in an independent cohort of 50 newly diagnosed, non-acute promyelocytic leukemia (APL) AML patients by quantitative RT-PCR and survival analysis.

Results

Microarray-based analysis suggested that expression of eight genes was each associated with 1-year and 3-year AML OS in both GSE12417 and GSE8970 datasets (p?<?0.05). Next, we validated our findings in an independent cohort of AML samples collected in our hospital. We found that ubiquitin-conjugating enzyme E2E1 (UBE2E1) expression was adversely correlated with AML survival (p?=?0.04). Multivariable analysis showed that UBE2E1 ^high patients had a significant shorter OS and shorter progression-free survival after adjusting other known prognostic factors (p?=?0.03). At last, we found that UBE2E1 expression was negatively correlated with patients’ response to induction chemotherapy (p?<?0.05).

Conclusions

In summary, we demonstrated that UBE2E1 expression was a novel prognostic factor in adult, non-APL AML patients.

     

Prognostic role of Wnt and Fzd gene families in acute myeloid leukaemia

Wnt-Fzd signalling pathway plays a critical role in acute myeloid leukaemia (AML) progression and oncogenicity. There is no study to investigate the prognostic value of Wnt and Fzd gene families in AML. Our study screened 84 AML patients receiving chemotherapy only and 71 also undergoing allogeneic haematopoietic stem cell transplantation (allo-HSCT) from the Cancer Genome Atlas (TCGA) database. We found that some Wnt and Fzd genes had significant positive correlations. The expression levels of Fzd gene family were independent of survival in AML patients. In the chemotherapy group, AML patients with high Wnt2B or Wnt11 expression had significantly shorter event-free survival (EFS) and overall survival (OS); high Wnt10A expressers had significantly longer OS than the low expressers (all P < .05), whereas, in the allo-HSCT group, the expression levels of Wnt gene family were independent of survival. We further found that high expression of Wnt10A and Wnt11 had independent prognostic value, and the patients with high Wnt10A and low Wnt11 expression had the longest EFS and OS in the chemotherapy group. Pathway enrichment analysis showed that genes related to Wnt10A, Wnt11 and Wnt 2B were mainly enriched in ‘cell morphogenesis involved in differentiation’, ‘haematopoietic cell lineage’, ‘platelet activation, signalling and aggregation’ and ‘mitochondrial RNA metabolic process’ signalling pathways. Our results indicate that high Wnt2B and Wnt11 expression predict poor prognosis, and high Wnt10A expression predicts favourable prognosis in AML, but their prognostic effects could be neutralized by allo-HSCT. Combined Wnt10A and Wnt11 may be a novel prognostic marker in AML.     

The impact on high‐grade serous ovarian cancer of obesity and lipid metabolism‐related gene expression patterns: the underestimated driving force affecting prognosis

To investigate whether specific obesity/metabolism‐related gene expression patterns affect the survival of patients with ovarian cancer. Clinical and genomic data of 590 samples from the high‐grade ovarian serous carcinoma (HGOSC) study of The Cancer Genome Atlas (TCGA) and 91 samples from the Australian Ovarian Cancer Study were downloaded from the International Cancer Genome Consortium (ICGC) portal. Clustering of mRNA microarray and reverse‐phase protein array (RPPA) data was performed with 83 consensus driver genes and 144 obesity and lipid metabolism‐related genes. Association between different clusters and survival was analyzed with the Kaplan–Meier method and a Cox regression. Mutually exclusive, co‐occurrence and network analyses were also carried out. Using RNA and RPPA data, it was possible to identify two subsets of HGOSCs with similar clinical characteristics and cancer driver mutation profiles (e.g. TP53), but with different outcome. These differences depend more on up‐regulation of specific obesity and lipid metabolism‐related genes than on the number of gene mutations or copy number alterations. It was also found that CD36 and TGF‐ß are highly up‐regulated at the protein levels in the cluster with the poorer outcome. In contrast, BSCL2 is highly up‐regulated in the cluster with better progression‐free and overall survival. Different obesity/metabolism‐related gene expression patterns constitute a risk factor for prognosis independent of the therapy results in the Cox regression. Prognoses were conditioned by the differential expression of obesity and lipid metabolism‐related genes in HGOSCs with similar cancer driver mutation profiles, independent of the initial therapeutic response.