MicroRNAs: molecular features and role in cancer

Effects of maternal nutrient restriction during gestation on bovine serum microRNA abundance

The objective was to determine the effects of maternal nutrient restriction during gestation on serum microRNA (miRNA) abundance in cattle. Primiparous Angus-cross cows (n=22) were fed either control (CON; to gain 1 Kg/week) or nutrient restricted (NR; 0.55% NEm) diets based on National Research Council requirements. On day 30 of gestation, cows were blocked by body condition and randomly assigned to one of three diets: CON (n=8) days 30-190; NR (n=7) days 30-110 followed by CON days 110-190 (NR/C); or CON (n=7) days 30-110 followed by NR days 110-190 (C/NR). At 190 days of gestation, maternal serum was collected for RNA isolation and analyzed using a miRNA microarray of known Bos taurus sequences. Data were normalized using LOWESS and analyzed via ANOVA. At 190 days of gestation, 16 miRNAs exhibited differential abundance (P<0.05) between treatments. Cows that underwent NR, irrespective of when the insult occurred, had downregulated bta-miR-126-3p compared to CON cows. Bta-miR-16b was downregulated and three miRNAs upregulated in NR/C compared to C/NR and CON cows. Additionally, seven miRNAs were downregulated and four miRNAs upregulated in C/NR compared to NR/C and CON cows. Comparison of NR/C and C/NR cows revealed three differentially abundant (P<0.04) miRNAs (bta-miR-2487_L-2R-3_1ss15CT, bta-miR-215, and bta-miR-760-5p). Top KEGG pathway enrichment of target genes included: pathways in cancer, PI3K-Akt signaling, focal adhesion, Ras signaling, proteoglycans in cancer, and MAPK signaling. In summary, maternal nutrient restriction altered serum miRNA abundance profiles irrespective of the time at which the nutritional insult was induced.

A vector projection similarity-based method for miRNA-disease association prediction

[S U M M A R Y] Many miRNA-disease association prediction models incorporate Gaussian interaction profile kernel similarity (GIPS). However, the GIPS fails to consider the specificity of the miRNA-disease association matrix, where matrix elements with a value of 0 represent miRNA and disease relationships that have not been discovered yet. To address this issue and better account for the impact of known and unknown miRNA-disease associations on similarity, we propose a method called vector projection similarity-based method for miRNA-disease association prediction (VPSMDA). In VPSMDA, we introduce three projection rules and combined with logistic functions for the miRNA-disease association matrix and propose a vector projection similarity measure for miRNAs and diseases. By integrating the vector projection similarity matrix with the original one, we obtain the improved miRNA and disease similarity matrix. Additionally, we construct a weight matrix using different numbers of neighbors to reduce the noise in the similarity matrix. In performance evaluation, both LOOCV and 5-fold CV experiments demonstrate that VPSMDA outperforms seven other state-of-the-art methods in AUC. Furthermore, in a case study, VPSMDA successfully predicted 10, 9, and 10 out of the top 10 associations for three important human diseases, respectively, and these predictions were confirmed by recent biomedical resources.

A Glimmer of Hope for Patients with a T3 Transformation Zone: miRNAs Are Potential Biomarkers for Cervical Dysplasia

BACKGROUND

This pilot study assesses the potential use of miRNAs in the triage of colposcopy patients with type 3 (nonvisible) cervical transformation zone (TZ). Type 3 TZ is a constitutional finding associated with many problems and controversies in colposcopy patient management. Here, we present miRNAs as a potential biomarker for the detection of CIN3 in these cases.

MATERIALS AND METHODS

Cervical mucosa samples (CMS) were collected from patients presenting with T3 transformation zone during routine workup using the Cytobrush. Depending on the histological and cytological result, as well as the result of the routinely performed HPV PCR, patients were divided into three groups: patients with a high-grade intraepithelial lesion (CIN3) and a positive high-risk HPV test (CIN3 group), patients without an intraepithelial lesion and a positive high-risk HPV test (HPV group), and healthy controls (N = no intraepithelial lesion and negative HPV test). The cervical mucus samples included in the study were tested for their expression levels of distinct miRNAs using qPCR.

RESULTS

All investigated miRNAs were consistently detectable in every sample. The CMSs of histologically graded CIN 3 showed consistently high expression levels of all eight miRNAs, whereas the CMSs from healthy patients (N) show generally lower expression levels. However, CMSs from patients of the HPV group represented a very heterogeneous group.

CONCLUSIONS

The data presented here can provide a solid basis for future research into a triage test for patients with a T3 transformation zone on the basis of commonly used clinical equipment.

Knowledge and expectations about miRNAs as biomarkers in head and neck squamous cell cancers

Head and neck squamous cell cancer patients suffer from a high postoperative recurrence rate and poor prognosis. Thus, it is essential to better understand the underlying molecular mechanisms and identify the role of new biomarkers. Recent research has shown that the dysregulation of microRNAs is a potential biomarker as a screening or prognostic tool. Moreover, the literature reveals its promising usefulness to select the best treatment strategy and monitor tumour response. The purpose of this review is to identify and synthesize the available literature on microRNAs as biomarkers that could help manage patients with head and neck squamous cell cancer. A search in scientific databases was completed, including all relevant articles related to circulating microRNAs in head and neck squamous cell cancer published in English or Spanish. We focused on articles whose main findings were related to their usefulness in diagnosis and prognosis. Conclusion: Knowledge of microRNAs opens the possibilities that these molecules offer in terms of monitoring cancer disease in a less-invasive, simple manner, allowing for serial sampling to assess the response to treatment and minimal residual disease. It is yet to be determined whether liquid biopsy will replace the traditional biopsy in the future but it represents a change in the paradigm of management of head and neck squamous cell cancer.

Systematic analysis of expression profiles of HMGB family members for prognostic application in non-small cell lung cancer

Background: Lung cancer is a significant challenge to human health. Members of the high mobility group (HMG) superfamily (HMGB proteins) are implicated in a wide variety of physiological and pathophysiological processes, but the expression and prognostic value of HMGB family members in non-small cell lung cancer (NSCLC) have not been elucidated.

Methods: In this study, ONCOMINE, UALCAN, GEPIA, Kaplan–Meier Plotter, starBase, OncomiR databases, and GeneMANIA were utilized to evaluate the prognostic significance of HMGB family members in NSCLC.

Results: HMGB2/3 expression levels were higher in NSCLC patients. HMGB1 expression was higher in lung squamous cell carcinoma (LUSC) and was lower in lung adenocarcinoma (LUAD) tissue than in normal lung tissue. HMGB2 expression was related to cancer stage. Increased HMGB1 mRNA expression levels were associated with improved lung cancer prognosis, including overall survival (OS), first-progression survival (FP), and post-progression survival (PPS). There was no significant association between HMGB2 levels and prognostic indicators. HMGB3 expression was associated with poorer OS. GeneMANIA and GO/KEGG pathway analysis showed that HMGB family members mainly associated with chromosome condensation, regulation of chromatin organization, and nucleosome binding in NSCLC. HMGBs expression were closely correlated with infiltrating levels of specific types of immune cells in NSCLC, especially Th2 cells, Th17 cells, and mast cells. hsa-miR-25-3p, hsa-miR-374a-3p, and hsa-miR-93-5p were significantly positively correlated with HMGB1, HMGB2, and HMGB3, respectively. However, hsa-miR-30a-5p was predicted to significantly negatively regulate HMGB3 expression.

Conclusion: Our study revealed that HMGB1 is positively related to the improved prognosis in NSCLC, and demonstrate that HMGB3 might be a risk factor for poorer survival of NSCLC patients.

Effects of nutrient restriction during early or mid-gestation in bovine on placental development and miRNA expression in the cotyledon

The objective of this study was to determine effects of maternal nutrient restriction (NR) during early or mid-gestation on uterine composition and miRNA expression in cotyledons. Primiparous Angus-cross cows (n = 38) were synchronized and inseminated using male sexed semen, blocked by body condition score and body weight (BW), and assigned to treatments. Animals were fed either: control (CON; gain 1 kg/week) or NR (55% maintenance energy and crude protein requirements) based on BW. An initial set of animals were fed either NR (n = 8) or CON (n = 8) from day 30-110 of gestation. A second set of animals were fed CON (n = 8) d 30-190 (CON/CON); NR (n = 7) day 30-110 followed by CON day 110-190 (NR/CON); or CON (n = 7) day 30-110 followed by NR day 110-190 (CON/NR). Cows were harvested on day 110 or 190 of gestation to collect placental tissues. RNA was isolated from cotyledon samples (3 animals/group) prior to microarray analysis using known Bos taurus microRNA sequences. Relative microRNA abundance was analyzed via ANOVA. Maternal NR increased (P < 0.05) cotyledon weight and total placentome surface area irrespective of gestational day. At day 110 of gestation, 51 microRNAs were reduced while 91 microRNAs observed greater abundance (P < 0.05) in NR verses CON cotyledons. At day 190 of gestation, 40 microRNAs were reduced and 26 microRNAs were increased (P < 0.05) in both NR/CON and CON/NR verses CON cotyledons. Top KEGG pathway analysis included: axon guidance, endocytosis, neuroactive ligand receptor interaction, and MAPK signaling pathway. Early-gestation maternal NR altered microRNA abundance to a greater extent than mid-gestation NR.

Down-Regulation of miR-194-5p for Predicting Metastasis in Breast Cancer Cells

MicroRNAs (miRNAs), as key negative regulators of gene expression, are closely related to tumor occurrence and progression. miR-194-5p (miR-194-1) has been shown to play a regulatory role in various cancers however, its biological function and mechanism of action in breast cancer have not yet been well explored. In this study, we use the UALCAN and LinkedOmics databases to analyze transcription expression in The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA). The epithelial-mesenchymal transition status of breast cancer cells was evaluated by wound-healing assay, trans-well assays, and gelatin zymography, while protein expression was assessed by Western blotting. miR-194-5p expression was found to be up-regulated in breast cancer clinical specimens but down-regulated in the triple-negative breast cancer (TNBC) cell line MDA-MB-231 and breast cancer clinical specimens in The Cancer Genome Atlas (TCGA). miR-194-5p significantly inhibited the expression of the epithelial marker ZO-1 and increased the expression of mesenchymal markers, including ZEB-1 and vimentin, in MDA-MB-231 cells. miR-194-5p significantly reduced the gelatin-degrading activity of matrix metalloproteinase-2 (MMP-2) and MMP-9 in zymography assays. In MDA-MB-231 cells and TCGA patient samples, ZEB-1 expression was significantly inversely correlated with miR-194-5p expression. High levels of miR-194-5p were associated with good overall survival. miR-194-5p regulates epithelial–mesenchymal transition (EMT) in TNBC. Our findings suggest that miR-194-5p functions as a tumor biomarker in breast cancer, providing new insights for the study of breast cancer development and metastasis.

MicroRNAs: Their Role in Metabolism, Tumor Microenvironment, and Therapeutic Implications in Head and Neck Squamous Cell Carcinoma

Simple Summary

Head and neck squamous cell carcinoma (HNSCC), which arises from the oral epithelium, is one of the most common cancers worldwide. Despite excellent diagnosis and treatment improvements, the mortality rate associated with HNSCC is still extremely high. Current data suggest that dysregulation of exosomes and metabolic abnormalities are involved in the initiation and progression of HNSCC. Thus, approaches for targeting exosomes in the tumor microenvironment and metabolic reprogramming pathways represent potential therapeutic strategies. Moreover, some miRNAs are thought to have significant functions in regulating the progression of HNSCC. The present article aims to summarize the current knowledge concerning the important miRNAs in both exosomes and cancer metabolism, as well as discuss future perspectives regarding their future diagnostic potential and treatment recommendations.

Abstract

MicroRNAs (miRNAs) are endogenous small non-coding RNA molecules that negatively regulate gene expression by binding to target mRNAs. Deregulated miRNAs can act as either oncogenic miRNAs or tumor suppressor miRNAs in controlling proliferation, differentiation, apoptosis, metastasis, epithelial–mesenchymal transition, and immune responses, which are all involved in the carcinogenesis process of HNSCC. Recent findings have shown that metabolic reprogramming is an important hallmark of cancer, which is necessary for malignant transformation and tumor development. Some reprogrammed metabolisms are believed to be required for HNSCC against an unfavorable tumor microenvironment (TME). The TME is composed of various cell types embedded in the altered extracellular matrix, among which exosomes, secreted by cancer cells, are one of the most important factors. Tumor-derived exosomes reshape the tumor microenvironment and play a crucial role in cell-to-cell communication during HNSCC development. Exosomes encapsulate many biomolecules, including miRNAs, circulate in body fluids, and can transmit intercellular regulatory messages to nearby and distant sites, which indicates that exosomal miRNAs have the potential to become non-invasive biomarkers. This review aims to clarify the functions of diverse miRNAs in HNSCC metabolic reprogramming and tumor-derived exosomes. In addition, it also emphasizes the potential role of miRNA as a biomarker in the diagnosis, prognosis, and treatment of HNSCC cancer.

MicroRNAs as Potential Predictors of Response to CDK4/6 Inhibitor Treatment

Simple Summary

MicroRNAs are endogenous non-coding 20–22 nucleotide long RNAs that play a fundamental role in the post-transcriptional control of gene expression. Consequently, microRNAs are involved in multiple biological processes of cancer and could be used as biomarkers with prognostic and predictive significance. Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have become a mainstay of treatment for patients with advanced hormone receptor-positive (HR) breast cancer. Despite the initial high response rates, approximately 10% of patients demonstrate primary resistance to CDK4/6 inhibitors while acquired resistance is almost inevitable. Considering the fundamental role of miRNAs in tumorigenesis, we aimed to explore the potential involvement of microRNAs in response to CDK4/6 inhibition in solid tumors. A number of microRNAs were shown to confer resistance or sensitivity to CDK4/6 inhibitors in preclinical studies, although this remains to be proved in human studies.

Abstract

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have emerged as novel treatment options in the management of advanced or metastatic breast cancer. MicroRNAs are endogenous non-coding 19–22-nucleotide-long RNAs that regulate gene expression in development and tumorigenesis. Herein, we systematically review all microRNAs associated with response to CDK4/6 inhibitors in solid tumors and hematological malignancies. Eligible articles were identified by a search of the MEDLINE and ClinicalTrials.gov databases for the period up to1 January 2021; the algorithm consisted of a predefined combination of the words “microRNAs”, “cancer” and “CDK 4/6 inhibitors”. Overall, 15 studies were retrieved. Six microRNAs (miR-126, miR-326, miR3613-3p, miR-29b-3p, miR-497 and miR-17-92) were associated with sensitivity to CDK4/6 inhibitors. Conversely, six microRNAs (miR-193b, miR-432-5p, miR-200a, miR-223, Let-7a and miR-21) conferred resistance to treatment with CDK4/6 inhibitors. An additional number of microRNAs (miR-124a, miR9, miR200b and miR-106b) were shown to mediate cellular response to CDK4/6 inhibitors without affecting sensitivity to treatment. Collectively, our review provides evidence that microRNAs could serve as predictive biomarkers for treatment with CDK4/6 inhibitors. Moreover, microRNA-targeted therapy could potentially maximize sensitivity to CDK4/6 inhibition.

miR-374a-5p inhibits non-small cell lung cancer cell proliferation and migration via targeting NCK1

Emerging studies have indicated that microRNAs (miRNAs/miRs) are involved in regulating non-small cell lung cancer (NSCLC)-associated processes. The present study aimed to evaluate the biological roles of miR-374a-5p in NSCLC. Using reverse transcription-quantitative PCR, the expression levels of miR-374a-5p were determined in NSCLC cells and a normal cell line. Functional experiments were performed to investigate the functions of miR-374a-5p in NSCLC. A luciferase activity reporter assay and rescue experiments were performed to validate NCK adaptor protein 1 (NCK1) as a functional target of miR-374a-5p. It was demonstrated that miR-374a-5p levels were decreased in NSCLC cell lines compared with those in a normal cell line. Furthermore, overexpression of miR-374a-5p inhibited NSCLC cell proliferation and migration in vitro. Of note, NCK1 overexpression reversed the effects of miR-375a-5p on NSCLC cell proliferation and migration. The present results confirmed the tumor suppressor role of miR-374a-5p via targeting NCK1 in NSCLC, indicating the importance of the miR-374a-5p/NCK1 axis in NSCLC.

Roles of microRNAs in Regulating Cancer Stemness in Head and Neck Cancers

Head and neck squamous cell carcinomas (HNSCCs) are epithelial malignancies with 5-year overall survival rates of approximately 40-50%. Emerging evidence indicates that a small population of cells in HNSCC patients, named cancer stem cells (CSCs), play vital roles in the processes of tumor initiation, progression, metastasis, immune evasion, chemo-/radioresistance, and recurrence. The acquisition of stem-like properties of cancer cells further provides cellular plasticity for stress adaptation and contributes to therapeutic resistance, resulting in a worse clinical outcome. Thus, targeting cancer stemness is fundamental for cancer treatment. MicroRNAs (miRNAs) are known to regulate stem cell features in the development and tissue regeneration through a miRNA-target interactive network. In HNSCCs, miRNAs act as tumor suppressors and/or oncogenes to modulate cancer stemness and therapeutic efficacy by regulating the CSC-specific tumor microenvironment (TME) and signaling pathways, such as epithelial-to-mesenchymal transition (EMT), Wnt/β-catenin signaling, and epidermal growth factor receptor (EGFR) or insulin-like growth factor 1 receptor (IGF1R) signaling pathways. Owing to a deeper understanding of disease-relevant miRNAs and advances in in vivo delivery systems, the administration of miRNA-based therapeutics is feasible and safe in humans, with encouraging efficacy results in early-phase clinical trials. In this review, we summarize the present findings to better understand the mechanical actions of miRNAs in maintaining CSCs and acquiring the stem-like features of cancer cells during HNSCC pathogenesis.

Long non-coding RNA FGD5-AS1 promotes non-small cell lung cancer cell proliferation through sponging hsa-miR-107 to up-regulate FGFRL1

Long non-coding RNA (lncRNA) FYVE, RhoGEF and PH domain containing 5 antisense RNA 1 (FGD5-AS1) has been reported as an oncogene in colorectal cancer, promoting its tumorgenesis. The present paper focused on searching the potential function of FGD5-AS1 in non-small cell lung carcinoma (NSCLC). There are connections between the expression of lncRNA FGD5-AS1 and human NSCLC tumor growth and progression. Also, the relationships between FGD5-AS1, hsa-miR-107 and mRNA fibroblast growth factor receptor like 1 (FGFRL1) are going to test their interaction in NSCLC cell lines, which may cause a series of biological behaviors of NSCLC cells. qRT-PCR analysis was conducted to test the expression of RNAs in different situation. CCK-8 experiment and clone formation assay were performed to assess proliferation of NSCLC cells. Also, connection between FGD5-AS1 and hsa-miR-107 were investigated by luciferase reporter assay and RNA pull-down assay. Rescue experiments were performed to verify the modulating relationship between FGD5-AS1, hsa-miR-107 and FGFRL1. High-level expression of FGD5-AS1 was found in NSCLC. FGD5-AS1 may promote the proliferation of NSCLC cells. Also, the combination between hsa-miR-107, FGD5-AS1 and NSCLC have been proved, which means they can play an interaction function in NSCLC cells. Thence, we concluded that lncRNA FGD5-AS1 promotes non-small cell lung cancer cell proliferation through sponging hsa-miR-107 to up-regulate FGFRL1.

The Role and Expression of Angiogenesis-Related miRNAs in Gastric Cancer

Gastric cancer (GC) is the fifth most frequently diagnosed malignant tumor and the third highest cause of cancer mortality worldwide. For advanced GC, many novel drugs and combinations have been tested, but results are still disappointing, and the disease is incurable in the majority of cases. In this regard, it is critical to investigate the molecular mechanisms underlying GC development. Angiogenesis is one of the hallmarks of cancer with a fundamental role in GC growth and progression. Ramucirumab, a monoclonal antibody that binds to vascular endothelial growth factor-2 (VEGFR-2), is approved in the treatment of advanced and pretreated GC. However, no predictive biomarkers for ramucirumab have been identified so far. Micro RNAs (miRNAs) are a class of evolutionarily-conserved single-stranded non-coding RNAs that play an important role (via post-transcriptional regulation) in essentially all biologic processes, such as cell proliferation, differentiation, apoptosis, survival, invasion, and migration. In our review, we aimed to analyze the available data on the role of angiogenesis-related miRNAs in GC.

Long non‑coding RNA MEG3 inhibits cell migration and invasion of non‑small cell lung cancer cells by regulating the miR‑21‑5p/PTEN axis

Long non-coding RNAs (lncRNAs) are involved in the occurrence and progression of numerous types of cancer. The aim of the present study was to evaluate the effect of the lncRNA maternally expressed gene 3 (MEG3) on the migration and invasion of non-small cell lung cancer (NSCLC) H1299 and PC9 cells. Reverse transcription-quantitative (RT-q)PCR analysis showed that MEG3 was downregulated in NSCLC PC9 and H1299 cells. Additionally, bioinformatics analysis indicated that MEG3 sponges microRNA (miR)-21-5p; miR-21-5p was predicted to target the phosphatase and tensin homolog (PTEN) 3′-untranslated region sequence. MEG3 overexpression led to miR-21-5p suppression and PTEN upregulation in PC9 and H1299 cells, as detected by RT-qPCR. Subsequently, western blot analysis confirmed that MEG3 overexpression enhanced PTEN expression levels and inhibited the PI3K/AKT signaling pathway in NSCLC cells. These effects were attenuated by miR-21-5p. Dual luciferase assay supported the sponging effect of MEG3 on miR-21-5p and validated the direct interaction between miR-21-5p and PTEN. Furthermore, Transwell assay demonstrated that MEG3 overexpression had an inhibitory effect on cell migration and invasion. MEG3 overexpression also mediated epithelial-to-mesenchymal transition by significantly enhancing E-cadherin and decreasing N-cadherin, Vimentin and matrix metalloprotein 9 expression levels in NSCLC cells, as indicated by western blot analysis. These changes were partially reversed by an miR-21-5p mimic. These results indicated that MEG3 acted as a tumor suppressor that inhibited NSCLC cell migration and invasion via sponging miR-21-5p, which, in turn, enhanced the expression levels of PTEN, in part via the PI3K/AKT signaling pathway. The results of the present study have suggested the potential of MEG3 as a novel therapeutic target for NSCLC treatment.

miR-155 promotes proliferation and epithelial-mesenchymal transition of MCF-7 cells

Breast cancer (BC) is the second leading cause of cancer-associated deaths among women worldwide. Increasing evidence has indicated that microRNAs (miRNAs) have demonstrated great potential for improving the diagnosis and therapy for BC. In the present study, miRNA-155 was detected in human BC tissues using reverse transcription-quantitative (RT-q)PCR. RT-qPCR and western blot assays were used to analyze the levels of transforming growth factor β receptor type II (TGFBR2) in human BC tissues. MCF-7 cells were cultured and treated with miR-155 inhibitor and an MTT assay was performed to determine the role of miR-155 on the proliferation of MCF-7 cells. Subsequently, TGFBR2 and epithelial-mesenchymal transition (EMT)-associated molecules were analyzed using RT-qPCR and western blot assays. The direct binding of miR-155 to TGFBR2 was validated using a dual luciferase assay. Higher levels of miR-155 and lower levels of TGFBR2 were expressed in human BC tissues compared with paired normal tissues. Furthermore, the expression levels of miR-155 were associated with the tumor size, TNM stage and metastasis status of BC. Transfection of MCF-7 cells with miR-155 inhibitors resulted in reduced cell proliferation and suppressed the EMT process, characterized by upregulated expression of the epithelial markers, E-cadherin and CK18, and downregulated expression of mesenchymal markers, fibronectin and smooth muscle actin α. Transfection of a miR-155 inhibitor also resulted in increased expression of TGFBR2, and miR-155 may have regulated TGFBR2 through direct binding to the 3'untranslated region of TGFBR2 as determined using a dual-luciferase assay. Based on the results of the present study, miR-155 may serve as a novel diagnostic biomarker and therapeutic target for patients with BC.

Down-Regulation of MiR-181c-5p Promotes Epithelial-to-Mesenchymal Transition in Laryngeal Squamous Cell Carcinoma via Targeting SERPINE1

Laryngeal squamous cell carcinoma (LSCC) arises from the squamous epithelium of the larynx and is associated with a high incidence of cervical lymph node metastasis. MicroRNAs (miRNAs) play a crucial role in the epigenetic regulation of cellular biological processes, including cancer metastasis. However, the molecular mechanisms of specific miRNAs responsible for LSCC metastasis and their clinical significance have yet to be fully elucidated. In this study, LSCC cohort datasets from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were downloaded and examined by comprehensive bioinformatics analysis, which revealed that upregulation of mRNA SERPINE1 and downregulation of miR-181c-5p were associated with unfavorable overall survival. Our analysis showed that SERPINE1 expression negatively correlated with the expression level of miR-181c-5p in our LSCC patient samples. Silencing of miR-181c-5p expression promoted cell migration and invasion in cell lines, whereas the overexpression of miR-181c-5p suppressed cell migration and epithelial-to-mesenchymal transition (EMT) through the downregulation of SERPINE1. Further analysis showed that the enhancement effect on EMT and metastasis induced by silencing miR-181c-5p could be rescued through knockdown of SERPINE1 expression in vitro. Collectively, our findings indicated that miR-181c-5p acted as an EMT suppressor miRNA by downregulation of SERPINE1 in LSCC and offers novel strategies for the prevention of metastasis in LSCC.

The knockdown of LncRNA AFAP1-AS1 suppressed cell proliferation, migration, and invasion, and promoted apoptosis by regulating miR-545-3p/hepatoma-derived growth factor axis in lung cancer

Lung cancer is one of the most common human cancers. Long noncoding RNA AFAP1-AS1 (LncRNA AFAP1-AS1) and microRNA-545-3p (miR-545-3p) were reported to play important roles in lung cancer development. This study aimed to elucidate the functional mechanisms of AFAP1-AS1 and miR-545-3p in lung cancer. Quantitative real time polymerase chain reaction was carried out to determine the levels of AFAP1-AS1, miR-545-3p and hepatoma-derived growth factor (HDGF). Cell proliferation, apoptosis, migration and invasion were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide assay, flow cytometry, and transwell migration and invasion assays, respectively. Furthermore, the interaction between miR-545-3p and AFAP1-AS1 or HDGF was predicted by bioinformatics analysis software starbase and confirmed by the dual luciferase reporter assay. Western blot assay was used to detect the protein level of HDGF. Besides, murine xenograft model was conducted through injecting A549 cells transfected with sh-AFAP1-AS1. The expression levels of AFAP1-AS1 and HDGF were increased, while miR-545-3p was decreased in lung cancer tissues and cells. AFAP1-AS1 knockdown suppressed lung cancer cell proliferation, migration, and invasion and induced apoptosis. Furthermore, AFAP1-AS1 mediated cell progression through regulating miR-545-3p expression. In addition, miR-545-3p negatively regulated the expression level of HDGF via binding 3'-untranslated region of HDGF. As expected, AFAP1-AS1 knockdown inhibited lung cancer progression via affecting miR-545-3p/HDGF axis. Besides, AFAP1-AS1 knockdown suppressed lung cancer tumor growth in vivo. Collectively, our results suggested that AFAP1-AS1 promoted the development of lung cancer via regulating miR-545-3p/HDGF axis, providing a potential target for the treatment of lung cancer.

Antioxidant defense mechanisms and its dysfunctional regulation in the mitochondrial disease, Friedreich's ataxia

Redox stress is associated with the pathogenesis of a wide variety of disease states. This can be amplified potentially through redox active iron deposits in oxidatively active organelles such as the mitochondrion. There are a number of disease states, including Friedreich's ataxia (FA) and sideroblastic anemia, where iron metabolism is dysregulated and leads to mitochondrial iron accumulation. Considering FA, which is due to the decreased expression of the mitochondrial protein, frataxin, this iron accumulation does not occur within protective storage proteins such as mitochondrial ferritin. Instead, it forms unbound biomineral aggregates composed of high spin iron(III), phosphorous and sulfur, which probably contributes to the observed redox stress. There is also a dysregulated response to the ensuing redox assault, as the master regulator of oxidative stress, nuclear factor erythroid 2-related factor-2 (Nrf2), demonstrates marked down-regulation. The dysfunctional response of Nrf2 in FA is due to multiple mechanisms including: (1) up-regulation of Keap1 that is involved in Nrf2 degradation; (2) activation of the nuclear Nrf2 export/degradation machinery via glycogen synthase kinase-3β (Gsk3β) signaling; and (3) inhibited nuclear translocation of Nrf2. More recently, increased microRNA (miRNA) 144 expression has been demonstrated to down-regulate Nrf2 in several disease states, including an animal model of FA. Other miRNAs have also demonstrated to be dysregulated upon frataxin depletion in vivo in humans and animal models of FA. Collectively, frataxin depletion results in multiple, complex responses that lead to detrimental redox effects that could contribute to the mechanisms involved in the pathogenesis of FA.

miR-103a-3p alleviates oxidative stress, apoptosis, and immune disorder in oxygen-glucose deprivation-treated BV2 microglial cells and rats with cerebral ischemia-reperfusion injury by targeting high mobility group box 1

Background

Cerebral ischemia-reperfusion injury (CI/R) is among the most common diseases affecting the central nervous system. Due to the poor efficacy and adverse side effects of the drugs used to treat CI/R in clinical trials, a new treatment strategy is urgently needed. In this study, we aimed to investigate whether miR-103a-3p alleviates CI/R in vivo and vitro and to explore the relevant mechanisms.

Methods

BV2 microglial cells underwent oxygen-glucose deprivation (OGD) treatment to imitate the pathophysiology of CI/R in vitro. A middle cerebral artery occlusion (MCAO) rat model was established to imitate the pathophysiology of CI/R in vivo. The expression levels of miR-103a-3p and HMGB1 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot. Flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, enzyme-linked immunosorbent assay (ELISA), and hematoxylin and eosin (H&E) and Nissl staining were used to evaluated apoptosis, oxidative stress, inflammatory response, and histopathology, respectively.

Results

OGD-stimulated BV2 microglial cells and brain tissues with CI/R had low expression of miR-103a-3p but high expression of high mobility group box 1 (HMGB1). As expected, miR-103a-3p and HMGB1 had a targeting relationship. Overexpression of HMGB1 enhanced the the levels of interleukin (IL)-1 beta, tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA), but reduced the content of superoxide dismutase (SOD), IL-4, and IL-10, in vitro. Moreover, high expression of HMGB1 aggravated the brain injury of the model rats, and increased the secretion of inflammatory factors, exacerbated oxidative stress, and further induced tissue apoptosis in the brain tissue. Importantly, these effects of HMGB1 overexpression were partly reversed by miR-103a-3p overexpression on HMGB1 interference.

Conclusions

HMGB1 is targeted by miR-103a-3p, which may be a new strategy in the treatment of CI/R.

The Use of Immunohistochemistry, Fluorescence in situ Hybridization, and Emerging Epigenetic Markers in the Diagnosis of Malignant Pleural Mesothelioma (MPM): A Review

Malignant pleural mesothelioma (MPM) is an aggressive asbestos related disease that is generally considered to be difficult to diagnose, stage and treat. The diagnostic process is continuing to evolve and requires highly skilled pathology input, and generally an extensive list of biomarkers for definitive diagnosis. Diagnosis of MPM requires histological evidence of invasion by malignant mesothelial cells often confirmed by various immunohistochemical biomarkers in order to separate it from pleural metastatic carcinoma. Often when invasion of neoplastic mesothelial cells into adjacent tissue is not apparent, further immunohistochemical testing - namely BAP1 and MTAP, as well as FISH testing for loss of p16 (CDKN2A) are used to separate reactive mesothelial proliferation due to benign processes, from MPM. Various combinations of these markers, such as BAP1 and/or MTAP immunohistochemistry alongside FISH testing for loss of p16, have shown excellent sensitivity and specificity in the diagnosis of MPM. Additionally, over the recent years, research into epigenetic marker use in the diagnosis of MPM has gained momentum. Although still in their research stages, various markers in DNA methylation, long non-coding RNA, micro RNA, circular RNA, and histone modifications have all been found to support diagnosis of MPM with generally good sensitivity and specificity. Many of these studies are however, limited by small sample sizes or other study limitations and further research into the area would be beneficial. Epigenetic markers show promise for use in the future to facilitate the diagnosis of MPM.

Thyroid Tumor: Investigating MicroRNA-21 Gene Suppression in FTC and FTA

The follicular thyroid carcinoma (FTC) and follicular thyroid adenoma (FTA) are malignant and benign thyroid neoplasms, respectively. MicroRNA (miRNA) expressions have been touted as an indicator for prognostic outcome in thyroid cancer. The study objective was to explore genes suppressed by miRNA-21-3p and miRNA-21-5p for potential therapeutic insights. Differentially expressed genes and their functional enrichment were obtained from 25 FTA and 27 FTC gene microarray dataset GSE82208 using R and Bioconductor tools. The miRNA target sites were obtained from miR-TarBase database. A unique gene list of differentially expressed FTC and FTA were entered into miR-TarBase database to obtain target genes for both miRNA-21-3p and miRNA-21-5p. The result showed that miRNA-21-3p and miRNA-21-5p downregulated TIMP3, MAT2A, TGFBR2, and PLAT gene in FTC and FTA leading to significant expression of acute phase-response to metallothionein, metal ions, and unfolded protein response (UPR). The computational analysis suggests that the suppression of miRNA-21-3p and miRNA-21-5p could be an intervention strategy for therapeutically targeting FTC and FTA treatments.

miR-29c-3p Increases Cell Viability and Suppresses Apoptosis by Regulating the TNFAIP1/NF-κB Signaling Pathway via TNFAIP1 in Aβ-Treated Neuroblastoma Cells

Alzheimer's disease (AD) is the most common cause of dementia among older people in worldwide. miR-29c-3p was reported to play a role in AD development. However, the detail function of miR-29c-3p in AD remains unclear. The aim of this research is to analyze the functional mechanism of miR-29c-3p in AD. The RNA levels of miR-29c-3p and Tumor necrosis factor-α-inducible protein-1 (TNFAIP1) were detected by Quantitative real time polymerase chain (qRT-PCR) reaction. Western blot assay was carried out to examine the protein levels of TNFAIP1, Bax, B-cell lymphoma-2 (Bcl-2), Cleaved caspase 3, and Nuclear factor-k-gene binding (NF-κB). The interaction between miR-29c-3p and TNFAIP1 was predicted by online tool TargrtScan and verified using the dual luciferase reporter assay and RNA immunoprecipitation RIP (RIP) assay. Besides, cell proliferation and apoptosis rate were determined by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. Aβ treatment decreased miR-29c-3p expression and increased TNFAIP1 expression. Overexpression of miR-29c-3p mitigated the effects of Aβ on proliferation and apoptosis. Similarly, knockdown of TNFAIP1 also reversed the effects of Aβ on cell progression. Interestingly, miR-29c-3p suppressed the expression of TNFAIP1 via binding to 3'UTR of TNFAIP1 mRNA. As expected, overexpression of TNFAIP1 reversed the effects of miR-29c-3p on Aβ-mediated cell progression. Besides, we also confirmed that miR-29c-3p affected Aβ-mediated cell progression by regulating TNFAIP1/NF-κB signaling pathway. In conclusion, our findings confirmed that miR-29c-3p attenuated Aβ-induced neurotoxicity through regulation of NF-κB signaling pathway by directly targeting TNFAIP1, providing the potential value for the treatment of AD patients.

Clinical significance of miR-1180-3p in hepatocellular carcinoma: a study based on bioinformatics analysis and RT-qPCR validation

miRNAs play an indispensable role in human carcinogenesis. Dysregulated miR-1180-3p has been observed in several types of cancer, including hepatocellular carcinoma (HCC). This study intends to correlate the expression level of miR-1180-3p with clinical features and overall survival in HCC patients. The expression and clinical significance of miR-1180-3p, selected from GEO and TCGA databases, were verified using an RT-qPCR method. The target genes of miR-1180-3p were obtained using 3 miRNA target gene prediction databases, and their functions were analyzed using the online tool WebGestalt. miR-1180-3p expression was significantly upregulated in 88 HCC tissues compared with non-tumor liver tissues (0.004 ± 0.009 vs. 0.002 ± 0.002, t = − 2.099, P = 0.038). Additionally, we found that the expression levels of miR-1180-3p were significantly correlated with tumor number (χ² = 9.157, P = 0.006) and MVI (χ² = 11.354, P = 0.003). Based on Kaplan–Meier analysis, patients with high miR-1180 expression had a shorter overall survival than those with low miR-1180-3p expression (P = 0.002). Furthermore, multivariate Cox analyses indicated that miR-1180-3p expression was an independent prognostic factor for overall survival (HR = 13.36, 95% CI 1.16, 153.69, P = 0.038). In addition, a total of 733 target genes of miR-1180-3p were found from three prediction databases. The GO analyses demonstrated that the target genes were closely related to the proliferation and malignancy of tumors. The KEGG analysis showed that target genes were enriched in several key cancer-related signaling pathways, including the Pathways in cancer, the Ras signaling pathway, and the MAPK signaling pathway. In conclusion, we demonstrate that miR-1180-3p is upregulated in HCC and is associated with a poor prognosis. Thus, miR-1180-3p might be useful as a prognostic marker for HCC.

How Does a Tumor Get Its Shape? MicroRNAs Act as Morphogens at the Cancer Invasion Front

The generation and organization of the invasion front shape of neoplasms is an intriguing problem. The intimate mechanism is not yet understood, but the prevailing theory is that it represents an example of morphogenesis. Morphogenesis requires the presence of specific molecules, known as morphogens (activators and inhibitors), which can diffuse and elicit dose-dependent responses in their target cells. Due to their ability to modulate most of the coding transcriptome, their well-established role in embryogenesis, and their capacity to rapidly move between neighboring and distant cells, we propose microRNAs as inhibitors that could shape the cancer invasion front. In order to explain the genesis of the tumor border, we use Alan Turing’s reaction diffusion model, refined by Meinhardt and Gierer. This assumes the existence of an activator called a, and an inhibitor called h, which we hypothesize could be a freely moving microRNA. We used the fractal dimension as a measure of tumor border irregularity. We observed that the change in fractal dimension associates with variations in the diffusion coefficient of the activator (D_a) or the inhibitor (D_h). We determined that the fractal dimension remains constant (i.e., the irregularity of the tumor border does not change) across a D_h interval, which becomes narrower as D_a rises. We therefore conclude that a change in fractal dimension occurs when the balance between D_a and D_h is disrupted. Biologically, this could be explained by a faulty distribution of the inhibitor caused by an abnormal density of the intercellular connection network. From a translational perspective, if experimentally confirmed, our observations can be used for a better diagnosis of cancer aggressiveness.

Functional miRNA Screening Identifies Wide-ranging Antitumor Properties of miR-3622b-5p and Reveals a New Therapeutic Combination Strategy in Ovarian Tumor Organoids

Novel therapeutic strategies are urgently required for the clinical management of chemoresistant ovarian carcinoma, which is the most lethal of the gynecologic malignancies. miRNAs hold promise because they play a critical role in determining the cell phenotype by regulating several hundreds of targets, which could constitute vulnerabilities of cancer cells. A combination of gain-of-function miRNA screening and real-time continuous cell monitoring allows the identification of miRNAs with robust cytotoxic effects in chemoresistant ovarian cancer cells. Focusing on miR-3622b-5p, we show that it induces apoptosis in several ovarian cancer cell lines by both directly targeting Bcl-xL and EGFR-mediating BIM upregulation. miR-3622b-5p also sensitizes cells to cisplatin by inhibiting Bcl-xL in ovarian cancer cell lines escaping BIM induction. miR-3622b-5p also exerts antimigratory capacities by targeting both LIMK1 and NOTCH1. These wide-ranging antitumor properties of miR-3622b-5p in ovarian cancer cells are mimicked by the associations of pharmacologic inhibitors targeting these proteins. The combination of an EGFR inhibitor together with a BH3-mimetic molecule induced a large decrease in cell viability in a panel of ovarian cancer cell lines and several ovarian patient-derived tumor organoids, suggesting the value of pursuing such a combination therapy in ovarian carcinoma. Altogether, our work highlights the potential of phenotype-based miRNA screening approaches to identify lethal interactions which might lead to new drug combinations and clinically applicable strategies.

Increased SIX-1 expression promotes breast cancer metastasis by regulating lncATB-miR-200s-ZEB1 axis

Patients with advanced breast cancer (BC) showed a higher incidence of regional and distant metastases. Sine oculis homeobox homolog 1 (SIX-1) has been confirmed to be a key tumorigenic and metastatic regulator in BC progression. Yet, molecular mechanisms behind SIX-1-induced BC metastases remain largely unknown. Here we found that SIX-1 was frequently up-regulated in BC and correlated with poor outcomes when tested in human BC tissue microarray. Then, we manipulated the expression of SIX-1 by via shRNA-mediated knockdown and lentivirus-mediated overexpression. Transwell assay in vitro and lung metastases model of nude mice in vivo showed that SIX-1 promoted BC cell invasion and migration in vitro, and facilitated metastases in vivo. Mechanistically, SIX-1 could promote the transcription of lncATB, which exerts critical pro-metastatic role in BC by directly binding to the miR-200 family, especially for miR-200c, to induce EMT and promote metastases. In conclusion, SIX-1 exerts its pro-metastatic role in BC through lncATB/miR-200s axis of EMT signalling pathway and could act as an important diagnostic marker as well as a significant therapeutic target for clinically advanced BC.

Amygdala-Based Altered miRNome and Epigenetic Contribution of miR-128-3p in Conferring Susceptibility to Depression-Like Behavior via Wnt Signaling

BACKGROUND

Recent studies suggest that microRNAs (miRNAs) can participate in depression pathogenesis by altering a host of genes that are critical in corticolimbic functioning. The present study focuses on examining whether alterations in the miRNA network in the amygdala are associated with susceptibility or resiliency to develop depression-like behavior in rats.

METHODS

Amygdala-specific altered miRNA transcriptomics were determined in a rat depression model following next-generation sequencing method. Target prediction analyses (cis- and trans) and qPCR-based assays were performed to decipher the functional role of altered miRNAs. miRNA-specific target interaction was determined using in vitro transfection assay in neuroblastoma cell line. miRNA-specific findings from the rat in vivo model were further replicated in postmortem amygdala of major depressive disorder (MDD) subjects.

RESULTS

Changes in miRNome identified 17 significantly upregulated and 8 significantly downregulated miRNAs in amygdala of learned helpless (LH) compared with nonlearned helpless rats. Prediction analysis showed that the majority of the upregulated miRNAs had target genes enriched for the Wnt signaling pathway. Among altered miRNAs, upregulated miR-128-3p was identified as a top hit based on statistical significance and magnitude of change in LH rats. Target validation showed significant downregulation of Wnt signaling genes in amygdala of LH rats. A discernable increase in expression of amygdalar miR-128-3p along with significant downregulation of key target genes from Wnt signaling (WNT5B, DVL, and LEF1) was noted in MDD subjects. Overexpression of miR-128-3p in a cellular model lead to a marked decrease in the expression of Dvl1 and Lef1 genes, confirming them as validated targets of miR-128-3p. Additional evidence suggested that the amygdala-specific diminished expression of transcriptional repressor Snai1 could be potentially linked to induced miR-128-2 expression in LH rats. Furthermore, an amygdala-specific posttranscriptional switching mechanism could be active between miR-128-3p and RNA binding protein Arpp21 to gain control over their target genes such as Lef1.

CONCLUSION

Our study suggests that in amygdala a specific set of miRNAs may play an important role in depression susceptibility, which could potentially be mediated through Wnt signaling.

Molecule mechanisms of Ganoderma lucidum treated hepatocellular carcinoma based on the transcriptional profiles and miRNA-target network

Ganoderma lucidum has salutary effects on tumor treatment, including pancreatic cancer and hepatocellular carcinoma. However, the molecular mechanisms underlying Ganoderma lucidum therapy is obscure. In this study, the Hepa1-6-bearing C57 BL/6 mouse model was utilized to explore the therapeutic efficacy of Ganoderma lucidum extract (GLE), documenting that it could effectively inhibit tumor growth. The microRNA (miRNA) profiles of GLE-treated and untreated mice were detected, and 25 differentially expressed (DE) miRNAs were determined, including 24 up-expressed and one down-expressed miRNAs. Using the ClusterOne algorithm, 8 hub miRNAs were isolated from the established miRNA-target network. The qRT-PCR assay demonstrated that these 8 miRNAs were up-expressed in the GLE treated tumor mice. Furthermore, the mRNA profiles showed that there are 76 DE mRNAs between GLE treated and model groups. The protein-protein interaction (PPI) network shows that Cntn1, Irs1, Nfkbia, Rybp and Ywhaz playing important roles, and qRT-PCR further revealed they were down-expressed in GLE treated Hepa1-6-bearing C57 BL/6 mice. The rebuilt miRNA-target network was shown that these 5 mRNAs were regulated by mmu-mir-23a-5p, -3102-3p, -337-3p, and -467a-3p, respectively. This study suggested that these 4 interesting miRNAs were potential biomarkers for evaluation of GLE efficacy, which may down-regulate the expression of Cntn1, Irs1, Nfkbia, Rybp and Ywhaz, and mediate many signaling pathways occurring in tumor treatment.

miR-6089/MYH9/β-catenin/c-Jun negative feedback loop inhibits ovarian cancer carcinogenesis and progression

The pathogenesis of ovarian cancer remains to be elucidated. Our previous study demonstrated that myosin heavy chain 9 (MYH9) overexpression was associated with poor prognosis of epithelial ovarian cancer. However, the mechanism of MYH9 and its regulation by microRNA (miR) is not clear. The results of the present study demonstrated that miR-6089 was one of the microRNAs targeting MYH9, and miR-6089 overexpression suppressed ovarian cancer cell proliferation, migration, invasion and metastasis in vivo and in vitro. Mechanistic studies confirmed that miR-6089 directly targeted MYH9 to inactivate the Wnt/β-catenin signalling pathway and its downstream epithelial-to-mesenchymal transition (EMT), cell-cycle factors and c-Jun, whereas overexpression of MYH9 reversed the inhibitory effects of miR-6089 overexpression in ovarian cancer cells by upregulating the Wnt/β-catenin and its downstream EMT, cell-cycle factors and c-Jun. Interestingly, miR-6089 was transcriptionally inhibited by c-Jun, a transcription factor which could be induced by MYH9 via the Wnt/β-catenin pathway. Thus miR-6089/MYH9/β-catenin/c-Jun formed a negative feedback loop in ovarian cancer. In clinical samples, miR-6089 negatively correlated with MYH9 expression. Our study is the first to demonstrate that miR-6089 serves as a tumor-suppressive miRNA, and miR-6089/MYH9/β-catenin/c-Jun negative feedback loop inhibits ovarian cancer carcinogenesis and progression.

Adipose-derived mesenchymal stem cells attenuate ischemic brain injuries in rats by modulating miR-21-3p/MAT2B signaling transduction

Aim

To explore the mechanism underlying the protective effect of adipose-derived mesenchymal stem cells (ADMSCs) against ischemic stroke by focusing on miR-21-3p/MAT2B axis.

Methods

Ischemic brain injury was induced in 126 rats by middle cerebral artery occlusion (MCAO). The effect of ADMSC administration on blood-brain barrier (BBB) condition, apoptosis, inflammation, and the activity of miR-21-3p/MAT2B axis was assessed. The role of miR-21-3p inhibition in the function of ADMSCs was further validated in in vitro neural cells.

Results

ADMSCs administration improved BBB condition, inhibited apoptosis, and suppressed inflammation. It also reduced the abnormally high level of miR-21-3p in MCAO rats. Dual luciferase assays showed that miR-21-3p directly inhibited the MAT2B expression in neural cells, and miR-21-3p inhibition by inhibitor or ADMSC-derived exosomes in neurons attenuated hypoxia/reoxygenation-induced impairments similarly to that of ADMSCs in vivo.

Conclusion

This study confirmed the protective effect of ADMSCs against ischemic brain injury exerted by suppressing miR-21-3p level and up-regulating MAT2B level.

Circulating miRNA Profiling in Plasma Samples of Ovarian Cancer Patients

Ovarian cancer is one of the most common cancer types in women characterized by a high mortality rate due to lack of early diagnosis. Circulating miRNAs besides being important regulators of cancer development could be potential biomarkers to aid diagnosis. We performed the circulating miRNA expression analysis in plasma samples obtained from ovarian cancer patients stratified into FIGO I, FIGO III, and FIGO IV stages and from healthy females using the NanoString quantitative assay. Forty-five miRNAs were differentially expressed, out of these 17 miRNAs showed significantly different expression between controls and patients, 28 were expressed only in patients, among them 19 were expressed only in FIGO I patients. Differentially expressed miRNAs were ranked by the network-based analysis to assess their importance. Target genes of the differentially expressed miRNAs were identified then functional annotation of the target genes by the GO and KEGG-based enrichment analysis was carried out. A general and an ovary-specific protein–protein interaction network was constructed from target genes. Results of our network and the functional enrichment analysis suggest that besides HSP90AA1, MYC, SP1, BRCA1, RB1, CFTR, STAT3, E2F1, ERBB2, EZH2, and MET genes, additional genes which are enriched in cell cycle regulation, FOXO, TP53, PI-3AKT, AMPK, TGFβ, ERBB signaling pathways and in the regulation of gene expression, proliferation, cellular response to hypoxia, and negative regulation of the apoptotic process, the GO terms have central importance in ovarian cancer development. The aberrantly expressed miRNAs might be considered as potential biomarkers for the diagnosis of ovarian cancer after validation of these results in a larger cohort of ovarian cancer patients.

Role of microRNA in the pathogenesis of systemic sclerosis tissue fibrosis and vasculopathy

Systemic Sclerosis (SSc) pathogenesis involves multiple immunological, vascular and fibroproliferative abnormalities that contribute to a severe and complex clinical picture. Vasculopathy and fibroproliferative alterations are two hallmark pathological processes in SSc that are responsible for the most severe clinical manifestations of the disease and determine its clinical outcome and mortality. However, the pathogenesis of SSc vasculopathy and of the uncontrolled SSc fibrotic process remain incompletely understood. Recent investigations into the molecular pathways involved in these processes have identified an important role for epigenetic processes that contribute to overall disease progression and have emphasized microRNAs (miRNAs) as crucial epigenetic regulators. MiRNAs hold unique potential for elucidating SSc pathogenesis, improving diagnosis and developing effective targeted therapies for the disease. This review examines the important role that miRNAs play in the development and regulation of vascular and fibroproliferative alterations associated with SSc pathogenesis and their possible participation in the establishment of pathogenetic connections between these two processes. This review also emphasizes that further understanding of the involvement of miRNA in SSc fibrosis and vasculopathy will very likely provide novel future research directions and allow for the identification of groundbreaking therapeutic interventions within these processes. MiR-21, miR- 31, and miR-155 are of particular interest owing to their important involvement in both SSc vasculopathy and fibroproliferative alterations.

MicroRNA-142-3p suppresses endometriosis by regulating KLF9-mediated autophagy in vitro and in vivo

The detailed pathogenesis of endometriosis remains largely unclear despite decades of research. Recent studies have demonstrated that miRNAs plays an important role in endometriosis. The expression of miR-142-3p was decreased in ectopic endometrial tissues, while KLF9 and VEGFA expression levels were increased. Overexpression of miR-142-3p or knockdown of KLF9 significantly suppressed CRL-7566 cell proliferation and metastasis, induced cell apoptosis, and decreased both cell autophagy and vascularization. Additionally, KLF9 was confirmed to be a direct target of miR-142-3p and to directly bind to the promoter of the VEGFA gene, regulating its expression. Finally, intraperitoneal injection of miR-142-3p lentivirus significantly attenuated ectopic endometriotic lesions in vivo.miR-142-3p directly targeted KLF9, regulated VEGFA expression, and was protective against the growth of ectopic endometriotic lesions. Therefore, the miR-142-3p/KLF9/VEGFA signalling pathway may be a potential target in endometriosis treatment.

MicroRNA-191 targets CCAAT/enhanced binding protein β and functions as an oncogenic molecule in human non-small cell lung carcinoma cells

The aberrant expression of microRNAs (miRs) may be involved in tumor growth and progression in human non-small cell lung carcinoma (NSCLC). The present study aimed to investigate the potential roles of miR-191 in NSCLC. Western blotting and reverse transcription-quantitative polymerase chain reaction were performed to assess protein and/or mRNA levels. Scratch wound healing and transwell assays were performed to determine the NSCLC cell migration and invasion. A luciferase demonstrated that CCAAT/enhanced binding protein β (C/EBPβ) was a target of miR-191. Previously, miR-191 has been reported to act as an oncogenic player in multiple human cancers. C/EBPβ has been identified as a target gene of miR-191; however, the roles and underlying mechanisms of miR-191 associated with the regulation of tumor invasion in NSCLC remain unknown. In the present study, it was demonstrated that miR-191 expression levels were higher in human NSCLC tumors compared with in normal adjacent tissue and elevated miR-191 expression levels were closely associated with tumor node metastasis stage in patients with NSCLC. Furthermore, transfection with miR-191 mimic inhibited C/EBPβ expression at the mRNA and protein levels and promoted A549 cell migration and invasion. C/EBPβ was reported to be the direct target gene of miR-191 using a dual luciferase reporter assay. Finally, C/EBPβ siRNA can mimic the effects of miR-191. These findings indicated that miR-191 may function as an oncogene in NSCLC, at least partially due to its negative regulatory on C/EBPβ.

Epigenetics: The master control of endothelial cell fate in cancer

The development of new blood vessels from pre-existing vasculature is called angiogenesis. The growth of tumors depends on a network of supplying vessels that provide them with oxygen and nutrients. Pro-angiogenic factors that are secreted by tumors will trigger the sprouting of nearby existing blood vessels towards themselves and therefore researchers have developed targeted therapy towards these pro-angiogenic proteins to inhibit angiogenesis. However, certain pro-angiogenic proteins tend to bypass the inhibition. Thus, instead of targeting these expressed proteins, research towards angiogenesis inhibition had been focused on a deeper scale, epigenetic modifications. Epigenetic regulatory mechanisms are a heritable change in a sequence of stable but reversible gene function modification yet do not affect the DNA primary sequence directly. Methylation of DNA, modification of histone and silencing of micro-RNA (miRNA)-associated gene are currently considered to initiate and sustain epigenetic changes. Recent findings on the subject matter have provided an insight into the mechanism of epigenetic modifications, thus this review aims to present an update on the latest studies.

MicroRNA heterogeneity in melanoma progression

The altered expression of miRNAs has been linked with neocarcinogenesis or the development of human malignancies including melanoma. Of significance, multiple clinical studies have documented that distinct sets of microRNAs (miRNAs) could be utilized as prognostic biomarkers for cancer development or predict the outcomes of treatment responses. To that end, an in-depth validation of such differentially expressed miRNAs is necessary in diverse settings of cancer patients in order to devise novel approaches to control tumor growth and/or enhance the efficacy of clinically-relevant therapeutic options. Moreover, considering the heterogeneity and sophisticated regulation of miRNAs, the precise delineation of their cellular targets could also be explored to design personalized medicine. Given the significance of miRNAs in regulating several key cellular processes of tumor cells including cell cycle progression and apoptosis, we review the findings of such miRNAs implicated in melanoma tumorigenesis. Understanding the novel mechanistic insights of such miRNAs will be useful for developing diagnostic or prognostic biomarkers or devising future therapeutic intervention for malignant melanoma.

Serum starvation induces cell death in NSCLC via miR-224

Purpose: Increasing evidence suggests that microRNAs (miRNAs) may be involved in the occurrence and progression of non-small cell lung cancer (NSCLC). In the present study, we used serum-starved A549 cells emulating tumor under a nutrient depletion stress in the microenvironment.

Patients and methods: We first detected the expression level of miR-224 between tumor tissues and the adjacent normal tissues. We analyzed the expression levels of miR-224 and its predicted target phosphatase and tensin homolog (PTEN) using quantitative real-time PCR (qRT-PCR) in starved A549 cells. Following transfection with miR-224 mimic or inhibitor in starved A549 cells, MTT assay, Annexin V FITC/PI staining, and LC-3 immunofluorence staining were performed to investigate the roles of miR-224 on proliferation, apoptosis, and autophagy. Next, the expression of apoptosis-related protein Bax and Bcl-2, autophagy-related proteins LC3, PI3K signaling, and target PTEN were measured using qRT-PCR and Western blot assays. The direct interaction between miR-224 and PTEN was validated with a dual luciferase assay.

Results: We found that the expression level of miR-224 in tumor tissues was significantly higher when compared with the adjacent normal tissues. We discovered a reciprocal expression pattern between miR-224 and PTEN in starved A549 cells, and transfection with miR-224 mimic led to down-regulation of PTEN. A dual luciferase assay further confirmed the direct interaction between miR-224 and 3ʹUTR of PTEN. Transfection with miR-224 mimic in starved A549 cells resulted in enhanced cell proliferation, reduced apoptosis, and autophagy, accompanied by increased expression of anti-apoptotic protein Bcl-2, decreased expression of pro-apoptotic protein Bax, and autophagy-related protein LC3. Activation of PI3K was observed in miR-224 mimic transfected cells. The reverse effects by the miR-224 inhibitor in all experiments were observed.

Conclusion: Taken together, we proved that miR-224 might play essential roles in cellular functions of nutrient-depleted A549 cells possibly through regulating the target PTEN and downstream signal PI3K, suggesting the potential of miR-224 to be a therapeutic target for NSCLC therapy.

The Role of MicroRNAs in Recurrence and Metastasis of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) affects 650,000 people worldwide and has a dismal 50% 5-year survival rate. Recurrence and metastasis are believed the two most important factors causing this high mortality. Understanding the biological process and the underlying mechanisms of recurrence and metastasis is critical to develop novel and effective treatment, which is expected to improve patients' survival of HNSCC. MicroRNAs are small, non-coding nucleotides that regulate gene expression at the transcriptional and post-transcriptional level. Oncogenic and tumor-suppressive microRNAs have shown to regulate nearly every step of recurrence and metastasis, ranging from migration and invasion, epithelial-mesenchymal transition (EMT), anoikis, to gain of cancer stem cell property. This review encompasses an overview of microRNAs involved in these processes. The recent advances of utilizing microRNA as biomarkers and targets for treatment, particularly on controlling recurrence and metastasis are also reviewed.

Blood Circulating miRNAs as Cancer Biomarkers for Diagnosis and Surgical Treatment Response

miRNAs can function as potential oncogenes or tumor suppressors. Altered expression of these molecules was correlated with the occurrence of many cancer diseases and therefore they are considered a molecular tool for non-invasive cancer diagnosis and prognosis. We searched for analyses concerning expression of blood circulating miRNA in cancer patients. The studies comprised of at least two miRNA expression measurements: before and after the surgical therapy were considered. We summarized latest reports on evaluation of the efficiency of anticancer therapy through observation of changes in expression of miRNA circulating in blood of patients treated with surgery alone. Twenty one research studies were identified. Thirty one different miRNAs were pointed out as potential both diagnostic and treatment response biomarkers since their deregulated expression before therapy returned to normal after receiving the treatment. Published data revealed a potential of circulating miRNA to become a tool giving a clinical follow up information on the efficiency of applied therapy. However, more observational studies on post-operative circulating miRNA expression changes are necessary.

Systematic review and meta-analysis of prognostic microRNA biomarkers for survival outcome in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal cancer (NPC), despite being one of the most malignant head and neck carcinomas (HNC), lacks comprehensive prognostic biomarkers that predict patient survival. Therefore, this systematic review and meta-analysis is aimed to evaluate the potential prognostic value of miRNAs as prognostic biomarkers in NPC.

METHODS

PRISMA guidelines were used to conduct this systematic review and meta-analysis study. Permutations of multiple "search key-words" were used for the search strategy, which was limited to articles published between January 2012 and March 2018. The retrieved articles were meticulously searched with multi-level screening by two reviewers and confirmed by other reviewers. Meta-analysis was performed using Hazard Ratios (HR) and associated 95% Confidence Interval (CI) of survival obtained from previously published studies. Publication bias was assessed by Egger's bias indicator test and funnel plot symmetry.

RESULTS

A total of 5069 patients across 21 studies were considered eligible for inclusion in the systematic review, with 65 miRNAs being evaluated in the subsequent meta-analysis. Most articles included in this study originated from China and one study from North Africa. The forest plot was generated using cumulated survival data, resulting in a pooled HR value of 1.196 (95% CI: 0.893-1.601) indicating that the upregulated miRNAs increased the likelihood of death of NPC patients by 19%.

CONCLUSION

To our knowledge, this is the first meta-analysis that examines the prognostic effectiveness of miRNAs as biomarkers in NPC patients. We noted that the combined effect estimate of HR across multiple studies indicated that increased miRNA expression in NPC potentially leads to poor overall survival. However, further large-scale prospective studies on the clinical significance of the miRNAs, with sizable cohorts are necessary in order to obtain conclusive results.

Exosomal transfer of obesity adipose tissue for decreased miR-141-3p mediate insulin resistance of hepatocytes

Exosomes, the nano-vesicles released from living cells, were the important mediator for cell-to-cell communication. In order to clarify whether the exosomes derived from obesity adipose tissue mediate insulin resistance of hepatocytes, we extract the exosomes from the adipose tissue of different mice models. Exosomes derived from ob/ob mice (Ob-exosomes), B6 mice fed with a high-fat diet (HFD-exosomes) and normal B6 mice (WT-exosomes) displayed similar size and molecular makers, but their effect on the insulin sensitivity of hepatocytes were obviously different or opposite. Abundant exosomal miRNAs in Ob-, HFD- and WT-exosomes were detected by the Next Generation Sequencing. The levels of miR-141-3p in Ob- and HFD-exosomes were significantly lower than WT-exosomes. MiR-141-3p can be effectively delivered into AML12 cells accompanied by the absorption of exosomes, but the absorption of miR-141-3p into AML12 cells could be blocked by GW4869, an inhibitor of exosome biogenesis and release. Importantly, the Ob-exosomes or miR-141-3p knockdown in WT--exosomes obviously inhibited the insulin response and glucose uptake of AML12 cells, however, the inhibitory effects on insulin function disappeared after the overexpression of miR-141-3p in Ob-exosomes or AML12 cells. The effects of miR-141-3p on insulin function could be achieved by improving the level of phosphorylation of AKT and enhancing insulin signal transduction. Therefore, the absorption of hepatocytes for exosomes released from obesity adipose tissue containing less miR-141-3p than healthy adipose tissue can significantly inhibit the insulin sensitivity and glucose uptake. Our study may certify a novel mechanism that the secretion of "harmful" exosomes from obesity adipose tissues cause insulin resistance.

Expression of miR‑542‑3p in osteosarcoma with miRNA microarray data, and its potential signaling pathways

Osteosarcoma (OS) is the most common pediatric primary bone tumor, with high malignancy rates and a poor prognosis following metastasis. At present, the role of microRNA (miR)-542-3p in OS remains to be elucidated. The purpose of the present study was to investigate the expression level of miR-542-3p in OS, and its potential molecular mechanisms, via a bioinformatics analysis. First, the expression of miR-542-3p in OS based on the continuous variables of the Gene Expression Omnibus database and PubMed was studied. Subsequently, the potential target genes of miR-542-3p were predicted using gene expression profiles and bioinformatics software. On the basis of the Database for Annotation, Visualization and Integrated Discovery, version 6.8, a study of gene ontology (GO) enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway knowledge base was conducted to explore the biological value of miR-542-3p in OS. Finally, the protein-protein interaction (PPI) network was completed using the STRING database. The expression of miR-542-3p in OS was revealed to be significantly higher compared with that in normal tissue. In total, 1,036 target genes of miR-542-3p were obtained. The results of the GO enrichment analysis revealed that the significant terms were ‘bone development’, ‘cell cycle arrest’ and ‘intracellular signal transduction’. The results of the KEGG analysis revealed the highlighted pathways that were targeted to miR-542-3p, including the sphingolipid signaling pathway (P=3.91×10⁻⁵), the phosphoinositide 3-kinase (PI3K)-AKT serine/threonine kinase (AKT) signaling pathway (P=3.17×10⁻⁵) and the insulin signaling pathway (P=1.04×10⁻⁵). The PPI network revealed eight hub genes: Ubiquitin-60S ribosomal protein L40, Ras-related C3 botulinum toxin substrate, mitogen-activated protein kinase 1, epidermal growth factor receptor, cystic fibrosis transmembrane conductance regulator, PI3K regulatory subunit 1, AKT1, and actin-related protein 2/3 complex subunit 1A, which may be the key target genes of miR-542-3p in OS. Taken together, these results have demonstrated that miR-542-3p was overexpressed in OS. The potential target genes and biological functions of miR-542-3p may provide novel insights into the differentially expressed genes that are involved in OS.

MicroRNA‑200a suppresses migration and invasion and enhances the radiosensitivity of NSCLC cells by inhibiting the HGF/c‑Met signaling pathway

Hepatocyte growth factor (HGF), an activator of the c‑Met signaling pathway, is involved in tumor invasiveness, metastasis and radiotherapy resistance. In the present study, a novel HGF regulatory pathway in lung cancer involving micro-RNAs (miRNAs/miR) is described. Immunohistochemical staining and western blot analyses demonstrated that HGF was upregulated and associated with miR‑200a downregulation in non‑small cell lung cancer (NSCLC) samples compared with normal lung tissues. The association between HGF and miR‑200a was associated with the degree of tumor malignancy and cell migration and invasion. miR‑200a negatively regulated HGF expression by targeting the 3'‑untranslated region of the HGF mRNA. miR‑200a overexpression induced HGF downregulation, decreased NSCLC cell migration and invasion, promoted apoptosis, and decreased cell survival in A549 and H1299 cells in response to ionizing radiation. The present results revealed a previously uncharacterized role of miRNA‑200a in regulating tumor malignancy and radiosensitivity by suppressing HGF expression, a key factor in the HGF/c‑Met pathway.

Investigation of the clinical significance and prognostic value of microRNA-145 in human hepatocellular carcinoma

We aimed to investigate the clinical significance and prognostic value of miR-145 in hepatocellular carcinoma (HCC).HCC tissue samples and adjacent normal liver tissues were obtained from 139 patients diagnosed with HCC. The relationships between the expression level of miR-145 and clinicopathologic factors were evaluated by Chi square test. Kaplan-Meier survival analysis with the log-rank test was used to evaluate the association between miR-145 expression and HCC prognosis.miR-145 was significantly down-regulated in HCC tissues compared with the adjacent noncancerous tissues (P < .001). Its expression level was significantly correlated with tumor size (P = .010), tumor number (P = .033), lymph node metastasis (P < .000), TNM stage (P < .001) and tumor differentiation (P < .001). Kaplan-Meier curves with log rank test showed that the overall survival of the patients with low miR-145 expression was significantly shorter in comparison with the high miR-145 expression patients (P = .043). Furthermore, multivariate analysis using the Cox proportional hazards model for all variables showed that miR-145 expression was an independent prognostic factor for overall survival (P = .033).Our results indicate that low expression of miR-145 is an independent poor prognostic factor for patients with HCC. Further investigations are needed to confirm our findings.

miR-381 induces sensitivity of breast cancer cells to doxorubicin by inactivation of MAPK signaling via FYN

The emergence of drug resistance is still a daunting challenge for the effective therapy of cancer patients. miRNAs have been elucidated as an important regulator in chemoresistance of anti-cancer drugs. miR-381 is found to exert tumor-suppressive effect in breast cancer. However, its role in modulating the sensitivity of doxorubicin (DOX) remains unknown. In this study, we found that miR-381 expression was down-regulated in DOX-resistant breast cancer cells. miR-381 overexpression increased DOX sensitivity and enhanced DOX-induced apoptosis in breast cancer cells. Moreover, miR-381 could directly target FYN to suppress its expression. Additionally, FYN knockdown displayed similar effect on DOX sensitivity as miR-381 up-regulation. Furthermore, FYN overexpression partly reversed miR-381-induced sensitivity to DOX. Finally, enforced expression of miR-381 also improved DOX sensitivity of breast cancer cells in vivo. In summary, miR-381 inactivated MAPK signaling by down-regulating FYN, thereby promoting the chemosensitization of breast cancer cells to DOX. Therefore, miR-381/FYN/MAPK pathway may be applied as a novel target to overcome DOX resistance in breast cancer patients.

Knockdown of miR-194-5p inhibits cell proliferation, migration and invasion in breast cancer by regulating the Wnt/β-catenin signaling pathway

Breast cancer is a major public health concern, due to its increasing incidence and limited effective treatment. The present study aimed to investigate the expression of microRNA (miR)‑194‑5p and its roles in breast cancer. The expression levels of miR‑194‑5p and SRY‑box 17 (SOX17) mRNA were detected in breast cancer tissues and cell lines by reverse transcription‑quantitative polymerase chain reaction. The protein expression levels were determined by western blotting. In addition, MTT, colony formation, scratch and Transwell assays were use to evaluate the characteristics of MCF‑7 cells with miR‑194‑5p knockdown. The target verification of miR‑194‑5p was determined by luciferase reporter assay. Furthermore, tumor‑bearing nude mice with miR‑194‑5p knockdown were used to assess the effects of miR‑194‑5p on tumor activity. In breast cancer tissues, miR‑194‑5p was upregulated, whereas SOX17 was downregulated. In addition, the expression levels of SOX17 and phosphorylated (p)‑β‑catenin in the cytosol and nucleus were increased in the miR‑194‑5p inhibitor group. In addition, cell proliferation, migration and invasion were inhibited in response to miR‑194‑5p knockdown. The luciferase reporter assay confirmed that SOX17 was a target gene of miR‑194‑5p. In the mouse studies, knockdown of miR‑194‑5p suppressed tumor growth and promoted SOX17 expression in nude mice with breast cancer. These findings suggested that knockdown of miR‑194‑5p may increase the expression of SOX17 and regulate the Wnt/β‑catenin signaling pathway in breast cancer cells; therefore, miR‑194‑5p may be considered a potential target for breast cancer prevention.

Exosomal miR-1246 in body fluids is a potential biomarker for gastrointestinal cancer

AIM

The aim was to systematically evaluate whether exosomal miRNAs could be regarded as potential minimally invasive biomarkers of diagnosis for gastrointestinal cancer.

METHODS

A systematic review and meta analysis of exosomal miRNA expression in gastrointestinal cancer were performed.

RESULTS

A total of 370 articles were retrieved from PubMed and EMBASE. The summary receiver operating characteristic curves of three miRNAs (miR-21, miR-1246 and miR-4644) were drawn, miR-21, miR-1246 and miR-4644 exhibited sensitivities of 0.66, 0.920 and 0.750, respectively; specificities were 0.87, 0.958 and 0.769, respectively; and areas under the curve for discriminating gastrointestinal cancer patients from control subjects were 0.876, 0.969 and 0.827, respectively.

CONCLUSION

Exosome miR-1246 had the highest level of diagnostic efficiency, which indicated that miR-1246 could be a biomarker.

Effect of dietary components on miRNA and colorectal carcinogenesis

Background

Colorectal cancer (CRC) is one of the most common cancers diagnosed and among the commonest causes of cancer-related mortality globally. Despite the various available treatment options, millions of people still suffer from this illness and most of these treatment options have several limitations. Therefore, a less expensive, non-invasive or a treatment that requires the use of dietary products remains a focal point in this review.

Main body

Aberrant microRNA expression has been revealed to have a functional role in the initiation and progression of CRC. These has shown significant promise in the diagnosis and prognosis of CRC, owing to their unique expression profile associated with cancer types and malignancies. Moreover, microRNA therapeutics show a great promise in preclinical studies, and these encourage further development of their clinical use in CRC patients. Additionally, emerging studies show the chemo-preventive potential of dietary components in microRNA modulation using several CRC models. This review examines the dietary interplay between microRNAs and CRC incidence. Improving the understanding of the interactions between microRNAs and dietary components in the carcinogenesis of CRC will assist the study of CRC progression and finally, in developing personalized approaches for cancer prevention and therapy.

Conclusion

Although miRNA research is still at its infancy, it could serve as a promising predictive biomarkers and therapeutic targets for CRC. Given the ever-expanding number of miRNAs, understanding their functional aspects represents a promising option for further research.