Prognostic role of microRNA-181a/b in hematological malignancies: a meta-analysis

Acovenoside A as a novel therapeutic approach to boost taxol and carboplatin apoptotic and antiproliferative activities in NSCLC: Interplay of miR-630/miR-181a and apoptosis genes

The aim of the present study is to explore the potential anticancer effect of the cardenolide; acovenoside A against non-small cell lung cancer (NSCLC), understand its molecular mechanism in inducing apoptosis and show the effect of its combination with carboplatin and taxol. MTT assay showed that the combination of acovenoside A with taxol and carboplatin caused 78.9% cytotoxicity reflecting the synergistic effect. The triple combination showed the best growth inhibition efficiency where the number of cells at the G2/M phase was decreased and boosted up apoptotic and necrotic activity. The combination also showed the most remarkable increase in gene expression of Bax and p53 and the least level of Bcl2. The gene expression of miRNA181a and miRNA630 was significantly upregulated in cell lines treated with the combination. The present study has proven that the underlying mechanism of acovenoside A is partially attributed to the upregulation of miR-630 and miR-181a gene expressions which in turn targets the intrinsic apoptosis genes as p53, Bax and Bcl2 as well as caspase 3. The present study is the first to address the valuable effect of using acovenoside A together with carboplatin and taxol in the treatment of NSCLC via exerting apoptotic, antiproliferative, and cytotoxic effects..

miR-181c regulates MCL1 and cell survival in GATA2 deficient cells

GATA2 is a transcription factor critical for hematopoiesis. Germline mutations in GATA binding protein 2 (GATA2) led to haploinsufficiency, severe cytopenias of multiple cell lineages, susceptibility to infections and strong propensity to develop myelodysplastic syndrome, and acute myeloid leukemia. Mechanisms of progressive cytopenias remain unclear. MicroRNA (miRNA) represents a unique mechanism of post-transcriptional gene regulation. In this study, miRNA profiles were evaluated and eight miRNAs were found to be differentially expressed (≥2-fold, P ≤ 0.05) in patient-derived cell lines (N = 13) in comparison to controls (N = 10). miR-9, miR-181a-2-3p, miR-181c, miR-181c-3p, miR-486-3p, and miR-582 showed increased expression, whereas miR-223 and miR-424-3p showed decreased expression. Cell death assays indicated that miR-181c potently induces cell death in lymphoid (Ly-8 and SP-53) and myeloid (HL-60) cell lines. miR-181c was predicted to target myeloid cell leukemia (MCL)1, which was confirmed by transfection assays, resulting in significantly reduced MCL1 mRNA and decreased live cell numbers. Bone marrow analysis of 34 GATA2 patients showed significantly decreased cellularity, CD34-positive cells, monocytes, dendritic cells, NK cells, B cells, and B cell precursors in comparison to healthy controls (N = 29; P < 0.001 for each), which was accompanied by decreased levels of MCL1 (P < 0.05). GATA2 expression led to significant repression of miR-181c expression in transfection experiments. Conversely, knockdown of GATA2 led to increased miR-181c expression. These findings indicate that miR-181c expression is increased and MCL1 levels decreased in GATA2 deficiency cells, and that GATA2 represses miR-181c transcription. Increased miR-181c may contribute to elevated cell death and cytopenia in GATA2 deficiency potentially through down-regulation of MCL1.

MicroRNA-Mediated Epigenetic Regulation of Rheumatoid Arthritis Susceptibility and Pathogenesis

MicroRNAs (miRNAs) play crucial roles in regulating the transcriptome and development of rheumatoid arthritis (RA). Currently, a comprehensive map illustrating how miRNAs regulate transcripts, pathways, immune system differentiation, and their interactions with terminal cells such as fibroblast-like synoviocytes (FLS), immune-cells, osteoblasts, and osteoclasts are still laking. In this review, we summarize the roles of miRNAs in the susceptibility, pathogenesis, diagnosis, therapeutic intervention, and prognosis of RA. Numerous miRNAs are abnormally expressed in cells involved in RA and regulate target genes and pathways, including NF-κB, Fas-FasL, JAK-STAT, and mTOR pathways. We outline how functional genetic variants of miR-499 and miR-146a partly explain susceptibility to RA. By regulating gene expression, miRNAs affect T cell differentiation into diverse cell types, including Th17 and Treg cells, thus constituting promising gene therapy targets to modulate the immune system in RA. We summarize the diagnostic and prognostic potential of blood-circulating and cell-free miRNAs, highlighting the opportunity to combine these miRNAs with antibodies to cyclic citrullinated peptide (ACCP) to allow accurate diagnosis and prognosis, particularly for seronegative patients. Furthermore, we review the evidence implicating miRNAs as promising biomarkers of efficiency and response of, and resistance to, disease-modifying anti-rheumatic drugs and immunotherapy. Finally, we discuss the autotherapeutic effect of miRNA intervention as a step toward the development of miRNA-based anti-RA drugs. Collectively, the current evidence supports miRNAs as interesting targets to better understand the pathogenetic mechanisms of RA and design more efficient therapeutic interventions.

Anticancer properties of vincristine is modulated by microRNAs in acute lymphoblastic leukemia Nalm6 cell line

Precursor B-cell acute lymphoblastic leukemia (B-ALL), a highly diverse disease, is the most widespread pediatric malignancy characterized by cytogenetic and molecular abnormalities such as altered microRNA (miR) expression signatures. MiRs are a class of short noncoding RNAs. Dysregulation in the expression of miRs plays a crucial role in different types of cancers. Vincristine is an antineoplastic drug with a broad spectrum of activity against different hematologic malignancies and is the first-line treatment for B-ALL. Previous studies have proposed miR-17 and miR-181/b as oncomirs and miR-34/a as a tumor suppressor in Nalm6 cells, thus in the current study, we investigated the effects of vincristine treatment on the expression of miR-17, miR-34/a and miR-181/b expression levels. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay was conducted to estimate the optimal concentration of vincristine in the Nalm-6 cell line. Expression of miRs was calculated using real-time PCR. Our results showed significant downregulation of miR-17 (FC = 0.226; P < 0.0004) in Nalm6 cells after vincristine treatment. Conversely, miR-34/a (FC = 4.823; P < 0.0001) was significantly upregulated. Also, the expression of miR-181/b (FC = 0.156; P < 0.3465) was not significantly different between the vincristine treated group and the control group. In conclusion, it is proposed that one of the mechanisms by which vincristine improves B-ALL is by modulating the expression of specific miRs. These specific miRs will serve as good diagnostic and prognostic biomarkers.

Targeting SOS1 overcomes imatinib resistance with BCR-ABL independence through uptake transporter SLC22A4 in CML

Resistance to the BCR-ABL inhibitor imatinib mesylate poses a major problem for the treatment of chronic myeloid leukemia. Imatinib resistance often results from a secondary mutation in BCR-ABL that interferes with drug binding. However, sometimes there is no mutation in BCR-ABL, and the basis of such BCR-ABL-independent imatinib mesylate resistance remains to be elucidated. SOS1, a guanine nucleotide exchange factor for Ras protein, affects drug sensitivity and resistance to imatinib. The depletion of SOS1 markedly inhibits cell growth either in vitro or in vivo and significantly increases the sensitivity of chronic myeloid leukemia cells to imatinib. Furthermore, LC-MS/MS and RNA-seq assays reveal that SOS1 negatively regulates the expression of SLC22A4, a member of the carnitine/organic cation transporter family, which mediates the active uptake of imatinib into chronic myeloid leukemia cells. HPLC assay confirms that intracellular accumulation of imatinib is accompanied by upregulation of SLC22A4 through SOS1 inhibition in both sensitive and resistant chronic myeloid leukemia cells. BAY-293, an inhibitor of SOS1/Ras, was found to depress proliferation and colony formation in chronic myeloid leukemia cells with resistance and BCR-ABL independence. Altogether these findings indicate that targeting SOS1 inhibition promotes imatinib sensitivity and overcomes resistance with BCR-ABL independence by SLC22A4-mediated uptake transport.

Targeting microRNA in hematologic malignancies

PURPOSE OF REVIEW

MiRNAs are critical regulators for gene expression. Numerous studies have revealed how miRNAs contribute to the pathogenesis of hematologic malignancies.

RECENT FINDINGS

The identification of novel miRNA regulatory factors and pathways crucial for miRNA dysregulation has been linked to hematologic malignancies. miRNA expression profiling has shown their potential to predict outcomes and treatment responses. Recently, targeting miRNA biogenesis or pathways has become a promising therapeutic strategy with recent miRNA-therapeutics being developed.

SUMMARY

We provide a comprehensive overview of the role of miRNAs for diagnosis, prognosis, and therapeutic potential in hematologic malignancies.

MicroRNA-181a as novel liquid biopsy marker of central nervous system involvement in pediatric acute lymphoblastic leukemia

Background

Refractory central nervous system (CNS) involvement is among the major causes of therapy failure in childhood acute leukemia. Applying contemporary diagnostic methods, CNS disease is often underdiagnosed. To explore more sensitive and less invasive CNS status indicators, we examined microRNA (miR) expressions and extracellular vesicle (EV) characteristics.

Methods

In an acute lymphoblastic leukemia (ALL) discovery cohort, 47 miRs were screened using Custom TaqMan Advanced Low-Density Array gene expression cards. As a validation step, a candidate miR family was further scrutinized with TaqMan Advanced miRNA Assays on serial cerebrospinal fluid (CSF), bone marrow (BM) and peripheral blood samples with different acute leukemia subtypes. Furthermore, small EV-rich fractions were isolated from CSF and the samples were processed for immunoelectron microscopy with anti-CD63 and anti-CD81 antibodies, simultaneously.

Results

Regarding the discovery study, principal component analysis identified the role of miR-181-family (miR-181a-5p, miR-181b-5p, miR-181c-5p) in clustering CNS-positive (CNS⁺) and CNS-negative (CNS^‒) CSF samples. We were able to validate miR-181a expression differences: it was about 52 times higher in CSF samples of CNS⁺ ALL patients compared to CNS^‒ cases (n = 8 vs. n = 10, ΔFC = 52.30, p = 1.5E−4), and CNS⁺ precursor B cell subgroup also had ninefold higher miR-181a levels in their BM (p = 0.04). The sensitivity of CSF miR-181a measurement in ALL highly exceeded those of conventional cytospin in the initial diagnosis of CNS leukemia (90% vs. 54.5%). Pellet resulting from ultracentrifugation of CNS⁺ CSF samples of ALL patients showed atypical CD63⁻/CD81⁻ small EVs in high density by immunoelectron microscopy.

Conclusions

After validating in extensive cohorts, quantification of miR-181a or a specific EV subtype might provide novel tools to monitor CNS disease course and further adjust CNS-directed therapy in pediatric ALL.

The Significance of miRNAs as a Prognostic Biomarker for Survival Outcome in T Cell - Acute Lymphoblastic Leukemia Patients: A Systematic Review and Meta-Analysis

Purpose

T-cell acute lymphoblastic leukemia (T-ALL) affects lymphoid cells. Previous studies have reported that miRNAs play a significant role in T-ALL prognosis and have the potential to function as biomarkers in T-ALL. Therefore, this systematic review and meta-analysis study was designed to evaluate the overall prognostic impact of miRNAs in T-ALL patients.

Methods

Eligible studies published between Jan 2010 and April 2018 were retrieved from online bibliographic databases based on multiple keywords to generate search strings. Meta-analysis was performed using the outcome measure, Hazard Ratio (HR). A survival analysis of all studies was conducted and a subsequent forest plot was generated to evaluate the pooled effect size, across all T-ALL patients. Subgroup analysis was conducted based on demographic characteristics and commonly represented miRNAs among the included studies.

Results

A total of 17 studies were included for systematic review, among which 16 studies were eligible for meta-analysis, which, in total discussed 32 different miRNAs. The mean effect size of HR value was 0.929 (CI 0.878–0984), which indicates a decrease in risk of death by 7.1%. The analysis was based on the random effects model with the heterogeneity measure index (I²) being 84.92%. The pooled effect size (HR) of upregulated and downregulated miRNA expressions on survival outcome in the T-ALL patient was 0.787 (CI 0.732–0.845) and 1.225 (CI 1.110–1.344) respectively. The subgroup analysis was performed based on demographic characteristics (age, gender, lactate dehydrogenase, WBC count) and expression of miR221 and miR46a.

Conclusion

Our systematic review and meta-analysis findings suggest that the overall miRNA expression is potentially associated with a decreased likelihood of death in T-ALL patients. Although our findings are inconclusive, the results point toward miRNA expression allowing for prognostic evaluation of T-ALL patients.

Circulating microRNA as diagnostic biomarkers for haematological cancers: a systematic review and meta-analysis

Purpose: Recent studies have validated microRNAs (miRNAs) as a diagnostic biomarker for haematological cancers. This study aimed to estimate the overall diagnostic accuracy of circulating miRNAs in haematological malignancies. Materials and Methods: Multiple databases (Google Scholar, PubMed, EMBASE, Cochrane Library,) were searched until 19th August 2017. Results: The meta-analysis included 50 studies from 20 publications. The diagnostic accuracy was assessed by pooled specificity, sensitivity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and area under the curve area (AUC) by random effect model. We used QUADAS (Quality Assessment for diagnostic accuracy studies) to evaluate the quality of the included studies. To perform the meta-analysis, we used Meta-Disk 1.4, Revman 5.3 and Stata 12.0 software. High diagnostic accuracy was demonstrated, with a sensitivity of 0.81, a specificity of 0.85, a PLR of 5.28, an NLR of 0.22, a DOR of 30.39, and an AUC of 0.91. Subgroup analyses showed better outcomes for the African population, combined miRNAs and leukaemia patients compared with other subgroups. Conclusion: Our results indicated that circulating miRNAs especially combined miRNA can be used as a diagnostic marker in haematological cancers.

Discovery of the Oncogenic Parp1, a Target of bcr-abl and a Potential Therapeutic, in mir-181a/PPFIA1 Signaling Pathway

miR-181a is downregulated in leukemia and affects its progression, drug resistance, and prognosis. However, the exact mechanism of its targets in leukemia, particularly in chronic myelogenous leukemia (CML), has not previously been established. Here, we use a multi-omics approach to demonstrate that protein tyrosine phosphatase, receptor type, f polypeptide, leukocyte common antigen (LAR) interacting protein (liprin), alpha 1 (PPFIA1) is a direct target for miR-181a in CML. Phospho-array assay shows that multiple phosphorylated proteins, particularly KIT signaling molecules, were downregulated in PPFIA1 inhibition. Additionally, PPFIA1 bound PARP1, a common molecule downstream of both PPFIA1 and BCR/ABL, to upregulate KIT protein through activation of nuclear factor kappa B (NF-κB)-P65 expression. Targeted inhibition of PPFIA1 and PARP1 downregulated c-KIT level, inhibited CML cell growth, and prolonged mouse survival. Overall, we report a critical regulatory miR-181a/PPFIA1/PARP1/NF-κB-P65/KIT axis in CML, and our preclinical study supports that targeted PPFIA1 and PARP1 may serve as a potential CML therapy.

MicroRNA-504 modulates osteosarcoma cell chemoresistance to cisplatin by targeting p53

Chemoresistance implicates the therapeutic value of cisplatin and remains a primary obstacle to its clinical use. MicroRNAs (miRs) negatively modulate the expression of their target genes and are associated with the occurrence and progression of various types of tumor. The abnormal expression of miR-504 has been reported in certain types of human tumor and has been associated with tumor prognosis. However, the association between miR-504 and cisplatin in human osteosarcoma remains unclear. The present study therefore aimed to assess the in vitro effects and possible mechanism of miR-504 in cell proliferation, apoptosis and cisplatin resistance in MG63 osteosarcoma cells. The results demonstrated that miR-504 was overexpressed in osteosarcoma tissues and cells. This overexpression also induced cell proliferation, as determined by MTT and EdU staining assays. Furthermore, miR-504 suppressed cisplatin-induced apoptosis, which was demonstrated via MTT, cell morphology analysis and flow cytometry. Cisplatin-induced G₁ arrest was also suppressed, which was determined by flow cytometry. The potential target genes of miR-504 were predicted using bioinformatics. p53 was confirmed to be a direct target of miR-504 using a luciferase reporter assay and western blot analysis revealed that miR-504 negatively regulated p53 expression at a molecular level. These results indicate that miR-504 contributes to cisplatin resistance in MG63 osteosarcoma cells by suppressing p53. miR-504 may therefore be a potential biomarker for cisplatin resistance in patients with osteosarcoma.

miR-29 promotes osteosarcoma cell proliferation and migration by targeting PTEN

Osteosarcoma (OS) is an aggressive malignant neoplasm that arises from primitively transformed cells of mesenchymal origin, and that exhibits osteoblastic differentiation and produces malignant osteoid. MicroRNAs (miRNAs) have been widely reported to have important regulatory roles in various human tumors, including OS. However, the potential mechanism of miR-29 in OS remains largely unknown. miR-29 was highly expressed in OS and overexpression of miR-29 promoted OS cell proliferation, as well as proliferating cell nuclear antigen (PCNA) expression and migration, whereas lower expression of miR-29 inhibited OS cell proliferation, PCNA expression and migration. In the present study, a dual-luciferase reporter system supporting phosphatase and tensin homolog (PTEN) was a target of miR-29 and its expression was inhibited by miR-29 mimic, but increased by miR-29 inhibitor. Overexpression of PTEN inhibited OS cell proliferation and migration and it could attenuate miR-29 promotion effect on OS progression. Overall, the results revealed that miR-29, as a tumor promoter, is involved in OS progression and metastasis by targeting PTEN, indicating that the miR-29/PTEN pathway is a potential therapeutic target for the treatment of OS.

miR‑23b‑3p promotes the apoptosis and inhibits the proliferation and invasion of osteosarcoma cells by targeting SIX1

Osteosarcoma (OS) is the most common primary malignant bone tumor and the third most common cancer that occurs during childhood and adolescence. Increasing evidence has suggested that microRNA (miR)‑23b‑3p has an important role in OS tumorigenesis; however, the underlying molecular mechanisms remain unknown. The aim of the present study was to investigate the expression levels of miR‑23b‑3p and sine oculis homeobox homolog 1 (SIX1) in OS tissues and cell lines (MG‑63, SaOS‑2 and U2OS), as well as to observe the effects of miR‑23b‑3p on U2OS cell viability, cell cycle, apoptosis and invasive ability. The results revealed that the expression levels of miR‑23b‑3p were significantly decreased in OS tissues and cell lines compared with tumor‑adjacent normal tissues and a non‑cancerous human fetal osteoblastic cell line (hFOB1.19). To investigate the underlying mechanisms of miR‑23b‑3p in OS tumorigenesis and progression, human U2OS cell lines over‑ or under expressing miR‑23b‑3p were established. The effects of miR‑23b‑3p on U2OS cell viability, cell cycle, apoptosis and invasion properties were determined by performing Cell Counting Kit‑8, flow cytometry and Transwell invasion assays. miR‑23b‑3p was revealed to suppress cell viability, proliferation and invasion, and to enhance the levels of cell apoptosis. Furthermore, SIX1 mRNA and protein expression levels in OS tissues and cell lines were significantly upregulated when compared with tumor‑adjacent normal tissues and hFOB 1.19 cells, which suggested that SIX1 expression levels may be inversely associated with miR‑23b‑3p levels in OS. Luciferase reporter system analysis demonstrated that miR‑23b‑3p binds to the SIX1 3'‑untranslated region. miR‑23b‑3p downregulation contributed to SIX1 upregulation, which facilitated the potentiation of cyclin D1 and vascular endothelial growth factor‑C expression levels, as well as the inhibition of caspase‑3 expression. Collectively, these results suggested that miR‑23b‑3p is downregulated and SIX1 is upregulated in OS cells, and that miR‑23b‑3p inhibition may suppress the proliferation and invasion of OS cells, and contribute to cell apoptosis via negative regulation of SIX1. miR‑23b‑3p/SIX1 may therefore represent a potential target for the treatment of OS.

Targeting the RAS/MAPK pathway with miR-181a in acute myeloid leukemia

Deregulation of microRNAs' expression frequently occurs in acute myeloid leukemia (AML). Lower miR-181a expression is associated with worse outcomes, but the exact mechanisms by which miR-181a mediates this effect remain elusive. Aberrant activation of the RAS pathway contributes to myeloid leukemogenesis. Here, we report that miR-181a directly binds to 3′-untranslated regions (UTRs); downregulates KRAS, NRAS and MAPK1; and decreases AML growth. The delivery of miR-181a mimics to target AML cells using transferrin-targeting lipopolyplex nanoparticles (NP) increased mature miR-181a; downregulated KRAS, NRAS and MAPK1; and resulted in decreased phosphorylation of the downstream RAS effectors. NP-mediated upregulation of miR-181a led to reduced proliferation, impaired colony formation and increased sensitivity to chemotherapy. Ectopic expression of KRAS, NRAS and MAPK1 attenuated the anti-leukemic activity of miR-181a mimics, thereby validating the relevance of the deregulated miR-181a-RAS network in AML. Finally, treatment with miR-181a-NP in a murine AML model resulted in longer survival compared to mice treated with scramble-NP control. These data support that targeting the RAS-MAPK-pathway by miR-181a mimics represents a novel promising therapeutic approach for AML and possibly for other RAS-driven cancers.

RalA, a GTPase targeted by miR-181a, promotes transformation and progression by activating the Ras-related signaling pathway in chronic myelogenous leukemia

BCR/ABL is a well-known activator of multiple signaling pathways. RalA, a Ras downstream signaling molecule and a small GTPase, plays an important role in Bcr-Abl-induced leukemogenesis but the exact mechanism remains elusive. Here, we show that RalA GTPase activity is commonly high in chronic myelogenous leukemia (CML) cell lines and patient samples. Overexpression of RalA results in malignant transformation and progression, and induces resistance to imatinib (IM) in BaF3 and K562 cell lines. RalA reduced survival and led to IM resistance in a xenografted mouse model. Ablation of RalA by either siRNA or miR-181a, a RalA targeting microRNA, attenuated the malignant phenotypes in K562 cells. RBC8, a selective Ral inhibitor, enhanced the inhibitory effects of IM in K562, KCL22 and BaF3-P210 cells. Interestingly, the phospho-specific protein microarray assay revealed that multiple phosphorylation signal proteins were decreased by RalA inhibition, including SAPK, JNK, SRC, VEGFR2, P38 MAPK, c-Kit, JunB, and Keratin18. Among them, P38 MAPK and SAPK/JNK are Ras downstream signaling kinases. Taken together, RalA GTPase might be an important oncogene activating the Ras-related signaling pathway in CML.

Prognostic value of miRNA-181a/b in colorectal cancer: a meta-analysis

AIMS

miR-181a and miR-181b have been investigated as prognostic biomarkers of colorectal cancer (CRC). However, there is controversy about the role of miR-181a and miR-181b in predicting CRC prognosis. Therefore, we performed this meta-analysis to evaluate prognostic values of miR-181a and miR-181b in CRC patients.

MATERIALS & METHODS

Studies were systemically searched from publications and analyzed, and 999 CRC cases in nine studies were examined in this meta-analysis.

RESULTS

Hazard ratio for overall survival of high miR-181a and miR-181b expression in CRC was 1.65. More prominent predictive effects were observed in black people, miR-181b group and small-sample-size group.

CONCLUSION

High levels of miR-181a and miR-181b predict poor overall survival in CRC patients. miR-181a and miR-181b are promising biomarkers for CRC prognosis.

High expression of CPNE3 predicts adverse prognosis in acute myeloid leukemia

CPNE3, a member of a Ca²⁺‐dependent phospholipid‐binding protein family, was identified as a ligand of ERBB2 and has a more general role in carcinogenesis. Here, we identified the prognostic significance of CPNE3 expression in acute myeloid leukemia (AML) patients based on two datasets. In the first microarray dataset (n = 272), compared to low CPNE3 expression (CPNE3^low), high CPNE3 expression (CPNE3^high) was associated with adverse overall survival (OS, P < 0.001) and event‐free survival (EFS, P < 0.001). In the second independent group of AML patients (TCGA dataset, n = 179), CPNE3^high was also associated with adverse OS and EFS (OS, P = 0.01; EFS, P = 0.036). Notably, among CPNE3^high patients, those received allogenic hematopoietic cell transplantation (HCT) had longer OS and EFS than those with chemotherapy alone (allogeneic HCT, n = 40 vs chemotherapy, n = 46), but treatment modules played an insignificant role in the survival of CPNE3^low patients (allogeneic HCT, n = 32 vs chemotherapy, n = 54). These results indicated that CPNE3^high is an independent, adverse prognostic factor in AML and might guide treatment decisions towards allogeneic HCT. To understand its inherent mechanisms, we investigated genome‐wide gene/microRNA expression signatures and cell signaling pathways associated with CPNE3 expression. In conclusion, CPNE3^high is an adverse prognostic biomarker for AML. Its effect may be attributed to the distinctive genome‐wide gene/microRNA expression and related cell signaling pathways.

MicroRNA-181a and its target Smad 7 as potential biomarkers for tracking child acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric hematologic tumor. MiR-181a was expected to have a role in the development of hematological malignancies; it might act as tumor suppressor or oncogene. Smad7 was selected as miR-181a target pair. It is a negative regulator for the TGF-β1 signaling pathway. In this study, relative expression levels of miR-181a by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), both Smad 7 and TGF-β1 proteins levels by enzyme linked immunosorbent assay (ELISA) were all measured in serum of 60 child, 30 with ALL and 30 age and sex matched healthy child as control group. MiR-181a expression showed highly significant decrease; plus a significant increase and decrease of Smad7 and TGF-β1 protein levels respectively, in serum samples of ALL as compared to control group. MiR-181a expression achieved a highly significant positive and a significant negative correlation with TGF-β1 and Smad7 respectively. Furthermore, the levels of Smad7 and TGF-β1 were negatively correlated with each other (p<0.05). Although, positivity rate of both Smad7 and TGF-β1 in ALL group increased with presence of hepatosplenomegaly, still there was no statistical significance. In conclusion, miR-181a could act as a tumor suppressor in pediatric ALL with over expression of its target pair, Smad7. Smad7 regulates TGF-β1 signaling via a negative feedback loop and mediates the interaction between TGF-β1 and other signaling pathways; suggesting that Smad7 over expression may have therapeutic potential in ALL.

MicroRNA-181 as a prognostic biomarker for survival in acute myeloid leukemia: a meta-analysis

Accumulating evidence has indicated that microRNA-181 (miR-181) is dysregulated in hematological malignancies, and associates with the clinical outcomes. However, the association of miR-181 expression levels with acute myeloid leukemia (AML) remains inconclusive, as publications from different groups have reported contradictory results. In this manuscript, a meta-analysis was performed to assess the prognostic significance of miR-181 in AML patients. Eligible studies were retrieved from PubMed, Embase and Cochrane Library databases, and a total of 6 studies including 815 AML patients were included in the final analysis. Hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were extracted and pooled to investigate the correlation between miR-181 and the survival of AML patients. Our results showed that elevated miR-181 expression was associated with increased survival in 395 American patients, and reduced survival in 325 Chinese patients. Both subgroup analyses and meta-regression indicated that the origin of AML patients contributed to the heterogeneity in the datasets evaluating the correlation between overall survival (OS) and miR-181. These results indicate that miR-181 can be used as a promising prognostic biomarker in AML patients, which may depend on the origin of patient population.

MicroRNA-203 inhibits proliferation and invasion, and promotes apoptosis of osteosarcoma cells by targeting Runt-related transcription factor 2

Accumulating evidence indicates that microRNA-203 (miR-203) is abnormally expressed in many human tumor tissues and significantly associated with the occurrence, development and clinical outcomes of human tumors. The aim of this study was to determine the target genes and functional significance of miR-203 in osteosarcoma cells. We found reduced expression of miR-203 in osteosarcoma tissues and cells (MG63 and U2-OS) compared with the adjacent normal tissues and normal osteoblastic cells (hFOB1.19), respectively. In vitro studies further demonstrated that exogenous miR-203 overexpression inhibited osteosarcoma cell proliferation and invasion, and promoted apoptosis. At the molecular level, our results confirmed that apoptosis, cell cycle and invasion-related proteins were regulated by miR-203. Our findings also revealed that Runt-related transcription factor 2 (RUNX2) was directly negatively regulated by miR-203. These results suggested that miR-203 may function as a tumor suppressor and may therefore have therapeutic potential in the treatment of human osteosarcoma.

The clinical characteristics and prognostic significance of AID, miR-181b, and miR-155 expression in adult patients with de novo B-cell acute lymphoblastic leukemia

This study aimed to investigate clinical characteristics and prognostic significance of activation-induced cytidine deaminase (AID) gene, miR-181b and miR-155 expression in de novo adult B-cell acute lymphoblastic leukemia (B-ALL) patients. Results showed that AID and miR-155 expression were higher in B-ALL patients than healthy controls, while miR-181b expression was lower in B-ALL patients. In addition, Ph⁺ B-ALLs had higher AID expression than Ph^- B-ALLs, and its high expression was associated with BCR-ABL. Moreover, B-ALL patients with AID^high or miR-181b^low expression had a shorter overall survival (OS). AID^high with miR-181b^low, AID^high with miR-155^low, miR-181b^low, miR-155^low, AID^high with miR-181b^low and miR-155^low expression were associated with shorter OS. Combination of the three molecules are more accurate predictors for unfavorable OS compared with univariate group. Therefore, AID, miR-181b and miR-155 provide clinical prognosis of adult de novo B-ALL patients and may refine their molecular risk classification.

Regulatory network analysis of microRNAs and genes in imatinib-resistant chronic myeloid leukemia

Targeted therapy in the form of selective breakpoint cluster region-abelson (BCR/ABL) tyrosine kinase inhibitor (imatinib mesylate) has successfully been introduced in the treatment of the chronic myeloid leukemia (CML). However, acquired resistance against imatinib mesylate (IM) has been reported in nearly half of patients and has been recognized as major issue in clinical practice. Multiple resistance genes and microRNAs (miRNAs) are thought to be involved in the IM resistance process. These resistance genes and miRNAs tend to interact with each other through a regulatory network. Therefore, it is crucial to study the impact of these interactions in the IM resistance process. The present study focused on miRNA and gene network analysis in order to elucidate the role of interacting elements and to understand their functional contribution in therapeutic failure. Unlike previous studies which were centered only on genes or miRNAs, the prime focus of the present study was on relationships. To this end, three regulatory networks including differentially expressed, related, and global networks were constructed and analyzed in search of similarities and differences. Regulatory associations between miRNAs and their target genes, transcription factors and miRNAs, as well as miRNAs and their host genes were also macroscopically investigated. Certain key pathways in the three networks, especially in the differentially expressed network, were featured. The differentially expressed network emerged as a fault map of IM-resistant CML. Theoretically, the IM resistance process could be prevented by correcting the included errors. The present network-based approach to study resistance miRNAs and genes might help in understanding the molecular mechanisms of IM resistance in CML as well as in the improvement of CML therapy.

Upregulated in Hepatitis B virus-associated hepatocellular carcinoma cells, miR-331-3p promotes proliferation of hepatocellular carcinoma cells by targeting ING5

Hepatitis B virus (HBV) is a major risk factor for development and progression of hepatocellular carcinoma (HCC). It has been reported that viral infection can interfere with cellular microRNA (miRNA) expression and participate in the pathogenesis of oncogenicity. Our miRNAs array data indicated that miR-331-3p expression in HCC cell lines increased, but the relationship between miR-331-3p expression and HBV activity is unclear. Here, we observed elevated expression of miR-331-3p in different HCC cell lines expressing HBV. HBV, especially HBx, promotes miR-331-3p expression by enhancing its promoter activity. Using a miRNA target prediction database miRBase, we identified ING5 to be a novel target gene of miR-331-3p. miR-331-3p could inhibit ING5 expression by directly targeting its 3′-untranslated region (3′-UTR). As predicted, HBV was confirmed to repress ING5 at both mRNA and protein levels by promoting miR-331-3p expression. Our result indicated that miR-331-3p expression promotes proliferation of SMMC7721 cells by inhibiting ING5. ING5 overexpression promoted cell apoptosis in HCC cell lines. We also found ING5 expression was decreased in tumor tissue of HCC patient with HBV infection compared to its expression in para-carcinoma tissues. Conclusion: These results showed that miR-331-3p is upregulated by HBV and promotes proliferation of HCC cells though repression of ING5 expression. These data provide new insights for understanding the mechanisms of HBV-related HCC pathogenesis.

The assessment of the robustness of microRNAs from oral cytological scrapings

BACKGROUND

Sampling of suspect oral lesions in the general dental clinic may increase early carcinoma detection thus oral cancer survival rates. One means of lesion sampling that is an alternative to incisional biopsy is cytological scraping. MicroRNA alterations are also being explored as a means of diagnosing carcinoma as an alternative to histopathology.

METHODS

We obtained cytological scrapings using 10 strokes ('light') or 40 strokes ('heavy') from the buccal mucosa of one healthy subject using a dermatological curette. MicroRNA was isolated from oral cytological scrapings immediately, or the scrapings were stored in buffer or RNA later, at 4°C, room temperature or 36°C, from 1 to 7 days prior to RNA isolation. All scrape comparisons and test conditions were conducted in triplicate. MicroRNAs were measured using qRT-PCR.

RESULTS

MicroRNAs can be obtained from cytological scrapings independent of the number of strokes and can be measured using qRT-PCR after storage under all conditions tested.

CONCLUSION

MicroRNAs are robust to a wide range of storage conditions that bodes well for use of cytological scrapings to be of use in a clinical setting as a chair side sampling method for suspect oral lesions.

Inhibition of microRNA-181a may suppress proliferation and invasion and promote apoptosis of cervical cancer cells through the PTEN/Akt/FOXO1 pathway

MicroRNAs (miRNAs) are endogenous, non-coding, small RNAs, which play a critical role in regulating varieties of the biological and pathologic processes. miR-181a has been reported to participate in tumorigenic progression. However, the roles of miR-181a in cervical cancer (CC) are still unknown. The aim of this research was to explore the effects and molecular mechanism of miR-181a in CC cells. In this paper, the levels of miR-181a in CC cell lines were determined by real-time PCR. We found that the levels of miR-181a were evidently enhanced in CC cell lines compared with normal cervical epithelium cells. Then, the miR-181a inhibitor was transiently transfected into HeLa and CaSKi cells using Lipofectamine 2000 reagent. Subsequently, the Cell Counting Kit-8 (CCK-8) and BrdU-ELISA results showed that down-regulation of miR-181a inhibited the cell viability and proliferation. Our data also demonstrated that miR-181a inhibitor arrested cell cycle progression of HeLa and CaSKi cells by up-regulation of p21 and p27 expressions. In addition, inhibition of miR-181a promoted apoptosis of HeLa and CaSKi cells due to increasing Bax expression and decreasing Bcl-2 expression. Ultimately, the effect of miR-181a inhibitor on the PTEN/Akt/FOXO1 signaling pathway was investigated by Western blot. From our results, down-regulation of miR-181a increased the expression of PTEN and decreased phosphorylation of Akt and FOXO1. Altogether, miR-181a might be an oncogene in CC cells. The potential mechanism was that inhibition of miR-181a might suppress proliferation and invasion and promote apoptosis of HeLa and CaSKi cells by modulating the PTEN/Akt/FOXO1 signaling pathway.

Evaluation of miR-27a, miR-181a, and miR-570 genetic variants with gallbladder cancer susceptibility and treatment outcome in a North Indian population

INTRODUCTION

miR-27a, miR-181a, and miR-570 genetic variants have been found to play an important role in many cancers, but their contribution in gallbladder carcinoma (GBC) has not been explored. Therefore, we investigated the role of these micro RNA (miRNA) genetic variants in terms of GBC susceptibility, therapeutic response, toxicities associated with chemo-radiotherapy and survival outcome.

METHODS

This study included 606 GBC patients and 200 healthy controls. From among the larger study cohort, 219 patients receiving adjuvant or palliative chemo-radiotherapy as per disease status were followed up for toxicity profile. Treatment response was recorded in 159 patients who received palliative chemo-radiotherapy. Genotypes were determined using allelic discrimination assay. Statistical analysis was carried out with SPSS version 16. Generalized multifactor dimensionality reduction (GMDR) analysis was performed for gene-gene interactions. Survival analysis was performed using Kaplan-Meier and Cox regression tests.

RESULTS

In univariate logistic regression analysis, no association with any of the studied polymorphisms was found in overall GBC susceptibility. Furthermore, univariate and multivariate analyses revealed no significant association with response to chemo-radiotherapy. In GMDR analysis, miR-27ars895819, miR-570rs4143815, and miR-181ars12537 combination was found as the best gene-gene interaction model for susceptibility and treatment response. Furthermore, miR-27ars895819miR-181ars12537 was associated with neutropenia toxicity in patients undergoing chemo-radiotherapy. However, miRNA variants had no influence over the survival outcomes of GBC patients (locally advanced, metastatic).

CONCLUSION

In conclusion, the miRNA variants cumulatively influence GBC susceptibility and treatment outcomes.

Mitogen-activated protein kinase binding protein 1 (MAPKBP1) is an unfavorable prognostic biomarker in cytogenetically normal acute myeloid leukemia

Mitogen-activated protein kinase binding protein 1 (MAPKBP1) is a key transcription factor in the NF-κB signalling pathway. In this study, associations between MAPKBP1 expression and molecular and clinical characteristics were evaluated by several microarray datasets. We found that MAPKBP1 was over-expressed in cytogenetically normal AML (CN-AML) patients compared to normal bone marrow. High MAPKBP1 expression (MAPKBP1^high) was associated with significantly shorter event-free survival (EFS; P = 0.0004) and overall survival (OS; P = 0.0006) than low MAPKBP1 expression (MAPKBP1^low) in a cohort of 157 CN-AML patients. In multivariable analyses, MAPKBP1^high remained associated with shorter EFS (P = 0.003) and OS (P = 0.01). Validation in an independent cohort of 162 CN-AML patients further confirmed the prognostic value of MAPKBP1 (OS, P = 0.00172). Gene-expression profiling revealed that some important oncogenes, including MYCN, MYB, CDK6 and CCND2, etc, were up-regulated, while cell signalling pathways leading to apoptosis, antigen processing, and natural killer cell-mediated cytotoxicity were down-regulated in MAPKBP1^high patients with CN-AML. MicroRNA expression profiling revealed thatsome oncogenic microRNAsincluding miR-155 and miR-126 were up-regulated, whilst anti-oncogenic microRNAsincluding miR-148a and miR-193a were down-regulated in MAPKBP1^high patients with CN-AML, which may underlie the pathological processes in this malignancy. Taken together, these findings suggest MAPKBP1^highis a novel, unfavourably prognostic biomarker for CN-AML risk-stratification.

Benzene-Induced Aberrant miRNA Expression Profile in Hematopoietic Progenitor Cells in C57BL/6 Mice

Benzene is a common environmental pollutant that causes hematological alterations. MicroRNAs (miRNAs) may play a role in benzene-induced hematotoxicity. In this study, C57BL/6 mice showed significant hematotoxicity after exposure to 150 mg/kg benzene for 4 weeks. Benzene exposure decreased not only the number of cells in peripheral blood but also hematopoietic progenitor cells in the bone marrow. Meanwhile, RNA from Lin⁻ cells sorted from the bone marrow was applied to aberrant miRNA expression profile using Illumina sequencing. We found that 5 miRNAs were overexpressed and 45 miRNAs were downregulated in the benzene exposure group. Sequencing results were confirmed through qRT-PCR. Furthermore, we also identified five miRNAs which significantly altered in Lin⁻c-Kit⁺ cells obtained from benzene-exposed mice, including mmu-miR-34a-5p; mmu-miR-342-3p; mmu-miR-100-5p; mmu-miR-181a-5p; and mmu-miR-196b-5p. In summary, we successfully established a classical animal model to induce significant hematotoxicity by benzene injection. Benzene exposure may cause severe hematotoxicity not only to blood cells in peripheral circulation but also to hematopoietic cells in bone marrow. Benzene exposure also alters miRNA expression in hematopoietic progenitor cells. This study suggests that benzene induces alteration in hematopoiesis and hematopoiesis-associated miRNAs.

MiR-221 increases osteosarcoma cell proliferation, invasion and migration partly through the downregulation of PTEN

Increasing evidence has demonstrated that microRNAs (miRNAs or miRs) are involved in cancer initiation and progression. Previous studies have indicated that miR-221 is one of the most consistently overexpressed miRNAs in multiple types of cancer. However, the role of miR-221 in osteosarcoma carcinogenesis and progression is not yet fully understood. Thus, the aim of the present study was to examine the expression of miR-221 in osteosarcoma and to determine the effects of miR-221 on the biological behavior of osteosarcoma cells. RT-qPCR revealed that the expression of miR-221 was significantly upregulated in the osteosarcoma tissues and osteosarcoma cell lines (p<0.05). In order to explore the role of miR-221 in osteosarcoma, the expression of miR-221 in the human osteosarcoma cell line MG‑63 was upregulated or downregulated by transfection with miR-221 mimic or miR-221 inhibitor, respectively. The results from RT-qPCR revealed that we had successfully generated MG‑63 cells in which miR-221 was either overexpressed or depleted. To investigate the effects of miR-221 on osteosarcoma cell proliferation, invasion and migration, a tetrazolium-based colorimetric assay, propidium iodide (PI) staining, a transwell migration assay and a wound healing assay were used in the present study. The results revealed that the proliferation, invasion and migration ability of the MG‑63 cells in which miR-221 was overexpressed was enhanced, and the proliferation, invasion and migration ability of the MG‑63 cells in which miR-221 was depleted was suppressed. The correlation between miR-221 and phosphatase and tensin homolog (PTEN) expression was investigated by RT-qPCR and western blot analysis. The results revealed that the downregulation of miR-221 significantly increased the expression of PTEN, whereas the upregulation of miR-221 significantly reduced the expression of PTEN. Taken together, our results suggest that miR-221 enhances the proliferation, invasion and migration ability of osteosarcoma cells partly by suppressing PTEN.

Hsa-microRNA-181a is a regulator of a number of cancer genes and a biomarker for endometrial carcinoma in patients: a bioinformatic and clinical study and the therapeutic implication

The aberrant expression of human microRNA-181a-1 (hsa-miR-181a) has been implicated in the pathogenesis of various cancers, serving as an oncogene or a tumor suppressor. However, the role of hsa-miR-181a in the pathogenesis of endometrial carcinoma (EC) and its clinical significance are unclear. This study aimed to search for the molecular targets of hsa-miR-181a using bioinformatic tools and then determine the expression levels of hsa-miR-181a in normal, hyperplasia, and EC samples from humans. To predict the targets of hsa-miR-181a, ten different algorithms were used, including miRanda-mirSVR, DIANA microT v5.0, miRDB, RNA22 v2, TargetMiner, TargetScan 6.2, PicTar, MicroCosm Targets v5, and miRWALK. Two algorithms, TarBase 6.0 and miRTarBase, were used to identify the validated targets of hsa-miR-181a-5p (a mature product of hsa-miR-181a), and the web-based Database for Annotation, Visualization and Integrated Discovery (DAVID) 6.7 was used to provide biological functional interpretation of the validated targets of hsa-miR-181a-5p. A total of 78 formalin-fixed, paraffin-embedded tissue specimens from 65 patients and 13 healthy subjects were collected and examined, including normal endometrium (n=13), endometrial hyperplasia (n=18), and EC (37 type I and 10 type II EC cases). Our bioinformatic studies have showed that hsa-miR-181a might regulate a large number of target genes that are important in the regulation of critical cell processes, such as cell fate, cell survival, metabolism, and cell death. To date, 313 targets of hsa-miR-181a have been validated, and 22 of these targets are cancer genes. The precision of predictions by all the algorithms for hsa-miR-181a-1’s targets was low. Many of these genes are involved in tumorigenesis of various cancers, including EC, based on the DAVID and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. In comparison with normal endometrial tissue, the expression level of hsa-miR-181a was significantly increased in type I and type II EC (P<0.05), and type II EC exhibited a significant higher expression level of hsa-miR-181a than that in type I EC (P<0.05). In addition, there was a significant increase in the expression level of hsa-miR-181a in type II EC compared with endometrial hyperplasia (P<0.05). Taken together, these results suggest that hsa-miR-181a may serve as an oncogene in endometrial tumorigenesis and that hsa-miR-181a might be used as a new biomarker in the prediction of prognosis of EC in clinical practice. More functional and mechanistic studies are needed to validate the role of hsa-miR-181a in the development, progression, and metastasis of EC.

High IDH1 expression is associated with a poor prognosis in cytogenetically normal acute myeloid leukemia

The prognostic value of IDH1 mutations has been systematically evaluated in acute myeloid leukemia (AML) patients recently. However, the role of IDH1 expression in AML is still under exploration. To investigate the clinical significance, we analyzed the IDH1/2 expression in 320 patients with cytogenetically normal AML (CN-AML) by quantitative real-time reverse-transcription polymerase chain reaction. High expression of IDH1 was predominant in patients with FLT3-ITD and DNMT3A mutations and less prevalent in cases with CEBPA double allele mutations. Strong association was observed between high IDH1 expression and low expression of microRNA 181 family. Prognosis was adversely affected by high IDH1 expression, with shorter overall survival and event-free survival in the context of clinical characteristics, including age, WBC count, and gene mutations of NPM1, FLT3-ITD, CEBPA, IDH1, IDH2 and DNMT3A in CN-AML. Moreover, the clinical outcome of IDH1 expression in terms of overall survival, event-free survival and complete remission rate still remained in multivariate models in CN-AML. Importantly, the prognostic value was validated using the published microarray data from 79 adult patients treated according to the German AMLCG-1999 protocol. Our results demonstrated that high IDH1 expression is associated with a poor prognosis of CN-AML.

MicroRNAs in B-cells: from normal differentiation to treatment of malignancies

MicroRNAs (miRNAs) are small non-coding RNAs that play important post-transcriptional regulatory roles in a wide range of biological processes. They are fundamental to the normal development of cells, and evidence suggests that the deregulation of specific miRNAs is involved in malignant transformation due to their function as oncogenes or tumor suppressors. We know that miRNAs are involved in the development of normal B-cells and that different B-cell subsets express specific miRNA profiles according to their degree of differentiation. B-cell-derived malignancies contain transcription signatures reminiscent of their cell of origin. Therefore, we believe that normal and malignant B-cells share features of regulatory networks controlling differentiation and the ability to respond to treatment. The involvement of miRNAs in these processes makes them good biomarker candidates. B-cell malignancies are highly prevalent, and the poor overall survival of patients with these malignancies demands an improvement in stratification according to prognosis and therapy response, wherein we believe miRNAs may be of great importance. We have critically reviewed the literature, and here we sum up the findings of miRNA studies in hematological cancers, from the development and progression of the disease to the response to treatment, with a particular emphasis on B-cell malignancies.

The association between abnormal microRNA-10b expression and cancer risk: a meta-analysis

Several studies have investigated the association between abnormal microRNA-10b expression and the risk of various developing cancers, but the results are inconsistent. We searched all publications addressing the level of microRNA-10b expression in cancer cases and noncancerous controls (Accessed: August 2014). Thirty-six studies on 14 types of cancer were included. Among them, 25 studies were subjected to the meta-analysis with a vote-counting strategy, 13 studies were estimated using odds ratio (OR) and diagnostic accuracy, and 2 studies were assessed by both methods. It was found that vestibular schwannomas ranked first among the reported cancer types with up-regulated microRNA-10b expression; melanoma ranked first among the reported cancer types with down-regulated microRNA-10b expression; while breast cancer and hepatocellular cancer presented inconsistent microRNA-10b regulation. Of 13 included studies calculated for OR and diagnostic accuracy, it was shown that high-expression of microRNA-10b could be significantly associated with cancer risk (OR = 32.80, 95% CI: 11.90–90.37, P<0.0001), and the area under the summary receiver operating characteristic (SROC) curve for microRNA-10b high-expression in the diagnosis of cancer is 0.81, which suggested that high-expression of microRNA-10b can predict worse outcomes in some types of cancer and the regular monitoring of miR-10b expression might be useful in the clinical practice.

microRNA-181 promotes prostate cancer cell proliferation by regulating DAX-1 expression

microRNAs (miRNAs) are a class of short noncoding RNA molecules that have a critical role in the initiation and progression of types of human cancer, including prostate cancer. In the present study, the expression of miR-181 in prostate cancer tissues was evaluated and was demonstrated to be significantly upregulated in prostate cancer tissues compared with that in adjacent normal tissues. The results of in vitro MTT and BrdU incorporation assays, as well as cell-cycle analysis, indicated that miR-181 overexpression markedly promoted the proliferation of LNCaP cells. Furthermore, miR-181 overexpression was found to promote the progression of LNCaP tumor growth in nude mice. Mechanistic studies demonstrated that dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1), a negative regulator of androgen receptor in prostate cancer, was inhibited by miR-181 overexpression. Therefore, the results from the present study suggest that miR-181 functions as a growth-suppressive miRNA during prostate cancer development.

The microRNAs as prognostic biomarkers for survival in esophageal cancer: a meta-analysis

OBJECTIVES

We performed this meta-analysis to summarize all the results from available studies, aiming delineating the prognostic role of miRNA in esophageal cancer.

DESIGN AND METHODS

We searched the electronic databases PubMed, EMBASE, and ISI Web of Science without time restrictions for the correlative literature to aggregate the survival results. Relevant data were extracted from studies investigating the relationship between miRNAs expression and survival in esophageal cancer patients. Pooled hazard ratios of miR-21 and miR-375 for OS in ESCC were calculated.

RESULTS

A total of 25 studies involving 2,258 subjects analyzed the relationship between miRNA and prognosis of EC. In all, thirty-nine miRNAs associated with prognosis were reported in these studies. The pooled HR of higher miR-21 expression compared with lower miR-21 expression in ESCC was 1.84 (95% CI: 1.41-2.40, P < 0.001), which could significantly predict poorer OS in ESCC. Besides, higher miR-375 was also a significant predictor for OS in ESCC, with a pooled HR of 0.55 (95% CI: 0.42-0.72, P < 0.001).

CONCLUSIONS

Our results support that miR-21 and miR-375 have a prognostic role in ESCC and may be useful therapeutic targets for the treatment of ESCC and meticulous follow-up for early detection of recurrence.

Up-regulated MicroRNA-181a induces carcinogenesis in hepatitis B virus-related hepatocellular carcinoma by targeting E2F5

Background

Accumulating evidence showed that microRNAs are involved in development and progression of multiple tumors. Recent studies have found that miR-181a were dysregulated in several types of cancers, however, the function of miR-181a in hepatocellular carcinoma (HCC) remains unclear. In this study we assessed the potential association between miR-181a, HBV and HCC.

Methods

The expression of miR-181a in HBV-expressing cells was determined by using qRT-PCR. Dual-Luciferase reporter Assay, qRT-PCR and western blot were performed to investigate the target genes of miR-181a. The effects of miR-181a on HCC proliferation were analyzed by MTS and colony formation assay. Tumor growth assay was used to analyze the effect of miR-181a on tumor formation.

Results

HBV up-regulated miR-181a expression by enhancing its promoter activity. Overexpression of miR-181a in hepatoma cells promoted cell growth in vitro and tumor formation in vivo. Conversely, inhibition of miR-181a suppressed the proliferation of HBV-expressing cells. Mechanism investigation revealed that miR-181a inhibited the expression of transcription factor E2F5 by specifically targeting its mRNA 3′UTR. Moreover, E2F5 inhibition induced cell growth and rescued the suppressive effect of miR-181a inhibitor on the proliferation of SMMC-7721 cells. Interestingly, we also discovered that HBV could down-regulate E2F5 expression.

Conclusions

Those results strongly suggested that HBV down-regulated E2F5 expression, in part, by up-regulating the expression of miR-181a. Up-regulation of miR-181a by HBV in hepatoma cells may contribute to the progression of HCC possibly by targeting E2F5, suggesting miR-181a plays important role in HCC development.

MicroRNAs linking inflamm-aging, cellular senescence and cancer

Epidemiological and experimental data demonstrate a strong correlation between age-related chronic inflammation (inflamm-aging) and cancer development. However, a comprehensive approach is needed to clarify the underlying molecular mechanisms. Chronic inflammation has mainly been attributed to continuous immune cells activation, but the cellular senescence process, which may involve acquisition of a senescence-associated secretory phenotype (SASP), can be another important contributor, especially in the elderly. MicroRNAs (miRs), a class of molecules involved in gene expression regulation, are emerging as modulators of some pathways, including NF-κB, mTOR, sirtuins, TGF-β and Wnt, that may be related to inflammation, cellular senescence and age-related diseases, cancer included. Interestingly, cancer development is largely avoided or delayed in centenarians, where changes in some miRs are found in plasma and leukocytes. We identified miRs that can be considered as senescence-associated (SA-miRs), inflammation-associated (inflamma-miRs) and cancer-associated (onco-miRs). Here we review recent findings concerning three of them, miR-21, -126 and -146a, which target mRNAs belonging to the NF-κB pathway; we discuss their ability to link cellular senescence, inflamm-aging and cancer and their changes in centenarians, and provide an update on the possibility of using miRs to block accumulation of senescent cells to prevent formation of a microenvironment favoring cancer development and progression.

MicroRNA 181a improves proliferation and invasion, suppresses apoptosis of osteosarcoma cell

MicroRNA 181a (miR-181a) was found dysregulated in a variety of human cancers and significantly associated with clinical outcome of cancer patients. However, the direct role of miR-181a has not yet been characterized in osteosarcoma progression. This study was aimed at investigating the effects of miR-181a on osteosarcoma cell biological behavior. First, the expression of miR-181a in osteosarcoma cell lines (MG63, HOS, SaOS-2, and U2OS) and a human osteoblastic cell line (hFOB1.19) was detected by qRT-PCR. Results showed that miR-181a was overexpressed in osteosarcoma cell lines compared to human osteoblastic cell line (hFOB1.19). To investigate the effects of miR-181a on proliferation, apoptosis, and invasion of osteosarcoma cells, we generated human osteosarcoma MG63 cells in which miR-181a was either overexpressed or depleted. The MG63 cell viability, cycle, apoptosis, and invasive ability were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide staining, propidium iodide (PI) staining, Annexin V-FITC/PI double staining, and Transwell invasion experiment, respectively. The results showed that MG63 cell viability, proliferation, and invasive abilities were suppressed, and the apoptosis was enhanced in the group with underexpression of miR-181a. The viability, proliferation, and invasive abilities were improved, and the apoptosis was inhibited in the group with overexpression of miR-181a. The results from Western blotting indicated that miR-181a might be associated with the up-regulation of bcl-2 and matrix metalloproteinase 9 and the down-regulation of tissue inhibitor of metalloproteinases-3 and p21 in MG63 cells. Taken together, our results suggested that miR-181a might facilitate proliferation and invasion and suppress apoptosis of osteosarcoma cells, which might be a potential target for the treatment of osteosarcoma.