The miR-17-92 microRNA cluster: a novel diagnostic tool in large B-cell malignancies

miRNome expression analysis in canine diffuse large B-cell lymphoma

Introduction

Lymphoma is a common canine cancer with translational relevance to human disease. Diffuse large B-cell lymphoma (DLBCL) is the most frequent subtype, contributing to almost fifty percent of clinically recognized lymphoma cases. Identifying new biomarkers capable of early diagnosis and monitoring DLBCL is crucial for enhancing remission rates. This research seeks to advance our knowledge of the molecular biology of DLBCL by analyzing the expression of microRNAs, which regulate gene expression by negatively impacting gene expression via targeted RNA degradation or translational repression. The stability and accessibility of microRNAs make them appropriate biomarkers for the diagnosis, prognosis, and monitoring of diseases.

Methods

We extracted and sequenced microRNAs from ten fresh-frozen lymph node tissue samples (six DLBCL and four non-neoplastic).

Results

Small RNA sequencing data analysis revealed 35 differently expressed miRNAs (DEMs) compared to controls. RT-qPCR confirmed that 23/35 DEMs in DLBCL were significantly upregulated (n = 14) or downregulated (n = 9). Statistical significance was determined by comparing each miRNA's average expression fold-change (2-Cq) between the DLCBL and healthy groups by applying the unpaired parametric Welch's 2-sample t-test and false discovery rate (FDR). The predicted target genes of the DEMs were mainly enriched in the PI3K-Akt-MAPK pathway.

Discussion

Our data point to the potential value of miRNA signatures as diagnostic biomarkers and serve as a guideline for subsequent experimental studies to determine the targets and functions of these altered miRNAs in canine DLBCL.

microRNA sequencing for biomarker detection in the diagnosis, classification and prognosis of Diffuse Large B Cell Lymphoma

Despite being considered a single disease, Diffuse Large B Cell Lymphoma (DLBCL) presents with variable backgrounds, which results in heterogeneous outcomes among patients, with 40% of them still having primary refractory disease or relapse. Thus, novel biomarkers are needed. In addition, multiple factors regarding its pathogenesis remain unclear. In this context, recent investigations point to the relevance of microRNAs (miRNAs) in cancer. However, regarding DLBCL, there is inconsistency in the data reported. Therefore, in this work, the main goals were to determine a miRNA set with utility as biomarkers for DLBCL diagnosis, classification, prognosis and treatment response, as well as to decipher the mechanism of action of deregulated miRNAs in the origin of the disease. We analyzed miRNA expression in a cohort of 78 DLBCL patients and 17 controls using small RNA sequencing and performed a miRNA-mRNA interaction network analysis. This way, we were able to define new miRNA expression signatures for diagnosis, classification, treatment response and prognosis, and we identified plausible mechanisms of action by which deregulated miRNAs could be involved in DLBCL pathogenesis. In summary, our study remarks that miRNAs could play an important role in DLBCL.

miR-155 and miR-92 levels in ALL, post-transplant aGVHD, and CMV: possible new treatment options

BACKGROUND

Acute lymphoblastic leukemia (ALL) is a malignancy that leads to altered blast cell proliferation, survival, and maturation and eventually to the lethal accumulation of leukemic cells. Recently, dysregulated expression of various micro-RNAs (miRNAs) has been reported in hematologic malignancies, especially ALL. Cytomegalovirus infection can induce ALL in otherwise healthy individuals, so a more detailed evaluation of its role in ALL-endemic areas like Iran is required.

METHODS

In this cross-sectional study, 70 newly diagnosed adults with ALL were recruited. The expression level of microRNA-155(miR-155) and microRNA-92(miR-92) was evaluated by real-time SYBR Green PCR. The correlations between the miRNAs mentioned above and the severity of disease, CMV infection, and acute graft vs. host disease after hematopoietic stem cell transplantation (HSCT) were assessed. B cell and T cell ALL distinction in the level of miRNAs was provided.

RESULTS

After the statistical analysis, our results indicated a marked increase in the expression of miR-155 and miR-92 in ALL patients vs. healthy controls (*P = 0.002-*P = 0.03, respectively). Also, it was shown that the expression of miR-155 and miR-92 was higher in T cell ALL compared to B cell ALL (P = 0.01-P = 0.004, respectively), CMV seropositivity, and aGVHD.

CONCLUSION

Our study suggests that the plasma signature of microRNA expression may act as a powerful marker for diagnosis and prognosis, providing knowledge outside cytogenetics. Elevation of miR-155 in plasma can be a beneficial therapeutic target for ALL patients, with consideration of higher plasma levels of miR-92 and miR-155 in CMV + and post-HSCT aGVHD patients.

Genetic variant in miR-17-92 cluster binding sites is associated with esophageal squamous cell carcinoma risk in Chinese population

BACKGROUND

Single nucleotide polymorphisms (SNPs) located in microRNA (miRNA) binding sites can affect the interactions between miRNAs and target genes, which is related to cancer susceptibility and tumorigenesis. However, the association between SNPs located in miR-17-92 cluster binding sites and ESCC risk remains unclear. Therefore, we aimed to explore the relationship between polymorphisms in miR-17-92 cluster binding sites and ESCC susceptibility.

METHODS

Six SNPs in the binding sites of miR-17-92 cluster were selected using bioinformatics databases, and their association with ESCC risk was investigated in a case-control study (including 488 cases and 512 controls) based on the population from high incidence areas of ESCC in China. We evaluated the SNP-SNP and SNP-smoking interactions using generalized multifactor dimensionality reduction (GMDR). Moreover, the expression of the miR-17-92 cluster and its target genes was determined in ESCC and adjacent normal tissues by quantitative real-time polymerase chain reaction (qRT-PCR). The dual-luciferase reporter assay was conducted to verify the effect of SNPs on the binding affinity between miRNAs and target genes.

RESULTS

We found that the SNP rs1804506 C > T had a significant association with the decreased ESCC risk. The SNP rs1804506 T allele was associated with a significantly decreased risk of ESCC in the additive model (OR = 0.817, 95% CI = 0.681-0.981, P = 0.030). The rs1804506 T allele had more striking effects on reducing ESCC risk in older individuals, female or non-smoker subgroups. We also found a significant interaction effect between rs1366600 and smoking by GMDR methods (P = 0.011). Additionally, the expression levels of miR-19a-3p and TGFBR3 were significantly downregulated in ESCC tissues compared with normal tissues, and the carriers of rs1804506 TT genotype had lower expression level of TGFBR3 than those of rs1804506 CC/CT genotype. Following dual-luciferase reporter assay showed that the rs1804506 T allele reduced the binding of miR-19a-3p and TGFBR3 3'-UTR.

CONCLUSIONS

Our findings suggest that the rs1804506 polymorphism in miR-17-92 cluster binding sites contributes to the susceptibility of ESCC, which might provide new clues and scientific evidence for the etiology and biomarkers for the prevention and treatment of ESCC.

Role of epigallocatechin-3- gallate in the regulation of known and novel microRNAs in breast carcinoma cells

Breast cancer comprises 30% of all cancer cases among the world’s women population. MicroRNAs are small, endogenous, non-coding RNAs that regulate cell proliferating and apoptotic pathways by modulating expressions of related genes. Phytochemicals like epigallocatechin-3-gallate (EGCG) are known to have a chemotherapeutic effect on cancer often through the regulation of microRNAs. The aim is to find out the key known and novel miRNAs, which are controlled by EGCG in breast cancer cell line MDA-MB-231. Next-generation sequencing (NGS) revealed 1,258 known and 330 novel miRNAs from untreated and 83 μM EGCG (IC50 value of EGCG) treated cells. EGCG modulated 873 known and 47 novel miRNAs in the control vs. treated sample. The hypothesis of EGCG being a great modulator of miRNAs that significantly control important cancer-causing pathways has been established by analyzing with Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein Analysis Through Evolutionary Relationships (PANTHER) database. Validation of known and novel miRNA expression differences in untreated vs. treated cells was done using qPCR. From this study, a few notable miRNAs were distinguished that can be used as diagnostics as well as prognostic markers for breast cancer.

Lymphoma cell-derived extracellular vesicles inhibit autophagy and apoptosis to promote lymphoma cell growth via the microRNA-106a/Beclin1 axis

Lymphoma is a common malignant tumor globally. Tumor-derived extracellular vesicles (Evs) participate in genetic information exchange between tumor cells. We investigated the role and mechanism of human Burkitt lymphoma cells Raji-derived Evs (Raji-Evs) in lymphoma cells. Effects of Evs on lymphoma cell proliferation, invasion, autophagy, and apoptosis were assessed using Cell Counting Kit-8 method, Transwell assay, laser confocal microscopy, Western blotting, and flow cytometry. microRNA (miR)-106a expression in lymphoma cells was determined using reverse transcription-quantitative polymerase chain reaction and then downregulated in Raji cells and then Evs were isolated (Evs-in-miR-106a) to evaluate its role in lymphoma cell growth. The binding relationship between miR-106a and Beclin1 was verified using RNA pull-down and dual-luciferase assays. Beclin1 was overexpressed in SU-DHL-4 and Farage cells and SU-DHL-4 cell autophagy and apoptosis were detected. The levels of miR-106a and Beclin1 in SU-DHL-4 cells were detected after adding autophagy inhibitors. The tumorigenicity assay in nude mice was performed to validate the effects of Raji-Evs in vivo. Raji-Evs promoted lymphoma cell proliferation and invasion and increased miR-106a. miR-106a knockdown reversed Evs-promoted lymphoma cell proliferation and invasion. miR-106a carried by Raji-Evs targeted Beclin1 expression. Beclin1 overexpression or miR-106a inhibitor reversed the effects of Evs on lymphoma cell autophagy and apoptosis. Autophagy inhibitors elevated miR-106a expression and lowered Beclin1 expression. Raji-Evs-carried miR-106a inhibited Beclin1-dependent autophagy and apoptosis in lymphoma cells, which were further verified in vivo, together with promoted tumor growth. We proved that Raji-Evs inhibited lymphoma cell autophagy and apoptosis and promoted cell growth via the miR-106a/Beclin1 axis.

The Profile of MicroRNA Expression in Bone Marrow in Non-Hodgkin’s Lymphomas

Non-Hodgkin’s lymphomas (NHLs) are a heterogeneous group of malignant lymphomas that can occur in both lymph nodes and extranodal sites. Bone marrow (BM) is the most common site of extranodal involvement in NHL. The objective of this study is to determine the unique profile of miRNA expression in BM affected by NHL, with the possibility of a differential diagnosis of NHL from reactive BM changes and acute leukemia (AL). A total of 180 cytological samples were obtained by sternal puncture and aspiration biopsy of BM from the posterior iliac spine. All the cases were patients before treatment initiation. The study groups were NHL cases (n = 59) and AL cases (acute lymphoblastic leukemia (n = 25) and acute myeloid leukemia (n = 49)); the control group consisted of patients with non-cancerous blood diseases (NCBDs) (n = 48). We demonstrated that expression levels of miRNA-124, miRNA-221, and miRNA-15a are statistically significantly downregulated, while the expression level of let-7a is statistically significantly upregulated more than 2-fold in BM in NHL compared to those in AL and NCBD. ROC analysis revealed that let-7a/miRNA-124 is a highly sensitive and specific biomarker for a differential diagnosis of BM changes in NHL from those in AL and NCBD. Therefore, we conclude that analysis of miRNA expression levels may be a promising tool for early diagnosis of NHL.

The Ambivalent Role of miRNAs in Carcinogenesis: Involvement in Renal Cell Carcinoma and Their Clinical Applications

The analysis of microRNA (miRNAs), small, non-coding endogenous RNA, plays a crucial role in oncology. These short regulatory sequences, acting on thousands of messenger RNAs (mRNAs), modulate gene expression at the transcriptional and post-transcriptional level leading to translational repression or degradation of target molecules. Although their function is required for several physiological processes, such as proliferation, apoptosis and cell differentiation, miRNAs are also responsible for development and/or progression of several cancers, since they may interact with classical tumor pathways. In this review, we highlight recent advances in deregulated miRNAs in cancer focusing on renal cell carcinoma (RCC) and provide an overview of the potential use of miRNA in their clinical settings, such as diagnostic and prognostic markers.

The Multifaceted Role and Utility of MicroRNAs in Indolent B-Cell Non-Hodgkin Lymphomas

Normal B-cell development is a tightly regulated complex procedure, the deregulation of which can lead to lymphomagenesis. One common group of blood cancers is the B-cell non-Hodgkin lymphomas (NHLs), which can be categorized according to the proliferation and spread rate of cancer cells into indolent and aggressive ones. The most frequent indolent B-cell NHLs are follicular lymphoma and marginal zone lymphoma. MicroRNAs (miRNAs) are small non-coding RNAs that can greatly influence protein expression. Based on the multiple interactions among miRNAs and their targets, complex networks of gene expression regulation emerge, which normally are essential for proper B-cell development. Multiple miRNAs have been associated with B-cell lymphomas, as the deregulation of these complex networks can lead to such pathological states. The aim of the present review is to summarize the existing information regarding the multifaceted role of miRNAs in indolent B-cell NHLs, affecting the main B-cell subpopulations. We attempt to provide insight into their biological function, the complex miRNA-mRNA interactions, and their biomarker utility in these malignancies. Lastly, we address the limitations that hinder the investigation of the role of miRNAs in these lymphomas and discuss ways that these problems could be overcome in the future.

Systematic review of the potential of MicroRNAs in the management of patients with follicular lymphoma

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma and usually presents as an indolent disease. However, some patients present poor outcomes, and FL can transform into more aggressive lymphomas, such as Diffuse Large B cell lymphoma (DLBCL). MicroRNAs (miRNA) are small RNA molecules that participate in posttranscriptional regulation of gene expression, that are emerging biomarkers in cancer. In this systematic review, we included studies evaluating miRNA expression in tumor tissue as diagnosis, transformation or prognosis biomarkers in FL. We identified several miRNAs, which could be diagnostic biomarkers in FL: miR-155-5p and miR-9-3p as miRNAs of potential utility for diagnosis of FL, and miR-150 and miR-17-92 cluster for differential diagnosis between FL and DLBCL. Prognosis and transformation prediction have not been studied in enough depth to draw solid conclusions. Further research is needed to exploit the potential of this field.

Non-Coding RNAs in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma worldwide. The molecular mechanisms underlying DLBCL have not been fully elucidated, and approximately 40% of patients who undergo standard chemoimmunotherapy still present with primary refractory disease or relapse. Non-coding RNAs (ncRNAs), a group of biomolecules functioning at the RNA level, are increasingly recognized as vital components of molecular biology. With the development of RNA-sequencing (RNA-Seq) technology, accumulating evidence shows that ncRNAs are important mediators of diverse biological processes such as cell proliferation, differentiation, and apoptosis. They are also considered promising biomarkers and better candidates than proteins and genes for the early recognition of disease onset, as they are associated with relative stability, specificity, and reproducibility. In this review, we provide the first comprehensive description of the current knowledge regarding three groups of ncRNAs—microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs)—focusing on their characteristics, molecular functions, as well as diagnostic and therapeutic potential in DLBCL. This review provides an exhaustive account for researchers to explore novel biomarkers for the diagnosis and prognosis of DLBCL and therapeutic targets.

Cluster miRNAs and cancer: Diagnostic, prognostic and therapeutic opportunities

MiRNAs are class of noncoding RNA important for gene expression regulation in many plants, animals and viruses. MiRNA clusters contain a set of two or more miRNA encoding genes, transcribed together as polycistronic miRNAs. Currently, there are approximately 159 miRNA clusters reported in the human genome consisting of miRNAs ranging from two or more miRNA genes. A large proportion of clustered miRNAs resides in and around the fragile sites or cancer associated genomic hotspots and plays an important role in carcinogenesis. Altered expression of miRNA cluster can be pro-tumorigenic or anti-tumorigenic and can be targeted for clinical management of cancer. Over the past few years, manipulation of miRNA clusters expression is attempted for experimental purpose as well as for diagnostic, prognostic and therapeutic applications in cancer. Re-expression of miRNAs by epigenetic therapy, genome editing such as clustered regulatory interspaced short palindromic repeats (CRISPR) and miRNA mowers showed promising results in cancer therapy. In this review, we focused on the potential of miRNA clusters as a biomarker for diagnosis, prognosis, targeted therapy as well as strategies for modulating their expression in a therapeutic context. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Processing > Processing of Small RNAs RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs.

Significance of the microRNA‑17‑92 gene cluster expressed in B‑cell non‑Hodgkin's lymphoma

To evaluate the prognostic value of the microRNA (miR)‑17‑92 gene cluster, the expression of miR‑17‑92 in B‑cell non‑Hodgkin's lymphoma (B‑NHL) was examined. Patients with B‑NHL, who received therapy in the Department of Hematology, Harbin Medical University Cancer Hospital between January 2012 and October 2014, were enrolled in the study. The expression of the miR‑17‑92 cluster in tumor tissue samples was detected by reverse transcription‑quantitative polymerase chain reaction analysis. The overall survival (OS) and event‑free survival (EFS) times were also investigated by the Kaplan‑Meier method and comparisons between groups were estimated using a log‑rank test. Three types of lymphoid cancer cells with wild‑type (WT), knockout of miR‑17‑92 (KO), and overexpression of miR‑17‑92 (TG), were utilized to establish a tumor xenograft model, and a reactive hyperplasia lymph cell was used as a control. The tumor incubation times and weights were examined. A total of 71 patients with B‑NHL were registered. No significant correlations were identified between the expression of miR‑17‑92 and clinical factors (P>0.05). Members of the miR‑17‑92 cluster exhibited various expression in the subtypes of B‑NHL, and the difference between follicular lymphoma (FL) and germinal center B‑cell like (GBC) was most marked. The overexpression of miR‑18, miR‑19a, and miR‑92a induced a marked reduction in the OS of patients with B‑NHL, and high‑levels of miR‑19a and miR‑92a led to a decline in EFS. The overexpression of miR‑17‑92 shortened the duration of incubation required for visualization of the xenograft tumor, whereas knockout led to inhibition of tumor formation. The expression of miR‑17‑92 in FL differed significantly from that in GBC, and miR‑19a may have a crucial effect on the OS and EFS of patients with B‑NHL.

miR-17∼92 in lymphocyte development and lymphomagenesis

microRNAs (miRNAs) down-modulate the levels of proteins by sequence-specific binding to their respective target mRNAs, causing translational repression or mRNA degradation. The miR-17∼92 cluster encodes for six miRNAs whose target recognition specificities are determined by their distinct sequence. In mice, the four miRNA families generated from the miR-17∼92 cluster coordinate to allow for proper lymphocyte development and effective adaptive immune responses following infection or immunization. Lymphocyte development and homeostasis rely on tight regulation of PI3K signaling to avoid autoimmunity or immunodeficiency, and the miR-17∼92 miRNAs appear as key mediators to appropriately tune PI3K activity. On the other hand, in lymphoid tumors overexpression of the miR-17∼92 miRNAs is a common oncogenic event. In this review, we touch on what we have learned so far about the miR-17∼92 miRNAs, particularly with respect to their role in lymphocyte development, homeostasis and pathology.

Systematic Review of the Potential of MicroRNAs in Diffuse Large B Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common subtype of invasive non-Hodgkin’s lymphoma (NHL). DLBCL presents with variable backgrounds, which results in heterogeneous outcomes among patients. Although new tools have been developed for the classification and management of patients, 40% of them still have primary refractory disease or relapse. In addition, multiple factors regarding the pathogenesis of this disease remain unclear and identification of novel biomarkers is needed. In this context, recent investigations point to microRNAs as useful biomarkers in cancer. The aim of this systematic review was to provide new insight into the role of miRNAs in the diagnosis, classification, treatment response and prognosis of DLBCL patients. We used the following terms in PubMed” ((‘Non-coding RNA’) OR (‘microRNA’ OR ‘miRNA’ OR ‘miR’) OR (‘exosome’) OR (‘extracellular vesicle’) OR (‘secretome’)) AND (‘Diffuse large B cell lymphoma’ OR ‘DLBCL’)” to search for studies evaluating miRNAs as a diagnosis, subtype, treatment response or prognosis biomarkers in primary DLBCL in human patient populations. As a result, the analysis was restricted to the role of miRNAs in tumor tissue and we did not consider circulating miRNAs. A total of thirty-six studies met the inclusion criteria. Among them, twenty-one were classified in the diagnosis category, twenty in classification, five in treatment response and nineteen in prognosis. In this review, we have identified miR-155-5p and miR-21-5p as miRNAs of potential utility for diagnosis, while miR-155-5p and miR-221-3p could be useful for classification. Further studies are needed to exploit the potential of this field.

Key microRNAs in the biology of breast cancer; emerging evidence in the last decade

microRNAs (miRNAs) are a family of small noncoding RNAs that play a pivotal role in the regulation of main biological and physiological processes, including cell cycle regulation, proliferation, differentiation, apoptosis, stem cell maintenance, and organ development. Dysregulation of these tiny molecules has been related to different human diseases, such as cancer. It has been estimated that more than 50% of these noncoding RNA sequences are placed on fragile sites or cancer-associated genomic regions. After the discovery of the first specific miRNA signatures in breast cancer, many studies focused on the involvement of these small RNAs in the pathophysiology of breast tumors and their possible clinical implications as reliable prognostic biomarkers or as a new therapeutic approach. Therefore, the present review will focus on the recent findings on the involvement of miRNAs in the biology of breast cancer associated with their clinical implications.

Serum miR-22 as potential non-invasive predictor of poor clinical outcome in newly diagnosed, uniformly treated patients with diffuse large B-cell lymphoma: an explorative pilot study

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of tumors, with aggressive clinical course that renders prognostication and choice of treatment strategy difficult. Chemo-immunotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP) is the current first-line treatment. MicroRNAs (miRNAs) are under investigation as novel diagnostic and prognostic biomarkers in several malignancies, including malignant lymphomas. While tissue miRNAs in DLBCL patients have been extensively studied as biomarkers, only few reports to date have evaluated the role of circulating/serum miRNAs as potential prognostic factors. Here circulating/serum miRNAs, including miR-22, were investigated as potential non-invasive biomarkers, with the aim of a better prognostic stratification of DLBCL patients.

METHODS

MiRNAs were selected by global expression profile of serum miRNAs of DLBCL patients, The Cancer Genome Atlas (TCGA) analysis and literature research. Serum and tissues miRNA expression profile in de novo DLBCL patients, consecutively enrolled for this study, were detected by quantitative real-time polymerase chain reaction. Relative expression was calculated using the comparative Ct method. Statistical significance was determined using the Mann-Whitney rank sum and Fisher's exact test. Survival analysis was conducted through the use of Kaplan-Meier method. Spearman's Rho was applied to study the correlation between miRNA distributions and days to first relapse. Experimentally validated miRNA-target interactions were assessed by miRTarBase database. Negative miRNA-mRNA correlation was evaluated in TCGA DLBCL dataset. Pathway analysis was performed by the functional annotation clustering DAVID tool.

RESULTS

We showed a significant modulation of serum miR-22 after R-CHOP treatment compared with basal values but no difference between baseline serum miRNAs values of DLBCL patients and healthy controls. High expression level of serum miR-22 in DLBCL at diagnosis (n = 36) is associated with a worse PFS and is independent of the currently used clinical prognostic index. Integrative and pathways analysis of miR-22 identified target genes involved in different important pathways such as p53 signaling.

CONCLUSIONS

Our data suggest that miR-22 is of potential interest as non-invasive biomarker to predict clinical outcome in DLBCL patients. Characterization of miR-22 pathways can pave the way to the development of targeted therapy approaches for specific subgroups of DLBCL patients.

Plasma microRNA panels to diagnose pancreatic cancer: Results from a multicenter study

Biomarkers for the early diagnosis of pancreatic cancer (PC) are urgent needed. Plasma microRNAs (miRNAs) might be used as biomarkers for the diagnosis of cancer. We analyzed 361 plasma samples from 6 surgical centers in China and performed machine learning approach. We gain insight of the association between the aberrant plasma miRNA expression and pancreatic disease. 671 microRNAs were screened in the discovery phase and 33 microRNAs in the training phase and 13 microRNAs in the validation phase. After the discovery phase and training phase, 2 diagnostic panels were constructed comprising 3 microRNAs in panel I (miR-486-5p, miR-126-3p, miR-106b-3p) and 6 microRNAs in panel II (miR-486-5p, miR-126-3p, miR-106b-3p, miR-938, miR-26b-3p, miR-1285). Panel I and panel II had high accuracy for distinguishing pancreatic cancer from chronic pancreatitis (CP) with area under the curve (AUC) values of 0.891 (Standard Error (SE): 0.097) and 0.889 (SE: 0.097) respectively, in the validation phase. Additionally, we demonstrated that the diagnostic value of the panels in discriminating PC from CP were comparable to that of carbohydrate antigen 19–9 (CA 19–9) 0.775 (SE: 0.053) (P = 0.1 for both). This study identified 2 diagnostic panels based on microRNA expression in plasma with the potential to distinguish PC from CP. These patterns might be developed as biomarkers for pancreatic cancer.

The miR-17-92 cluster/QKI2/β-catenin axis promotes osteosarcoma progression

Quaking(QKI) is an RNA binding protein, and it has been shown to serve as a tumor suppressor. However, the expression and functions of QKI in osteosarcoma progression remain poorly understood. In this study, we aimed to explore the expression of QKI2 in osteosarcoma tissues and to determine the mechanisms underlying aberrant QKI2 expression and the effect of QKI2 on osteosarcoma progression. We found that QKI2 was significantly down-regulated in osteosarcoma tissues compared with adjacent normal bone tissues. Using a series of molecular biological techniques, we demonstrated that all members of the miR-17-92 cluster were up-regulated and contributed to the down-regulation of QKI2 expression in osteosarcoma. Functional examination showed that QKI2 inhibited the proliferation, migration and invasion of osteosarcoma cells via decreasing the expression of β-catenin. Conclusively, we revealed that the regulatory axis consisting of the miR-17-92 cluster/QKI2/β-catenin plays a crucial role in the development and progression of osteosarcoma.

Plasma microRNA profiling: Exploring better biomarkers for lymphoma surveillance

Early detection of relapsed lymphoma improves response and survival. Current tools lack power for detection of early relapse, while being cumbersome and expensive. We searched for sensitive biomarkers that precede clinical relapse, and serve for further studies on therapy response and relapse. We recruited 20 healthy adults, 14 diffuse large B-cell lymphoma (DLBCL) patients and 11 Hodgkin lymphoma (HL) patients at diagnosis. Using small-RNA sequencing we identified in DLBCL patients increased plasma levels of miR-124 and miR-532-5p, and decreased levels of miR-425, miR-141, miR-145, miR-197, miR-345, miR-424, miR-128 and miR-122. In the HL group, we identified miR-25, miR-30a/d, miR-26b, miR-182, miR-186, miR-140* and miR-125a to be up-regulated, while miR-23a, miR-122, miR-93 and miR-144 were down-regulated. Pathway analysis of potential mRNAs targets of these miRNA revealed in the DLBCL group potential up-regulation of STAT3, IL8, p13k/AKT and TGF-B signaling, and potential down-regulation of the PTEN and p53 pathways; while in the HL group we have found the cAMP-mediated pathway and p53 pathway to be potentially down-regulated. Survival analyses revealed that plasma levels of miR-20a/b, miR-93 and miR-106a/b were associated with higher mortality. In conclusion, we identified sets of dysregulated circulating miRNA that might serve as reliable biomarkers for relapsed lymphoma.

miR-17-92基因簇在肿瘤发生发展中作用的研究进展

肿瘤是威胁全世界人类健康和影响社会经济的重要因素. 近年来, 随着经济的发展, 肿瘤的发病率呈明显上升趋势, 但是其病因尚未完全阐明. 越来越多的证据显示肿瘤的发生和遗传因素有关, 随着病理生理学和遗传学的发展, 许多学者认为生物标志物可以预测癌症甚至指导临床治疗. 微小RNA(microRNA, miRNA)是非编码小分子RNA, 在发育、生理、病理过程以及肿瘤发生等环节中起着重要的调节作用. miR-17-92基因簇是研究较为深入、最有特点的miRNA, 被认为是原癌基因miRNA的代表, 在多种肿瘤的发生发展中起着至关重要的作用. 本文就miR-17-92基因簇在肿瘤发生发展中的作用及功能进行综述.

miR-130A as a diagnostic marker to differentiate malignant mesothelioma from lung adenocarcinoma in pleural effusion cytology

BACKGROUND

Malignant pleural mesothelioma is a rare tumor with a dismal prognosis, usually presenting with recurrent effusions. However, the majority of malignant pleural effusions are due to lung adenocarcinoma (AdC). The distinction between these tumors has considerable therapeutic and medicolegal implications and can be very challenging both histologically and cytologically. Appropriate immunohistochemistry (IHC) is required to support the diagnosis. MicroRNA (miRNA) expression analysis could be a viable diagnostic tool for distinguishing between these tumors. The purpose of the current study was to assess the reliability of miRNAs as diagnostic markers to differentiate epithelioid malignant mesothelioma (MM) from lung AdC.

METHODS

Bioinformatic analysis of publicly searchable data sets regarding miRNA expression profiling was performed to select the most significant differentially expressed miRNAs. These were analyzed by quantitative polymerase chain reaction on histologic (41 MM cases and 40 lung AdC cases) and cytological (26 MM cases and 27 lung AdC cases) specimens and the diagnostic performances were assessed.

RESULTS

miR-130a, miR-193a, miR-675, miR-141, miR-205, and miR-375 were found to be the best distinguishing markers. Of these, only miR-130a was significantly overexpressed in MM compared with lung AdC (P =.029 in histologic and P =.014 in cytological samples). miR-130a demonstrated a sensitivity of 77%, a specificity of 67%, a positive predictive value of 69%, a negative predictive value of 75%, and an accuracy of 72% in identifying MM.

CONCLUSIONS

The diagnostic performances of miR-130a expression analysis and IHC appear to be similar. miR-130a quantification could be used reliably as second-level diagnostic tool to differentiate MM from lung AdC in pleural effusion cytology, mainly in those cases with ambiguous or negative IHC. Further validation is needed. Cancer Cytopathol 2017;125:635-43. © 2017 American Cancer Society.

The Effects of Antisense miRNA-20a Alone or in Combination with Imatinib on K562 Cell Proliferation

Objective: The effects of microRNA-20a (miR-20a) antisense oligonucleotides (ASODNs) on the proliferation and apoptosis of K562 cells were investigated, and the effects of these ASODNs in combination with imatinib on K562 cells were preliminarily observed.

Methods: miR-20a ASODNs and scrambled oligonucleotides (SODNs) were chemically synthesized, and the later was used as the control. miR-20a ASODNs were transfected into K562 cells using Lipofectamine 2000 transfection reagent, and the expression of miR-20a was detected using real-time quantitative RT-PCR (qRT-PCR). The CCK8 assay was performed to detect the inhibition of the cell growth rate. The cells were stained by Hoechst 33258 to detect apoptotic cell morphology. Annexin V/PI double staining was used to detect the cell apoptosis rate using flow cytometry. The protein expression levels of E2F1, P21, and Bim in the K562 cell line were detected using western blotting.

Results: The qRT-PCR results showed that the expression level of miR-20a in K562 cells transfected with miR-20a ASODNs was lower than those in the normal control, SODN and blank transfection groups (p < 0.05). miR-20a ASODNs significantly inhibited the growth of K562 cells as compared to the controls (p < 0.05). The Hoechst staining results showed morphological changes, suggesting apoptosis. The cell apoptosis rates in the ASODN group was (13.9 ± 1.5)%, which was significantly higher than that in the normal control group (1.84 ± 0.21)%, blank transfection group (3.21 ± 0.32)%, and SODN group (3.72 ± 0.44)% (p < 0.05). The protein expression of E2F1 and P21 in K562 cells transfected with miR-20a ASODNs were higher, while the level of Bim protein was significantly lower than that in the control groups. When miR-20a ASODNs were combined with imatinib, the growth of K562 cells was significantly inhibited as compared to the ASODN treatment alone, imatinib alone, and SODN+imatinib groups (p < 0.05).

Conclusions: miR-20a ASODNs could induce apoptosis and inhibit the proliferation of K562 cells. In addition, imatinib combined with miR-20a ASODNs can increase the inhibitory effect on K562 cell proliferation.

An integrative transcriptomic analysis reveals bisphenol A exposure-induced dysregulation of microRNA expression in human endometrial cells

Bisphenol A (BPA) are commonly used in the manufacture of polycarbonate plastics. Higher BPA exposure levels have been found in patients with endometrial hyperplasia that is one of risk factors of endometrial cancer (EC). Aberrant microRNAs (miRNAs) regulation has been observed in the development of cancer. Thus, this study investigated whether BPA exposure can disrupt miRNA regulation and its gene expression regarding to EC carcinogenic progress. Microarray experiments of miRNA and mRNA were performed in human endometrial cancer RL95-2 cells with treatment of low-to-moderate (10, 10³ and 10⁵nM) BPA to explore the aberrant genes corresponding to human EC progression. According to the analysis of KEGG pathway and Cytoscape gene network, this study identified that BPA exposure reduced miR-149 expression to down-regulate DNA repair gene ARF6 (ADP-ribosylation factor 6) and tumor protein p53 (TP53), and up-regulate CCNE2 (cyclin E2) potentially to interrupt cell cycle. BPA also increased miR-107 to suppress hedgehog signaling factors, suppressor of fused homolog (SUFU) and GLI family zinc finger 3 (GLI3) to activate hedgehog signaling for cell proliferation underlying carcinogenesis. Furthermore, the BPA-induced cell proliferation was attenuated by transfection with miR-149 mimic and miR-107 inhibitor. These findings provided an insight into potential epigenetic mechanism of BPA exposure on the risk of endometrial carcinogenesis.

Image-guided fine-needle aspiration cytology and flow cytometry phenotyping of neck lymphadenopathy for the diagnosis of recurrent lymphoma

OBJECTIVE

In patients with a history of lymphoma, each lymphadenopathy should be carefully evaluated. The aims of this study were to evaluate (i) the usefulness of high-resolution ultrasonography (US), US-guided fine-needle aspiration cytology (FNAC) and flow cytometry phenotyping (FCP) together in the diagnosis of recurrent lymphoma and (ii) whether these tools were independent predictors of correct results.

DESIGN

Retrospective cohort study with stepwise forward logistic regression analysis of results.

SETTING

Tertiary referral centre.

PARTICIPANTS

A total of 151 patients with a history of lymphoma who developed a cervical mass during follow-up.

METHODS

On neck US, a lymphadenopathy was shown in 129 (85.4%) patients (median age 57 years, range 18-78 years), and US-guided FNAC combined with FCP were immediately performed. All patients had surgical excision and subsequent histological examination of the enlarged node(s), to establish lymphoma subclassification.

RESULTS

Final histology confirmed recurrence in 82 (63.6%) patients. According to the logistic regression analysis, FNAC and FCP were independent predictors of correct results (P = 0.009 and 0.028, respectively) and did not interfere with each other. The sensitivity, specificity and accuracy of the combination of all of the tools were 98.8%, 100% and 99.2%, respectively, and the area under the receiver operating characteristic curve was 0.902 (95% CI: 0.797-0.986).

CONCLUSION

This minimally invasive procedure is easily performed and should be recommended for all patients with cervical lymphadenopathy and a history of lymphoma, avoiding the need of core-biopsy or surgical excision if recurrence was excluded.

Dysregulated MicroRNA Expression Profiles and Potential Cellular, Circulating and Polymorphic Biomarkers in Non-Hodgkin Lymphoma

A large number of studies have focused on identifying molecular biomarkers, including microRNAs (miRNAs) to aid in the diagnosis and prognosis of the most common subtypes of non-Hodgkin lymphoma (NHL), Diffuse Large B-cell Lymphoma and Follicular Lymphoma. NHL is difficult to diagnose and treat with many cases becoming resistant to chemotherapy, hence the need to identify improved biomarkers to aid in both diagnosis and treatment modalities. This review summarises more recent research on the dysregulated miRNA expression profiles found in NHL, as well as the regulatory role and biomarker potential of cellular and circulating miRNAs found in tissue and serum, respectively. In addition, the emerging field of research focusing on miRNA single nucleotide polymorphisms (miRSNPs) in genes of the miRNA biogenesis pathway, in miRNA genes themselves, and in their target sites may provide new insights on gene expression changes in these genes. These miRSNPs may impact miRNA networks and have been shown to play a role in a host of different cancer types including haematological malignancies. With respect to NHL, a number of SNPs in miRNA-binding sites in target genes have been shown to be associated with overall survival.

MicroRNAs in Lymphoma: Regulatory Role and Biomarker Potential

Although it is now evident that microRNAs (miRNAs) play a critical regulatory role in many, if not all, pathological and physiological processes, remarkably they have only formally been recognized for less than fifteen years. These endogenously produced short non-coding RNAs have created a new paradigm of gene control and have utility as both novel biomarkers of cancer and as potential therapeutics. In this review we consider the role of miRNAs in lymphoid biology both under physiological (i.e. lymphopoiesis) and malignant (i.e. lymphomagenesis) conditions. In addition to the functional significance of aberrant miRNA expression in lymphomas we discuss their use as novel biomarkers, both as a in situ tumour biomarker and as a non-invasive surrogate for the tumour by testing miRNAs in the blood of patients. Finally we consider the use of these molecules as potential therapeutic agents for lymphoma (and other cancer) patients and discuss some of the hurdles yet to be overcome in order to translate this potential into clinical practice

Preoperative Prediction of Lymph Node Status by Circulating Mir-18b and Mir-20a During Chemoradiotherapy in Patients with Rectal Cancer

BACKGROUND

In locally advanced rectal cancer, therapeutic success of preoperative chemoradiotherapy (CRT) ranges from resistance to complete regression. For those patients that respond well to CRT, local resection (LR) procedures are currently under investigation to minimize surgical morbidity and to improve functional outcome. To maintain the oncologic benefit appropriate staging procedures are essential. However, current clinical assessment and imaging techniques need further improvement.

METHODS

Five miRNAs associated with rectal cancer (miR-17, miR-18b, miR-20a, miR-31, and miR-193-3p) were analyzed in the plasma of rectal cancer patients (n = 42) using qPCR. Expression levels were assessed before, during and after CRT and analyzed in regard to patients' lymph node status obtained after total mesorectal excision and intensive histopathological work-up.

RESULTS

Four of the five miRNAs revealed reliable results in the plasma. miR-31 was excluded due to its low expression. MicroRNA-17, 18b, 20a, and 193-3p showed altering expression levels at different time points. Only 43% (miR-17), 43% (miR-18b), 53% (miR-20a), and 60% (miR-193-3p) showed a continuous in- or decrease of miRNA expression. The reduced expression of miR-18b and miR-20a during CRT was found to be significantly associated with postoperative lymph node negativity (p < 0.05).

CONCLUSION

MicroRNA expression in patient plasma changes during preoperative CRT. The alteration is not continuous and the meaning requires additional analysis on a larger patient cohort. The co-occurrence of reduced miR-18b and miR-20a expression with lymph node negativity after preoperative CRT could help to stratify the surgical procedure with respect to total mesorectal excision and LR if validated prospectively.

MicroRNAs in diffuse large B-cell lymphoma

The aberrant expression of microRNAs (miRs) has a significant impact on the biological characteristics of lymphocytes, and is important in the pathogenesis of diffuse large B-cell lymphoma (DLBCL). It has been demonstrated, using miR profiling and detecting distinct miR signatures, that certain miRs may accurately distinguish different subtypes and prognostic classifications of DLBCL, as well as distinguish DLBCL from other more indolent lymphomas, including follicular lymphoma. miRs are excellent biomarkers for cancer diagnosis and prognosis. In DLBCL, specific miR expression profiles in the tissues of patients are associated with prognosis and clinical outcome. Over the past decade, there has been substantial investigation concerning the pathogenetic, diagnostic and prognostic roles of miRs in DLBCL. The aim of the present review is to describe the aberrant expression of miRs in DLBCL, and the functions, potential clinical use and possible therapeutic targets of miRs in this disease.

Novel drug targets for personalized precision medicine in relapsed/refractory diffuse large B-cell lymphoma: a comprehensive review

Diffuse large B-cell lymphoma (DLBCL) is a clinically heterogeneous lymphoid malignancy and the most common subtype of non-Hodgkin's lymphoma in adults, with one of the highest mortality rates in most developed areas of the world. More than half of DLBLC patients can be cured with standard R-CHOP regimens, however approximately 30 to 40 % of patients will develop relapsed/refractory disease that remains a major cause of morbidity and mortality due to the limited therapeutic options.Recent advances in gene expression profiling have led to the identification of at least three distinct molecular subtypes of DLBCL: a germinal center B cell-like subtype, an activated B cell-like subtype, and a primary mediastinal B-cell lymphoma subtype. Moreover, recent findings have not only increased our understanding of the molecular basis of chemotherapy resistance but have also helped identify molecular subsets of DLBCL and rational targets for drug interventions that may allow for subtype/subset-specific molecularly targeted precision medicine and personalized combinations to both prevent and treat relapsed/refractory DLBCL. Novel agents such as lenalidomide, ibrutinib, bortezomib, CC-122, epratuzumab or pidilizumab used as single-agent or in combination with (rituximab-based) chemotherapy have already demonstrated promising activity in patients with relapsed/refractory DLBCL. Several novel potential drug targets have been recently identified such as the BET bromodomain protein (BRD)-4, phosphoribosyl-pyrophosphate synthetase (PRPS)-2, macrodomain-containing mono-ADP-ribosyltransferase (ARTD)-9 (also known as PARP9), deltex-3-like E3 ubiquitin ligase (DTX3L) (also known as BBAP), NF-kappaB inducing kinase (NIK) and transforming growth factor beta receptor (TGFβR).This review highlights the new insights into the molecular basis of relapsed/refractory DLBCL and summarizes the most promising drug targets and experimental treatments for relapsed/refractory DLBCL, including the use of novel agents such as lenalidomide, ibrutinib, bortezomib, pidilizumab, epratuzumab, brentuximab-vedotin or CAR T cells, dual inhibitors, as well as mechanism-based combinatorial experimental therapies. We also provide a comprehensive and updated list of current drugs, drug targets and preclinical and clinical experimental studies in DLBCL. A special focus is given on STAT1, ARTD9, DTX3L and ARTD8 (also known as PARP14) as novel potential drug targets in distinct molecular subsets of DLBCL.

miR-19a and SOCS-1 expression in the differential diagnosis of laryngeal (glottic) verrucous squamous cell carcinoma

BACKGROUND

Laryngeal verrucous squamous cell carcinoma (VSCC) is a highly differentiated squamous cell carcinoma (SCC), the diagnosis of which can meet with many pitfalls: benign hyperplastic lesions and conventional SCC are the most important differential diagnoses. The microRNA miR-19a is overexpressed in many solid tumours and regulates the suppressor of cytokine signalling-1 (SOCS-1) expression.

AIMS

The main endpoints were to assess miR-19a and SOCS-1 expression in glottic VSCC, and the former's potential role in differentiating between glottic VSCC, conventional SCC and hyperplastic lesions.

METHODS

The expression of MiR-19a (by reverse transcription and quantitative real-time PCR) and SOCS-1 (by immunohistochemistry, rabbit polyclonal anti-SOCS-1 antibody) was assessed in 11 consecutive cases of glottic VSCC, 20 of papillary hyperplasia and 42 cases of conventional SCC.

RESULTS

Mean miR-19a expression was significantly higher (p = 0.000) in malignant glottic lesions (conventional SCC/VSCC) than in benign conditions. Significant differences in mean miR-19a expression also emerged between conventional SCC and papillary hyperplasia (p = 0.000), and between conventional SCC and VSCC (p = 0.03). miR-19a expression was not statistically associated with SOCS-1 immunoreactivity or immunostaining intensity in VSCC, conventional SCC or papillary hyperplasia.

CONCLUSIONS

Our preliminary outcomes suggest the utility of miR-19a in the challenging differential diagnosis of laryngeal VSCC. Although miR-19a has been found to regulate SOCS-1 expression, this evidence was not confirmed by this investigation.

The High Expression of the microRNA 17-92 Cluster and its Paralogs, and the Downregulation of the Target Gene PTEN, Is Associated with Primary Cutaneous B-Cell Lymphoma Progression

The oncogenic microRNA (miR) 17-92 cluster has a causative role in the lymphomagenesis of nodal B-cell lymphomas, by activating proliferation and inhibiting apoptosis. Here we analyzed primary cutaneous B-cell lymphomas for the miR-17-92 cluster and its paralogs miR-106a-363 and miR-106b-25. In 22 primary cutaneous diffuse large B-cell lymphomas, leg type (PCLBCL-LT) compared with 22 primary cutaneous follicle center lymphomas (PCFCLs), we found that miR-20a and miR-106a were overexpressed. Multivariate Cox analysis showed that higher miR-20a and miR-20b expression levels were associated with shorter disease-free and overall survival, independently from histological type. Gene expression profiling also showed a downregulation of 8 candidate target genes of miR-20a, miR-20b, and miR-106a in PCLBCL-LT compared with PCFCL. Among the candidate target genes, PTEN, NCOA3, and CAPRIN2 were confirmed to be underexpressed in PCLBCL-LT using quantitative reverse transcriptase-PCR on CD20-positive laser-microdissected tumor cells. In multivariate Cox analysis, lower PTEN mRNA expression level was associated with shorter disease-free survival (DFS), independently from the histological type. Altogether, this molecular and bioinformatic study of 44 patient skin biopsy samples showed that the oncogenic miR-17-92 cluster and its paralogs were involved in cutaneous B-cell lymphoma progression, and that the downregulation of the target gene PTEN was associated with shorter DFS.

MicroRNAs in B-cell lymphomas: how a complex biology gets more complex

MicroRNAs (miRNAs) represent important regulators of gene expression besides transcriptional control. miRNA regulation can be involved in the cell developmental fate decisions, but can also have more subtle roles in buffering stochastic fluctuations in gene expression. They participate in pathways fundamental to B-cell development like B-cell receptor (BCR) signalling, B-cell migration/adhesion, cell-cell interactions in immune niches, and the production and class-switching of immunoglobulins. miRNAs influence B-cell maturation, generation of pre-, marginal zone, follicular, B1, plasma and memory B cells. In this review, we discuss miRNAs with essential functions in malignant B-cell development (such as miR-150, miR-155, miR-21, miR-34a, miR-17-92 and miR-15-16). We also put these miRNAs in the context of normal B-cell differentiation, as this is intimately connected to neoplastic B-cell development. We review miRNAs' role in the most common B-cell malignancies, including chronic lymphocytic leukaemia (CLL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and mantle cell lymphoma (MCL). We focus on miR-contribution to the regulation of important signalling pathways (such as NF-κB, PI3K/AKT and TGF-β), BCR signalling and its modulators (such as PTEN, SHIP-1, ZAP-70, GAB1 and BTK), anti- and pro-apoptotic proteins (such as BCL2, MCL1, TCL1, BIM, p53 and SIRT1) and transcription factors (such as MYC, MYB, PU.1, FOXP1 and BCL6). We also discuss the association of miRNAs' expression levels with the patients' survival and response to therapy, summarizing their potential use as predictive and prognostic markers. Importantly, the targeting of miRNAs (like use of anti-miR-155 or miR-34a mimic) could provide a novel therapeutic approach as evidenced by tumour regression in xenograft mouse models and initial promising data from clinical trials.

MicroRNA expression in human endometrial adenocarcinoma

Background

MicroRNAs are small non-coding RNAs that play crucial roles in the pathogenesis of different cancer types. The aim of this study was to identify miRNAs that are differentially expressed in endometrial adenocarcinoma compared to healthy endometrium. These miRNAs can potentially be used to develop a panel for classification and prognosis in order to better predict the progression of the disease and facilitate the choice of treatment strategy.

Methods

Formalin fixed paraffin embedded endometrial tissue samples were collected from the Örebro university hospital. QPCR was used to quantify the expression levels of 742 miRNAs in 30 malignant and 20 normal endometrium samples. After normalization of the qPCR data, miRNAs differing significantly in expression between normal and cancer samples were identified, and hierarchical clustering analysis was used to identify groups of miRNAs with coordinated expression profiles.

Results

In comparisons between endometrial adenocarcinoma and normal endometrium samples 138 miRNAs were found to be significantly differentially expressed (p < 0.001) among which 112 miRNAs have not been previous reported for endometrial adenocarcinoma.

Conclusion

Our study shows that several miRNAs are differentially expressed in endometrial adenocarcinoma. These identified miRNA hold great potential as target for classification and prognosis of this disease. Further analysis of the differentially expressed miRNA and their target genes will help to derive new biomarkers that can be used for classification and prognosis of endometrial adenocarcinoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-014-0088-6) contains supplementary material, which is available to authorized users.

Serum microRNAs in HIV-infected individuals as pre-diagnosis biomarkers for AIDS-NHL

OBJECTIVE

To determine if changes in levels of serum microRNAs (miRNAs) were seen preceding the diagnosis of AIDS-related non-Hodgkin lymphoma (AIDS-NHL).

DESIGN

Serum miRNA levels were compared in 3 subject groups from the Multicenter AIDS Cohort Study: HIV-negative men (n = 43), HIV-positive men who did not develop NHL (n = 45), and HIV-positive men before AIDS-NHL diagnosis (n = 62, median time before diagnosis, 8.8 months).

METHODS

A total of 175 serum-enriched miRNAs were initially screened to identify differentially expressed miRNAs among these groups and the results validated by quantitative polymerase chain reaction. Receiver-operating characteristic analysis was then performed to assess biomarker utility.

RESULTS

Higher levels of miR-21 and miR-122, and a lower level of miR-223, were able to discriminate HIV-infected from the HIV-uninfected groups, suggesting that these miRNAs are biomarkers for HIV infection but are not AIDS-NHL specific. Among the HIV-infected groups, a higher level of miR-222 was able to discriminate diffuse large B-cell lymphoma (DLBCL) and primary central nervous system lymphoma (PCNSL) subjects from HIV-infected subjects who did not develop NHL, with area under the receiver-operating characteristic curve of 0.777 and 0.792, respectively. At miR-222 cutoff values of 0.105 for DLBCL and 0.109 for PCNSL, the sensitivity and specificity were 75% and 77%, and 80% and 82%, respectively.

CONCLUSIONS

Altered serum levels of miR-21, miR-122, and miR-223 are seen in HIV-infected individuals. Higher serum level of miR-222 has clear potential as a serum biomarker for earlier detection of DLBCL and PCNSL among HIV-infected individuals.

Programmed cell death 4 and microRNA 21 inverse expression is maintained in cells and exosomes from ovarian serous carcinoma effusions

BACKGROUND

Ovarian serous carcinoma (OSC) is a fatal gynecologic malignancy usually presenting with bilateral localization and malignant peritoneal effusion. Programmed cell death 4 (PDCD4) is a tumor suppressor gene whose expression is directly controlled by microRNA-21 (miR-21). Exosomes are small cell-derived vesicles that participate in intercellular communication, delivering their cargo of molecules to specific cells. Exosomes are involved in several physiological and pathological processes including oncogenesis, immunomodulation, angiogenesis, and metastasis. The current study analyzed the expression of PDCD4 and miR-21 in resected OSC specimens and in cells and exosomes from OSC peritoneal effusions.

METHODS

PDCD4 was immunohistochemically examined in 14 normal ovaries, 14 serous cystadenoma (CA), and 14 OSC cases. Quantitative reverse transcriptase-polymerase chain reaction analysis of PDCD4 and miR-21 expression was performed in CA and OSC cases and in cells and exosomes obtained from 10 OSC and 10 nonneoplastic peritoneal effusions. miR-21 was also evaluated by in situ hybridization.

RESULTS

Immunohistochemistry demonstrated a gradual PDCD4 loss from normal ovaries to CA and OSC specimens. Quantitative reverse transcriptase-polymerase chain reaction displayed higher PDCD4 messenger RNA levels in CA specimens compared with OSC cases and highlighted miR-21 overexpression in OSC specimens. In situ hybridization detected miR-21 only in OSC cells. This PDCD4 and miR-21 inverse expression was also noted in cells and exosomes from OSC peritoneal effusions compared with nonneoplastic effusions.

CONCLUSIONS

PDCD4 and miR-21 are involved in OSC oncogenesis. The transfer of miR-21 by exosomes could promote oncogenic transformation in target cells distant from the primary tumor without direct colonization by cancer cells and could be used as a diagnostic tool.

Evaluation of the prognostic role of pSTAT3 expression in temporal bone squamous cell carcinoma

OBJECTIVE

Temporal bone squamous cell carcinoma (SCC) accounts for less than 0.2% of all head and neck tumors. Although some progress has been made in treating this aggressive tumor, the prognosis in advanced cases remains poor. More effective therapeutic strategies need to be considered, including receptor-mediated carcinoma-targeted therapy. Phosphorylated STAT3 (pSTAT3) regulates many genes that are necessarily expressed in cancer initiation, development, and progression, being involved in proliferation, anti-apoptosis, invasion, angiogenesis, and immune surveillance evasion. The aim of the present study was to preliminarily investigate the potential prognostic role of pSTAT3 expression in temporal bone SCC.

STUDY DESIGN

Retrospective clinicopathologic investigation.

SETTING

Tertiary referral centers.

PATIENTS

Twenty-five consecutively operated patients with primary temporal bone SCC.

INTERVENTION

pSTAT3 immunohistochemical expression in primary temporal bone SCCs was assessed with the aid of computer-based image analysis.

MAIN OUTCOME MEASURES

Conventional clinicopathologic parameters and pSTAT3 expression were correlated with SCC prognosis.

RESULTS

pT, stage, and surgical margin status were significantly related with recurrence rate (p = 0.002, p = 0.01, and p = 0.047, respectively) and disease-free survival (DFS) (p = 0.0049, p = 0.031, and p = 0.035, respectively). pT classification was also related with disease-specific survival (DSS) (p = 0.035). The SCC recurrence rate did not correlate with pSTAT3 expression. Statistical analyses ruled out any significant difference in DFS or DSS when patients were stratified by pSTAT3 expression (>80.0% or ≤80.0%).

CONCLUSION

Despite our preliminary results, the role of pSTAT3 in temporal bone SCC warrants further investigation in larger series because there is increasing evidence in preclinical models to indicate that inhibiting STAT3 phosphorylation can be a useful addition to different anticancer strategies.

miRNA gene counts in chromosomes vary widely in a species and biogenesis of miRNA largely depends on transcription or post-transcriptional processing of coding genes

MicroRNAs target specific mRNA(s) to silence its expression and thereby regulate various cellular processes. We have investigated miRNA gene counts in chromosomes for 20 different species and observed wide variation. Certain chromosomes have extremely high number of miRNA gene compared with others in all the species. For example, high number of miRNA gene in X chromosome and the least or absence of miRNA gene in Y chromosome was observed in all species. To search the criteria governing such variation of miRNA gene counts in chromosomes, we have selected three parameters- length, number of non-coding and coding genes in a chromosome. We have calculated Pearson's correlation coefficient of miRNA gene counts with length, number of non-coding and coding genes in a chromosome for all 20 species. Major number of species showed that number of miRNA gene was not correlated with chromosome length. Eighty five percent of species under study showed strong positive correlation coefficient (r ≥ 0.5) between the numbers of miRNA gene vs. non-coding gene in chromosomes as expected because miRNA is a sub-set of non-coding genes. 55% species under study showed strong positive correlation coefficient (r ≥ 0.5) between numbers of miRNA gene vs. coding gene. We hypothesize biogenesis of miRNA largely depends on coding genes, an evolutionary conserved process. Chromosomes having higher number of miRNA genes will be most likely playing regulatory roles in several cellular processes including different disorders. In humans, cancer and cardiovascular disease associated miRNAs are mostly intergenic and located in Chromosome 19, X, 14, and 1.

miR-20b regulates expression of proteinase-activated receptor-1 (PAR-1) thrombin receptor in melanoma cells

The proteinase-activated receptor 1 (PAR-1) plays a central role in melanoma progression and its expression level is believed to correlate with the degree of cancer invasiveness. Here, we show that PAR-1 is post-transcriptionally regulated by miR-20b microRNA in human melanoma cells. PAR-1 was found to be expressed in metastatic melanoma cells but was barely detectable in primary melanoma. By transducing primary melanoma cells with a lentivirus containing a 3'-UTR construct of PAR-1 mRNA, we could show that endogenous melanoma microRNAs interacted with PAR-1 3'-UTR and silenced a fused luciferase reporter. Transfection of an inhibitor against miR-20b into primary melanoma cells reversed this process. Finally, transfection of miR-20b mimic into metastatic melanoma cells caused downregulation of the luciferase reporter. We conclude that miR-20b regulates expression of melanoma PAR-1 receptor, which may explain the differential expression of PAR-1 observed in human melanoma.

Reversible, interrelated mRNA and miRNA expression patterns in the transcriptome of Rasless fibroblasts: functional and mechanistic implications

Background

4-Hydroxy-tamoxifen (4OHT) triggers Cre-mediated K-Ras removal in [H-Ras^-/-;N-Ras^-/-;K-Ras^lox/lox;RERT^ert/ert] fibroblasts, generating growth-arrested “Rasless” MEFs which are able to recover their proliferative ability after ectopic expression of Ras oncoproteins or constitutively active BRAF or MEK1.

Results

Comparison of the transcriptional profiles of Rasless fibroblasts with those of MEFs lacking only H-Ras and N-Ras identified a series of differentially expressed mRNAs and microRNAs specifically linked to the disappearance of K-Ras from these cells. The rescue of cell cycle progression in Rasless cells by activated BRAF or MEK1 resulted in the reversal of most such transcriptional mRNA and microRNA alterations.

Functional analysis of the differentially expressed mRNAs uncovered a significant enrichment in the components of pathways regulating cell division, DNA/RNA processing and response to DNA damage. Consistent with G1/S blockade, Rasless cells displayed repression of a series of cell cycle-related genes, including Cyclins, Cyclin-dependent kinases, Myc and E2F transcription targets, and upregulation of Cyclin-dependent kinase inhibitors. The profile of differentially expressed microRNAs included a specific set of oncomiR families and clusters (repressed miR-17 ~ 92, miR-106a ~ 363, miR-106b ~ 25, miR-212 ~ 132, miR-183 ~ 182, and upregulated miR-335) known for their ability to target a specific set of cellular regulators and checkpoint sensors (including Rb, E2F and Cdkns) able to modulate the interplay between the pro- and anti-proliferative or stress-response pathways that are reversibly altered in Rasless cells.

Conclusions

Our data suggest that the reversible proliferation phenotype of Rasless cells is the pleiotropic result of interplay among distinct pro- and anti-proliferative, and stress-response pathways modulated by a regulatory circuitry constituted by a specific set of differentially expressed mRNAs and microRNAs and preferentially targeting two cross-talking signalling axes: Myc-Rb-E2F-dependent and Cdkns-p53-dependent pathways.

B-cell malignancies in microRNA Eμ-miR-17~92 transgenic mice

miR-17∼92 is a polycistronic microRNA (miR) cluster (consisting of miR-17, miR-18a, miR-19a, miR-19b, miR-20a, and miR-92a) which frequently is overexpressed in several solid and lymphoid malignancies. Loss- and gain-of-function studies have revealed the role of miR-17∼92 in heart, lung, and B-cell development and in Myc-induced B-cell lymphomas, respectively. Recent studies indicate that overexpression of this locus leads to lymphoproliferation, but no experimental proof that dysregulation of this cluster causes B-cell lymphomas or leukemias is available. To determine whether miR-17∼92- overexpression induces lymphomagenesis/leukemogenesis, we generated a B-cell-specific transgenic mouse model with targeted overexpression of this cluster in B cells. The miR-17∼92 overexpression was driven by the Eµ-enhancer and Ig heavy-chain promoter, and a 3' GFP tag was added to the transgene to track the miR expression. Expression analysis using Northern Blot and quantitative RT-PCR confirmed 2.5- to 25-fold overexpression of all six miRs in the transgenic mice spleens as compared with spleens from wild-type mice. Eµ-miR-17∼92 mice developed B-cell malignancy by the age of 12-18 mo with a penetrance of ∼80% (49% splenic B-cell lymphoproliferative disease, 28% lymphoma). At this stage mice exhibited severe splenomegaly with abnormal B-cell-derived white pulp expansion and enlarged lymph nodes. Interestingly, we found three classes of B-cell lymphomas/leukemias at varying grades of differentiation. These included expansion of CD19(+) and CD5(+) double-positive B cells similar to the aggressive form of human B-cell chronic lymphocytic leukemia, B220(+) CD43(+) B1-cell proliferation, and a CD19(+) aggressive diffuse large B-cell lymphoma-like disease, as assessed by flow cytometry and histopathological analysis.

Protein kinase CK2 inhibition down modulates the NF-κB and STAT3 survival pathways, enhances the cellular proteotoxic stress and synergistically boosts the cytotoxic effect of bortezomib on multiple myeloma and mantle cell lymphoma cells

CK2 is a pivotal pro-survival protein kinase in multiple myeloma that may likely impinge on bortezomib-regulated cellular pathways. In the present study, we investigated CK2 expression in multiple myeloma and mantle cell lymphoma, two bortezomib-responsive B cell tumors, as well as its involvement in bortezomib-induced cytotoxicity and signaling cascades potentially mediating bortezomib resistance. In both tumors, CK2 expression correlated with that of its activated targets NF-κB and STAT3 transcription factors. Bortezomib-induced proliferation arrest and apoptosis were significantly amplified by the simultaneous inhibition of CK2 with two inhibitors (CX-4945 and K27) in multiple myeloma and mantle cell lymphoma cell lines, in a model of multiple myeloma bone marrow microenvironment and in cells isolated from patients. CK2 inhibition empowered bortezomib-triggered mitochondrial-dependent cell death. Phosphorylation of NF-κB p65 on Ser529 (a CK2 target site) and rise of the levels of the endoplasmic reticulum stress kinase/endoribonuclease Ire1α were markedly reduced upon CK2 inhibition, as were STAT3 phospho Ser727 levels. On the contrary, CK2 inhibition increased phospho Ser51 eIF2α levels and enhanced the bortezomib-dependent accumulation of poly-ubiquitylated proteins and of the proteotoxic stress-associated chaperone Hsp70. Our data suggest that CK2 over expression in multiple myeloma and mantle cell lymphoma cells might sustain survival signaling cascades and can antagonize bortezomib-induced apoptosis at different levels. CK2 inhibitors could be useful in bortezomib-based combination therapies.

mir-17-92: a polycistronic oncomir with pleiotropic functions

Neoplastic transformation is caused by accumulation of genetic lesions that ultimately convert normal cells into tumor cells with uncontrolled proliferation and survival, unlimited replicative potential, and invasive growth. Emerging evidence has highlighted the functional importance of non-coding RNAs, particularly microRNAs (miRNAs), in the initiation and progression of tumor development. The mir-17-92 miRNA is among the best characterized miRNA oncogenes, whose genomic amplification or aberrant elevation are frequently observed in a variety of tumor types. Unlike protein-coding oncogenes, where one transcript produces one protein, mir-17-92 encodes a polycistronic miRNA transcript that yields six individual miRNA components. This unique gene structure, shared by many important miRNA oncogenes and tumor suppressors, underlies the unique functionality of mir-17-92 in a cell type and context-dependent manner. Recent functional dissection of mir-17-92 indicates that individual mir-17-92 components perform distinct biological functions, which collectively regulate multiple related cellular processes during development and disease. The structural complexity of mir-17-92 as a polycistronic miRNA oncogene, along with the complex mode of interactions among its components, constitutes the molecular basis for its unique functional complexity during normal and tumor development.

Role of microRNA deregulation in the pathogenesis of diffuse large B-cell lymphoma (DLBCL)

MicroRNAs (miRNAs) are small endogenous RNA molecules that regulate gene expression at the post-transcriptional level through its sequence complementation with target mRNAs. An individual miRNA species can simultaneously influence the expression of multiple genes and conversely, several miRNAs can synchronously control expression of specific gene product mRNA levels. Thus, miRNAs expression in cells has to be precisely regulated and alterations in miRNA levels may cause an aberrant expression of genes involved in oncogenic pathways and consequently result in cancer development. Indeed, miRNA expression is often deregulated in many cancers, including B-cell lymphomas. Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of B-cell lymphomas with different genetic backgrounds, morphologic features, and responses to therapy. Over the past decade, miRNAs emerged as a new tool for understanding DLBCL biology, and promising candidate molecular markers in DLBCL classification and treatment. In this review, we will focus on miRNAs aberrantly expressed in DLBCL and discuss the putative mechanisms of this deregulation. Additionally, we will summarize miRNAs' involvement in the identification of DLBCL subgroups, and their potential role as diagnostic/prognostic biomarkers as well as specific therapeutic targets for DLBCL.