MicroRNAs and Cancer: A Long Story for Short RNAs

Gra-CRC-miRTar: The pre-trained nucleotide-to-graph neural networks to identify potential miRNA targets in colorectal cancer

Colorectal cancer (CRC) is the third most diagnosed cancer and the second deadliest cancer worldwide representing a major public health problem. In recent years, increasing evidence has shown that microRNA (miRNA) can control the expression of targeted human messenger RNA (mRNA) by reducing their abundance or translation, acting as oncogenes or tumor suppressors in various cancers, including CRC. Due to the significant up-regulation of oncogenic miRNAs in CRC, elucidating the underlying mechanism and identifying dysregulated miRNA targets may provide a basis for improving current therapeutic interventions. In this paper, we proposed Gra-CRC-miRTar, a pre-trained nucleotide-to-graph neural network framework, for identifying potential miRNA targets in CRC. Different from previous studies, we constructed two pre-trained models to encode RNA sequences and transformed them into de Bruijn graphs. We employed different graph neural networks to learn the latent representations. The embeddings generated from de Bruijn graphs were then fed into a Multilayer Perceptron (MLP) to perform the prediction tasks. Our extensive experiments show that Gra-CRC-miRTar achieves better performance than other deep learning algorithms and existing predictors. In addition, our analyses also successfully revealed 172 out of 201 functional interactions through experimentally validated miRNA-mRNA pairs in CRC. Collectively, our effort provides an accurate and efficient framework to identify potential miRNA targets in CRC, which can also be used to reveal miRNA target interactions in other malignancies, facilitating the development of novel therapeutics.

MiR-630 Promotes Radioresistance by Induction of Anti-Apoptotic Effect via Nrf2-GPX2 Molecular Axis in Head-Neck Cancer

Head and neck cancer (HNC) ranks among the top ten prevalent cancers worldwide. Radiotherapy stands as a pivotal treatment component for HNC; however, radioresistance in cancerous cells often leads to local recurrence, becoming a substantial factor in treatment failure. MicroRNAs (miRNAs) are compact, non-coding RNAs that regulate gene expression by targeting mRNAs to inhibit protein translation. Although several studies have indicated that the dysregulation of miRNAs is intricately linked with malignant transformation, understanding this molecular family's role in radioresistance remains limited. This study determined the role of miR-630 in regulating radiosensitivity in HNC. We discovered that miR-630 functions as an oncomiR, marked by its overexpression in HNC patients, correlating with a poorer prognosis. We further delineated the malignant function of miR-630 in HNC cells. While it had a minimal impact on cell growth, the miR-630 contributed to radioresistance in HNC cells. This result was supported by decreased cellular apoptosis and caspase enzyme activities. Moreover, miR-630 overexpression mitigated irradiation-induced DNA damage, evidenced by the reduced levels of the γ-H2AX histone protein, a marker for double-strand DNA breaks. Mechanistically, the overexpression of miR-630 decreased the cellular ROS levels and initiated Nrf2 transcriptional activity, resulting in the upregulation of the antioxidant enzyme GPX2. Thus, this study elucidates that miR-630 augments radioresistance by inducing an anti-apoptotic effect via the Nrf2-GPX2 molecular axis in HNC. The modulation of miR-630 may serve as a novel radiosensitizing target for HNC.

Tumor-Suppressive and Immunomodulating Activity of miR-30a-3p and miR-30e-3p in HNSCC Cells and Tumoroids

Head and neck squamous cell carcinomas (HNSCCs) are heterogeneous tumors, well known for their frequent relapsing nature. To counter recurrence, biomarkers for early diagnosis, prognosis, or treatment response prediction are urgently needed. miRNAs can profoundly impact normal physiology and enhance oncogenesis. Among all of the miRNAs, the miR-30 family is frequently downregulated in HNSCC. Here, we determined how levels of the 3p passenger strands of miR-30a and miR-30e affect tumor behavior and clarified their functional role in LA-HNSCC. In a retrospective study, levels of miR-30a-3p and miR-30e-3p were determined in 110 patients and correlated to overall survival, locoregional relapse, and distant metastasis. miR-30a/e-3p were expressed in HNSCC cell lines and HNSCC patient-derived tumoroids (PDTs) to investigate their effect on tumor cells and their microenvironment. Both miRNAs were found to have a prognosis value since low miR-30a/e-3p expression correlates to adverse prognosis and reduces overall survival. Low expression of miR-30a/e-3p is associated with a shorter time until locoregional relapse and a shorter time until metastasis, respectively. miR-30a/e-3p expression downregulates both TGF-βR1 and BMPR2 and attenuates the survival and motility of HNSCC. Results were confirmed in PDTs. Finally, secretomes of miR-30a/e-3p-transfected HNSCC activate M1-type macrophages, which exert stronger phagocytic activities toward tumor cells. miR-30a/e-3p expression can discriminate subgroups of LA-HNSCC patients with different prognosis, making them good candidates as prognostic biomarkers. Furthermore, by targeting members of the TGF-β family and generating an immune-permissive microenvironment, they may emerge as an alternative to anti-TGF-β drugs to use in combination with immune checkpoint inhibitors.

APE1 controls DICER1 expression in NSCLC through miR-33a and miR-130b

Increasing evidence suggests different, not completely understood roles of microRNA biogenesis in the development and progression of lung cancer. The overexpression of the DNA repair protein apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) is an important cause of poor chemotherapeutic response in lung cancer and its involvement in onco-miRNAs biogenesis has been recently described. Whether APE1 regulates miRNAs acting as prognostic biomarkers of lung cancer has not been investigated, yet. In this study, we analyzed miRNAs differential expression upon APE1 depletion in the A549 lung cancer cell line using high-throughput methods. We defined a signature of 13 miRNAs that strongly correlate with APE1 expression in human lung cancer: miR-1246, miR-4488, miR-24, miR-183, miR-660, miR-130b, miR-543, miR-200c, miR-376c, miR-218, miR-146a, miR-92b and miR-33a. Functional enrichment analysis of this signature revealed its biological relevance in cancer cell proliferation and survival. We validated DICER1 as a direct functional target of the APE1-regulated miRNA-33a-5p and miR-130b-3p. Importantly, IHC analyses of different human tumors confirmed a negative correlation existing between APE1 and Dicer1 protein levels. DICER1 downregulation represents a prognostic marker of cancer development but the mechanisms at the basis of this phenomenon are still completely unknown. Our findings, suggesting that APE1 modulates DICER1 expression via miR-33a and miR-130b, reveal new mechanistic insights on DICER1 regulation, which are of relevance in lung cancer chemoresistance and cancer invasiveness.

miR-221/222 as biomarkers and targets for therapeutic intervention on cancer and other diseases: A systematic review

Among deregulated microRNAs (miRs) in human malignancies, miR-221 has been widely investigated for its oncogenic role and as a promising biomarker. Moreover, recent evidence suggests miR-221 as a fine-tuner of chronic liver injury and inflammation-related events. Available information also supports the potential of miR-221 silencing as promising therapeutic intervention. In this systematic review, we selected papers from the principal databases (PubMed, MedLine, Medscape, ASCO, ESMO) between January 2012 and December 2020, using the keywords “miR-221” and the specific keywords related to the most important hematologic and solid malignancies, and some non-malignant diseases, to define and characterize deregulated miR-221 as a valuable therapeutic target in the modern vision of molecular medicine. We found a major role of miR-221 in this view.

Pan-Cancer Analysis Reveals Common and Specific Relationships between Intragenic miRNAs and Their Host Genes

MicroRNAs (miRNAs) are small endogenous non-coding RNAs that play important roles in regulating gene expression. Most miRNAs are located within or close to genes (host). miRNAs and their host genes have either coordinated or independent transcription. We performed a comprehensive investigation on co-transcriptional patterns of miRNAs and host genes based on 4707 patients across 21 cancer types. We found that only 11.6% of miRNA-host pairs were co-transcribed consistently and strongly across cancer types. Most miRNA-host pairs showed a strong coexpression only in some specific cancer types, demonstrating a high heterogenous pattern. For two particular types of intergenic miRNAs, readthrough and divergent miRNAs, readthrough miRNAs showed higher coexpression with their host genes than divergent ones. miRNAs located within non-coding genes had tighter co-transcription with their hosts than those located within protein-coding genes, especially exonic and junction miRNAs. A few precursor miRNAs changed their dominate form between 5' and 3' strands in different cancer types, including miR-486, miR-99b, let-7e, miR-125a, let-7g, miR-339, miR-26a, miR-16, and miR-218, whereas only two miRNAs with multiple host genes switched their co-transcriptional partner in different cancer types (miR-219a-1 with SLC39A7/HSD17B8 and miR-3615 with RAB37/SLC9A3R1). miRNAs generated from distinct precursors (such as miR-125b from miR-125b-1 or miR-125b-2) were more likely to have cancer-dependent main contributors. miRNAs and hosts were less co-expressed in KIRC than other cancer types, possibly due to its frequent VHL mutations. Our findings shed new light on miRNA biogenesis and cancer diagnosis and treatments.

LINC01272 Suppressed Cell Multiplication and Induced Apoptosis Via Regulating MiR-7-5p/CRLS1 Axis in Lung Cancer

LINC01272 is a long non-coding RNA (lncRNA) that has been considered as a biomarker for many diseases including lung squamous cell carcinoma. Here, we investigated the function and mechanism of LINC01272 on lung cancer (LC). The differential expression of LINC01272 in LC and normal samples was analyzed by GEPIA based on the data from TCGA-LUAD database, as survival prognosis was analyzed through Kaplan-Meier Plotter. LINC01272 overexpression plasmid and miR-7-5p mimic were transfected into A549 and PC-9 cells. LINC01272, miR-7-5p and cardiolipin synthase 1 (CRLS1) mRNA expression was measured by quantitative reverse transcription-polymerase chain reaction. Cell viability was detected through MTT assay. Cell multiplication was evaluated by cell formation assay. Cell apoptosis was assessed through flow cytometry assay. Through bioinformatics, the target miRNA of LINC01272 and downstream genes of miR-7-5p were predicted. The targeting relationship was tested by dual luciferase reporter analysis. CRLS1, B-cell lymphoma-2 (Bcl-2), BCL2-associated X (Bax) and cleaved caspase-3 protein levels were detected through western blot. LINC01272 was downregulated in LC and low LINC01272 expression had poor prognosis. In A549 and PC-9 cells, LINC01272 inhibited cell viability and multiplication and induced apoptosis. LINC01272 negatively regulated miR-7-5p and CRLS1 was a target of miR-7-5p. MiR-7-5p reversed the effect of LINC01272 on viability, multiplication, apoptosis and expression of miR-7-5p and CRLS1 as well as apoptosis-related factors (Bcl-2, Bax and cleaved caspase-3). LINC01272 suppressed cell multiplication and induced apoptosis via regulating the miR-7-5p/CRLS1 axis in LC.

Downregulation of miR-497-5p prevents liver ischemia-reperfusion injury in association with MED1/TIMP-2 axis and the NF-κB pathway

Liver ischemia-reperfusion (I/R) injury is a common clinical pathological phenomenon, which is accompanied by the occurrence in liver transplantation. However, the underlying mechanism is not yet fully understood. MicroRNAs (miRNAs) play an important role in liver I/R injury. Therefore, the study of miRNAs function will contribute a new biological marker diagnosis of liver I/R injury. This study aims to evaluate effects of miR-497-5p in liver I/R injury in mice. The related regulatory factors of miR-497-5p in liver I/R injury were predicted by bioinformatics analysis. Vascular occlusion was performed to establish the liver I/R injury animal models. Hypoxia/reoxygenation (H/R) was performed to establish the in vitro models. Hematoxylin-eosin (HE) staining was conducted to assess liver injury. The inflammatory factors were evaluated by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was adopted to assess the cell apoptosis. The expression of miR-497b-5p was increased in liver I/R injury. Knockdown of miR-497b-5p inhibited the production of inflammatory factors and cell apoptosis. Overexpression of mediator complex subunit 1 (MED1) and tissue inhibitor of metalloproteinase 2 (TIMP2) inhibited cell apoptosis to alleviate liver I/R injury. miR-497b-5p could activate the nuclear factor kappa-B (NF-κB) pathway by inhibiting the MED1/TIMP-2 axis to promote liver I/R injury. This study may provide a new strategy for the treatment of liver I/R injury.

MicroRNA-148a-3p inhibits the proliferation of cervical cancer cells by regulating the expression levels of DNMT1 and UTF1

MicroRNAs (miRs) serve a key role in carcinogenesis. miR-148a-3p has been demonstrated to act as a tumor suppressor in several tumors, such as epithelial ovarian cancer and esophageal cancer. However, to the best of our knowledge, the role of miR-148a-3p in cervical cancer remains unclear. In the present study, the expression levels of miR-148a-3p measured by reverse transcription-quantitative PCR were significantly decreased in cervical cancer tissues compared with that in normal cervical tissues. Furthermore, overexpression of miR-148a-3p markedly suppressed the proliferation of cervical cancer cells. The luciferase reporter assay demonstrated that DNA methyltransferase 1 (DNMT1) was the target gene of miR-148a-3p and that its expression measured by western blotting was inhibited by miR-148a-3p in cervical cancer cells. Correlation analysis highlighted that the expression levels of the undifferentiated embryonic cell transcription factor-1 (UTF1) were negatively associated with the expression levels of DNMT1 in cervical cancer tissues. Furthermore, DNMT1 knockdown increased the expression of UTF1 and decreased the methylation level of UTF1 promoter. These data demonstrated the expression levels of UTF1 were regulated by DNMT1 methylation in cervical cancer cells. Collectively, the results of the present study suggested that miR-148a-3p may inhibit the proliferation of cervical cancer cells by regulating the expression levels of DNMT1/UTF1, which provides potential therapeutic targets for cervical cancer.

MicroRNA-124 inhibits hepatic stellate cells inflammatory cytokines secretion by targeting IQGAP1 through NF-κB pathway

Liver fibrosis is a health concern that leads to organ failure mediated via production of inflammatory cytokines and fibrotic biomarkers. To date, there was no direct approved antifibrotic therapy, and current treatment was mainly the removal of the causative factor. Recent studies demonstrated that aberrant expression of miR-124 was involved in the progression of various liver diseases including hepatocellular carcinoma (HCC). However, whether miR-124 could function as a transcriptional regulator in the inflammatory cytokines secretion of liver fibrosis remains unclear. In this study, we demonstrated that the expression of miR-124 was downregulated in liver fibrosis tissues and TNF-α-induced LX-2 cells, concomitant with the upregulated expression of IQGAP1, suggesting that miR-124 and IQGAP1 might be associated with the development of inflammation in liver fibrosis. Therefore, we demonstrated that the overexpression of miR-124 and knockdown of IQGAP1 could lead to the downregulation of TNF-α, IL-1β and IL-6. While knockdown of miR-124 or overexpression of IQGAP1 showed reversed results. Moreover, dual luciferase reporter assays demonstrated that miR-124 specifically targeted the 3'-UTR of IQGAP1, and thus inhibited the expression of IQGAP1. Mechanistically, we found that the expression changes of miR-124 and IQGAP1 could be involved in inhibition or activation of NF-κB signaling pathway in response to TNF-α. In conclusion, these results indicated that miR-124 plays a crucial role in TNF-α-induced LX-2 cells via regulating NF-κB signaling pathway.

Genomic Instability in Multiple Myeloma: A "Non-Coding RNA" Perspective

Simple Summary

Genomic instability (GI) plays an important role in the pathobiology of multiple myeloma (MM) by promoting the acquisition of several tumor hallmarks. Molecular determinants of GI in MM are continuously emerging and will be herein discussed, with specific regard to non-coding RNAs. Targeting non-coding RNA molecules known to be involved in GI indeed provides novel routes to dampen such oncogenic mechanisms in MM.

Abstract

Multiple myeloma (MM) is a complex hematological malignancy characterized by abnormal proliferation of malignant plasma cells (PCs) within a permissive bone marrow microenvironment. The pathogenesis of MM is unequivocally linked to the acquisition of genomic instability (GI), which indicates the tendency of tumor cells to accumulate a wide repertoire of genetic alterations. Such alterations can even be detected at the premalignant stages of monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) and, overall, contribute to the acquisition of the malignant traits underlying disease progression. The molecular basis of GI remains unclear, with replication stress and deregulation of DNA damage repair pathways representing the most documented mechanisms. The discovery that non-coding RNA molecules are deeply dysregulated in MM and can target pivotal components of GI pathways has introduced a further layer of complexity to the GI scenario in this disease. In this review, we will summarize available information on the molecular determinants of GI in MM, focusing on the role of non-coding RNAs as novel means to tackle GI for therapeutic intervention.

MicroRNAs as Predictive Biomarkers of Resistance to Targeted Therapies in Gastrointestinal Tumors

The advent of precision therapies against specific gene alterations characterizing different neoplasms is revolutionizing the oncology field, opening novel treatment scenarios. However, the onset of resistance mechanisms put in place by the tumor is increasingly emerging, making the use of these drugs ineffective over time. Therefore, the search for indicators that can monitor the development of resistance mechanisms and above all ways to overcome it, is increasingly important. In this scenario, microRNAs are ideal candidate biomarkers, being crucial post-transcriptional regulators of gene expression with a well-known role in mediating mechanisms of drug resistance. Moreover, as microRNAs are stable molecules, easily detectable in tissues and biofluids, they are the ideal candidate biomarker to identify patients with primary resistance to a specific targeted therapy and those who have developed acquired resistance. The aim of this review is to summarize the major studies that have investigated the role of microRNAs as mediators of resistance to targeted therapies currently in use in gastro-intestinal neoplasms, namely anti-EGFR, anti-HER2 and anti-VEGF antibodies, small-molecule tyrosine kinase inhibitors and immune checkpoint inhibitors. For every microRNA and microRNA signature analyzed, the putative mechanisms underlying drug resistance were outlined and the potential to be translated in clinical practice was evaluated.

Identification of MiR-93-5p Targeted Pathogenic Markers in Acute Myeloid Leukemia through Integrative Bioinformatics Analysis and Clinical Validation

Acute myeloid leukemia (AML) is a type of hematological malignancy with diverse genetic pathogenesis. Identification of the miR-93-5p targeted pathogenic markers could be useful for AML diagnosis and potential therapy. We collected 751 miR-93-5p targeted and AML-related genes by integrating the results of multiple databases and then used the expression profile of TCGA-LAML to construct a coexpression function network of AML WGCNA. Based on the clinical phenotype and module trait relationship, we identified two modules (brown and yellow) as interesting dysfunction modules, which have a significant association with cytogenetics risk and FAB classification systems. GO enrichment and KEGG analysis showed that these modules are mainly involved with cancer-associated pathways, including MAPK signal pathway, p53 signal pathway, JAK-STAT signal pathway, TGF-beta signaling pathway, mTOR signaling pathway, VEGF signaling pathway, both associated with the occurrence of AML. Besides, using the STRING database, we discovered the top 10 hub genes in each module, including MAPK1, ACTB, RAC1, GRB2, MDM2, ACTR2, IGF1R, CDKN1A, YWHAZ, and YWHAB in the brown module and VEGFA, FGF2, CCND1, FOXO3, IGFBP3, GSF1, IGF2, SLC2A4, PDGFBM, and PIK3R2 in the yellow module. The prognosis analysis result showed that six key pathogens have significantly affected the overall survival and prognosis in AML. Interestingly, VEGF with the most significant regulatory relationship in the yellow modules significantly positively correlated with the clinical phenotype of AML. We used qPCR and ELISA to verify miR-93-5p and VEGF expression in our clinical samples. The results exhibited that miR-93-5p and VEGF were both highly expressed in AML.

MiRNA-200C expression in Fanconi anemia pathway functionally deficient lung cancers

The Fanconi Anemia (FA) pathway is essential for human cells to maintain genomic integrity following DNA damage. This pathway is involved in repairing damaged DNA through homologous recombination. Cancers with a defective FA pathway are expected to be more sensitive to cross-link based therapy or PARP inhibitors. To evaluate downstream effectors of the FA pathway, we studied the expression of 734 different micro RNAs (miRNA) using NanoString nCounter miRNA array in two FA defective lung cancer cells and matched control cells, along with two lung tumors and matched non-tumor tissue samples that were deficient in the FA pathway. Selected miRNA expression was validated with real-time PCR analysis. Among 734 different miRNAs, a cluster of microRNAs were found to be up-regulated including an important cancer related micro RNA, miR-200C. MiRNA-200C has been reported as a negative regulator of epithelial-mesenchymal transition (EMT) and inhibits cell migration and invasion by promoting the upregulation of E-cadherin through targeting ZEB1 and ZEB2 transcription factors. miRNA-200C was increased in the FA defective lung cancers as compared to controls. AmpliSeq analysis showed significant reduction in ZEB1 and ZEB2 mRNA expression. Our findings indicate the miRNA-200C potentially play a very important role in FA pathway downstream regulation.

Serum miR-195-5p Exhibits Clinical Significance in the Diagnosis of Essential Hypertension with Type 2 Diabetes Mellitus by Targeting DRD1

OBJECTIVES

Diagnosis and management of essential hypertension (EH) or type 2 diabetes mellitus (T2DM) by combining comprehensive treatment and classificatory diagnosis have been continuously improved. However, understanding the pathogenesis of EH patients with concomitant T2DM and subsequent treatment remain the major challenges owing to the lack of non-invasive biomarkers and information regarding the underlying mechanisms.

METHODS

Herein, we collected 200 serum samples from EH and/or T2DM patients and healthy donors (N). Gene-expression profiling was conducted to identify candidate microRNAs with clinical significance. Then, a larger cohort of the aforementioned patients and 50 N were used to identify the correlation between the tumor suppressor miR-195-5p and EH and/or T2DM. The dual-luciferase reporter assay was used to explore the target genes of miR-195-5p. The suppressive effects of miR-195-5p on the 3'-UTR of the dopamine receptor D1 (DRD1) transcript in EH patients with concomitant T2DM were verified as well.

RESULTS

Compared with that in other groups, serum miR-195-5p was highly downregulated in EH patients with concomitant T2DM. miR-195-5p overexpression efficiently suppressed DRD1 expression by binding to the two 3'-UTRs. Additionally, two single nucleotide polymorphisms, including 231T-A and 233C-G, in the miR-195-5p binding sites of the DRD1 3'-UTR were further identified. Collectively, we identified the potential clinical significance of DRD1 regulation by miR-195-5p in EH patients with concomitant T2DM.

CONCLUSIONS

Our data suggested that miR-195-5p circulating in the peripheral blood served as a novel biomarker and therapeutic target for EH and T2DM, which could eventually help address major challenges during the diagnosis and treatment of EH and T2DM.

OncomiRs miR-106a and miR-17 negatively regulate the nucleoside-derived drug transporter hCNT1

High-affinity uptake of natural nucleosides as well as nucleoside derivatives used in anticancer therapies is mediated by human concentrative nucleoside transporters (hCNTs). hCNT1, the hCNT family member that specifically transports pyrimidines, is also a transceptor involved in tumor progression. In particular, oncogenesis appears to be associated with hCNT1 downregulation in some cancers, although the underlying mechanisms are largely unknown. Here, we sought to address changes in colorectal and pancreatic ductal adenocarcinoma-both of which are important digestive cancers-in the context of treatment with fluoropyrimidine derivatives. An analysis of cancer samples and matching non-tumoral adjacent tissues revealed downregulation of hCNT1 protein in both types of tumor. Further exploration of the putative regulation of hCNT1 by microRNAs (miRNAs), which are highly deregulated in these cancers, revealed a direct relationship between the oncomiRs miR-106a and miR-17 and the loss of hCNT1. Collectively, our findings provide the first demonstration that hCNT1 inhibition by these oncomiRs could contribute to chemoresistance to fluoropyrimidine-based treatments in colorectal and pancreatic cancer.

Cardioinformatics: the nexus of bioinformatics and precision cardiology

Cardiovascular disease (CVD) is the leading cause of death worldwide, causing over 17 million deaths per year, which outpaces global cancer mortality rates. Despite these sobering statistics, most bioinformatics and computational biology research and funding to date has been concentrated predominantly on cancer research, with a relatively modest footprint in CVD. In this paper, we review the existing literary landscape and critically assess the unmet need to further develop an emerging field at the multidisciplinary interface of bioinformatics and precision cardiovascular medicine, which we refer to as 'cardioinformatics'.

The Role of Noncoding RNAs in B-Cell Lymphoma

In recent years, emerging evidence has suggested that noncoding RNAs (ncRNAs) participate in nearly every aspect of biological processes and play a crucial role in the genesis and progression of numerous tumors, including B-cell lymphoma. The exploration of ncRNA dysregulations and their functions in B-cell lymphoma provides new insights into lymphoma pathogenesis and is essential for indicating future clinical trials and optimizing the diagnostic and therapeutic strategies. In this review, we summarize the role of ncRNAs in B-cell lymphoma and discuss their potential in clinical applications.

miR-491-3p is Downregulated in Retinoblastoma and Inhibit Tumor Cells Growth and Metastasis by Targeting SNN

Retinoblastoma (Rb) is the most common pediatric malignant tumor of the eyes. Previous studies demonstrated that miR-491-3p is downregulated in various cancers. However, its function in Rb remains unknown. A total of 15 pairs of primary Rb tissues and adjacent noncancerous tissues were collected. Quantitative real-time PCR (qRT-PCR) was used to investigate the expression profiles of miR-491-3p. qRT-PCR, western blotting and in situ immunocytochemistry were performed to investigate the expression profiles of epithelial–mesenchymal transition-related proteins (E-cadherin, Vimentin and N-cadherin) in Rb tissues and Rb cell lines as well as cell morphology. Cell proliferation was estimated by MTS and colony formation assays. Apoptosis was determined by FACS, cell migration and invasion were analyzed using transwell chambers. MiR-491-3p’s target genes were predicted using target gene prediction databases. The interplay between miR-491-3p and SNN was evaluated through dual luciferase reporter gene assay. MiR-491-3p was significantly downregulated in mixed collection of 15 pairs of Rb tissues and Rb cell lines. Overexpression of miR-491-3p enhanced apoptosis, and significantly suppressed proliferation, migration and invasion of Rb cells. In contrast, the present of miR-491-3p inhibitor showed reversed results which apoptosis decreased, while cell proliferation of ARPE-19 cells increased. In addition, miR-491-3p increased the expression of E-cadherin, and dramatically decreased the expression of Vimentin and N-cadherin in Rb tissues and Rb cell lines, noticeable changes in morphology, too, as cells became less cohesive and more adhering. We found out that SNN was the pairing target of miR-491-3p and result showed that miR-491-3p and SNN interacted with each other. We also found out that the effects of miR-491-3p were in Rb cells were almost entirely canceled out at the overexpression of SNN. Our findings collectively suggest that miR-491-3p is an important tumor suppressor in Rb, which inhibits tumor growth and metastasis in Rb. These implicate it may be explored as a new therapeutic target in Rb.

MicroRNAs as mediators of drug resistance mechanisms

MicroRNAs are small RNA transcripts involved in fine-tuning of several cellular mechanisms and pathways crucial for maintaining cells' homeostasis like apoptosis, differentiation, inflammation and cell-cycle regulation. They act by regulation of gene expression at post-transcriptional level through fine-tuning of target proteins expression. Expression of microRNAs is cell-type specific and since their discovery they have been proven to be deregulated in various disorders including cancer. Several lines of evidence are emerging that link microRNAs to drug resistance mechanisms in tumours given their important role in modulating oncogenic and tumour suppressive mechanisms. This review will focus on latest knowledge of the roles and mechanisms of microRNAs as mediators to drug resistance and the implications for future therapies.

Diagnostic performance for declined microRNA-133a in pancreatic cancer

MicroRNA-133a (MiR-133a) is proven to exhibit a decreasing tendency in several cancers, as well as pancreatic cancer. Through the present study, we inspected performance for serum miR-133a in diagnosing pancreatic cancer. Serum samples were collected from 110 pancreatic cancer and 64 healthy persons. Relative messenger RNA level for miR-133a in serum specimens was gauged adopting quantitative real-time polymerase chain reaction (qRT-PCR), and compared betwixt two groups employing the Student t test. Receiver operating characteristics (ROC) analysis evaluated miR-133a performance in diagnosing pancreatic cancer. MiR-133a displayed a declining trend among pancreatic cancer samples, compared to the healthy controls (P < .001). The reduced miR-133a degree held strong relation to tumor dimension (P = .002), vessel invasion (P = .004), tumor lymph node metastasis stage (P = .002), and lymph node metastasis (P < .001). In addition, ROC analysis demonstrated that the area under the curve value was 0.893, accompanied by a sensitivity of 90.6% and a specificity of 87.2%, revealing fine execution for serum miR-133a in diagnosing cancer. The downregulation of miR-133a might possess a tight relation to hostile advancement in pancreatic cancer. Serum miR-133a could function as a potential diagnostic indicator for pancreatic cancer.

Cyclin D1 promotes secretion of pro-oncogenic immuno-miRNAs and piRNAs

The molecular mechanisms governing the secretion of the non-coding genome are poorly understood. We show herein that cyclin D1, the regulatory subunit of the cyclin-dependent kinase that drives cell-cycle progression, governs the secretion and relative proportion of secreted non-coding RNA subtypes (miRNA, rRNA, tRNA, CDBox, scRNA, HAcaBox. scaRNA, piRNA) in human breast cancer. Cyclin D1 induced the secretion of miRNA governing the tumor immune response and oncogenic miRNAs. miR-21 and miR-93, which bind Toll-Like Receptor 8 to trigger a pro-metastatic inflammatory response, represented >85% of the cyclin D1-induced secreted miRNA transcripts. Furthermore, cyclin D1 regulated secretion of the P-element Induced WImpy testis (PIWI)-interacting RNAs (piRNAs) including piR-016658 and piR-016975 that governed stem cell expansion, and increased the abundance of the PIWI member of the Argonaute family, piwil2 in ERα positive breast cancer. The cyclin D1-mediated secretion of pro-tumorigenic immuno-miRs and piRNAs may contribute to tumor initiation and progression.

Potential Onco-Suppressive Role of miR122 and miR144 in Uveal Melanoma through ADAM10 and C-Met Inhibition

Uveal melanoma (UM) is a rare tumor of the eye that leads to deadly metastases in about half of the patients. ADAM10 correlates with c-Met expression in UM and high levels of both molecules are related to the development of metastases. MiR122 and miR144 modulate ADAM10 and c-Met expression in different settings. We hypothesized a potential onco-suppressive role for miR122 and miR144 through modulation of ADAM10 and c-Met in UM. We analyzed the UM Cancer Genome Atlas data portal (TCGA) dataset, two other cohorts of primary tumors and five human UM cell lines for miR122 and miR144 expression by miR microarray, RT-qPCR, Western blotting, miR transfection and luciferase reporter assay. Our results indicate that miR122 and miR144 are expressed at low levels in the UM cell lines and in the TCGA UM dataset and were down-modulated in a cohort of seven UM samples, compared to normal choroid. Both miR122 and miR144 directly targeted ADAM10 and c-Met. Overexpression of miR122 and miR144 led to reduced expression of ADAM10 and c-Met in the UM cell lines and impaired cell proliferation, migration, cell cycle and shedding of c-Met ecto-domain. Our results show that miR122 and miR144 display an onco-suppressive role in UM through ADAM10 and c-Met modulation.

Current and Emerging Biomarkers Predicting Bone Metastasis Development

Bone is one of the preferential sites of distant metastases from malignant tumors, with the highest prevalence observed in breast and prostate cancers. Patients with bone metastases (BMs) may experience skeletal-related events, such as severe bone pain, pathological fractures, spinal cord compression, and hypercalcemia, with negative effects on the quality of life. In the last decades, a deeper understanding of the molecular mechanisms underlying the BM onset has been gained, leading to the development of bone-targeting agents. So far, most of the research has been focused on the pathophysiology and treatment of BM, with only relatively few studies investigating potential predictors of risk for BM development. The ability to select such "high-risk" patients could allow early identification of those most likely to benefit from interventions to prevent or delay BM. This review summarizes several evidences for the potential use of specific biomarkers able to predict early the BM development.

MicroRNAs alteration as early biomarkers for cancer and neurodegenerative diseases: New challenges in pesticides exposure

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Current knowledge linking pesticide exposure, cancer and neuro-degenerative diseases to dysregulation of microRNA network was summarized.

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Literature indicates differential miRNA expression targeting biomolecules and pathways involved in cancer and neurodegenerative diseases.

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Evaluation of miRNA expression may be used to develop new non-invasive strategies for the prediction and prognosis of diseases including cancer.

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The application of miRNAs as diagnostic and therapeutic biomarkers in the clinical field is extremely challenging.

This review summarizes the current knowledge linking cancer and neuro-degenerative diseases to dysregulation of microRNA network following pesticide exposure. Most findings revealed differential miRNA expression targeting biomolecules and pathways involved in various neoplastic localizations and neurodegenerative diseases.

A growing body of evidence in recent literature indicates that alteration of specific miRNAs can represent an early biomarker of disease following exposure to chemical agents, including pesticides. Different miRNAs seem to regulate cell proliferation, apoptosis, migration, invasion, and metastasis via many biological pathways through modulation of the expression of target mRNAs.

The evaluation of miRNA expression levels may be used to develop new non-invasive strategies for the prediction and prognosis of many diseases, including cancer. However, the application of miRNAs as diagnostic and therapeutic biomarkers in the clinical field is extremely challenging.

High Expression of microRNA-143 is Associated with Favorable Tumor Immune Microenvironment and Better Survival in Estrogen Receptor Positive Breast Cancer

microRNA-143 (miR-143) is a well-known tumor suppressive microRNA that exhibits anti-tumoral function by targeting KRAS signaling pathways in various malignancies. We hypothesized that miR-143 suppresses breast cancer progression by targeting KRAS and its effector molecules. We further hypothesized that high expression of miR-143 is associated with a favorable tumor immune microenvironment of estrogen receptor (ER)-positive breast cancer patients which result in improved survival. Two major publicly available breast cancer cohorts; The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) were used. The miR-143 high expression group was associated with increased infiltration of anti-cancer immune cells and decreased pro-cancer immune cells, as well as enrichment of the genes relating to T helper (Th1) cells resulting in improved overall survival (OS) in ER-positive breast cancer patients. To the best of our knowledge, this is the first study to demonstrate that high expression of miR-143 in cancer cells associates with a favorable tumor immune microenvironment, upregulation of anti-cancer immune cells, and suppression of the pro-cancer immune cells, associating with better survival of the breast cancer patients.

Effects of MIR143 on rat sarcoma signaling networks in solid tumors: A brief overview

Rat sarcoma (RAS) is a well-known oncogene that plays important roles in cancer proliferation, cell survival and cell invasion. RAS exists as three major isoforms, Kirsten rat sarcoma (KRAS), Harvey rat sarcoma (HRAS) and neuroblastoma rat sarcoma (NRAS). Mutations of these genes account for approximately 30% of all cancers. Among them, KRAS mutations are the most common, responsible for 85%, followed by NRAS (12%) and HRAS (3%). Although the development of RAS inhibitors has been explored for over the past decade, so far, no effective inhibitor has been found. MicroRNA (miRNA) are a class of small non-coding RNA that control the gene expression of pleural target genes at the post-transcriptional level. MiRNA play critical roles in the physiological and pathological processes at work in cancers, such as cell proliferation, cell death, cell invasion and metastasis. MicroRNA-143 (MIR143) is known to function as a tumor suppressor in a variety of cancers. One of its known mechanisms is suppression of RAS expression and its effector signaling pathways, such as PI3K/AKT and MAPK/ERK. Within the last five years, we developed a potent chemically modified MIR143-3p that enabled us to elucidate the details of the KRAS signaling networks at play in colon and other cancer cells. In this review, we will discuss the role of MIR143-3p in those RAS signaling networks that are related to various biological processes of cancer cells. In addition, we will discuss the possibility of the use of MIR143 as a therapeutic drug for targeting RAS signaling networks.

ARRB1-Promoted NOTCH1 Degradation Is Suppressed by OncomiR miR-223 in T-cell Acute Lymphoblastic Leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is a type of aggressive leukemia with inferior prognosis. Although activating mutations of NOTCH1 are observed in most T-ALL cases, these mutations alone are not sufficient to drive the full development of T-ALL. β-Arrestins (ARRB) are versatile and multifunctional adapter proteins that regulate diverse cellular functions, including promoting the development of cancer. However, the role of ARRBs in T-ALL has largely remained elusive. In this study, we showed that ARRB1 is expressed at low levels in assayed T-ALL clinical samples and cell lines. Exogenous ARRB1 expression inhibited T-ALL proliferation and improved the survival of T-ALL xenograft animals. ARRB1 facilitated NOTCH1 ubiquitination and degradation through interactions with NOTCH1 and DTX1. Mechanistically, the oncogenic miRNA (oncomiR) miR-223 targets the 3'-UTR of ARRB1 (BUTR) and inhibits its expression in T-ALL. Furthermore, overexpression of the ARRB1-derived miR-223 sponge suppressed T-ALL cell proliferation and induced apoptosis. Collectively, these results demonstrate that ARRB1 acts as a tumor suppressor in T-ALL by promoting NOTCH1 degradation, which is inhibited by elevated miR-223, suggesting that ARRB1 may serve as a valid drug target in the development of novel T-ALL therapeutics.Significance: These findings highlight a novel tumor suppressive function of the adaptor protein β-arrestin1 in T-ALL.

Selection and validation of miR-1280 as a suitable endogenous normalizer for qRT-PCR Analysis of serum microRNA expression in Hepatocellular Carcinoma

Normalization procedures for the qRT-PCR analysis of miRNA in biological samples are recommended to reduce the variability caused by pre-analytical factors. Since there is no universal standardized normalization strategy for miRNA qRT-PCR studies, we conducted a throughout study to evaluate a panel of small non-coding RNAs (sncRNAs) as reference gene candidate for biomarker studies in serum samples of patients with hepatocellular carcinoma (HCC). Five sncRNAs (miR-1280, miR-1275, SNORD-116, SNORD-68, and U6) were chosen as candidate of reference genes. This study included 122 patients with HCC and was organized into a "pilot phase" consisting of 20 serum samples of HCC patients, and a "validation phase" of 102 patients. Expression level of these candidates were analyzed by qRT-PCR. Assessment of gene stability was performed using four different integrative platforms (geNorm NormFinder, Bestkeeper, and the Delta Ct method). To determine the gene stability during the follow-up of the patient, we extend the analysis of the validation cohort at T1 (1 month after treatment) and T2 (6 month after treatment). MiR-1280 was identified as the most stably expressed reference gene in both pilot and validation phase also during the follow-up. MiR-1280 appears a reliable reference gene candidate in biomarker studies.

Pan-cancer analysis reveals cooperativity of both strands of microRNA that regulate tumorigenesis and patient survival

Recently, both 5p and 3p miRNA strands are being recognized as functional instead of only one, leaving many miRNA strands uninvestigated. To determine whether both miRNA strands, which have different mRNA-targeting sequences, cooperate to regulate pathways/functions across cancer types, we evaluate genomic, epigenetic, and molecular profiles of >5200 patient samples from 14 different cancers, and RNA interference and CRISPR screens in 290 cancer cell lines. We identify concordantly dysregulated miRNA 5p/3p pairs that coordinately modulate oncogenic pathways and/or cell survival/growth across cancers. Down-regulation of both strands of miR-30a and miR-145 recurrently increased cell cycle pathway genes and significantly reduced patient survival in multiple cancers. Forced expression of all four strands show cooperativity, reducing cell cycle pathways and inhibiting lung cancer cell proliferation and migration. Therefore, we identify miRNA whose 5p/3p strands function together to regulate core tumorigenic processes/pathways and reveal a previously unknown pan-cancer miRNA signature with patient prognostic power.

5p and 3p miRNA strands have different mRNA-targeting sequences and may both functionally impact gene expression in cancer. Here, the authors undertake a pan-cancer analysis that indicates 5p/3p miRNA strands function together to regulate tumorigenic processes.

The Non-Coding RNA Landscape of Plasma Cell Dyscrasias

Despite substantial advancements have been done in the understanding of the pathogenesis of plasma cell (PC) disorders, these malignancies remain hard-to-treat. The discovery and subsequent characterization of non-coding transcripts, which include several members with diverse length and mode of action, has unraveled novel mechanisms of gene expression regulation often malfunctioning in cancer. Increasing evidence indicates that such non-coding molecules also feature in the pathobiology of PC dyscrasias, where they are endowed with strong therapeutic and/or prognostic potential. In this review, we aim to summarize the most relevant findings on the biological and clinical features of the non-coding RNA landscape of malignant PCs, with major focus on multiple myeloma. The most relevant classes of non-coding RNAs will be examined, along with the mechanisms accounting for their dysregulation and the recent strategies used for their targeting in PC dyscrasias. It is hoped these insights may lead to clinical applications of non-coding RNA molecules as biomarkers or therapeutic targets/agents in the near future.

Novel therapeutic targets for cancer metastasis

Introduction: Metastatic cancers are extremely difficult to treat, and account for the vast majority of cancer-related deaths. The dissemination of tumor cells to distant sites is highly dynamic, asynchronous, and involves both tumor and host intrinsic factors. Effective therapeutic targets to block metastasis will need to disrupt key pathways that are required for multiple stages of metastasis.Areas covered: This review discusses the heterogeneity of cancers and metastasis, with an emphasis on motility as a key driver trait of metastasis. Recent metastatic cancer studies that identified either host or cancer cell intrinsic factors important for metastasis, using single gene-deficient animal models or 3D intravital imaging of avian embryo models, are also discussed. Potential metastatic blocking targets are listed as they relate to metastatic cancer therapy.Expert opinion: The development of metastatic disease is a complex interplay of genetic and epigenetic factors from the host and cancer cells acting in a patient-specific manner. Inhibiting key driver traits of metastasis should yield survival benefit at any stage of the disease, and we look forward to the next generation of personalized medicines for cancer therapy that target cancer cell motility for increased therapeutic efficacy.

MiR-155-5p exerts tumor-suppressing functions in Wilms tumor by targeting IGF2 via the PI3K signaling pathway

BACKGROUND

MicroRNA-155-5p (miR-155-5p) has been reported to play an oncogenic role in different human malignancies; however, its role in Wilms tumor (WT) remains unclear.

METHODS

Differentially expressed miRNAs (DE-miRNAs) and mRNAs (DEGs) in WT blood and tissues were identified by using miRNA microarray and RNA-sequencing. Bioinformatics prediction and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to predict the potential functions of DE-miRNAs. DE-miRNAs and DEGs in WT obtained from Gene Expression Omnibus (GEO) and Therapeutically Applicable Research to Generate Effective Treatments (TARGET) were identified by using the "edgeR" package. RT-qPCR was used to explore miR-155-5p and IGF2 expression and their clinical significance in WT specimens. A rhabdoid cell line (G401) and Ewing sarcoma cell line (SK-NEP-1) were used. Immunohistochemical staining, western blotting and dual-luciferase reporter assays were performed to study the mechanisms involved. The CCK-8, flow cytometry, wound healing and transwell assays were performed to identify the effects of miR-155-5p and IGF2 knockdown on cell proliferation, apoptosis, migration and invasion, respectively.

RESULTS

MiR-155-5p was downregulated in both blood and tissues from WT patients who did not receive chemotherapy before surgery but was upregulated in tissues from WT patients who had received chemotherapy before surgery. IGF2, PI3K, AKT and mTOR were found to be upregulated in WT tissues. Additionally, miR-155-5p and IGF2 were significantly correlated with TNM stage and lymphatic metastasis in WT patients. Molecular mechanism exploration indicated that IGF2 was downregulated by miR-155-5p via direct binding to its 3' untranslated region in cell lines. Furthermore, IGF2, PI3K, AKT and mTOR expression was inversely correlated with miR-155-5p expression, and PI3K, AKT and mTOR expression was positively correlated with IGF2 expression in cell culture. Functional studies demonstrated that miR-155-5p upregulation and IGF2 knockdown suppressed cell proliferation, migration and invasion and induced cell apoptosis. Moreover, the tumor-suppressing effects of miR-155-5p in cells were abrogated by miR-155-5p inhibitor treatment.

CONCLUSIONS

Taken together, these findings suggest that miR-155-5p functions as a tumor suppressor in WT through inactivating the PI3K/AKT/mTOR signaling pathway by directly targeting IGF2. Thus, miR-155-5p might be a novel therapeutic target for WT.

Plasma miR-30a-5p as an early novel noninvasive diagnostic and prognostic biomarker for lung cancer

Aim: Circulation miRNAs have become increasingly appreciated in the diagnosis and prognosis of lung cancer. This study aims to identify and evaluate plasma miRNA-30a-5p as an early noninvasive biomarker for the diagnosis and prognosis of lung cancer. Pateints & methods: Expression levels of plasma miRNA 30a-5p were measured by quantitative real-time PCR. Receiver operating characteristic analysis and area under the curve were used to differentiate malignant from benign tumors and from healthy controls. Kaplan-Meier curves and Cox regression were used to determine survival and prognosis. Results: Our results suggest that the level of miRNA-30a-5p in plasma might be a considerable early novel noninvasive diagnostic and prognostic biomarker for lung cancer. Conclusion: Prospective studies must be performed to confirm this new early novel noninvasive diagnostic and prognostic biomarker for lung cancer.

Multitag-Regulated Cascade Reaction: A Generalizable Ultrasensitive MicroRNA Biosensing Approach for Cancer Prognosis

Ultrasensitive PCR-free microRNA (miR) analysis based on biosensors with enzyme-free nucleic acid amplification and reusable surface has great clinical significance in cancer prognosis. However, building such a biosensing strategy has long been challenging due to uncontrollable miR-triggered cascade amplifiers and insufficient sensing surface regeneration capability. To meet the challenge, for the first time, a general approach, named enzyme-free multitag-regulated cascade reaction (MCR), is developed to fabricate reliable trace miR biosensors. As a proof of concept, miR let-7a is detected on an evanescent wave fluorescent optical-fiber biosensing platform. The size and morphology of well-formed MCR assemblies (∼1 μm in length) are characterized by atomic force microscopy. This MCR method achieves a 30 000-fold improved sensitivity (detection limit 0.8 fM) compared to the MCR-free system and can detect abnormal urinary miR levels in lung cancer patients. Moreover, the biosensor is robust enough to be reused for over 100 cycles, which greatly reduces the cost of single detection. In sum, MCR is developed as a generalizable ultrasensitive miR biosensing approach for cancer prognosis, which opens a broad field for facile enzyme-free biosensing applications by nucleic acid assembling regulation.

Synthetic small-molecule RNA ligands: future prospects as therapeutic agents

RNA is one of the most intriguing and promising biological targets for the discovery of innovative drugs in many pathologies and various biologically relevant RNAs that could serve as drug targets have already been identified. Among the most important ones, one can mention prokaryotic ribosomal RNA which is the target of several marketed antibiotics, viral RNAs or oncogenic microRNAs that are tightly involved in the development and progression of various cancers. Oligonucleotides are efficient and specific RNA targeting agents but suffer from poor pharmacodynamic and pharmacokinetic properties. For this reason, a number of synthetic small-molecule ligands have been identified and studied upon screening of chemical libraries or focused design of RNA binders. In this review, we report the most relevant examples of synthetic compounds bearing sufficient selectivity to envisage clinical studies and future therapeutic applications with a particular attention for the main strategies that can be undertaken toward the improvement of selectivity and biological activity.

MicroRNA-664 suppresses the growth of cervical cancer cells via targeting c-Kit

Background

Cervical cancer is the second most common malignant cancer in women worldwide. Evidence indicated that miR-664 was significantly downregulated in cervical cancer. However, the mechanisms by which miR-664 regulates the tumorigenesis of cervical cancer remain unclear. Thus, this study aimed to investigate the role of miR-664 in cervical cancer.

Methods

Quantitative reverse transcription polymerase chain reaction was used to detect the level of miR-664 in tumor tissues and cell line. The dual luciferase reporter system assay and Western blotting were used to explore the interaction of miR-664 and c-Kit in cervical cancer.

Results

The expression of miR-664 in patients with cervical cancer was dramatically decreased compared with that in adjacent tissues. MiR-664 mimics significantly inhibited proliferation in SiHa cells via inducing apoptosis. In addition, miR-664 mimics induced apoptosis in SiHa cells via increasing the expressions of Bax and active caspase 3 and decreasing the level of Bcl-2. Moreover, dual-luciferase assay showed that c-Kit was the directly binding target of miR-664 in SiHa cells; overexpression of miR-664 downregulated the expression of c-Kit. Meanwhile, upregulation of miR-664 significantly decreased the levels of c-Myc and Cyclin D in cells. Furthermore, miR-664 markedly inhibited tumor growth of cervical cancer in xenograft.

Conclusion

Our data indicated that miR-664 exerted antitumor effects on SiHa cells by directly targeting c-Kit in vitro and in vivo. Therefore, miR-664 might be a potential therapeutic target for the treatment of patients with cervical cancer.

MicroRNA‑let‑7a inhibition inhibits LPS‑induced inflammatory injury of chondrocytes by targeting IL6R

Osteoarthritis (OA) is a type of degenerative joint disease that affects the health of the elderly. OA is characterized by articular cartilage degradation and joint inflammation. The present study aimed to investigate the role and mechanism of microRNA-let-7a (Let-7a) in OA by examining its role in lipopolysaccharide (LPS)-induced cartilage inflammatory injury in ATDC5 cells. ATDC5 cells were treated with various concentrations of LPS. The present results suggested that 5 and 10 µg/ml LPS significantly inhibited ATDC5 cell viability, and 5 µg/ml LPS was selected for further experiments. Reverse transcription-quantitative PCR (RT-qPCR) results suggested that treatment with LPS significantly induced the expression levels of multiple inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and IL-8, and increased the expression level of Let-7a in ATDC5 cells. IL-6 receptor (IL-6R) was identified to be a direct target of Let-7a using TargetScan and a dual-luciferase reporter assay. Subsequently, Cell Counting Kit-8 and flow cytometry analyses identified that Let-7a inhibitor could significantly promote cell viability and reduce cell apoptosis in ATDC5 cells treated with LPS, and these effects could be reversed by transfection with small interfering (si)RNA-IL-6R. ELISA was used to examine the expression of inflammatory factors in ATDC5 cells following treatment with LPS. Additionally, RT-qPCR and western blotting were performed to detect the mRNA and protein expression level of IL-6R and STAT3. The present results suggested that Let-7a inhibitor significantly reduced the expression level of TNF-α, IL-1β, IL-6 and IL-8 in ATDC5 cells, and this effect was reversed by transfecting siRNA-IL-6R. Moreover, RT-qPCR and western blot assay results suggested that Let-7a inhibitor significantly increased the expression level of IL-6R and phosphorylated STAT3, and these effects could be reversed by siRNA-IL-6R. Collectively, Let-7a inhibitor increased cell proliferation, reduced apoptosis and inhibited inflammatory response in ATDC5 cells treated with LPS. The present study provided a new potential therapeutic target for OA treatment.

The Clinical Potential of Oligonucleotide Therapeutics against Pancreatic Cancer

Although many diagnostic and therapeutic modalities for pancreatic cancer have been proposed, an urgent need for improved therapeutic strategies remains. Oligonucleotide therapeutics, such as those based on antisense RNAs, small interfering RNA (siRNA), microRNA (miRNA), aptamers, and decoys, are promising agents against pancreatic cancer, because they can identify a specific mRNA fragment of a given sequence or protein, and interfere with gene expression as molecular-targeted agents. Within the past 25 years, the diversity and feasibility of these drugs as diagnostic or therapeutic tools have dramatically increased. Several clinical and preclinical studies of oligonucleotides have been conducted for patients with pancreatic cancer. To support the discovery of effective diagnostic or therapeutic options using oligonucleotide-based strategies, in the absence of satisfactory therapies for long-term survival and the increasing trend of diseases, we summarize the current clinical trials of oligonucleotide therapeutics for pancreatic cancer patients, with underlying preclinical and scientific data, and focus on the possibility of oligonucleotides for targeting pancreatic cancer in clinical implications.

RNA-based diagnostic and therapeutic strategies for cardiovascular disease

Cardiovascular diseases are the leading cause of death globally and are associated with increasing financial expenditure. With the availability of next-generation sequencing technologies since the early 2000s, non-coding RNAs such as microRNAs, long non-coding RNAs and circular RNAs have been assessed as potential therapeutic targets for numerous diseases, including cardiovascular diseases. In this Review, we summarize current approaches employed to screen for novel coding and non-coding RNA candidates with diagnostic and therapeutic potential in cardiovascular disease, including next-generation sequencing, functional high-throughput RNA screening and single-cell sequencing technologies. Furthermore, we highlight viral-based delivery tools that have been widely used to evaluate the therapeutic utility of both coding and non-coding RNAs in the context of cardiovascular disease. Finally, we discuss the potential of using oligonucleotide-based molecular products such as modified RNA, small interfering RNA and RNA mimics/inhibitors for the treatment of cardiovascular diseases. Given that many non-coding RNAs have not yet been functionally annotated, the number of potential RNA diagnostic and therapeutic targets for cardiovascular diseases will continue to expand for years to come.

MicroRNA-374a Governs Aggressive Cell Behaviors of Glioma by Targeting Prokineticin 2

MicroRNA-374a has been abnormally expressed in several cancer types; however, its role in glioma remains unclear. Therefore, we aimed to investigate whether microR-374a participated in the progression of glioma. Expression of microR-374a in glioma cell lines and normal cell line was measured by quantitative real-time polymerase chain reaction. Luciferase reporter assay and Western blot were used to detect the targets of microR-374a. In vitro functional experiments were conducted to investigate the biological role of microR-374a. Low expression of microR-374a was found in glioma cell lines. Prokineticin 2 was identified as a direct target of microR-374a in glioma. Investigations on the mechanisms related to glioma progression showed that microR-374a inhibited glioma cell proliferation, cell cycle progression, and cell invasion through targeting Prokineticin 2. Taken together, these results revealed that microR-374a functions as tumor suppressor by targeting Prokineticin 2, suggesting it might be a novel therapeutic target for glioma.

MicroRNA-3162-5p-Mediated Crosstalk between Kallikrein Family Members Including Prostate-Specific Antigen in Prostate Cancer

BACKGROUND

MicroRNAs mediate biological processes through preferential binding to the 3' untranslated region (3' UTR) of target genes. Studies have shown their association with prostate cancer (PCa) risk through single-nucleotide polymorphisms (SNPs), known as miRSNPs. In a European cohort, 22 PCa risk-associated miRSNPs have been identified. The most significant miRSNP in the 3' UTR of Kallikrein-related peptidase 3 (KLK3) created a binding site for miR-3162-5p. Here we investigated the miR-3162-5p-KLK interaction and the clinical implication of miR-3162-5p in PCa.

METHODS

We tested the role of miR-3162-5p in PCa etiology using IncuCyte live-cell imaging and anchorage-independent growth assays. The effect of miR-3162-5p on KLK and androgen receptor (AR) expression was measured by RT-quantitative (q)PCR and target pulldown assays. KLK3 proteolytic activity was determined by DELFIA^® immunoassay. Mass spectrometry identified pathways affected by miR-3162-5p. miR-3162-5p expression was measured in clinical samples using RT-qPCR.

RESULTS

miR-3162-5p affected proliferation, migration, and colony formation of LNCaP cells by regulating the expression of KLK2-4 and AR by direct targeting. KLK3 protein expression was regulated by miR-3162-5p consistent with lower KLK3 proteolytic activity observed in LNCaP-conditioned media. KLK/AR pulldown and mass spectrometry analysis showed a potential role of miR-3162-5p in metabolic pathways via KLK/AR and additional targets. Increased miR-3162-5p expression was observed in prostate tumor tissues with higher Gleason grade.

CONCLUSIONS

Our study provides an insight into possible involvement of miR-3162-5p in PCa etiology by targeting KLKs and AR. It highlights clinical utility of miR-3162-5p and its interactive axis as a new class of biomarkers and therapeutic targets for PCa.

MDA-9/Syntenin: An emerging global molecular target regulating cancer invasion and metastasis

With few exceptions, metastasis is the terminal stage of cancer with limited therapeutic options. Metastasis consists of numerous phenotypic and genotypic alterations of cells that are directly and indirectly induced by multiple intrinsic (cellular) and extrinsic (micro-environmental) factors. To metastasize, a cancer cell often transitions from an epithelial to mesenchymal morphology (EMT), modifies the extracellular matrix, forms emboli and survives in the circulation, escapes immune surveillance, adheres to sites distant from the initial tumor and finally develops a blood supply (angiogenesis) and colonizes in a secondary niche (a micrometastasis). Scientific advances have greatly enhanced our understanding of the precise molecular and genetic changes, operating independently or collectively, that lead to metastasis. This review focuses on a unique gene, melanoma differentiation associated gene-9 (also known as Syntenin-1; Syndecan Binding Protein (sdcbp); mda-9/syntenin), initially cloned and characterized from metastatic human melanoma and shown to be a pro-metastatic gene. In the last two decades, our comprehension of the diversity of actions of MDA-9/Syntenin on cellular phenotype has emerged. MDA-9/Sytenin plays pivotal regulatory roles in multiple signaling cascades and orchestrates both metastatic and non-metastatic events. Considering the relevance of this gene in controlling cancer invasion and metastasis, approaches have been developed to uniquely and selectively target this gene. We also provide recent updates on strategies that have been successfully employed in targeting MDA-9/Syntenin resulting in profound pre-clinical anti-cancer activity.

Interplay Between ncRNAs and Cellular Communication: A Proposal for Understanding Cell-Specific Signaling Pathways

Intercellular communication is essential for the development of specialized cells, tissues, and organs and is critical in a variety of diseases including cancer. Current knowledge states that different cell types communicate by ligand–receptor interactions: hormones, growth factors, and cytokines are released into the extracellular space and act on receptors, which are often expressed in a cell-type-specific manner. Non-coding RNAs (ncRNAs) are emerging as newly identified communicating factors in both physiological and pathological states. This class of RNA encompasses microRNAs (miRNAs, well-studied post-transcriptional regulators of gene expression), long non-coding RNAs (lncRNAs) and other ncRNAs. lncRNAs are diverse in length, sequence, and structure (linear or circular), and their functions are described as transcriptional regulation, induction of epigenetic changes and even direct regulation of protein activity. They have also been reported to act as miRNA sponges, interacting with miRNA and modulating its availability to endogenous mRNA targets. Importantly, lncRNAs may have a cell-type-specific expression pattern. In this paper, we propose that lncRNA–miRNA interactions, analogous to receptor–ligand interactions, are responsible for cell-type-specific outcomes. Specific binding of miRNAs to lncRNAs may drive cell-type-specific signaling cascades and modulate biochemical feedback loops that ultimately determine cell identity and response to stress factors.

Serum miRNAs Expression and SNAP-25 Genotype in Alzheimer's Disease

MicroRNAs (miRNAs) are small non-coding RNAs that control gene expression by binding their 3' untranslated region (3'UTR) region; these molecules play a fundamental role in several pathologies, including Alzheimer's disease (AD). Synaptosomal-associated protein of 25 kDa (SNAP-25) is a vesicular protein of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) involved in neural plasticity and in the exocytosis of neurotransmitters, processes that are altered in AD. Recent results showed that a reduction of SNAP-25 is associated with dementia, and that the rs363050 SNAP-25 polymorphism correlates with cognitive decline and brain atrophy, as well as with the outcome of multistructured rehabilitation in AD patients. We verified the presence of possible correlations between the serum concentration of miRNAs that bind the SNAP-25 3'UTR region and AD. Six different microRNAs (miR-181a-5p, miR-361-3p, miR-23a-3p, miR-15b-3p, 130a-3p and miR-27b-3p) that bind the SNAP-25 3'UTR region were measured by qPCR in serum of AD patients (n = 22), mild cognitive impairment (MCI) subjects (n = 22) and age- and sex-matched controls (n = 22); analysis of results was done stratified for the rs363050 SNAP-25 genotype. Results showed that miR-27b-3p, miR-23a-3p and miR181a-5p serum concentration was significantly reduced in rs363050 SNAP-25 GG homozygous AD patients. Notably, concentration of these miRNAs was comparable in rs363050 AA homozygous AD patients, MCI and healthy controls (HCs). Data herein suggest that miRNAs that bind the SNAP-25 3'UTR region interact with SNAP-25 polymorphisms to influence the neural plasticity typical of AD brains, possibly as a consequence of modulatory activity on SNAP-25 mRNA and/or protein.

MicroRNA-34a-5p suppresses tumorigenesis and progression of glioma and potentiates Temozolomide-induced cytotoxicity for glioma cells by targeting HMGA2

Glioma is a frequently diagnosed brain tumors and Temozolomide (TMZ) is a common chemotherapeutic drug for glioma. High mobility group AT-hook 2 (HMGA2) was reported to be linked with glioma pathogenesis and Temozolomide (TMZ)-induced cytotoxicity. Our present study aimed to further search for the upstream regulatory microRNAs (miRNAs) of HMGA2 in glioma. RT-qPCR assay was conducted to measure the expression of HMGA2 mRNA and microRNA-34a-5p (miR-34a-5p). HMGA2 protein expression was examined by western blot assay. Cell proliferative ability and cell viability was assessed by CCK-8 assay. Cell migratory and invasive capacities were estimated by Transwell migration and invasion assay. Bioinformatics analysis and luciferase reporter assay was conducted to investigate the potential interaction between miR-34a-5p and HMGA2. Mouse xenograft experiments were performed to further test the roles of TMZ, miR-34a-5p and HMGA2, alone or in combination, in glioma tumorigenesis in vivo. We found HMGA2 expression was notably upregulated in glioma tissues and cells, and associated with glioma grade and poor prognosis. HMGA2 knockdown or miR-34a-5p overexpression inhibited migration, invasion, proliferation and enhanced TMZ-induced cytotoxicity in glioma cells. Moreover, HMGA2 was a target of miR-34a-5p. And, miR-34a-5p expression was remarkably reduced in glioma tissues and cells. MiR-34a-5p exerted its function through targeting HMGA2 in glioma cells. HMGA2 knockdown or miR-34a-5p overexpression inhibited tumor growth and enhanced TMZ-mediated anti-tumor effect in glioma xenograft models. We concluded MiR-34a-5p suppressed tumorigenesis and progression of glioma and potentiated TMZ-induced cytotoxicity for glioma cells by targeting HMGA2, deepening our understanding on molecular basis of HMGA2 in glioma.

NRF2 orchestrates the redox regulation induced by radiation therapy, sustaining embryonal and alveolar rhabdomyosarcoma cells radioresistance

PURPOSE

Tumor cells generally exhibit higher levels of reactive oxygen species (ROS), however, when stressed, tumor cells can undergo a process of 'Redox Resetting' to acquire a new redox balance with stronger antioxidant systems that enable cancer cells to become resistant to radiation therapy (RT). Here, we describe how RT affects the oxidant/antioxidant balance in human embryonal (RD) and alveolar (RH30) rhabdomyosarcoma (RMS) cell lines, investigating on the molecular mechanisms involved.

METHODS

Radiations were delivered using an x-6 MV photon linear accelerator and their effects were assessed by vitality and clonogenic assays. The expression of specific antioxidant-enzymes, such as Superoxide Dismutases (SODs), Catalase (CAT) and Glutathione Peroxidases 4 (GPx4), miRNAs (miR-22, -126, -210, -375, -146a, -34a) and the transcription factor NRF2 was analyzed by quantitative polymerase chain reaction (q-PCR) and western blotting. RNA interference experiments were performed to evaluate the role of NRF2.

RESULTS

Doses of RT higher than 2 Gy significantly affected RMS clonogenic ability by increasing ROS production. RMS rapidly and efficiently brought back ROS levels by up-regulating the gene expression of antioxidant enzymes, miRNAs as well as of NRF2. Silencing of NRF2 restrained the RMS ability to counteract RT-induced ROS accumulation, antioxidant enzyme and miRNA expression and was able to increase the abundance of γ-H2AX, a biomarker of DNA damage, in RT-treated cells.

CONCLUSIONS

Taken together, our data suggest the strategic role of oxidant/antioxidant balance in restraining the therapeutic efficiency of RT in RMS treatment and identify NRF2 as a new potential molecular target whose inhibition might represent a novel radiosensitizing therapeutic strategy for RMS clinical management.

Extracellular Vesicles as Conduits of Non-Coding RNA Emission and Intercellular Transfer in Brain Tumors

Non-coding RNA (ncRNA) species have emerged in as molecular fingerprints and regulators of brain tumor pathogenesis and progression. While changes in ncRNA levels have been traditionally regarded as cell intrinsic there is mounting evidence for their extracellular and paracrine function. One of the key mechanisms that enables ncRNA to exit from cells is their selective packaging into extracellular vesicles (EVs), and trafficking in the extracellular space and biofluids. Vesicular export processes reduce intracellular levels of specific ncRNA in EV donor cells while creating a pool of EV-associated ncRNA in the extracellular space and biofluids that enables their uptake by other recipient cells; both aspects have functional consequences. Cancer cells produce several EV subtypes (exosomes, ectosomes), which differ in their ncRNA composition, properties and function. Several RNA biotypes have been identified in the cargo of brain tumor EVs, of which microRNAs are the most studied, but other species (snRNA, YRNA, tRNA, and lncRNA) are often more abundant. Of particular interest is the link between transforming oncogenes and the biogenesis, cargo, uptake and function of tumor-derived EV, including EV content of oncogenic RNA. The ncRNA repertoire of EVs isolated from cerebrospinal fluid and serum is being developed as a liquid biopsy platform in brain tumors.

Non-Coding RNAs in Breast Cancer: Intracellular and Intercellular Communication

Non-coding RNAs (ncRNAs) are regulators of intracellular and intercellular signaling in breast cancer. ncRNAs modulate intracellular signaling to control diverse cellular processes, including levels and activity of estrogen receptor α (ERα), proliferation, invasion, migration, apoptosis, and stemness. In addition, ncRNAs can be packaged into exosomes to provide intercellular communication by the transmission of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) to cells locally or systemically. This review provides an overview of the biogenesis and roles of ncRNAs: small nucleolar RNA (snRNA), circular RNAs (circRNAs), PIWI-interacting RNAs (piRNAs), miRNAs, and lncRNAs in breast cancer. Since more is known about the miRNAs and lncRNAs that are expressed in breast tumors, their established targets as oncogenic drivers and tumor suppressors will be reviewed. The focus is on miRNAs and lncRNAs identified in breast tumors, since a number of ncRNAs identified in breast cancer cells are not dysregulated in breast tumors. The identity and putative function of selected lncRNAs increased: nuclear paraspeckle assembly transcript 1 (NEAT1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), steroid receptor RNA activator 1 (SRA1), colon cancer associated transcript 2 (CCAT2), colorectal neoplasia differentially expressed (CRNDE), myocardial infarction associated transcript (MIAT), and long intergenic non-protein coding RNA, Regulator of Reprogramming (LINC-ROR); and decreased levels of maternally-expressed 3 (MEG3) in breast tumors have been observed as well. miRNAs and lncRNAs are considered targets of therapeutic intervention in breast cancer, but further work is needed to bring the promise of regulating their activities to clinical use.