MicroRNA-192 regulates cell proliferation and cell cycle transition in acute myeloid leukemia via interaction with CCNT2

A novel therapeutic strategy: the significance of exosomal miRNAs in acute myeloid leukemia

Acute myeloid leukemia (AML) is a fast-growing blood cancer that interferes with the normal growth of blood cells in the bone marrow and blood. It is characterized by its unpredictable outlook and high death rate. The main treatment for AML is chemotherapy, but this often results in drug resistance and the possibility of the disease returning. For this reason, new biomarkers are necessary to diagnose, predict, and treat this disease. Research has demonstrated that cells responsible for AML release exosomes that interact with the disease's microenvironment. These exosomes have significant roles in promoting leukemia growth, suppressing normal hematopoiesis, facilitating angiogenesis, and contributing to drug resistance in AML. Further investigations have shown that these exosomes contain miRNAs, which are transferred to target cells and have functional roles. Biomarkers are utilized to assess various aspects of tumor cell behavior, including proliferation, apoptosis, angiogenesis, changes in the microenvironment, transfer of drug resistance, and stability in serum and blood plasma. In this research, we showed that exosomal miRNAs and exosomes have the potential to be used as indicators for detecting various phases of AML and can aid in its medical treatment. Furthermore, they can be specifically targeted for therapeutic purposes in addressing this condition.

Circ_0001602 aggravates the progression of acute myeloid leukemia by regulating the miR-192-5p/ZBTB20 axis

BACKGROUND

Acute myeloid leukemia (AML) is a malignant blood cancer with a poor prognosis and complex pathogenesis. Recently, the critical role of circular RNAs (circRNAs) has been demonstrated in the malignant progression of AML. This study aimed to investigate the functional role and underlying mechanism of circ_0001602 in AML development.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) assay was conducted for detecting the expression of circ_0001602, CCND3, microRNA-192-5p (miR-192-5p), and Zinc Finger and BTB Domain-Containing Protein 20 (ZBTB20) mRNA. RNase R assay and Actinomycin D assay were implemented to determine the characteristics of circ_0001602. Cell counting Kit-8 (CCK-8) assay was performed to evaluate cell proliferation. Flow cytometry was employed for assessing cell cycle distribution and apoptosis. Dual-luciferase reporter assay and RIP assay were utilized for confirming the interactions between miR-192-5p and circ_0001602 or ZBTB20.

RESULTS

Circ_0001602 and ZBTB20 were upregulated and miR-192-5p level was reduced in AML tissues and cells. Depletion of circ_0001602 repressed cell proliferation and induced cell cycle arrest and apoptosis in AML cells. Functionally, circ_0001602 was identified to be the sponge of miR-192-5p, and miR-192-5p silence restored the suppressive effects of circ_0001602 knockdown on AML cell progression. Furthermore, ZBTB20 was a target of miR-192-5p, and ZBTB20 overexpression neutralized the miR-192-5p-mediated inhibiting actions on the malignant phenotypes of AML cells. Besides, circ_0001602 could sponge miR-192-5p to positively regulate ZBTB20 expression.

CONCLUSION

Circ_0001602 contributed to AML cell development at least partially through modulating the miR-192-5p/ZBTB20 axis, which provided new insights for AML treatment.

Nanoparticles Mediated circROBO1 Silencing to Inhibit Hepatocellular Carcinoma Progression by Modulating miR-130a-5p/CCNT2 Axis

Background

Circular RNAs (circRNAs) are becoming vital biomarkers and therapeutic targets for malignant tumors due to their high stability and specificity in tissues. However, biological functions of circRNAs in hepatocellular carcinoma (HCC) are still not well studied.

Methods

Gene Expression Omnibus (GEO) database and qRT-PCR were used to evaluate expression of circROBO1 (hsa_circ_0066568) in HCC tissues and cell lines. CCK-8, colony formation, EdU staining, flow cytometry for cell cycle analysis, and xenograft model assays were performed to detect the circROBO1 function in vitro and in vivo. RNA pull-down, RNA immunoprecipitation (RIP), and Luciferase reporter assays were used to investigate the relationship among circROBO1, miR-130a-5p, and CCNT2. More importantly, we developed nanoparticles made from poly lactic-co-glycolic acid (PLGA) and polyethylene glycol (PEG) chains as the delivery system of si-circROBO1 and then applied them to HCC in vitro and in mice.

Results

circROBO1 was obviously upregulated in HCC tissues and cell lines, and elevated circROBO1 was closely correlated with worse prognosis for HCC patients. Functionally, knocking down circROBO1 significantly suppressed HCC cells growth in vitro and in mice. Mechanistically, circROBO1 acted as a competing endogenous RNA to downregulate miR-130a-5p, leading to CCNT2 expression upregulation. Furthermore, miR-130a-5p mimic or CCNT2 knockdown reversed the role of circROBO1 overexpression on HCC cells, which demonstrated that circROBO1 promoted HCC development via miR-130a-5p/CCNT2 axis. In addition, we developed nanoparticles loaded with si-circROBO1, named as PLGA-PEG (si-circROBO1) NPs, which significantly prevented the proliferation of HCC cells, and did not exhibit apparent toxicity to major organs in vivo.

Conclusion

Our findings firstly demonstrate that circROBO1 overexpression promotes HCC progression by regulating miR-130a-5p/CCNT2 axis, which may serve as an effective nanotherapeutic target for HCC treatment.

A miRNA screening identifies miR-192-5p as associated with response to azacitidine and lenalidomide therapy in myelodysplastic syndromes

BACKGROUND

miRNAs are small non-coding RNAs that regulate gene expression and are linked to cancer development and progression. miRNA profiles are currently studied as new prognostic factors or therapeutic perspectives. Among hematological cancers, myelodysplastic syndromes at higher risk of evolution into acute myeloid leukemia are treated with hypomethylating agents, like azacitidine, alone or in combination with other drugs, such as lenalidomide. Recent data showed that, during azacitidine and lenalidomide therapy, the concurrent acquisition of specific point mutations affecting inositide signalling pathways is associated with lack or loss of response to therapy. As these molecules are implicated in epigenetic processes, possibly involving miRNA regulation, and in leukemic progression, through the regulation of proliferation, differentiation and apoptosis, here we performed a new miRNA expression analysis of 26 high-risk patients with myelodysplastic syndromes treated with azacitidine and lenalidomide at baseline and during therapy. miRNA array data were processed, and bioinformatic results were correlated with clinical outcome to investigate the translational relevance of selected miRNAs, while the relationship between selected miRNAs and specific molecules was experimentally tested and proven.

RESULTS

Patients' overall response rate was 76.9% (20/26 cases): complete remission (5/26, 19.2%), partial remission (1/26, 3.8%), marrow complete remission (2/26, 7.7%), hematologic improvement (6/26, 23.1%), hematologic improvement with marrow complete remission (6/26, 23.1%), whereas 6/26 patients (23.1%) had a stable disease. miRNA paired analysis showed a statistically significant up-regulation of miR-192-5p after 4 cycles of therapy (vs baseline), that was confirmed by real-time PCR analyses, along with an involvement of BCL2, that was proven to be a miR-192-5p target in hematopoietic cells by luciferase assays. Furthermore, Kaplan-Meier analyses showed a significant correlation between high levels of miR-192-5p after 4 cycles of therapy and overall survival or leukemia-free survival, that was stronger in responders, as compared with patients early losing response and non-responders.

CONCLUSIONS

This study shows that high levels of miR-192-5p are associated with higher overall survival and leukemia-free survival in myelodysplastic syndromes responding to azacitidine and lenalidomide. Moreover, miR-192-5p specifically targets and inhibits BCL2, possibly regulating proliferation and apoptosis and leading to the identification of new therapeutic targets.

Circular RNAs: pivotal role in the leukemogenesis and novel indicators for the diagnosis and prognosis of acute myeloid leukemia

Acute myeloid leukemia (AML) is an aggressive hematological malignancy and affected patients have poor overall survival (OS) rates. Circular RNAs (circRNAs) are a novel class of non-coding RNAs (ncRNAs) with a unique loop structure. In recent years, with the development of high-throughput RNA sequencing, many circRNAs have been identified exhibiting either up-regulation or down-regulation in AML patients compared with healthy controls. Recent studies have reported that circRNAs regulate leukemia cell proliferation, stemness, and apoptosis, both positively and negatively. Additionally, circRNAs could be promising biomarkers and therapeutic targets in AML. In this study, we present a comprehensive review of the regulatory roles and potentials of a number of dysregulated circRNAs in AML.

Hub Genes and Long Noncoding RNAs That Regulates It Associated with the Prognosis of Esophageal Squamous Cell Carcinoma Based on Bioinformatics Analysis

Objective

Through bioinformatics analysis methods, the public databases GEO and TCGA were used to research mRNA and squamous cell carcinoma of the esophagus, construct a lncRNA-mRNA network, and screen hub genes and lncRNAs related to prognosis.

Method

Download esophageal squamous cell carcinoma-related mRNA and lncRNA datasets GEO and TCGA public datasets, as well as clinical data, use bioinformatic tools to perform gene differential expression analysis on the datasets to obtain differentially expressing mRNA (DEmRNA) and lncRNA (DElncRNA), and plot volcano plots and cluster heatmaps. The differential intersection of differentially expressed DEmRNA and DElncRNA was extracted by Venn diagram and imported into CytoScape software, a regulatory network visualization software, to construct a lncRNA-mRNA network and use cytoHubba and MCODE plug-ins to screen hub genes and key lncRNAs. The DEmRNA in the network was imported into the Gene and Protein Interaction Retrieval Database (STRING), gene-encoded protein-protein interactions (PPI) network maps were created, and the genes in the PPI network maps were submitted to GO functional annotation and pathway enrichment analysis using Kyoto Encyclopedia of Gene Genomes (KEGG) (KEGG). The link between hub gene and prognosis was studied using the clinical data collected by TCGA.

Result

Retrieve the datasets GSE23400 and GSE38129 from the GEO database and the esophageal squamous cell carcinoma-related mRNAs from TCGA databases and then obtain intersection. Differentially regulated genes revealed a correlation of 326 (up) with 191 (down) in terms of the differential intersection; for this study, we need to collect the GSE130078 dataset from GEO, as well as the lncRNAs from TCGA databases that are connected to esophageal squamous cell cancer. There were 184 differentially up- and downregulated genes in the differential intersection. A differential intersection network of the differential intersection lncRNA-mRNA network allowed us to identify the hub genes, including COL5A2 (COL3A1), COL1A1 (COL1A1), CTD-2171N6.1 (CTD-2171N6.1), and RP11-863P13.3 (RP11-863P13.3). The extracellular matrix, which is important in protein digestion and absorption, was shown to be the primary site of functional enrichment, as shown by GO/KEGG analysis. Squamous cell carcinoma of the mouth and throat is associated with a poor prognosis because of a change in the extracellular matrix structure caused by specific long noncoding RNA (lncRNA) regulatory upregulation.

Conclusion

For the purpose of predicting the prognosis of cancer of the esophagus, researchers studied the esophageal squamous cell carcinoma-related hub genes and important noncoding RNAs (ncRNAs).

VEGFA's distal enhancer regulates its alternative splicing in CML

Enhancer demethylation in leukemia has been shown to lead to overexpression of genes which promote cancer characteristics. The vascular endothelial growth factor A (VEGFA) enhancer, located 157 Kb downstream of its promoter, is demethylated in chronic myeloid leukemia (CML). VEGFA has several alternative splicing isoforms with different roles in cancer progression. Since transcription and splicing are coupled, we wondered whether VEGFA enhancer activity can also regulate the gene's alternative splicing to contribute to the pathology of CML. Our results show that mutating the VEGFA +157 enhancer promotes exclusion of exons 6a and 7 and activating the enhancer by tethering a chromatin activator has the opposite effect. In line with these results, CML patients present with high expression of +157 eRNA and inclusion of VEGFA exons 6a and 7. In addition, our results show that the positive regulator of RNAPII transcription elongation, CCNT2, binds VEGFA's promoter and enhancer, and its silencing promotes exclusion of exons 6a and 7 as it slows down RNAPII elongation rate. Thus our results suggest that VEGFA's +157 enhancer regulates its alternative splicing by increasing RNAPII elongation rate via CCNT2. Our work demonstrates for the first time a connection between an endogenous enhancer and alternative splicing regulation of its target gene.

Circular RNA circ_0005774 contributes to proliferation and suppresses apoptosis of acute myeloid leukemia cells via circ_0005774/miR-192-5p/ULK1 ceRNA pathway

Circular RNAs (circRNAs) and microRNAs (miRNAs) have been emerging as new players in acute myeloid leukemia (AML). Hsa_circ_0005774 (circ_0005774) is an upregulated circRNA in pediatric AML, while its role is uncovered. Thus, we intended to measure the function and mechanism of circ_0005774 in AML leukemogenesis. Real time-quantitative PCR revealed that circ_0005774 was highly expressed in blood of pediatric AML patients and AML cells (HL-60 and NB4), accompanied with downregulated miRNA-192-5p (miR-192-5p) which was a crucial tumor-associated and leukemia-related miRNA. Circ_0005774 was abundant in miRNA response element according to CSCD software, and miR-192-5p was identified as a target of circ_0005774, as evidenced by RNA immunoprecipitation and dual-luciferase reporter assays. Cell viability assay, flow cytometry and western blotting were performed to measure cell functions. Accordingly, blocking circ_0005774 and/or overexpressing miR-192-5p could enhance apoptosis rate of HL-60 and NB4 cells, but suppress cell viability and cell cycle entrance, accompanied with depression of proliferation markers including proliferating cell nuclear antigen (PCNA), CyclinD1 and B cell lymphoma 2 (Bcl-2). Meanwhile, depleting miR-192-5p counteracted the role of circ_0005774 knockdown in AML cells. Uncoordinated 51-like kinase 1 (ULK1) was previously demonstrated to be associated with diagnosis, prognosis and therapeutic strategy for AML, and restoring ULK1 could abrogate miR-192-5p overexpression-induced effects in HL-60 and NB4 cells. Notably, ULK1 was a downstream target of miR-192-5p and indirectly modulated by circ_0005774. In conclusion, circ_0005774 knockdown repressed cell proliferation and promoted apoptosis of AML cells partially through regulating miR-192-5p/ULK1 axis.

MicroRNA-216b regulates cell proliferation, invasion and cycle progression via interaction with cyclin T2 in gastric cancer

Gastric cancer has become the second most common malignant tumor in the world, revealing the molecular mechanism of gastric cancer development is essential for the treatment of gastric cancer and improvement of prognosis. Recent studies have shown that microRNAs may play a carcinogenic or tumor-suppressive role in many types of cancer. It has been detected that miR-216b is down-regulated in many cancer types, indicating that miR-216b can be used as a prognostic marker for these particular types of cancer. However, the effect of miR-216b on gastric cancer remains unclear. In the present study, miR-216 was observed to be significantly down-regulated in cancer tissues compared to normal tissues, and the level of miR-216b in various gastric cancer cell lines was decreased. In addition, miR-216b overexpression inhibits proliferation, migration, invasion, cell cycle and apoptosis of gastric cancer cells. We further verified that the inhibitory effect of miR-216b on proliferation and invasion of gastric cancer cells is mediated by cyclin T2. Overexpression of cyclin T2 can reverse the anti-cancer effect of miR-216b mimics. The results further enriched the mechanism of miR-216b in the development and progression of gastric cancer.

Decitabine shows anti-acute myeloid leukemia potential via regulating the miR-212-5p/CCNT2 axis

Previous research has revealed the involvement of microRNA-212-5p (miR-212-5p) and cyclin T2 (CCNT2) in acute myeloid leukemia (AML). However, whether the miR-212-5p/CCNT2 axis is required for the function of decitabine in AML has not been well elucidated. Quantitative reverse transcription-polymerase chain reaction was used to examine enrichment of miR-212-5p. The relationship between CCNT2 and miR-212-5p was verified by the luciferase reporter assay. Cell apoptosis was evaluated by flow cytometry and western blot. CCK-8 assay was performed to determine cell viability. Decitabine significantly repressed cell viability, while promoted cell apoptosis. Meanwhile, the expression levels of cyclinD1, CDK4, and Bcl-2 were suppressed in cells with decitabine exposure, but Bax and caspase-3 expression levels were upregulated. Besides, miR-212-5p upregulation had the similar function with decitabine in AML cell proliferation and apoptosis. Subsequently, restoration of CCNT2 attenuated miR-212-5p overexpression-induced effects in Kasumi-1 and SKNO-1 cells. In addition, miR-212-5p depletion reversed decitabine-induced CCNT2 downregulation. The miR-212-5p/CCNT2 axis had an implication in the anti-leukemic effect of decitabine in AML.

The Role of Non-Coding RNAs in Controlling Cell Cycle Related Proteins in Cancer Cells

Cell cycle is regulated by a number of proteins namely cyclin-dependent kinases (CDKs) and their associated cyclins which bind with and activate CDKs in a phase specific manner. Additionally, several transcription factors (TFs) such as E2F and p53 and numerous signaling pathways regulate cell cycle progression. Recent studies have accentuated the role of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in the regulation of cell cycle. Both lncRNAs and miRNAs interact with TFs participating in the regulation of cell cycle transition. Dysregulation of cell cycle regulatory miRNAs and lncRNAs results in human disorders particularly cancers. Understanding the role of lncRNAs, miRNAs, and TFs in the regulation of cell cycle would pave the way for design of anticancer therapies which intervene with the cell cycle progression. In the current review, we describe the role of lncRNAs and miRNAs in the regulation of cell cycle and their association with human malignancies.

Comparative profiling of exosomal miRNAs in human adult peripheral and umbilical cord blood plasma by deep sequencing

Aim: To assess differential expression profiles of miRNAs in exosomes derived from human peripheral blood (PB) and umbilical cord blood (UCB). Materials & methods: Small RNA sequencing was performed to characterize the miRNA expression in plasma exosomes processed from UCB of five healthy newborns and PB of five normal adult volunteers, and differentially expressed miRNAs were further analyzed. Results: A total of 65 exosomal miRNAs, including 46 upregulated and 19 downregulated, showed differential expression between UCB and PB. Target genes of these miRNAs were mainly enriched in signaling pathways associated with pregnancy, cancers, cell mobility and nervous system. Conclusion: Exosomal miRNAs may have essential roles in the biological functions of UCB, suggesting the therapeutic and biomarker potentials of exosomes in UCB.

Long non-coding RNA NEAT1/miR-338-3p axis impedes the progression of acute myeloid leukemia via regulating CREBRF

Background

Acute myeloid leukemia (AML) is a heterogeneous hematological disease. Our purpose of the research was to investigate the regulatory influence of long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1)/microRNA-338-3p (miR-338-3p)/CREB3 regulatory factor (CREBRF) in AML progression.

Methods

The associated RNA and protein levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. Cell growth was assessed through colony formation assay and 3-(4,5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Flow cytometry was exploited to determine the apoptosis rate. Cell migration and invasion were detected by transwell assay. The combination of miR-338-3p and NEAT1 or CREBRF was analyzed via the dual-luciferase reporter assay.

Results

NEAT1 and CREBRF were down-regulated in AML tissues and cells. NEAT1 up-regulation suppressed cell growth, migration and invasion but enhanced apoptosis of AML cells. Inhibition of CREBRF reverted the NEAT1-induced effects on AML cells. Moreover, NEAT1 directly targeted miR-338-3p and miR-338-3p targeted CREBRF. NEAT1/miR-338-3p could affect cellular behaviors of AML cells via the modulation of CREBRF.

Conclusion

NEAT1/miR-338-3p axis repressed the AML progression through regulating CREBRF, which might afford a favorable perspective for the AML treatment molecularly.

New signatures of poor CD4 cell recovery after suppressive antiretroviral therapy in HIV-1-infected individuals: involvement of miR-192, IL-6, sCD14 and miR-144

Up to 40% of newly diagnosed cases of HIV-1 infection are late diagnoses, with a profound decrease in CD4 cell counts in many cases. One-third of these individuals do not achieve optimal CD4 cell recovery (OR) after suppressive antiretroviral treatment (ART). This retrospective/longitudinal study of poor recovery (PR) included 79 HIV-1-infected individuals with CD4 count <200 cells/mm³ (25 PR and 54 OR) before ART. After suppressive ART, 21 PR and 24 OR individuals were further analysed, including paired samples. Selected miRs and plasma inflammatory markers were determined to investigate their potential predictive/diagnostic value for poor recovery. miR-192, IL-6 and sCD14 were independently associated with CD4 recovery before ART (p = 0.031, p = 0.007, and p = 0.008, respectively). The combination of these three factors returned a good discrimination (predictive value for PR) value of 0.841 (AUC, p < 0.001). After suppressive ART, miR-144 was independently associated with CD4 recovery (p = 0.017), showing a moderate discrimination value of 0.730 (AUC, p = 0.008) for PR. Our study provides new evidence on the relationship between miRs and HIV-1 infection that could help improve the management of individuals at HIV-1 diagnosis. These miRs and cytokines signature sets provide novel tools to predict CD4 cell recovery and its progression after ART.

Tumour-specific microRNA expression pattern in canine intestinal T-cell-lymphomas

Intestinal T-cell lymphomas are common in dogs, but histopathological diagnosis remains challenging because of accompanying enteritis with lymphocyte involvement. Invasively taken full-layer biopsies are still required for reliable differentiation. The detection of specific microRNA expression patterns in canine intestinal T-cell lymphoma could provide new possibilities to differ intestinal lymphoma from benign inflammation and could lead to further understanding of lymphomagenesis. The objective of this study was to characterize microRNA expression in distinct groups of formalin-fixed and paraffin-embedded samples from canine intestinal T-cell lymphomas, lymphoplasmacellular enteritis and healthy intestinal tissue. In a preliminary test with two samples per group, total RNA was extracted (RNEasy FFPE Kit, Qiagen), reverse transcribed (miScript II RT Kit, Qiagen) and pre-amplified (miScript PreAmp PCR Kit, Qiagen). We performed comparative quantitative PCR on microRNA PCR Array plates (Qiagen) with pre-fabricated reactions for 183 different mature canine microRNAs. Subsequently, 12 microRNAs with conspicuous expression changes in the lymphoma group were selected and microRNA expression of all samples (n = 8) per group was analysed with individual microRNA assays (miScript Primer Assays, Qiagen) on the reverse transcribed RNA without pre-amplification. Our results revealed lymphoma-specific expression patterns, with down-regulation of the tumour-suppressing microRNAs miR-194, miR-192, miR-141 and miR-203, and up-regulation of oncogenic microRNAs, including microRNAs from the miR-106a~363 cluster. In addition, we detected only slight expression alterations between healthy intestinal tissue and lymphoplasmacellular enteritis cases. We conclude that microRNA expression patterns can be used to separate T-cell lymphomas from healthy tissue and benign inflammatory disorders.

miR-362-5p promotes cell proliferation and cell cycle progression by targeting GAS7 in acute myeloid leukemia

Recently, miR-362-5p has attracted special interest as a novel prognostic predictor in acute myeloid leukemia (AML). However, its biological function and underlying molecular mechanism in AML remain to be further defined. Herein, we found that a significant increase in miR-362-5p expression was observed in AML patients and cell lines using quantitative real-time PCR. The expression of miR-362-5p was altered in THP-1 and HL-60 cells by transfecting with miR-362-5p mimic or inhibitor. A series of experiments showed that inhibition of miR-362-5p expression significantly suppressed cell proliferation, induced G0/G1 phase arrest and attenuated tumor growth in vivo. On the contrary, ectopic expression of miR-362-5p resulted in enhanced cell proliferation, cell cycle progression and tumor growth. Moreover, growth arrest-specific 7 (GAS7) was confirmed as a direct target gene of miR-362-5p and was negatively modulated by miR-362-5p. GAS7 overexpression imitated the tumor suppressive effect of silenced miR-362-5p on THP-1 cells. Furthermore, miR-362-5p knockdown or GAS7 overexpression obviously down-regulated the expression levels of PCNA, CDK4 and cyclin D1, but up-regulated p21 expression. Collectively, our findings demonstrate that miR-362-5p exerts oncogenic effects in AML by directly targeting GAS7, which might provide a promising therapeutic target for AML.

Identification of distinctive long noncoding RNA competitive interactions and a six-methylated-gene prognostic signature in acute myeloid leukemia with -5/del(5q) or -7/del(7q)

BACKGROUND

Acute myeloid leukemia (AML) with -5/del(5q) or -7/del(7q) has special clinical and biological characteristics, but its molecular mechanisms and risk stratification remain unknown.

METHODS

The RNA sequencing and DNA methylation of 23 patients with -5/del(5q) or -7/del(7q) and 128 patients with other subtypes of acute myeloid leukemia were obtained from The Cancer Genome Atlas (TCGA). The regulatory mechanisms of competitive endogenous RNA (ceRNA) network and DNA methylation on gene expression were explored. To find robust and specific risk stratification for this AML subtype, a prognostic model was established and evaluated through four independent data sets.

RESULTS

We identified 966 differentially expressed long noncoding RNA, 2274 differentially expressed genes, and 47 differentially expressed microRNAs, and constructed a ceRNA network. After the integrated analysis of differentially methylated and expressed genes, 19 genes showed the opposite trend between the methylation variation and gene expression. An six-methylated-gene prognostic signature which highly correlated with overall survival was established, and the performance was validated by leave-one-out cross validation method and permutation test. Furthermore, the excellent prognostic value of this model was supported by an independent cohort, while specificity of this model was validated by three independent data sets, suggesting it as a predictive classifier with high efficiency for distinguishing those with -5/del(5q) or -7/del(7q) from other AML subtypes.

CONCLUSIONS

The ceRNA network may provide new ideas for the diagnosis and treatment for patients with -5/del(5q) or -7/del(7q).The six-methylated-gene prognostic signature was a robust, specific, and clinically practical risk stratification for the outcome of patients with AML having -5/del(5q) or -7/del(7q).

Role of microRNAs, circRNAs and long noncoding RNAs in acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant tumor of the immature myeloid hematopoietic cells in the bone marrow (BM). It is a highly heterogeneous disease, with rising morbidity and mortality in older patients. Although researches over the past decades have improved our understanding of AML, its pathogenesis has not yet been fully elucidated. Long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are three noncoding RNA (ncRNA) molecules that regulate DNA transcription and translation. With the development of RNA-Seq technology, more and more ncRNAs that are closely related to AML leukemogenesis have been discovered. Numerous studies have found that these ncRNAs play an important role in leukemia cell proliferation, differentiation, and apoptosis. Some may potentially be used as prognostic biomarkers. In this systematic review, we briefly described the characteristics and molecular functions of three groups of ncRNAs, including lncRNAs, miRNAs, and circRNAs, and discussed their relationships with AML in detail.

MicroRNA-204 Potentiates the Sensitivity of Acute Myeloid Leukemia Cells to Arsenic Trioxide

Although arsenic trioxide (ATO) is a well-known antileukemic drug used for acute promyelocytic leukemia treatment, the development of ATO resistance is still a big challenge. We previously reported that microRNA-204 (miR-204) was involved in the regulation of acute myeloid leukemia (AML) cell apoptosis, but its role in chemoresistance is poorly understood. In the present study, we showed that miR-204 was significantly increased in AML cells after ATO treatment. Interestingly, the increased miR-204 level that was negatively correlated with ATO induced the decrease in cell viability and baculoviral inhibition of apoptosis protein repeat-containing 6 (BIRC6) expression. Overexpression of miR-204 potentiated ATO-induced AML cell growth inhibition and apoptosis. Furthermore, miR-204 directly targets to the 3′-UTR of BIRC6. Upregulation of miR-204 decreased BIRC6 luciferase activity and expression, which subsequently enhanced the expression of p53. Restoration of BIRC6 markedly reversed the effect of miR-204 on the regulation of AML cell sensitivity to ATO. Taken together, our study demonstrates that miR-204 decreases ATO chemoresistance in AML cells at least partially via promoting BIRC6/p53-mediated apoptosis. miR-204 represents a novel target of ATO, and upregulation of miR-204 may be a useful strategy to improve the efficacy of ATO in AML treatment.

miR-192 Is Overexpressed and Promotes Cell Proliferation in Prostate Cancer

OBJECTIVE

Prostate cancer (PCa) is one of the most prevalent types of cancer among men worldwide. The incidence of PCa is increasing in China. Therefore, there is an urgent need to identify novel diagnostic and prognostic markers for PCa to improve the treatment of the disease.

METHODS

The Cancer Genome Atlas (TCGA) and GEO database were used to analyze the expression of miR-192, and the relationship between miR-192 and the clinical features of patients with PCa. Cell cycle and cell proliferation assay were used to detect the functional roles of miR-192 in PCa. Bioinformatic analysis for miR-192-5p was performed using gene ontology and KEGG analysis.

RESULTS

By analyzing the dataset of TCGA, we found that miR-192 was overexpressed in PCa samples compared to normal tissues and was upregulated in high-grade PCa compared to low-grade PCa. We also observed that higher miR-192 expression was associated with a shorter biochemical recurrence-free survival time. Our results also demonstrated that miR-192 promoted PCa cell proliferation and cell cycle progression.

CONCLUSION

These results suggest that miR-192 may be considered for use as a potential diagnostic and therapeutic target of PCa.

MicroRNA in leukemia: Tumor suppressors and oncogenes with prognostic potential

Leukemia is known as a progressive malignant disease, which destroys the blood-forming organs and results in adverse effects on the proliferation and development of leukocytes and their precursors in the blood and bone marrow. There are four main classes of leukemia including acute leukemia, chronic leukemia, myelogenous leukemia, and lymphocytic leukemia. Given that a variety of internal and external factors could be associated with the initiation and progression of different types of leukemia. One of the important factors is epigenetic regulators such as microRNAs (miRNAs) and long noncoding RNAs (ncRNA). MiRNAs are short ncRNAs which act as tumor suppressor (i.e., miR-15, miR-16, let-7, and miR-127) or oncogene (i.e., miR-155, miR-17-92, miR-21, miR-125b, miR-93, miR-143-p3, miR-196b, and miR-223) in leukemia. It has been shown that deregulation of these molecules are associated with the initiation and progression of leukemia. Hence, miRNAs could be used as potential therapeutic candidates in the treatment of patients with leukemia. Moreover, increasing evidence revealed that miRNAs could be used as diagnostic and prognostic biomarkers in monitoring patients in early stages of disease or after received chemotherapy regimen. It seems that identification and development of new miRNAs could pave to the way to the development new therapeutic platforms for patients with leukemia. Here, we summarized various miRNAs as tumor suppressor and oncogene which could be introduced as therapeutic targets in treatment of leukemia.

Adenylate cyclase 7 regulated by miR-192 promotes ATRA-induced differentiation of acute promyelocytic leukemia cells

Adenylate cyclase 7 (AC7) has been reported to participate in various biological processes during cancer progression. However, the roles of AC7 in all-trans retinoic acid (ATRA)-induced differentiation of acute promyelocytic leukemia (APL) cells are still unknown. In this study, firstly, our results showed that AC7 affected intracellular cAMP level and influenced ATRA-induced differentiation of APL cells. Secondly, we revealed that miR-192 could directly target AC7 expression and knockdown of miR-192 promoted ATRA-induced APL cell differentiation by regulating AC7 expression. Furthermore, we found that AC7 expression was lower in patients with relapsed APL than that in patients with newly diagnosed APL, while miR-192 expression was relatively higher in patients with relapsed APL. Taken together, our results show that miR-192-mediated AC7 could play important roles in differentiation of APL cells, AC7 and miR-192 might be new biomarkers and therapeutic targets for patients with relapsed APL.

MicroRNAs in Autoimmunity and Hematological Malignancies

Autoimmunity and hematological malignancies are often concomitant in patients. A causal bidirectional relationship exists between them. Loss of immunological tolerance with inappropriate activation of the immune system, likely due to environmental and genetic factors, can represent a breeding ground for the appearance of cancer cells and, on the other hand, blood cancers are characterized by imbalanced immune cell subsets that could support the development of the autoimmune clone. Considerable effort has been made for understanding the proteins that have a relevant role in both processes; however, literature advances demonstrate that microRNAs (miRNAs) surface as the epigenetic regulators of those proteins and control networks linked to both autoimmunity and hematological malignancies. Here we review the most up-to-date findings regarding the miRNA-based molecular mechanisms that underpin autoimmunity and hematological malignancies.

OncomiR or antioncomiR: Role of miRNAs in Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a hematopoietic progenitor/stem cell disorder in which neoplastic myeloblasts are stopped at an immature stage of differentiation and lost the normal ability of proliferation and apoptosis. MicroRNAs (miRNAs) are small noncoding, single-stranded RNA molecules that can mediate the expression of target genes. While miRNAs mean to contribute the developments of normal functions, abnormal expression of miRNAs and regulations on their corresponding targets have often been found in the developments of AML and described in recent years. In leukemia, miRNAs may function as regulatory molecules, acting as oncogenes or tumor suppressors. Overexpression of miRNAs can down-regulate tumor suppressors or other genes involved in cell differentiation, thereby contributing to AML formation. Similarly, miRNAs can down-regulate different proteins with oncogenic activity as tumor suppressors. We herein review the current data on miRNAs, specifically their targets and their biological function based on apoptosis in the development of AML.

In-depth profiling of miRNA regulation in the body wall of sea cucumber Apostichopus japonicus during skin ulceration syndrome progression

MicroRNAs (miRNAs) are small non-coding RNAs that mediate mRNA degradation or translation repression. Previous study showed that the expression of miRNAs was significantly changed in the body wall of sea cucumber Apostichopus japonicus after skin ulceration syndrome (SUS) infection, which is a dynamic process. However, the critical miRNAs from body wall that involved in different infection stages of SUS remain unknown. In this study, four cDNA libraries were constructed with the body wall from healthy and three SUS-infected stages of A. japonicus. A total of 248 conserved miRNAs and five novel miRNAs were identified through Illumina HiSeq 2000 platform. Compared to the control, 238 miRNAs showed significant differential expression at three stages of SUS progression. Totally, 3149 miRNA-mRNA pairs were identified by target prediction and 314 miRNA-mRNA pairs showed negative correlation. It is noteworthy that 15 miRNAs and four mRNAs were located at the crucial positions of the network built with the anti-correlated miRNA-mRNA pairs. GO and KEGG enrichment analysis indicated that the predicted targets were involved in many immune-related processes. Deep analysis of miR-31c-5p, miR-29b-3p, NF-kB, mucin 2 and titin showed that they may play important roles in the pathogens attachment and recognition, signaling transduction and lesions repair of A. japonicus after SUS infection. These results would be useful for further investigating the potential roles of critical miRNAs and mRNAs in A. japonicus immune regulation.

Downregulation of miR‑135a predicts poor prognosis in acute myeloid leukemia and regulates leukemia progression via modulating HOXA10 expression

MicroRNA‑135a (miR‑135a) has been shown to exert important roles in various human cancer types, such as glioblastoma, thyroid carcinoma and renal carcinoma. However, the function of miR‑135a in acute myeloid leukemia (AML) remains largely unknown. In the present study, it was demonstrated that miR‑135a expression was significantly downregulated in AML cells compared with normal control cells. Furthermore, the downregulation of miR‑135a in patients with AML predicted poor prognosis. Through functional experiments, overexpression of miR‑135a was demonstrated to significantly inhibit the proliferation and cell cycle of AML cells, while it promoted cellular apoptosis. miR‑135a directly targeted HOXA10 in AML cells. miR‑135a overexpression significantly suppressed the mRNA and protein levels of HOXA10 in AML cells. Moreover, there was an inverse association between miR‑135a expression and HOXA10 level in AML samples. Additionally, by ectopic expression of HOXA10, restoration of HOXA10 significantly abolished the effects of miR‑135a overexpression on AML cell proliferation, cell cycle and apoptosis. In conclusion, the present study demonstrated that miR‑135a serves as a tumor suppressor in AML by targeting HOXA10, and miR‑135a may be a promising prognostic biomarker for AML patients.

Severity of Systemic Inflammatory Response Syndrome Affects the Blood Levels of Circulating Inflammatory-Relevant MicroRNAs

The systemic inflammatory response syndrome (SIRS) is a potentially lethal response triggered by diverse forms of tissue injury and infection. When systemic inflammation is triggered by infection, the term sepsis is used. Understanding how inflammation is mediated and regulated is of enormous medical importance. We previously demonstrated that circulating inflammatory-relevant microRNAs (CIR-miRNAs) are candidate biomarkers for differentiating sepsis from SIRS. Here, we set out to determine how CIR-miRNA levels reflect SIRS severity and whether they derive from activated immune cells. Clinical disease severity scores and markers of red blood cell (RBC) damage or immune cell activation were correlated with CIR-miRNA levels in patients with SIRS and sepsis. The release of CIR-miRNAs modulated during SIRS was assessed in immune cell cultures. We show that severity of non-infective SIRS, but not sepsis is reflected in the levels of miR-378a-3p, miR-30a-5p, miR-30d-5p, and miR-192-5p. These CIR-miRNA levels positively correlate with levels of the redox biomarker, peroxiredoxin-1 (Prdx-1), which has previously been shown to be released by immune cells during inflammation. Furthermore, in vitro activated immune cells produce SIRS-associated miR-378a-3p, miR-30a-5p, miR-30d-5p, and miR-192-5p. Our study furthers the understanding of the origin, role, and trafficking of CIR-miRNAs as potential regulators of inflammation.

MicroRNAs as New Biomarkers for Diagnosis and Prognosis, and as Potential Therapeutic Targets in Acute Myeloid Leukemia

Acute myeloid leukemias (AML) are clonal disorders of hematopoietic progenitor cells which are characterized by relevant heterogeneity in terms of phenotypic, genotypic, and clinical features. Among the genetic aberrations that control disease development there are microRNAs (miRNAs). miRNAs are small non-coding RNAs that regulate, at post-transcriptional level, translation and stability of mRNAs. It is now established that deregulated miRNA expression is a prominent feature in AML. Functional studies have shown that miRNAs play an important role in AML pathogenesis and miRNA expression signatures are associated with chemotherapy response and clinical outcome. In this review we summarized miRNA signature in AML with different cytogenetic, molecular and clinical characteristics. Moreover, we reviewed the miRNA regulatory network in AML pathogenesis and we discussed the potential use of cellular and circulating miRNAs as biomarkers for diagnosis and prognosis and as therapeutic targets.

MicroRNA, an Antisense RNA, in Sensing Myeloid Malignancies

Myeloid malignancies, including myelodysplastic syndromes and acute myeloid leukemia, are clonal diseases arising in hematopoietic stem or progenitor cells. In recent years, microRNA (miRNA) expression profiling studies have revealed close associations of miRNAs with cytogenetic and molecular subtypes of myeloid malignancies, as well as outcome and prognosis of patients. However, the roles of miRNA deregulation in the pathogenesis of myeloid malignancies and how they cooperate with protein-coding gene variants in pathological mechanisms leading to the diseases have not yet been fully understood. In this review, we focus on recent insights into the role of miRNAs in the development and progression of myeloid malignant diseases and discuss the prospect that miRNAs may serve as a potential therapeutic target for leukemia.