A small piece in the cancer puzzle: microRNAs as tumor suppressors and oncogenes

Intronic miR-6741-3p targets the oncogene SRSF3: Implications for oral squamous cell carcinoma pathogenesis

Epigenetic silencing through methylation is one of the major mechanisms for downregulation of tumor suppressor miRNAs in various malignancies. The aim of this study was to identify novel tumor suppressor miRNAs which are silenced by DNA hypermethylation and investigate the role of at least one of these in oral squamous cell carcinoma (OSCC) pathogenesis. We treated cells from an OSCC cell line SCC131 with 5-Azacytidine, a DNA methyltransferase inhibitor, to reactivate tumor suppressor miRNA genes silenced/downregulated due to DNA methylation. At 5-day post-treatment, total RNA was isolated from the 5-Azacytidine and vehicle control-treated cells. The expression of 2,459 mature miRNAs was analysed between 5-Azacytidine and control-treated OSCC cells by the microRNA microarray analysis. Of the 50 miRNAs which were found to be upregulated following 5-Azacytidine treatment, we decided to work with miR-6741-3p in details for further analysis, as it showed a mean fold expression of >4.0. The results of qRT-PCR, Western blotting, and dual-luciferase reporter assay indicated that miR-6741-3p directly targets the oncogene SRSF3 at the translational level only. The tumor-suppressive role of miR-6741-3p was established by various in vitro assays and in vivo study in NU/J athymic nude mice. Our results revealed that miR-6741-3p plays a tumor-suppressive role in OSCC pathogenesis, in part, by directly regulating SRSF3. Based on our observations, we propose that miR-6741-3p may serve as a potential biological target in tumor diagnostics, prognostic evaluation, and treatment of OSCC and perhaps other malignancies.

Functional Analysis of BRCA1 3'UTR Variants Predisposing to Breast Cancer

Purpose

Breast Cancer (BC) is the main female cancer diagnosed worldwide, and it has been described that few genes, such as BRCA1, have a high penetrance for this type of cancer. In this manuscript, we were interested in evaluating the effect of 3'UTR variants on BRCA1 expression.

Patients and Methods

To accomplish this objective, Whole Exome Sequencing (WES) data of 400 patients with unselected BC was used to filter variants located in the region of interest of BRCA1 gene, finding two of them (c.*36C>G and c.*369_373del). miRGate and miRanda in silico tools were used to predict microRNA (miRNA) interaction.

Results

The two variants (c.*36C>G, c.*369_373del) were predicted to affect miRNA interaction. After cloning of BRCA1 3'UTR into pMIR-Report vector, the construct was transfected into two BC cell lines (MDA-MB-231 and MCF-7), and the variant c.*36C>G evidenced overexpression of reporter gene luciferase, showing that the transcript was not being degraded by the miRNA in MDA-MB-231 cells.

Conclusion

The variant seems to protect against Triple Negative BC probably due to the expression level of miRNA in this particular cell line (MDA-MB-231). This is consistent with the clinical history of the patients who harbor BC Hormone Receptors positive (HR+).

Emerging roles of miR-145 in gastrointestinal cancers: A new paradigm

Gastrointestinal (GI) carcinomas are a group of cancers affecting the GI tract and digestive organs, such as the gastric, liver, bile ducts, pancreas, small intestine, esophagus, colon, and rectum. MicroRNAs (miRNAs) are small functional non-coding RNAs (ncRNAs) which are involved in regulating the expression of multiple target genes; mainly at the post-transcriptional level, via complementary binding to their 3'-untranslated region (3'-UTR). Increasing evidence has shown that miRNAs have critical roles in modulating of various physiological and pathological cellular processes and regulating the occurrence and development of human malignancies. Among them, miR-145 is recognized for its anti-oncogenic properties in various cancers, including GI cancers. MiR-145 has been implicated in diverse biological processes of cancers through the regulation of target genes or signaling, including, proliferation, differentiation, tumorigenesis, angiogenesis, apoptosis, metastasis, and therapy resistance. In this review, we have summarized the role of miR-145 in selected GI cancers and also its downstream molecules and cellular processes targets, which could lead to a better understanding of the miR-145 in these cancers. In conclusion, we reveal the potential diagnostic, prognostic, and therapeutic value of miR-145 in GI cancer, and hope to provide new ideas for its application as a biomarker as well as a therapeutic target for the treatment of these cancer.

Systematic analyzing a five- miRNA panel and its diagnostic value of plasma expression in colorectal cancer

BACKGROUND

Aberrant expression of miRNAs have been implicated in cancers, but the role of miRNAs in colorectal cancer (CRC) remains need to be elucidated. This study aimed to identify miRNAs that related to colorectal cancer (CRC) pathogenesis and determine the diagnostic value.

METHODS

Three GEO datasets (GSE128449, GSE35602 and GSE49246) with 131 samples were used to screen miRNAs that differential expression between tumor and control tissues. The expression of the identified miRNAs was validated in 50 clinical tissue samples and the GSE35834 dataset. The clinical significance of these miRNAs was analyzed in the TCGA dataset and clinical tissue samples. The expression of miRNAs in tissues and plasma samples were tested by RT-PCR assay in clinical samples, and their diagnostic value was determined.

RESULTS

The analysis of three GEO datasets revealed that miR-595 and miR-1237 were upregulated, while miR-126, miR-139, and miR-143 were downregulated in CRC tissues compared to control tissues. The differential expression of the five miRNAs in CRC tissues was confirmed using clinical tissue samples and GEO databases. There was no significant correlation between the TNM stage and tumor stage of CRC and any of the five miRNAs. Plasma expression of the miRNAs differed significantly between CRC and non-cancer patients, and each miRNA had moderate diagnostic value for CRC. Combining the five miRNAs provided better diagnostic potential for CRC than a single miRNA.

CONCLUSIONS

This study demonstrated that five miRNAs were related to the pathogenesis of CRC, but independent of the stage of CRC; Plasma expression of these miRNAs have moderate diagnostic value, and combination of these miRNAs showed better diagnostic ability in CRC.

MicroRNAs as biomarkers for early diagnosis, targeting and prognosis of prostate cancer

Globally, prostate cancer (PC) is leading cause of cancer-related mortality in men worldwide. Despite significant advances in the treatment and management of this disease, the cure rates for PC remains low, largely due to late detection. PC detection is mostly reliant on prostate-specific antigen (PSA) and digital rectal examination (DRE); however, due to the low positive predictive value of current diagnostics, there is an urgent need to identify new accurate biomarkers. Recent studies support the biological role of microRNAs (miRNAs) in the initiation and progression of PC, as well as their potential as novel biomarkers for patients' diagnosis, prognosis, and disease relapse. In the advanced stages, cancer-cell-derived small extracellular vesicles (SEVs) may constitute a significant part of circulating vesicles and cause detectable changes in the plasma vesicular miRNA profile. Recent computational model for the identification of miRNA biomarkers discussed. In addition, accumulating evidence indicates that miRNAs can be utilized to target PC cells. In this article, the current understanding of the role of microRNAs and exosomes in the pathogenesis and their significance in PC prognosis, early diagnosis, chemoresistance, and treatment are reviewed.

Hsa-miR-223-3p participates in the process of anthracycline-induced cardiomyocyte damage by regulating NFIA gene

Irreversible cardiomyopathy was caused by the therapeutic of anthracyclines in the chemotherapy of cancers. The cell apoptosis and autophagy were induced by anthracyclines in AC16 cells. MiR-223-3p ascends in anthracycline-treated AC16, but the expression of nuclear factor I-A (NFIA) was specifically down-regulated. However, the underlying molecular mechanism between NFIA and miR-223-3p is unclear now in AC16 cells. In our research, NFIA expression was dampened in AC16 cells by miR-223-3p mimics. Additionally, miR-223-3p knockdown hindered the apoptosis and autophagy in anthracycline-treated AC16. Furthermore, NFIA was predicted and verified as a miR-223-3p's downstream target and rescued the functions of miR-223-3p. These findings illustrated that miR-223-3p advances anthracycline-stimulated cardiomyocyte damage progression by targeting NFIA, implying the promising therapeutic function of miR-223-3p on cardiomyocyte damage in cancer patients.

Helicobacter pylori infection induces abnormal expression of pro-angiogenic gene ANGPT2 and miR-203a in AGS gastric cell line

Helicobacter pylori colonizes the stomach and induces an inflammatory response that can develop into gastric pathologies including cancer. The infection can alter the gastric vasculature by the deregulation of angiogenic factors and microRNAs. In this study, we investigate the expression level of pro-angiogenic genes (ANGPT2, ANGPT1, receptor TEK), and microRNAs (miR-135a, miR-200a, miR-203a) predicted to regulate those genes, using H. pylori co-cultures with gastric cancer cell lines. In vitro infections of different gastric cancer cell lines with H. pylori strains were performed, and the expression of ANGPT1, ANGPT2, and TEK genes, and miR-135a, miR-200a, and miR-203a, was quantified after 24 h of infection (h.p.i.). We performed a time course experiment of H. pylori 26695 infections in AGS cells at 6 different time points (3, 6, 12, 28, 24, and 36 h.p.i.). The angiogenic response induced by supernatants of non-infected and infected cells at 24 h.p.i. was evaluated in vivo, using the chicken chorioallantoic membrane (CAM) assay. In response to infection, ANGPT2 mRNA was upregulated at 24 h.p.i, and miR-203a was downregulated in AGS cells co-cultured with different H. pylori strains. The time course of H. pylori 26695 infection in AGS cells showed a gradual decrease of miR-203a expression concomitant with an increase of ANGPT2 mRNA and protein expression. Expression of ANGPT1 and TEK mRNA or protein could not be detected in any of the infected or non-infected cells. CAM assays showed that the supernatants of AGS-infected cells with 26695 strain induced a significantly higher angiogenic and inflammatory response. Our results suggest that H. pylori could contribute to the process of carcinogenesis by downregulating miR-203a, which further promotes angiogenesis in gastric mucosa by increasing ANGPT2 expression. Further investigation is needed to elucidate the underlying molecular mechanisms.

Molecular mechanisms of microRNA-301a during tumor progression and metastasis

Cancer is known as one of the leading causes of human deaths globally. Late diagnosis is considered as one of the main reasons for the high mortality rate among cancer patients. Therefore, the introduction of early diagnostic tumor markers can improve the efficiency of therapeutic modalities. MicroRNAs (miRNAs) have a key role in regulation of cell proliferation and apoptosis. MiRNAs deregulation has been frequently reported during tumor progressions. Since, miRNAs have a high stability in body fluids; they can be used as the reliable non-invasive tumor markers. Here, we discussed the role of miR-301a during tumor progressions. MiR-301a mainly functions as an oncogene via the modulation of transcription factors, autophagy, epithelial-mesenchymal transition (EMT), and signaling pathways. This review paves the way to suggest miR-301a as a non-invasive marker for the early tumor diagnosis. MiR-301a can also be suggested as an effective target in cancer therapy.

miR-383-5p serves as a tumor suppressor in bladder cancer by suppressing PI3K/AKT signaling pathway

BACKGROUND

MicroRNAs have been proven to be key molecules in human malignancy. However, to our knowledge, there is no study reporting miR-383-5p expression level and the role it plays in bladder cancer (BC).

METHODS

We identified miR-383-5p to be one of the tumor-suppressing genes through using data from The Cancer Genome Atlas (TCGA) and GEO database. We evaluate the expression and activity of miR-383-5p in both BC tissue and cell lines. The impacts of miR-383-5p on proliferative, migratory ability and apoptotic rate in BC cell were evaluated by utilizing CCK-8 kits, flow cytometry, and Transwell assays. qRT-PCR, western blot, and luciferase reporter assays have been adopted to investigate the underlying mechanisms. In vivo tumorigenicity testing was conducted to determine the impact of miR-383-5p on BC cellular proliferative capacity.

RESULTS

Reduced miR-383-5p expression has been determined in BC tissue than in normal bladder tissue. Furthermore, BC cell proliferative, migratory ability was inhibited while apoptosis enhanced in vitro and in vivo by miR-383-5p up-regulation. In vitro and in vivo, silencing miR-383-5p considerably improved the growth and invasive capacity of cell, while decreased the apoptotic rates of BC cells.

CONCLUSION

miR-383-5p plays its role as a tumor-suppressing gene by suppressing the PI3K/AKT signaling, hence preventing the development of BC.

A Tumor and Immune-Related Micro-RNA Signature Predicts Relapse-Free Survival of Melanoma Patients Treated with Ipilimumab

Despite the unprecedented advances in the treatment of melanoma with immunotherapy, there continues to be a major need for biomarkers of clinical benefits and immune resistance associated with immune checkpoint inhibitors; microRNA could play a vital role in these efforts. This study planned to identify differentially expressed miRNA molecules that may have prognostic value for clinical benefits. Patients with surgically operable regionally advanced melanoma were treated with neoadjuvant ipilimumab (10 mg/kg intravenously every 3 weeks × two doses) bracketing surgery. Tumor biospecimens were obtained at baseline and surgery, and microRNA (miRNA) expression profiling was performed on the tumor biopsies. We found that an expression profile consisting of a 4-miRNA signature was significantly associated with improved relapse-free survival (RFS). The signature consisted of biologically relevant molecules previously reported to have prognostic value in melanoma and other malignancies, including miR-34c, miR-711, miR-641, and miR-22. Functional annotation analysis of target genes for the 4-miRNA signature was significantly enriched for various cancer-related pathways, including cell proliferation regulation, apoptosis, the MAPK signaling pathway, and the positive regulation of T cell activation. Our results presented miRNAs as potential biomarkers that can guide the treatment of melanoma with immune checkpoint inhibitors. These findings warrant further investigation in relation to CTLA4 blockade and other immune checkpoint inhibitors. ClinicalTrials.gov NCT00972933.

Molecular Characterization of Microrna Interference and Aristolochic Acid Intoxication Found in Upper Tract Urothelial Carcinoma in Patients with Balkan Endemic Nephropathy: A Systematic Review of the Current Literature

The term "aristolochic acid nephropathy" (AAN) is used to include any form of toxic interstitial nephropathy that is caused either by ingestion of plants containing aristolochic acids (AA) or by the environmental contaminants in food such as in Balkan endemic nephropathy (BEN). Aristolochic acid (AA) intoxication is strongly associated with the development of upper tract urothelial carcinoma (UTUC); however, the underlying molecular mechanism remains to be defined. MicroRNAs (miRNA) regulate several biological processes, including cell proliferation, differentiation, and metabolism, acting as oncogenes or tumor suppressors. A unique miRNA expression profile suggested that miRNAs could function as regulators in UTUC developmental processes. This review aimed to summarize data available in the literature about underlying molecular mechanisms leading to the expression of miRNAs in AA-UTUC patients with BEN. Strong correlation in AA-UTUC has a distinctive gene alteration pattern, AL-DNA adducts, and a unique tumor protein (TP53) mutational spectrum AAG to TAG (A: T→T: A) transversion in codon 139 (Lys → Stop) of exon 5 activates the p53 tumor suppressor protein. Further, p53 protein is responsible not only for the expression of miRNAs but also acts as a target molecule for miRNAs and plays a crucial function in the AA-UTUC pathogenicity through activation of cyclin-dependent kinase (CyclinD1) and cyclin protein kinase 6(CDK6) to support cell cycle arrest. This study, proposed a molecular mechanism that represented a possible unique relationship between AA intoxication, miRNAs expression, and the progression of UTUC in patients with BEN.

Melatonin targeting non-coding RNAs in cancer: Focus on mechanisms and potential therapeutic targets

Despite, melatonin is mainly known as a regulatory factor for circadian rhythm, its notable role in other fundamental biological processes, such as redox homeostasis and programmed cell death, has been found. In this line, a growing body of evidence indicated that melatonin could apply an inhibitory effect on the tumorigenic processes. Hence, melatonin might be considered an efficient adjuvant agent for cancer treatment. Besides, the physiological and pathological functions of non-coding RNAs (ncRNAs) in various disease, particularly cancers, have been expanded over the past two decades. It is well-established that ncRNAs can modulate the gene expression at various levels, thereby, ncRNAs. can regulate the numerous biological processes, including cell proliferation, cell metabolism, apoptosis, and cell cycle. Recently, targeting the ncRNAs expression provides a novel insight in the therapeutic approaches for cancer treatment. Moreover, accumulating investigations have revealed that melatonin could impact the expression of different ncRNAs in a multiple disorders, including cancer. Therefore, in the precent study, we discuss the potential roles of melatonin in modulating the expression of ncRNAs and the related molecular pathways in different types of cancer. Also, we highlighted its importance in therapeutic application and translational medicine in cancer treatment.

MiR-214-3p targets Ras-related protein 14 (RAB14) to inhibit cellular migration and invasion in esophageal Cancer cells

BACKGROUND

MicroRNA (miR)-214-3p is emerging as an important tumor suppressor in esophageal cancer. In this study, we examined the interaction between miR-214-3p and RAB14, a membrane trafficking protein shown to exert oncogenic functions in other malignancies, in esophageal cancer cells.

METHODS

Studies were performed in a human esophageal epithelial cell line and a panel of esophageal cancer cell lines, as well in human specimens. MiR-214-3p expression was measured by digital PCR. Biotinylated RNA pull-down and luciferase reporter assays assessed binding. The xCELLigence RTCA system measured cell migration and invasion in real time. A lentiviral expression vector was used to create an esophageal cancer cell line stably expressing miR-214-3p.

RESULTS

MiR-214-3p expression was decreased in esophageal cancer cell lines and human specimens compared to non-malignant controls. RAB14 mRNA stability and protein expression were decreased following miR-214-3p overexpression. Binding between miR-214-3p and RAB14 mRNA was observed. Either forced expression of miR-214-3p or RAB14 silencing led to a marked decrease in cellular migration and invasion. Esophageal cancer cells stably expressing miR-214-3p demonstrated decreased growth in a subcutaneous murine model.

CONCLUSIONS

These results further support the tumor-suppressive role of miR-214-3p in esophageal cancer cells by demonstrating its ability to regulate RAB14 expression.

miR-134 Inhibits Cervical Cancer Cell Invasion via Targeting Cortactin

Cervical cancer is a common malignancy, and miR-134 involves in multiple tumors. The present study aims to explore its expression and role in cervical cancer. miR-134 level in cervical cancer and para-carcinoma tissues was detected by RT-PCR. Cells were transfected with miR-134 mimics or inhibitor followed by measuring cell behaviors. The results of bioinformatics analysis showed that miR-134 targeted the downstream CTTN. miR-134 inhibited the biological behaviors of cervical cancer cells through suppressing the downstream cell division cycle 42 (Cdc42)/neural Wiskott-Aldrich syndrome protein (N-WASP) signals. Moreover, miR-134, through regulating CTTN, negatively regulated invasion and inhibited the degradation of extracellular matrix in cervical cancer cells. In conclusion, miR-134 targets CTTN to inhibit the invasion of cervical cancer, thereby inhibiting metastasis.

Bioinformatics analysis of miRNAs in the neuroblastoma 11q-deleted region reveals a role of miR-548l in both 11q-deleted and MYCN amplified tumour cells

Neuroblastoma is a childhood tumour that is responsible for approximately 15% of all childhood cancer deaths. Neuroblastoma tumours with amplification of the oncogene MYCN are aggressive, however, another aggressive subgroup without MYCN amplification also exists; rather, they have a deleted region at chromosome arm 11q. Twenty-six miRNAs are located within the breakpoint region of chromosome 11q and have been checked for a possible involvement in development of neuroblastoma due to the genomic alteration. Target genes of these miRNAs are involved in pathways associated with cancer, including proliferation, apoptosis and DNA repair. We could show that miR-548l found within the 11q region is downregulated in neuroblastoma cell lines with 11q deletion or MYCN amplification. In addition, we showed that the restoration of miR-548l level in a neuroblastoma cell line led to a decreased proliferation of these cells as well as a decrease in the percentage of cells in the S phase. We also found that miR-548l overexpression suppressed cell viability and promoted apoptosis, while miR-548l knockdown promoted cell viability and inhibited apoptosis in neuroblastoma cells. Our results indicate that 11q-deleted neuroblastoma and MYCN amplified neuroblastoma coalesce by downregulating miR-548l.

The clinical utility of dysregulated microRNA expression in paediatric solid tumours

MicroRNAs (miRNAs) are short, non-protein-coding genes that regulate the expression of numerous protein-coding genes. Their expression is dysregulated in cancer, where they may function as oncogenes or tumour suppressor genes. As miRNAs are highly resistant to degradation, they are ideal biomarker candidates to improve the diagnosis and clinical management of cancer, including prognostication. Furthermore, miRNAs dysregulated in malignancy represent potential therapeutic targets. The use of miRNAs for these purposes is a particularly attractive option to explore for paediatric malignancies, where the mutational burden is typically low, in contrast to cancers affecting adult patients. As childhood cancers are rare, it has taken time to accumulate the necessary body of evidence showing the potential for miRNAs to improve clinical management across this group of tumours. Here, we review the current literature regarding the potential clinical utility of miRNAs in paediatric solid tumours, which is now both timely and justified. Exploring such avenues is warranted to improve the management and outcomes of children affected by cancer.

Prognostic value of micro-RNA 375, 133, 143, 145 in esophageal carcinoma: A systematic review and meta-analysis

Many studies have confirmed that micro-RNA (mir) is related to the prognosis of esophageal carcinoma (EC), suggesting the mir could be used to guide the therapeutic strategy of EC. Some of mir molecules are considered as favorable prognostic factors for EC. The purpose of our study is to evaluate the prognostic potential of mir-375, 133, 143, 145 in primary EC, we summarized all the results from available studies, aiming delineating the prognostic role of mir in EC. Relevant studies were identified by searching databases including Medline, Embase, Web of science, Cochrane Library. The studies which explored the prognostic value of mir-375, 133, 143, 145 expressions on survival outcomes in patients with EC were included in this study. The hazard ratios (HR) and their responding 95% confidence interval (CI) were also extracted. A total of 25 studies were collected, including 1260 patients, and the prognostic values of four mirs in EC were analyzed. Survival outcomes including overall survival (OS), progression-free survival (PFS) and disease-free survival (DFS) were used as the primary endpoint to evaluate the prognostic value of mir. The pooled analysis results showed that up-regulation of mir-375 indicated favorable OS (HR=0.50; 95%CI: 0.37-0.69; P<0.001). In addition, the up-regulation of mir-133 (HR=0.40, 95%CI: 0.24-0.65, P<0.001), 143 (HR=0.40, 95%CI: 0.21-0.76, P < 0.001) and 145 (HR=0.55, 95%CI: 0.34-0.90, P<0.001) are also proved as protected factors in EC. Therefore, our study demonstrated that these mirs may have the potential to be used as prognostic biomarkers for EC in clinical practice.

Identification and characterization of novel CD274 (PD-L1) regulating microRNAs and their functional relevance in melanoma

BACKGROUND

Immune checkpoint inhibitors directed against programmed cell death 1 (PDCD1/PD1) receptor and programmed cell death-ligand 1 (CD274/PD-L1) have been recently successfully implemented for the treatment of many cancers, but the response rate of tumour patients is still limited due to intrinsic and acquired resistances. However, the underlying molecular mechanisms of this limited response have still to be defined in detail. The aim of this study is to uncover processes inhibiting PDCD1/CD274 expression thereby enhancing anti-tumour immune responses. The identification and characterization of microRNAs (miRNAs) targeting the 3'-untranslated region (3'-UTR) as well as the coding sequence (CDS) of CD274 will provide the basis for a new drug development.

METHODS

Human melanoma cell lines and tissue samples were subjected to mRNA and/or protein expression analysis using qPCR, Western blot, flow cytometry, and/or immunohistochemistry. The data were correlated to clinical parameters. MiRNA trapping by RNA in vitro affinity purification (miTRAP) technology in combination with small RNA sequencing and different bioinformatics tools were employed to identify CD274-regulating miRNAs.

RESULTS

Screening based on miTRAP in combination with RNAseq identified a large number of novel CD274-regulating candidate miRNAs, from which eight selected miRNAs were functionally validated. Five out of eight miRNAs were able to significantly reduce CD274 surface expression indicating that these miRNAs directly bind to the 3'-UTR or CDS of the CD274 gene. The miRNA-mediated inhibition of CD274 expression was accompanied by an increased T cell recognition. Furthermore, an inverse expression of three CD274-regulating miRNAs and CD274 was demonstrated in melanoma lesions. A CD274 miRNA score was generated, which was associated with disease progression and reduced survival of melanoma patients.

CONCLUSIONS

These data revealed a novel mechanism that miRNAs targeting the CDS of immune checkpoint genes are functional, have prognostic relevance, and also the potential for the development of novel miRNA-based therapies.

Reduced miR-371b-5p expression drives tumor progression via CSDE1/RAC1 regulation in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer; however, specific prognostic biomarkers have not yet been developed. In this study, we identified dysregulated microRNAs (miRNAs) in TNBC by profiling miRNA and mRNA expression. In patients with TNBC, miR-371b-5p expression was reduced, and miR-371b-5p overexpression significantly mitigated TNBC cell growth, migration, and invasion. In addition, we found that expression of cold shock domain-containing protein E1 (CSDE1), a direct target gene of miR-371b-5p, was upregulated in TNBC cells, and inhibition of CSDE1 expression alleviated TNBC cell growth by regulating RAC1 transcription. Mechanistically, CSDE1, phosphorylated C-terminal domain (p-CTD) of RNA polymerase II (RNAPII), and CDK7 form a complex, and downregulation of CSDE1 leads to weak interaction between RNAPII p-CTD and CDK7, resulting in a decrease in RNAPII p-CTD expression to reduce RAC1 transcript levels in CSDE1-deficient TNBC cells. Our data demonstrate that miR-371b-5p is a tumor-suppressive miRNA that regulates the CSDE1/Rac1 axis and could be a potential prognostic biomarker for TNBC.

Novel insights into the mechanisms by which lncRNA HOTAIR regulates migration and invasion in HeLa cells

HOTAIR, as one of the few well-studied oncogenic lncRNAs, is involved in human tumorigenesis and is dys-regulated in most human cancers. The transcription co-activator factor YAP1 is broadly expressed in many tissues, and promotes cancer metastasis and progression. However, the precise biological roles of HOTAIR and YAP1 in cancer cells remain unclear. In this study, we showed that HOTAIR regulates H3K27 histone modification in the promoter of miR-200a to mediate miR-200a expression by recruiting EZH2. YAP1, as a potential target gene of miR-200a, aggravated the effects of miR-200a on the migration and invasion of HeLa cells. YAP1 activated the transcription of RPL23, which is a novel downstream transcriptional-regulator of YAP1. Agreement with this, the expression of YAP1 and RPL23 was dramatically decreased after injecting HeLa cells transfected with siHOTAIR in a xenograft mouse model. Accordingly, we propose a novel model of the molecular mechanism by which HOTAIR promotes the migration and invasion of cancer cells involving the miR-200a-3p/YAP1/RPL23 axis.

Network Approaches to Study Endogenous RNA Competition and Its Impact on Tissue-Specific microRNA Functions

microRNAs are small non-coding RNAs that play a key role in regulating gene expression. These molecules exert their function through sequence complementarity with microRNA responsive elements and are typically located in the 3' untranslated region of mRNAs, negatively regulating expression. Even though the relevant role of miRNA-dependent regulation is broadly recognized, the principles governing their ability to lead to specific functional outcomes in distinct cell types are still not well understood. In recent years, an intriguing hypothesis proposed that miRNA-responsive elements act as communication links between different RNA species, making the investigation of microRNA function even more complex than previously thought. The competing endogenous RNA hypothesis suggests the presence of a new level of regulation, whereby a specific RNA transcript can indirectly influence the abundance of other transcripts by limiting the availability of a common miRNA, acting as a "molecular sponge". Since this idea has been proposed, several studies have tried to pinpoint the interaction networks that have been established between different RNA species and whether they contribute to normal cell function and disease. The focus of this review is to highlight recent developments and achievements made towards the process of characterizing competing endogenous RNA networks and their role in cellular function.

Development and validation of a circulating microRNA panel for the early detection of breast cancer

BACKGROUND

Mammography is widely used for breast cancer screening but suffers from a high false-positive rate. Here, we perform the largest comprehensive, multi-center study to date involving diverse ethnic groups, for the identification of circulating miRNAs for breast cancer screening.

METHODS

This study had a discovery phase (n = 289) and two validation phases (n = 374 and n = 379). Quantitative PCR profiling of 324 miRNAs was performed on serum samples from breast cancer (all stages) and healthy subjects to identify miRNA biomarkers. Two-fold cross-validation was used for building and optimising breast cancer-associated miRNA panels. An optimal panel was validated in cohorts with Caucasian and Asian samples. Diagnostic ability was evaluated using area under the curve (AUC) analysis.

RESULTS

The study identified and validated 30 miRNAs dysregulated in breast cancer. An optimised eight-miRNA panel showed consistent performance in all cohorts and was successfully validated with AUC, accuracy, sensitivity, and specificity of 0.915, 82.3%, 72.2% and 91.5%, respectively. The prediction model detected breast cancer in both Caucasian and Asian populations with AUCs ranging from 0.880 to 0.973, including pre-malignant lesions (stage 0; AUC of 0.831) and early-stage (stages I-II) cancers (AUC of 0.916).

CONCLUSIONS

Our panel can potentially be used for breast cancer screening, in conjunction with mammography.

The High Ratio of the Plasma miR-96/miR-99b Correlated With Poor Prognosis in Patients With Metastatic Colorectal Cancer

Object: This study aims to clarify the expression of plasma miRNA in CRC patients, and to clarify the potential use of these miRNAs in diagnosis and prognosis, and to establish a prognostic model to initially explore its clinical value.

Methods: We detected the expression of 6 miRNAs in normal colon epithelial cell lines and colorectal cancer cell lines by qRT-PCR and they were validated in the tissues of three subtypes: 20 healthy subjects, 41 pCRC and 49 mCRC patients. COX regression and ROC analyses use to evaluate the diagnostic and prognostic efficacy of candidate miRNAs. Subsequently, we initially established a nomogram prognostic model. MiRNA is also used to construct miRNA-mRNA interaction network and PPI network modules.

Results: Five miRNAs showed significant differential expression in pCRC, mCRC patients and normal groups. ROC analysis showed that CEA, miR-96, miR-99b and miR-96/miR-99b are distinguishable from pCRC and mCRC patients, with AUC ranging from 0.65 to 0.91; among them, the ratio of miR-96/miR-99b is stronger than any diagnostic indicators, such as CEA and CA125. Multivariate survival analysis identified miR-96, miR-99b, N stage, M stage and clinical stage as independent prognostic indicators of mCRC. The nomogram based on these 5 characteristics has satisfactory prognostic values.

Conclusion: Our data indicate that plasma miR-96/miR-99b can be used as a promising biomarker for early detection of mCRC patients; our nomogram has a promising evaluation value.

MicroRNA expression signature and target prediction in familial and sporadic primary macronodular adrenal hyperplasia (PMAH)

BACKGROUND

Primary macronodular adrenal hyperplasia (PMAH), previously termed ACTH-independent macronodular adrenal hyperplasia (AIMAH), is a rare cause of Cushing's syndrome usually characterized by functioning adrenal macronodules and increased cortisol production.

METHODS

To screen and analyse the microRNA (miRNA) profile of PMAH in order to elucidate its possible pathogenesis, a miRNA microarray was used to test tissue samples from patients with familial PMAH, patients with sporadic PMAH and normal control samples of other nontumour adrenocortical tissues and identify characteristic microRNA expression signatures. Randomly selected miRNAs were validated by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, the key signalling pathways and miRNAs involved in PMAH pathogenesis were determined by gene ontology and pathway analysis.

RESULTS

Characteristic microRNA expression signatures were identified for patients with familial PMAH (16 differentially expressed microRNAs) and patients with sporadic PMAH (8 differentially expressed microRNAs). The expression of the selected miRNAs was confirmed by qRT-PCR, suggesting the high reliability of the miRNA array analysis results. Pathway analysis showed that the most enriched pathway was the renal cell carcinoma pathway. Overexpression of miR-17, miR-20a and miR-130b may inhibit glucocorticoid-induced apoptosis in PMAH pathogenesis.

CONCLUSION

We identified the miRNA signatures in patients with familial and sporadic PMAH. The differentially expressed miRNAs may be involved in the mechanisms of PMAH pathogenesis. Specific miRNAs, such as miR-17, miR-20a and miR-130b, may be new targets for further functional studies of PMAH.

Reiterating the Emergence of Noncoding RNAs as Regulators of the Critical Hallmarks of Gall Bladder Cancer

Gall bladder cancer (GBC) is a rare and one of the most aggressive types of malignancies, often associated with a poor prognosis and survival. It is a highly metastatic cancer and is often not diagnosed at the initial stages, which contributes to a poor survival rate of patients. The poor diagnosis and chemoresistance associated with the disease limit the scope of the currently available surgical and nonsurgical treatment modalities. Thus, there is a need to explore novel therapeutic targets and biomarkers that will help relieve the severity of the disease and lead to advanced therapeutic strategies. Accumulating evidence has correlated the atypical expression of various noncoding RNAs (ncRNAs), including circular RNAs (circRNAs), long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and small nucleolar RNAs (snoRNA) with the increased cell proliferation, epithelial-mesenchymal transition (EMT), invasion, migration, metastasis, chemoresistance, and decreased apoptosis in GBC. Numerous reports have indicated that the dysregulated expression of ncRNAs is associated with poor prognosis and lower disease-free and overall survival in GBC patients. These reports suggest that ncRNAs might be considered novel diagnostic and prognostic markers for the management of GBC. The present review recapitulates the association of various ncRNAs in the initiation and progression of GBC and the development of novel therapeutic strategies by exploring their functional and regulatory role.

Modular network inference between miRNA-mRNA expression profiles using weighted co-expression network analysis

Connecting transcriptional and post-transcriptional regulatory networks solves an important puzzle in the elucidation of gene regulatory mechanisms. To decipher the complexity of these connections, we build co-expression network modules for mRNA as well as miRNA expression profiles of breast cancer data. We construct gene and miRNA co-expression modules using the weighted gene co-expression network analysis (WGCNA) method and establish the significance of these modules (Genes/miRNAs) for cancer phenotype. This work also infers an interaction network between the genes of the turquoise module from mRNA expression data and hubs of the turquoise module from miRNA expression data. A pathway enrichment analysis using a miRsystem web tool for miRNA hubs and some of their targets, reveal their enrichment in several important pathways associated with the progression of cancer.

Diagnosis of pulmonary nodules by DNA methylation analysis in bronchoalveolar lavage fluids

BACKGROUND

Lung cancer is the leading cause of cancer-related mortality. The alteration of DNA methylation plays a major role in the development of lung cancer. Methylation biomarkers become a possible method for lung cancer diagnosis.

RESULTS

We identified eleven lung cancer-specific methylation markers (CDO1, GSHR, HOXA11, HOXB4-1, HOXB4-2, HOXB4-3, HOXB4-4, LHX9, MIR196A1, PTGER4-1, and PTGER4-2), which could differentiate benign and malignant pulmonary nodules. The methylation levels of these markers are significantly higher in malignant tissues. In bronchoalveolar lavage fluid (BALF) samples, the methylation signals maintain the same differential trend as in tissues. An optimal 5-marker model for pulmonary nodule diagnosis (malignant vs. benign) was developed from all possible combinations of the eleven markers. In the test set (57 tissue and 71 BALF samples), the area under curve (AUC) value achieves 0.93, and the overall sensitivity is 82% at the specificity of 91%. In an independent validation set (111 BALF samples), the AUC is 0.82 with a specificity of 82% and a sensitivity of 70%.

CONCLUSIONS

This model can differentiate pulmonary adenocarcinoma and squamous carcinoma from benign diseases, especially for infection, inflammation, and tuberculosis. The model's performance is not affected by gender, age, smoking history, or the solid components of nodules.

Tumor-Associated Macrophages as Multifaceted Regulators of Breast Tumor Growth

Breast cancer is the most commonly occurring cancer in women of Western countries and is the leading cause of cancer-related mortality. The breast tumor microenvironment contains immune cells, fibroblasts, adipocytes, mesenchymal stem cells, and extracellular matrix. Among these cells, macrophages or tumor-associated macrophages (TAMs) are the major components of the breast cancer microenvironment. TAMs facilitate metastasis of the breast tumor and are responsible for poor clinical outcomes. High TAM density was also found liable for the poor prognosis of breast cancer. These observations make altering TAM function a potential therapeutic target to treat breast cancer. The present review summarizes the origin of TAMs, mechanisms of macrophage recruitment and polarization in the tumor, and the contributions of TAMs in tumor progression. We have also discussed our current knowledge about TAM-targeted therapies and the roles of miRNAs and exosomes in re-educating TAM function.

Potential value of MicroRNA-21 as a biomarker for predicting the prognosis of patients with breast cancer: A protocol for meta-analysis and bioinformatics analysis

BACKGROUND

The latest global cancer data from 2020 shows that breast cancer has replaced lung cancer as the number one cancer in the world. Searching for new biomarkers of breast cancer has important clinical significance for early diagnosis, prediction of prognosis, and targeted therapy. MicroRNA-21 (miRNA-21) can be used as a new molecular marker for early diagnosis, prognosis, and treatment of tumors. However, the expression of miRNA-21 in breast cancer and its prognosis are not clear. Therefore, this study conducted a meta-analysis to further clarify the relationship between the expression of miRNA-21 in breast cancer and prognosis. At the same time, we carried out bioinformatics analysis to further analyze the possible molecular mechanism of miRNA-21, so as to provide potential clinical indicators for the diagnosis, treatment, and prognosis of patients.

METHODS

PubMed, Medline, Embase, Web of Science, Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, and other databases were used to retrieve the published relevant literatures. Include the eligible research, extract the survival data hazard ratios and 95% confidence intervals and other information. STATA16.0 software was used for meta-analysis. Download the miRNA data of breast cancer through the Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database. The data extracted for independent sample t test and ROC curve was drawn. OncomiR plotted the survival curve of miRNA-21 on the prognosis of breast cancer. The target genes of miRNA-21 were predicted, and the Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were analyzed. STRING database and Cytoscape construct protein-protein interaction (PPI) network to obtain Hub gene. The correlation between the expression level of Hub gene in breast cancer and the abundance of immune cell infiltration was analyzed by TIMER database and verified by Kaplan-Meien plotter database.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

In this study, meta-analysis and bioinformatics analysis were used to further explore the prognosis, mechanism, and related pathways of miRNA-21 in breast cancer.

ETHICS AND DISSEMINATION

The private information from individuals will not be published. This systematic review also should not damage participants' rights. Ethical approval is not available. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/R32A9.

MicroRNAs: immune modulators in cancer immunotherapy

MicroRNA (miRNA) is a class of endogenous small non-coding RNA of 18–25 nucleotides and plays regulatory roles in both physiological and pathological processes. Emerging evidence support that miRNAs function as immune modulators in tumors. MiRNAs as tumor suppressors or oncogenes are also found to be able to modulate anti-tumor immunity or link the crosstalk between tumor cells and immune cells surrounding. Based on the specific regulating function, miRNAs can be used as predictive, prognostic biomarkers, and therapeutic targets in immunotherapy. Here, we review new findings about the role of miRNAs in modulating immune responses, as well as discuss mechanisms underlying their dysregulation, and their clinical potentials as indicators of tumor prognosis or to sensitize cancer immunotherapy.

Tumor-Derived Exosomes Enriched by miRNA-124 Promote Anti-tumor Immune Response in CT-26 Tumor-Bearing Mice

Exosomes have been introduced as a new alternative delivery system for the transmission of small molecules. Tumor-derived exosomes (TEXs) not only contain tumor-associated antigens to stimulate antitumor immune responses but also act as natural carriers of microRNAs. The aim of the current study was to evaluate the efficacy of miR-124-3p-enriched TEX (TEXomiR) as cell-free vaccine in the induction of antitumor immune responses in a mouse model of colorectal cancer. Briefly, the exosomes were isolated from cultured CT-26 cell line, and modified calcium chloride method was used to deliver miR-124-3p mimic into the exosomes. We used a CT-26-induced BALB/c mouse model of colorectal cancer and analyzed the effect of TEXomiR on survival, tumor size, spleen and tumor-infiltrated lymphocytes, and splenocyte proliferation. Furthermore, intra-tumor regulatory T cells, cytotoxic activity of the splenocytes, and cytokine secretion was also evaluated to describe the anti-tumor immune response. When the tumor size reached 100 mm³, the mice were injected with TEXomiR, TEX, and/or phosphate-buffered saline (PBS) subcutaneously three times with 3-day interval, and then tumor size was monitored every 2 days. The in vitro results indicated that TEXs could efficiently deliver functional miR-124-3p mimic. The in vivo evaluation in tumor-bearing mice showed that treatment with TEXomiR can elicit a stronger anti-tumor immune response than unloaded TEX and PBS. Significant tumor growth inhibition and increased median survival time was achieved in tumor-bearing mice treated with TEXomiR. A significant decrease in CD4/CD8 and Treg/CD8 ratio in tumor tissue was demonstrated. Moreover, increased cytotoxicity and proliferation of splenocytes in the TEXomiR group compared to the TEX and PBS groups were identified. Taken together, our data demonstrated that tumor-derived exosomes efficiently deliver miR-124-3p mimic, and TEXomiR promotes anti-tumor immune responses.

The emerging function and clinical significance of circRNAs in Thyroid Cancer and Autoimmune Thyroid Diseases

Thyroid cancer (TC) is one of the most common malignant tumors, with high morbidity and mortality rates worldwide. The incidence of TC, especially that of papillary thyroid carcinoma (PTC); has increased rapidly in recent decades. Autoimmune thyroid disease (AITD) is closely related to TC and has an estimated prevalence of 5%. Thus, it is becoming increasingly important to identify potential diagnostic biomarkers and therapeutic targets for TC and AITD. Circular RNAs (circRNAs) are a class of non-coding RNAs with covalently bonded circular structures that lack 5'-3' polarity and polyadenylated tails. Several circRNAs play crucial roles in the development of various diseases, including TC and AITD, and could be important new biomarkers and/or targets for the diagnosis and therapy of such disorders. Although there are four subtypes of TC, research on circRNA has largely focused on its connection to PTC. Therefore, this review mainly summarizes the relationships between circRNAs and PTC and AITD, including the molecular mechanisms underlying these relationships. In particular, the functions of “miRNA sponges” and their interactions with proteins and RNA are discussed. The possible targeting of circRNAs for the prevention, diagnosis, and treatment of TC and AITD is also described. CircRNAs could be potential biomarkers of TC and AITD, although validation will be required before they can be implemented in clinical practice.

Vitamin D and Non-coding RNAs: New Insights into the Regulation of Breast Cancer

Breast cancer, a life-threatening serious disease with a high incident rate among women, is responsible for thousands of cancer-associated death worldwide. Numerous investigations have evaluated the possible mechanisms related to this malignancy. Among them, non-coding RNAs (ncRNAs), i.e., microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs have recently attracted attention of researchers. In addition to recent studies for evaluating the role of ncRNAs in breast cancer etiology, some investigations have revealed that vitamin D has regulatory and therapeutic roles in breast cancer. Moreover, an important link between vitamin D and ncRNAs in cancer therapy has been highlighted. Herein, the aim of this study was to discuss the available data on the mentioned link in breast cancer.

Micro-RNA: The darkhorse of cancer

The discovery of micro RNAs (miRNA) in cancer has opened up new vistas for researchers in recent years. Micro RNAs area set of small, endogenous, highly conserved, non-coding RNAs that control the expression of about 30% genes at post-transcriptional levels. Typically, microRNAs impede the translation and stability of messenger RNAs (mRNA), control genes associated with cellular processes namely inflammation, cell cycle regulation, stress response, differentiation, apoptosis, and migration. Compelling findings revealed that miRNA mutations or disruption correspond to diverse human cancers and suggest that miRNAs can function as tumor suppressors or oncogenes. Here we summarize the literature on these master regulators in clinical settings from last three decades as both abrupt cancer therapeutics and as an approach to sensitize tumors to chemotherapy. This review highlights (I) the prevailing perception of miRNA genomics, biogenesis, as well as function; (II) the significant advancements in regulatory mechanisms in the expression of carcinogenic genes; and (III) explains, how miRNA is utilized as a diagnostic and prognostic biomarker for the disease stage indicating survival as well as therapeutic targets in cancer.

Nanoporous Anodic Alumina-Based Sensor for miR-99a-5p Detection as an Effective Early Breast Cancer Diagnostic Tool

Circulating microRNAs have emerged as potential diagnostic biomarkers. The deregulation of the microRNA miR-99a-5p has been previously described as an effective biomarker of early breast cancer. Herein, we present a new nanoporous anodic alumina (NAA)-based biosensor that can detect plasma miR-99a-5p with high sensitivity and selectivity. NAA pores are loaded with rhodamine B and capped with a specific oligonucleotide that is able to block cargo release until the target is present. In the presence of miR-99a-5p, the capping oligonucleotide recognizes the miR-99a-5p sequence and displaces it allowing the release of the encapsulated dye. This method is able to successfully distinguish healthy controls from breast cancer patients, even at early stages with high efficiency, showing the presented system as a promising tool for breast cancer detection.

FGF16 regulated by miR-520b enhances the cell proliferation of lung cancer

FGF16 is implicated in the progression of some specific types of cancers, such as embryonic carcinoma, ovarian cancer, and liver cancer. Yet, the function of FGF16 in the development of lung cancer remains largely unexplored. In this study, we present the novel function of FGF16 and the regulation of miR-520b on FGF16 in lung cancer progression. In clinical lung cancer tissues, FGF16 is overexpressed and its high level is negatively associated with the low level of miR-520b. Furthermore, both the transcription and translation levels of FGF16 are restrained by miR-520b in lung cancer cells. For the regulatory mechanism investigation, miR-520b is able to directly bind to the 3′-untranslated region (3′UTR) of FGF16 mRNA, leading to its mRNA cleavage in the cells. Functionally, miR-520b reduces the growth of lung cancer and its inhibitor anti-miR520b is able to promote the growth through competing endogenous miR-520b. Moreover, FGF16 silence using RNA interference is capable of doing great damage to anti-miR-520b-accelerated growth of lung cancer. Thus, our finding indicates that FGF16 is a new target gene of miR-520b in lung cancer. For lung cancer, FGF16 may serve as a novel biomarker and miR-520b/FGF16 may be useful in clinical treatment.

Kaposi's Sarcoma-associated Herpesvirus microRNA mutants modulate cancer hallmark phenotypic differences in human endothelial cells

Kaposi's sarcoma (KS) results from the transformation of Kaposi's sarcoma-associated herpesvirus (KSHV)-infected endothelial cells. The contribution of the KSHV microRNAs (miRNAs) to the process of oncogenesis in endothelial cells has not been fully elucidated. To better understand the contributions of individual miRNAs to oncogenesis-related cellular phenotypes, we used KSHV miRNA knockout mutants, each one lacking one of the twelve miRNA genes. An additional mutant lacked all miRNAs. Since KSHV infection causes a variety of phenotypic changes in endothelial cells, we tested the mutants for their ability to effect such changes in Telomerase-Immortalized Vein Endothelial (TIVE) cells infected with each of the mutant viruses. Wild type- and mutant-infected as well as uninfected cells were evaluated for perturbations to proliferation, migration, tubule formation, and glycolysis. We found broad variation between the different viruses in these aspects. With respect to proliferation rate, ΔmiR-K12-3, ΔmiR-K12-8, and ΔmiR-K12-11 showed significant impairment. Cells infected with ΔmiR-K12-11 had reduced migration. In tubule formation, the ΔmiR-K12-5, -6, and -7 viruses were deficient. At the same time, cells infected with the ΔmiR-K12-10 virus showed dysregulated glycolysis. By combining these observations with previously published KSHV miRNA targetome lists from ribonomics data, we were able to functionally validate a number of new miRNA targets in specific pathways. As proof of concept, miR-K12-3 was shown to target Cathepsin D, a strong promoter of apoptosis. Taken together, the results demonstrate that KSHV miRNAs play different roles in inducing the phenotypic changes which are characteristic of transformed cells.Importance: Kaposi's sarcoma-associated herpesvirus (KSHV) causes Kaposi's sarcoma (KS). The contribution of KSHV microRNAs (miRNAs) to oncogenesis is not fully understood. This is particularly true for human endothelial cells, the cell type from which KS tumors are derived. Here we used a panel of KSHV miRNA knockout viruses in order to shed light on the roles of individual miRNAs in the process of transformation. Latently infected endothelial cells were studied for phenotypic changes related to cancer, including proliferation, migration, angiogenesis, glycolysis, and apoptosis. The mutant-infected cell lines displayed a wide range of phenotypes in these selected measures of oncogenesis which differed from wild type-infected cells and from each other. These results indicate that KSHV miRNAs contribute to different aspects of oncogenesis, and that each one has a unique role to play.

To study the role of pre-treatment microRNA (micro ribonucleic acid) expression as a predictor of response to chemoradiation in locally advanced carcinoma cervix

Background

Concurrent chemoradiotherapy followed by brachytherapy is the standard of care in locally advanced carcinoma cervix. There is no prognostic factor at present to predict the outcome of disease in locally advanced carcinoma cervix.

Aim

Differential expression of microRNAs can be used as biomarkers to predict clinical response in locally advanced carcinoma cervix patients.

Methods

Thirty‐two patients of locally advanced carcinoma cervix with International Federation of Gynecology and Obstetrics Stage IB‐IVA were enrolled from 2017 to 2018. Expression of microRNA‐9 5p, ‐31 3p, ‐100 5p, ‐125a 5p, ‐125b‐5p, and –200a 5p in formalin‐fixed paraffin embedded (FFPE) biopsied tissue were analyzed by real time quantitative reverse transcriptase polymerase chain reaction (RT qPCR). Pretreatment evaluation was done with clinical examination and MRI pelvis. All patients received concurrent chemoradiotherapy followed by brachytherapy. Patients were evaluated for the clinical response after 3 months of treatment, with clinical examination and MRI pelvis scan using RECIST 1.1 criteria. Patients with no residual disease were classified as Complete responders (CR) and with residual or progressive disease were classified as Nonresponders (NR). Results were statistically analyzed using Mann Whiney U test to examine significant difference between the expression of microRNA between complete responders (CR) and nonresponders (NR).

Results

microRNA‐100 5p was upregulated in complete responders (CR) which showed a trend towards statistical significance (p value = 0.05).

Conclusion

microRNA‐100 5p can serve as a potential molecular biomarker in predicting clinical response to chemoradiation in locally advanced Carcinoma cervix. Its role should be further investigated in a larger study population.

Flavonoid display ability to target microRNAs in cancer pathogenesis

MicroRNAs (miRNAs) are non-coding, conserved, single-stranded nucleotide sequences involved in physiological and developmental processes. Recent evidence suggests an association between miRNAs' deregulation with initiation, promotion, progression, and drug resistance in cancer cells. Besides, miRNAs are known to regulate the epithelial-mesenchymal transition, angiogenesis, autophagy, and senescence in different cancer types. Previous reports proposed that apart from the antioxidant potential, flavonoids play an essential role in miRNAs modulation associated with changes in cancer-related proteins, tumor suppressor genes, and oncogenes. Thus, flavonoids can suppress proliferation, help in the development of drug sensitivity, suppress metastasis and angiogenesis by modulating miRNAs expression. In the present review, we summarize the role of miRNAs in cancer, drug resistance, and the chemopreventive potential of flavonoids mediated by miRNAs. The potential of flavonoids to modulate miRNAs expression in different cancer types demonstrate their selectivity and importance as regulators of carcinogenesis. Flavonoids as chemopreventive agents targeting miRNAs are extensively studied in vitro, in vivo, and pre-clinical studies, but their efficiency in targeting miRNAs in clinical studies is less investigated. The evidence presented in this review highlights the potential of flavonoids in cancer prevention/treatment by regulating miRNAs, although further investigations are required to validate and establish their clinical usefulness.

microRNA-27b inhibits cell proliferation and invasion in bladder cancer by targeting engrailed-2

Background: Bladder cancer is considered a malignant tumour characterised by great heterogeneity. Engrailed-2 may be a gene implicated in bladder cancer. Bioinformatics analysis found base pair complementation between microRNA-27b and engrailed-2. The present study aimed to investigate the reciprocal association between microRNA-27b and engrailed-2 in bladder cancer.

Methods: The microRNA-27b and the protein of engrailed-2 in the tissues and cells of the bladder were detected. The processes of apoptosis, proliferation, invasion, and migration of tumour cells were evaluated. The co-action between microRNA-27b and engrailed-2 was detected by a luciferase reporter system. Finally, the interaction between microRNA-27b and engrailed-2 was further verified in vivo.

Results: The study found that the expression level of microRNA-27b is lower in bladder cancer tissues and cells than that in neighbouring ordinary tissues, whereas the opposite outcome was observed regarding the expression level of engrailed-2. Furthermore, microRNA-27b expression level is not significantly linked to the age of patients with bladder cancer; however, it is significantly associated with the clinicopathological grade of bladder cancer. Notably, engrailed-2 is negatively regulated by microRNA-27b. Transfection with microRNA-27b was associated with a significant reduction in the activity of bladder cancer cells and promoted apoptosis, while engrailed-2 restoration effectively reversed the above effects of microRNA-27b on bladder cancer in vitro and in vivo.

Conclusions: In conclusion, engrailed-2 is engaged in the development and process of bladder cancer through the negative mediation of microRNA-27b; additionally, microRNA-27b/engrailed-2 could form a signalling pathway with a significant effect on the process of bladder cancer.

Downregulation of MST4 Underlies a Novel Inhibitory Role of MicroRNA Let-7a in the Progression of Retinoblastoma

Purpose

Retinoblastoma (RB) is the most common intraocular malignancy in children. Deregulation of several microRNAs (miRNAs) has been identified in RB. However, the specific effect of let-7a on RB remains unclear. The present study aims to explore the effect of let-7a on malignant biological behaviors of RB cells and angiogenesis in RB.

Methods

The expressions of let-7a and mammalian sterile-20 like kinase 4 (MST4) in RB were determined with the use of real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. Next, in order to explore effects of let-7a and MST4 on RB cellular functions, RB cells were transfected with let-7a-mimic, let-7a inhibitor, si-MST4, or co-transfected with let-7a-mimic and oe-MST4 plasmids. Subsequently, the interaction among let-7a, MST4, and the MAPK signaling pathway was evaluated by RT-qPCR, dual-luciferase reporter gene assay, and Western blot analysis. Finally, the effects of let-7a and MST4 were further confirmed in vivo by injecting nude mice with RB cells stably expressing let-7a agomir or sh-MST4.

Results

Rb tissues and cells presented with downregulated Let-7a and upregulated MST4. Let-7a negatively targeted MST4 to block the activation of the MAPK signaling pathway. Upregulation of let-7a promoted apoptosis, and facilitated proliferation, angiogenesis, migration, and invasion of RB cells by decreasing MST4. Elevation of let-7a or silencing MST4 restricted angiogenesis and tumorigenesis in RB mice.

Conclusions

Taken together, let-7a inhibits angiogenesis in RB by silencing MST4 and inhibiting the MAPK signaling pathway.

Hyaluronic acid engrafted metformin loaded graphene oxide nanoparticle as CD44 targeted anti-cancer therapy for triple negative breast cancer

BACKGROUND

Triple negative breast cancer (TNBC) is the most aggressive form of breast cancer with limited treatment modalities. It is associated with high propensity of cancer recurrence.

METHODS

UV Spectroscopy, FTIR, DLS, Zeta potential, TEM and SEM were employed to characterize nanoparticles. MTT assay, Wound healing assay, SEM, Immunocytochemistry analysis, Western blot, RT-PCR, mammosphere formation assay were employed to study apoptosis, cell migration and stemness. Tumor regression was studied in chick embryo xenograft and BALB/c mice model.

RESULTS

Hylaluronic acid engrafted metformin loaded graphene oxide (HA-GO-Met) nanoparticles exhibited an anti-cancer efficacy at much lower dosage as compared to metformin alone. HA-GO-Met nanoparticles induced apoptosis and inhibited cell migration of TNBC cells by targeting miR-10b/PTEN axis via NFkB-p65. Upregulation of PTEN affected pAKT(473) expression that induced apoptosis. Cell migration was inhibited by reduction of pFAK/integrinβ1 expressions. Treatment inhibited epithelial mesenchymal transition (EMT) and reduced stemness as evident from the increase in E-cadherin expression, inhibition of mammosphere formation and low expression levels of stemness markers including nanog, oct4 and sox2 as compared to control. Moreover, tumor regression was studied in chick embryo xenograft and BALB/c mice model. HA-GO-Met nanoparticle treatment reduced tumor load and nullified toxicity in peripheral organs imparted by tumor.

CONCLUSIONS

HA-GO-Met nanoparticles exhibited an enormous anti-cancer efficacy in TNBC in vitro and in vivo.

GENERAL SIGNIFICANCE

HA-GO-Met nanoparticles induced apoptosis and attenuated cell migration in TNBC. It nullified overall toxicity imparted by tumor load. It inhibited EMT and reduced stemness and thereby addressed the issue of cancer recurrence.

Concomitant Up-Regulation of Hsa- Mir-374 and Down-Regulation of Its Targets, GSK-3β and APC, in Tissue Samples of Colorectal Cancer

BACKGROUND

The WNT-pathway is involved in several cancers, including colorectal cancer (CRC). Many cell signaling components and pathways are controlled by microRNAs. The main purpose of the present study was to investigate the expression of hsa-miR-374, and its two target genes of the Wnt-pathway in CRC clinical samples.

METHODS

In this study, we predicted the miRNAs targeting key genes of WNT-pathway using bioinformatics algorithms. The expression levels of hsa-miR-374, APC and GSK-3β on 48 pairs of Formalin-Fixed Paraffin-Embedded (FFPE) CRC tumors and marginal-tumors were evaluated using real time-PCR. Additionally, the hsa-miR-374a-5p precursor sequence was amplified by whole-blood DNA as a template. This amplicon was cloned into pEGFP-c1 expression vector and transfected into SW742 cells. Aside from this, MTT assay was performed to evaluate the effect of miR-374 on cell viability.

RESULTS

The bioinformatics analysis indicated that hsa-miR-374 binds to the regulatory region the key components of WNT-pathway, including APC and GSK-3β considering the recognition elements and mirSVR scores. Our results revealed significant down-regulation of GSK-3β (0.94 times, p= 0.0098) and APC (0.96 times, p= 0.03) and up-regulation of miR-374 (1.22 times, p= 0.0071) on tumor samples compared with their normal pairs. Meanwhile, the results of the over-expression of miR-374 showed down-regulation of APC and GSK-3β. MTT-assay also indicated that the miR-374 increased cell survival.

CONCLUSION

The results of our study indicated a concomitant change in the expression of miR-374 and its two related target genes, in clinical samples of CRC. Hsa-miR-374 might be as a helpful biomarker or therapeutic target in CRC.

Bioinformatics analysis of the microRNA-mRNA network in sebaceous gland carcinoma of the eyelid

Sebaceous gland carcinoma (SGC) of the eyelid is an uncommon aggressive tumor with a relatively high rate of local recurrence and a poor prognosis following metastasis. However, the molecular mechanisms underlying the pathogenesis of SGC remain unclear. The purpose of the present study was to clarify microRNA (miRNA) expression profiles in SGC and to explore novel miRNA-mRNA networks of SGC. A small RNA-sequencing analysis was performed to identify miRNAs differentially expressed between SGC and sebaceous adenoma control samples. Bioinformatics analyses were conducted to reveal biological functions, canonical pathways and molecular interaction networks using integrated miRNA-mRNA datasets, including mRNA expression profiles of SGC from our previous study. The present results demonstrated that 16 upregulated miRNAs and 516 downregulated mRNAs were associated with loss of lipid metabolism function and enriched in cholesterol biosynthesis pathways. By contrast, 29 downregulated miRNAs and 194 upregulated mRNAs were mainly associated with the promotion of cell survival and proliferation in addition to enrichment of DNA damage-induced cell cycle-regulation pathways. Furthermore, network analyses revealed that the upregulated miRNAs, miR-130a-3p and miR-939-5p, and the downregulated miRNAs, miR-146a-5p, miR-149-3p, miR-193a-3p, miR-195-5p and miR-4671-3p, could be upstream regulators related to these functional changes of SGC. These results improved the understanding of molecular mechanisms of SGC and may help to improve the diagnosis of SGC.

Expression of microRNA-181a and microRNA-196b in Egyptian Pediatric acute Lymphoblastic Leukemia

Background:

Differential expression of miRNA provides important insights into pathogenesis of cancer including leukemia. Deregulation of microRNA may contribute to hematopoietic malignancies. In this study, we aimed to evaluate the role of miR-181a and miR-196b in acute lymphoblastic leukemia (ALL) and correlate their expression with clinical and laboratory data.

Methods:

The study was performed on bone marrow samples of 70 consecutive newly diagnosed pediatric (ALL) patients, of which 56 were evaluated for both miR-181a and miR-196b (all 70 for miR-181a) by real-time quantitative reverse transcriptase polymerase chain reaction (RT-qPCR). In addition, bone marrow from seven age and sex matched healthy controls derived from donors of bone marrow transplantation were assessed.

Results:

miR-181a expression was significantly up-regulated in ALL patients compared with healthy controls (p<0.001). However, miR-196b expression was significantly down-regulated in patients compared with healthy controls (p=0.038).

Conclusion:

Our results suggest that miR-181a has an oncogenic, while miR-196b has a tumor suppressive role in pediatric ALL patients. A finding which demonstrate the potential role of these microRNAs in pathogenesis of pediatric ALL. Also, estimation of their expression level may provide a tool for confirmation of a diagnosis of childhood ALL and could be a possible predictor of early relapse.

A novel quantification platform for point-of-care testing of circulating MicroRNAs based on allosteric spherical nanoprobe

MiRNA-150, a gene regulator that has been revealed to be abnormal expression in non-small cell lung cancer (NSCLC), can be regarded as a serum indicator for diagnosis and monitoring of NSCLC. Herein, a new sort of nanoprobe, termed allosteric spherical nanoprobe, was first developed to sense miRNA-150. Compared with conventional hairpin, this new nanoprobe possesses more enrichment capacity and reaction cross section. Structurally, it consists of magnetic nanoparticles and dual-hairpin. In the absence of miRNA-150, the spherical nanoprobes form hairpin structure through DNA self-assembly, which could promote the Förster resonance energy transfer (FRET) of fluorophore (FAM) and quencher (BHQ1) nearby. However, in the presence of target, the target-probe hybridization can open the hairpin and form the active “Y” structure which separated fluorophore and quencher to yield “signal on” fluorescence. In the manner of multipoint fluorescence detection, the target-bound allosteric spherical nanoprobe could provide high detection sensitivity with a linear range of 100 fM to 10 nM and a detection limit of 38 fM. More importantly, the proposed method can distinguish the expression of serum miRNA-150 among NSCLC patients and healthy people. Finally, we hoped that the potential bioanalytical application of this nanoprobe strategy will pave the way for point-of-care testing (POCT).

Anti-cancer effect of miR-139-3p on laryngeal squamous cell carcinoma by targeting rab5a: In vitro and in vivo studies

BACKGROUND

Laryngeal squamous cell carcinoma is the second most common head and neck squamous cell carcinoma. Nowadays, as traditional treatment methods are gradually limited, the development of new treatment methods needs to be resolved. This study aimed to investigate the role of microRNA(miR)-139-3p in laryngeal squamous cell carcinoma, and further explored the underlying mechanism.

METHODS

In this study, we first used quantitative real time polymerase chain reaction (qRT-PCR) to detect the level of miR-139-3p in laryngeal squamous cell carcinoma tissue. Then, TargetScan and dual luciferase reporter assay were used to explore and verify whether rab5a was a direct target of miR-139-3p. Thereafter, the expression of miR-139-3p and rab5a in laryngeal squamous cell carcinoma cell line SNU46 was changed by transfection with miR-139-3p mimic or rab5a-plasmid. Then, SNU46 cell proliferation, cell apoptosis, cell cycle, cell migration and cell invasion were determined using Cell Counting Kit-8 (CCK-8), flow cytometry, scratch assay and Transwell assay, respectively. Finally, mouse tumor formation experiments were used to test whether miR-139-3p still exerted its role in inhibiting laryngeal squamous cell carcinoma in vivo.

RESULTS

Compared with the adjacent normal tissues, miR-139-3p significantly down-regulated in laryngeal squamous cell carcinoma tissue. It was confirmed by dual luciferase reporter experiment that rab5a was a direct target of miR-139-3p. Moreover, the up-regulation of miR-139-3p could effectively inhibit the proliferation, migration and invasion of laryngeal squamous cell carcinoma cells, and induced cell cycle arrest and apoptosis. In the molecular level study, we found that up-regulation of miR-139-3p inhibited the expression of rab5a in SNU46 cells. In addition, the protein and mRNA expression of factors related to cell migration, invasion, proliferation and apoptosis, such as integrin β1, Focal adhesion kinase (FAK), paxillin, B cell lymphoma-2 (bcl-2), nuclear factor-kappaB (NF-κB), vascular endothelial growth factor (VEGF), matrix metalloproteinase 9 (MMP9), in SNU46 cells were changed after miR-139-3p up-regulation. Consistent with the results of in vitro studies, in vivo experiments showed that miR-139-3p mimic inhibited laryngeal squamous cell carcinoma tumor growth. All the effects of miR-139-3p on laryngeal squamous cell carcinoma were reversed by rab5a over-expression.

CONCLUSION

miR-139-3p could inhibit laryngeal squamous cell carcinoma by targeting rab5a both in vitro and in vivo.

miR-499 rs3746444 and miR-196a-2 rs11614913 Are Associated with the Risk of Glioma, but Not the Prognosis

Previous studies of correlations of microRNA (miR)-499 rs3746444 and miR-196a-2 rs11614913 polymorphisms with glioma risk have yielded inconsistent results. In this study, relationships between these two polymorphisms and glioma risk and survival were evaluated. In total, 605 patients and 1,300 controls were genotyped. rs3746444 increased glioma risk in five genetic models (GA versus AA, odds ratio [OR], 95% confidence interval [CI] = 1.31 [1.05–1.66], p = 0.02; GG versus AA, OR [95% CI] = 10.70 [6.13–18.69], p < 0.0001; GA + GG versus AA, OR [95% CI] = 1.82 [1.47–2.24], p < 0.0001; GG versus AA + GA, OR [95% CI] = 9.99 [5.74–17.40], p < 0.0001; G versus A, OR [95% CI] = 2.18 [1.82–2.60], p < 0.0001). rs11614913 decreased glioma risk in a recessive model (OR [95% CI] = 0.79 [0.64–0.97], p = 0.03). No relationships between either SNP and survival were found. rs3746444 in the miR-499 seed region could affect target recognition. Bioinformatics analyses indicated that miR-499 rs3746444 is involved in various biological processes and pathways, including “cell adhesion molecule binding,” “positive regulation of catabolic process,” “NF-kappa B pathway,” and “PI3K-Akt pathway,” by targeting mRNAs. Our results suggested that miR-499 rs3746444 and miR-196a-2 rs11614913 have crucial roles in glioma susceptibility.

RFCM3: Computational Method for Identification of miRNA-mRNA Regulatory Modules in Cervical Cancer

Cervical cancer is a leading severe malignancy throughout the world. Molecular processes and biomarkers leading to tumor progression in cervical cancer are either unknown or only partially understood. An increasing number of studies have shown that microRNAs play an important role in tumorigenesis so understanding the regulatory mechanism of miRNAs in gene-regulatory network will help elucidate the complex biological processes that occur during malignancy. Functional genomics data provides opportunities to study the aberrant microRNA-messenger RNA (miRNA-mRNA) interaction. Identification of miRNA-mRNA regulatory modules will aid deciphering aberrant transcriptional regulatory network in cervical cancer but is computationally challenging. In this regard, an algorithm, termed as relevant and functionally consistent miRNA-mRNA modules (RFCM³), is proposed. It integrates miRNA and mRNA expression data of cervical cancer for identification of potential miRNA-mRNA modules. It selects set of miRNA-mRNA modules by maximizing relation of mRNAs with miRNA and functional similarity between selected mRNAs. Later, using the knowledge of the miRNA-miRNA synergistic network different modules are fused and finally a set of modules are generated containing several miRNAs as well as mRNAs. This type of module explains the underlying biological pathways containing multiple miRNAs and mRNAs. The effectiveness of the proposed approach over other existing methods has been demonstrated on a miRNA and mRNA expression data of cervical cancer with respect to enrichment analyses and other standard metrices. The prognostic value of the genes in a module with respect to cervical cancer is also demonstrated. The approach was found to generate more robust, integrated, and functionally enriched miRNA-mRNA modules in cervical cancer.