MicroRNA-495 Regulates Migration and Invasion in Prostate Cancer Cells Via Targeting Akt and mTOR Signaling

Bioinformatics-Assisted Extraction of All PCa miRNAs and their Target Genes

INTRODUCTION

To retrieve, and classify PCa miRNAs and identify the functional relationship between miRNAs and their targets through literature collection with computational analysis.

BACKGROUND

MicroRNAs play a role in gene regulation, which can either repress or activate the gene. Hence, the functions of miRNAs are dependent on the target gene. This study will be the first of its kind to combine computational analysis with corpus PCa data. Effectively, our study reported the huge number of miRNAs associated with PCa along with functional information.

OBJECTIVE

The identification and classification of previously known full PCa miRNAs and their targets were made possible by mining the literature data. Systems Biology and curated data mining assisted in identifying optimum miRNAs and their target genes for PCa therapy.

METHODS

PubMed database was used to collect the PCa literature up to December 2021. Pubmed. mineR package was used to extract the microRNAs associated articles and manual curation was performed to classify the microRNAs based on the function in PCa. PPI was constructed using the STRING database. Pathway analysis was performed using PANTHER and ToppGene Suite Software. Functional analysis was performed using ShinyGO software. Cluster analysis was performed using MCODE 2.0, and Hub gene analysis was performed using cytoHubba. The genemiRNA network was reconstructed using Cytoscape.

RESULTS

Unique PCa miRNAs were retrieved and classified from mined PCa literature. Six hundred and five unique miRNAs from 250 articles were considered as oncomiRs to trigger PCa. One hundred and twenty unique miRNAs from 118 articles were considered Tumor Suppressor miRNAs to suppress the PCa. Twenty-four unique miRNAs from 22 articles were utilized as treatment miRNAs to treat PCa. miRNAs target genes and their significant pathways, functions and hub genes were identified.

CONCLUSION

miR-27a, miR-34b, miR-495, miR-23b, miR-100, miR-218, Let-7a family, miR-27a- 5p, miR-34c, miR-34a, miR-143/-145, miR-125b, miR-124 and miR-205 with their target genes AKT1, SRC, CTNNB1, HRAS, MYC and TP53 are significant PCa targets.

MicroRNA-495: a therapeutic and diagnostic tumor marker

Therapeutic and diagnostic progresses have significantly reduced the mortality rate among cancer patients during the last decade. However, there is still a high rate of mortality among cancer patients. One of the important reasons involved in the high mortality rate is the late diagnosis in advanced tumor stages that causes the failure of therapeutic strategies in these patients. Therefore, investigating the molecular mechanisms involved in tumor progression has an important role in introducing the efficient early detection markers. MicroRNAs (miRNAs) as stable factors in body fluids are always considered as non-invasive diagnostic and prognostic markers. In the present review, we investigated the role of miR-495 in tumor progression. It has been reported that miR-495 has mainly a tumor suppressor function through the regulation of transcription factors and tyrosine kinases as well as cellular processes such as multidrug resistance, chromatin remodeling, and signaling pathways. This review can be an effective step towards introducing the miR-495 as a non-invasive diagnostic/prognostic marker as well as a suitable target in tumor therapy.

Downregulated miR-495-3p in colorectal cancer targets TGFβR1, TGFβR2, SMAD4 and BUB1 genes and induces cell cycle arrest

BACKGROUND

Hsa-miR-495 (miR-495) has been extensively investigated in cancer initiation and progression. On the other hand, our bioinformatics analysis suggested that miR-495 exerts its effects through targeting of TGFβ signaling components.

METHODS & RESULTS

In order to investigate such an effect, miR-495 precursor was overexpressed in HEK293T, SW480, and HCT116 cells, which was followed by downregulation of TGFβR1, TGFβR2, SMAD4, and BUB1 putative target genes, detected by RT-qPCR. Also, luciferase assay supported the direct interaction of miR-495 with 3'UTR sequences of TGFβR1, TGFβR2, SMAD4, and BUB1 genes. Furthermore, a negative correlation of expression between miR-495-3p and some of these target genes was deduced in a set of colorectal and breast cancer cell lines. Then, flow cytometry analysis showed that the overexpression of miR-495 in HCT116 and HEK293T resulted in an arrest at the G1 phase. Consistently, western blotting analysis showed a significant reduction of the Cyclin D1 protein in the cells overexpressing miR-495, pointing to downregulation of the TGFβ signaling pathway and cell cycle arrest. Finally, microarray data analysis showed that miR-495-3p is significantly downregulated in colorectal tumors, compared to the normal pairs.

CONCLUSIONS

Overall, the results of the current study introduced miR-495-3p as a cell cycle progression suppressor, which may negatively regulate TGFβR1, TGFβR2, SMAD4, and BUB1 genes. This finding suggests miR-495-3p as a tumor suppressor candidate for further evaluation.

MiR-495-3p regulates cell migration and invasion in papillary thyroid carcinoma

Background

Papillary thyroid carcinoma (PTC) is the most prevalent histotype of thyroid cancer and the presence of BRAFV600E mutation in these tumors is related to the malignancy and prognosis of the disease. In recent years attention has been focused on the role of microRNAs in the biology of PTC cells, especially in their role in the modulation of pathways related to tumorigenesis. DLK1-DIO3-derived miRNAs have been shown to play important roles in tumor context and are globally downregulated in PTC.

Methods

Based on a previous in silico target prediction and gene enrichment analysis, we identified miR-495-3p as the candidate with the highest tumor suppressor potential role in PTC among DLK1-DIO3-derived miRNAs. We used bioinformatics and an in vitro model of miR-495-3p overexpression to further understand the influence of this molecule on the tumorigenic processes of PTC.

Results

Overexpression of miR-495-3p impaired cell migration and invasion of PTC cells harboring the BRAFV600E mutation and affected the expression of targets predicted in the bioinformatic analysis, such as TGFB2, EREG and CCND1.

Conclusion

Overall, our results indicate that the loss of miR-495-3p expression during PTC development might play an important role in its progression.

Role of miRNA-495 and NRXN-1 and CNTN-1 mRNA Expression and Its Prognostic Importance in Breast Cancer Patients

Breast cancer is a heterogeneous disease in which genetic factors are involved in disease worsening and higher mortality. Epidemiological and clinical research revealed that breast cancer incidence continues to rise. 100 histopathologically confirmed untreated newly diagnosed cases of invasive ductal carcinoma (IDC) of breast and 100 healthy subjects were involved and blood samples were collected in non-EDTA plain vials. Serum was separated by centrifugation, total RNA was extracted from serum, and cDNA synthesis was done to study the miRNA-495 and neurexin-1 (NRXN-1) and contactin 1 (CNTN-1) mRNA expression by QRT-PCR. The expression levels of miRNA-495, NRXN-1, and CNTN-1 were expressed in fold change. The present study observed decreased relative miRNA-495 expression (0.07-fold) while an increase in NRXN-1 (11.61-fold) and CNTN-1 (4.92-fold) was observed among breast cancer patients compared to healthy controls. A significant difference was observed in miRNA-495 expression with menopausal status (p=0.0001) and TNM stages (p=0.02). It was observed that NRXN-1 expression was significantly associated with menopausal status (p=0.03), lymph node involvement (p < 0.0001), estrogen receptor (ER) status (p=0.03), progesterone receptor (PR) status (p=0.005), TNM stages (p < 0.0001), and distant metastases (p < 0.0001). CNTN-1 expression was also found to be associated with lymph node involvement (p=0.01), PR status (p=0.03), HER2 status (p=0.04), TNM stages (p < 0.0001), and distant metastases (p < 0.0001). ROC suggested that NRXN-1 and CNTN-1 could be the important predictive marker for disease advancement and distant organ metastases. The study concluded that the decreased expression of miR-495 observed in breast cancer patients showed a negative correlation with NRXN-1 while the increased expression of NRXN-1 and CNTN-1 was linked with disease advancement and distant metastases and could be the important predictive marker for breast cancer patients.

Adhesion of monocytes and endothelial cells isolated from the human aorta suppresses by miRNA-PEI particles

Background

Knowledge of stenosis in coronary arteries requires an understanding of the cellular and molecular processes that occur throughout the leukocyte rolling process. In this study, the roles of miR-125a-5p and miR-495-3p were investigated on the adhesion of endothelial cells (ECs) isolated from the human aorta.

Methods

Human primary endothelial cells were obtained from the aorta of people who had died of brain death. Whole blood was used to isolate the monocytes. The miR-125 and miR-495 were predicted and transfected into ECs using Poly Ethylene Imine (PEI). The expression levels of adhesion molecules and monocyte recruitment were identified by the RT-qPCR technique and Leukocyte-Endothelial Adhesion Assay kit, respectively.

Results

The ICAM-1, ICAM-2 and VCAM-1 expression levels decreased significantly in the miR-495/PEI-transfected ECs (P < 0.05) while in the miR-125/PEI-transfected ECs only the ICAM-2 and ITGB-2 expression levels decreased significantly (P < 0.05) as compared to the miR-synthetic/PEI-transfected ECs. Furthermore, the monocyte adhesion was decreased in the miR-125 and miR-mix/PEI-transfected ECs as compared to the miR-synthetic/PEI-transfected ECs (P = 0.01 and P = 0.04, respectively).

Conclusion

According to the findings, the efficient relations between miR-125 and adhesion molecules may be responsible for the inhibition of monocyte rolling.

lncRNA UCA1 induced by SP1 and SP3 forms a positive feedback loop to facilitate malignant phenotypes of colorectal cancer via targeting miR-495

AIMS

Long noncoding RNA (LncRNA) urothelial cancer associated 1 (UCA1) was dysregulated in colorectal cancers (CRC) and promoted tumor progression of CRC. The aims of this study are to further investigate the underlying mechanism.

MAIN METHODS

Short hairpin RNAs (shRNAs) were applied for gene knockdown. microRNA mimic and pcDNA-UCA1 plasmids were transfected for miR-495 and UCA1 overexpression, respectively. MTT was applied to determine cell viability and sensitivity of 5-fluorouracil (FU). Transwell assays were performed to evaluate cell migration/invasion. Angiogenesis was evaluated by tube formation. Western blotting and quantitative PCR were utilized for protein and mRNA detection, respectively. The interaction of UCA1, miR-495 and SP1/SP3 were explored by dual-luciferase assay. RNA pulldown was adopted to determine the UCA1/miR-495 interaction.

KEY FINDINGS

UCA1 was significantly upregulated in CRC tissues. UCA1 enhanced cell proliferation, migration/invasion, angiogenesis, epithelial-mesenchymal transition, and resistance to 5-FU in CRC cell lines. MiR-495 was inversely correlated to the expression of UCA1. The results indicated that UCA1 sponged miR-495, leading to the disinhibition of SP1/SP3 expression. SP1/SP3 induced the expression of DNA methyltransferases and, in turn, contributed to UCA1 mediated tumor-promoting actions. Reduction of SP1/SP3 exerted anti-cancer effects, which can be reversed by forced expression of UCA1.

SIGNIFICANCE

UCA1-miR-495-SP1/SP3 axis is dysregulated in CRC and contributed to malignant phenotypes of CRC. UCA1-SP1/SP3 may form a positive feedback loop in CRC.

Non-coding RNAs: Emerging from the discovery to therapeutic applications

The knowledge about non-coding RNAs (ncRNAs) is rapidly increasing with new data continuously emerging, regarding their diverse types, applications, and roles. Particular attention has been given to ncRNA with regulatory functions, which may have a critical role both in biological and pathological conditions. As a result of the diversity of ncRNAs and their ubiquitous involvement in several biologic processes, ncRNA started to be considered in the biomedical field, with immense potential to be exploited either as biomarkers or as therapeutic agents in certain pathologies. Indeed, ncRNA-based therapeutics have been proposed in many disorders and some even reached clinical trials. However, to prepare an RNA product suitable for pharmacological applications, certain criteria must be fulfilled, and it has to be guaranteed RNA purity, stability, and bioactivity. So, in this review, the different types of ncRNAs are identified and characterized, by describing their biogenesis, functions, and applications. A perspective on the main challenges and innovative approaches for the future and broad therapeutic application of RNA is also presented.

Long non‑coding RNA SNHG20 promotes colorectal cancer cell proliferation, migration and invasion via miR‑495/STAT3 axis

Colorectal cancer (CRC) is one of the primary causes of cancer-associated mortality worldwide. However, the potential molecular mechanism of CRC progression remains unknown. Long non-coding RNA small nucleolar RNA host gene 20 (SNHG20) has been demonstrated to be involved in the development and progression of a variety of tumors, including CRC. However, the involvement of SNHG20 in CRC progression remains unclear. The aim of the present study was to investigate the functional role and molecular mechanism of SNHG20 in CRC progression. In the present study, SNHG20 expression was found to be significantly upregulated in CRC tissues and cell lines. Association analysis indicated that high SNHG20 expression was significantly association with greater tumor size (P=0.014), tumor invasion depth (P=0.019), positive lymph node status (P=0.022), distant metastasis (P=0.017) and advanced tumor node metastasis stage (P=0.038). Loss-of-function experiments indicated that SNHG20 knockdown could significantly suppress proliferation, migration and invasion in vitro. Notably, SNHG20 knockdown significantly inhibited tumor growth and lung metastasis in vivo. Bioinformatics analysis and luciferase reporter assays confirmed that microRNA (miR)-495 was a direct target of SNHG20. Rescue assays indicated that miR-495 inhibitor reversed the suppressive effects of SNHG20 knockdown on CRC progression. Moreover, STAT3 was identified as a downstream target of miR-495 in CRC. STAT3 overexpression partially rescued the inhibitory effects of SNHG20 knockdown on CRC progression. Taken together, the results revealed that SNHG20 facilitated CRC progression by regulating STAT3 expression and by sponging miR-495.

Activation of the KDM5A/miRNA-495/YTHDF2/m6A-MOB3B axis facilitates prostate cancer progression

Background

Accumulating evidence supports that lysine-specific demethylase 5 (KDM5) family members act as oncogenic drivers. This study was performed to elucidate the potential effects of KDM5A on prostate cancer (PCa) progression via the miR-495/YTHDF2/m6A-MOB3B axis.

Methods

The expression of KDM5A, miR-495, YTHDF2 and MOB3B was validated in human PCa tissues and cell lines. Ectopic expression and knockdown experiments were developed in PCa cells to evaluate their effects on PCa cell proliferation, migration, invasion and apoptosis. Mechanistic insights into the interaction among KDM5A, miR-495, YTHDF2 and MOB3B were obtained after dual luciferase reporter, ChIP, and PAR-CLIP assays. Me-RIP assay was used to determine m6A modification level of MOB3B mRNA in PCa cells. Mouse xenograft models of PCa cells were also established to monitor the tumor growth.

Results

KDM5A was highly expressed in human PCa tissues and cell lines. Upregulated KDM5A stimulated PCa cell proliferation, migration and invasion, but reduced cell apoptosis. Mechanistically, KDM5A, as a H3K4me3 demethylase, bound to the miR-495 promoter, which led to inhibition of its transcription and expression. As a target of miR-495, YTHDF2 could inhibit MOB3B expression by recognizing m6A modification of MOB3B mRNA and inducing mRNA degradation. Furthermore, KDM5A was found to downregulate MOB3B expression, consequently augmenting PCa cell proliferation, migration and invasion in vitro and promoting tumor growth in vivo via the miR-495/YTHDF2 axis.

Conclusion

In summary, our study highlights the potential of histone demethylase KDM5A activity in enhancing PCa progression, and suggests KDM5A as a promising target for PCa treatment.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13046-020-01735-3.

Long non-coding RNA NORAD exhaustion represses prostate cancer progression through inhibiting TRIP13 expression via competitively binding to miR-495-3p

Background

Prostate cancer (PCa) is a malignant heterogeneous tumor that threatens men's health. Long non-coding RNA activated by DNA damage (NORAD) and microRNA-495-3p (miR-495-3p) have been revealed to be concerned with the tumorigenesis and progression of diverse cancers. Nevertheless, the regulatory mechanism between NORAD and miR-495-3p in PCa is unclear.

Methods

The expression of NORAD, miR-495-3p, and thyroid hormone receptor interactor 13 (TRIP13) mRNA was detected with quantitative real-time polymerase chain reaction (qRT-PCR). The levels of Bcl-2, Bax, Cleaved-casp-3, TRIP13, cyclin D1, and PCNA were detected through western blot analysis. The proliferation, apoptosis, migration, and invasion of PCa cells were assessed through 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), flow cytometry, or transwell assays. The relationship between NORAD or TRIP13 and miR-495-3p was confirmed via dual-luciferase reporter, RIP, or RNA pull-down assays.

Results

NORAD and TRIP13 were upregulated while miR-495-3p was downregulated in PCa tissues and cells. Both NORAD silencing and miR-495-3p upregulation accelerated cell apoptosis and curbed cell proliferation, migration, and invasion in PCa cells. Also, NORAD silencing repressed tumor growth in vivo. Notably, NORAD modulated TRIP13 expression by competitively binding to miR-495-3p. Furthermore, miR-495-3p repression reversed NORAD knockdown-mediated effects on the malignant behaviors of PCa cells. Moreover, TRIP13 enhancement overturned the effects of miR-495-3p overexpression on the proliferation, apoptosis, migration, and invasion of PCa cells.

Conclusion

NORAD depletion inhibited PCa advancement via the miR-495-3p/ TRIP13 axis, which provided a potential tactic for PCa treatment.

CircSMARCA5 Facilitates the Progression of Prostate Cancer Through miR-432/PDCD10 Axis

Background: Circular RNAs (circRNAs) have been reported to be implicated in the pathogenesis of prostate cancer (PCa). Herein, the authors explore the role and molecular mechanism of circRNA SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 5 (circSMARCA5) in PCa. Materials and Methods: The levels of circSMARCA5, SMARCA5, miR-432, and programmed cell death 10 (PDCD10) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). The circular structure and stability of circSMARCA5 were validated by qRT-PCR using Oligo dT primer, transcriptional inhibitor actinomycin D, or RNase R treatment, respectively. Cell proliferation, migration, invasion, epithelial/mesenchymal transition (EMT), and glycolysis were detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), transwell migration and invasion assays, Western blot assay, and Glucose or Lactate Detection Kit, respectively. The target relationship between miR-432 and circSMARCA5 or PDCD10 was validated by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Western blot was performed to detect the protein expression of PDCD10 in PCa cells. Results: CircSMARCA5 was aberrantly upregulated, and was a circular and stable RNA in PCa cells. CircSMARCA5 accelerated the proliferation, metastasis, and glycolysis of PCa cells. MiR-432 was a direct target of circSMARCA5, and circSMARCA5 accelerated the development of PCa through miR-432 in PCa cells. PDCD10 was a direct target of miR-432, and PDCD10 addition reversed the inhibitory effects of miR-432 accumulation on the proliferation, metastasis, and glycolysis of PCa cells. CircSMARCA5 upregulated the expression of PDCD10 through sponging miR-432 in PCa cells. Conclusion: CircSMARCA5 deteriorated PCa through the miR-432/PDCD10 axis. CircSMARCA5/miR-432/PDCD10 axis might be an underlying therapeutic target for PCa treatment.

How microRNAs affect the PD-L1 and its synthetic pathway in cancer

Programmed cell death-ligand 1 (PD-L1) is a glycoprotein that is expressed on the cell surface of both hematopoietic and nonhematopoietic cells. PD-L1 play a role in the immune tolerance and protect self-tissues from immune system attack. Dysfunction of this molecule has been highlighted in the pathogenesis of tumors, autoimmunity, and infectious disorders. MicroRNAs (miRNAs) are endogenous molecules that are classified as small non-coding RNA with approximately 20-22 nucleotides (nt) length. The function of miRNAs is based on complementary interactions with target mRNA via matching completely or incompletely. The result of this function is decay of the target mRNA or preventing mRNA translation. In the past decades, several miRNAs have been discovered which play an important role in the regulation of PD-L1 in various malignancies. In this review, we discuss the effect of miRNAs on PD-L1 expression and consider the effect of miRNAs on the synthetic pathway of PD-L1, especially during cancers.

Detection of Extracellular Vesicle RNA Using Molecular Beacons

Extracellular vesicles (EVs) have recently emerged as intercellular conveyors of biological information and disease biomarkers. Identification and characterization of RNA species in single EVs are currently challenging. Molecular beacons (MBs) represent an attractive means for detecting specific RNA molecules. Coupling the MBs to cell-penetrating peptides (CPPs) provides a fast, effective, and membrane-type agnostic means to deliver MBs across the plasma membrane and into the cytosol. Here, we generated RBCs-derived EVs by complement activation and tested the ability of MBs coupled with CPP to detect miRNAs from RBC-EVs. Our results showed that RBC and RBC-EVs miRNA-451a can be detected using MB-CPP, and the respective fluorescence levels can be measured by nano-flow cytometry. MB-based detection of RNA via nano-flow cytometry creates a powerful new analytical framework in which a simple addition of a reagent allows profiling of specific RNA species present within certain EV subsets.

Retracted: Identification of Prognosis Biomarkers of Prostatic Cancer in a Cohort of 498 Patients from TCGA

The article entitled, "Identification of prognosis biomarkers of prostatic cancer in a cohort of 498 patients from TCGA," by Chen Z and Hu H. (J Comput Biol Dec 2019: e-pub ahead of print; DOI: 10.1089/cmb.2019.0224) is being officially retracted at the authors' request due to errors found in the data after publication of the article. The detected errors render the results and conclusion irreproducible, and therefore, invalid. Based on the communications received from the authors, the editorial leadership of Journal of Computational Biology agreed to retract the published paper. However, after retracting the article, it was also discovered that the same article had been previously published in volume 43, issue 6 of the journal, Current Problems in Cancer, published by Elsevier. The publisher of Journal of Computational Biology was in communication with Elseivier since simultaneous submission and/or publication is a violation of the proper protocols of peer review, and they are conducting their own evaluation. Journal of Computational Biology also notified the authors' institution of the infraction. Journal of Computational Biology, its Editor, and its Publisher are committed to preserving the integrity of the scientific record for the community it serves.

Genome-wide analysis to identify a novel microRNA signature that predicts survival in patients with stomach adenocarcinoma

Objective: Using genome-wide screening, this study was aimed at identifying prognostic microRNA (miRNA) in those patients suffering from stomach adenocarcinoma (STAD).

Methods: A genome-wide miRNA sequencing dataset and relevant STAD clinical information was obtained via The Cancer Genome Atlas (TCGA). Prognostic miRNA selection was carried out through a whole genome multivariate Cox regression model in order to establish a prognostic STAD signature.

Results: Eleven miRNAs (hsa-mir-509-2, hsa-mir-3917, hsa-mir-495, hsa-mir-653, hsa-mir-3605, hsa-mir-2115, hsa-mir-1292, hsa-mir-137, hsa-mir-6511b-1, hsa-mir-145, and hsa-mir-138-2) were recognized as prognostic and used for the construction of a STAD prognostic signature. This signature exhibited good performance in predicting prognosis (adjusted P<0.0001, adjusted hazard ratio= 3.047, and 95% confidence interval=2.148-4.323). The time-dependent receiver operating characteristic examination exhibited area under curve values of 0.711, 0.697, 0.716, 0.733, 0.805, and 0.805, for 1-, 2-, 3-, 4-, 5-, and 10-year overall survival (OS) estimation, respectively. Comprehensive survival analysis suggests that the 11-miRNA prognostic signature acts as an independent feature of STAD prognosis and exhibits superior performance in OS prediction when compared to traditional clinical parameters. Furthermore, fourteen miRNA target genes were linked to STAD OS. These included SERPINE1, MLEC, ANGPT2, C5orf38, FZD7, MARCKS, PDGFD, DUSP6, IRS1, PSAT1, TENM3, TMEM127, BLMH, and TIRAP. Functional and gene set enrichment analysis suggested that target genes and the 11-miRNA prognostic signature were both participate in various biological processes and pathways, including the growth factor beta, Wnt, and Notch signaling pathways.

Conclusions: By means of a genome-wide analysis, an 11-miRNA expression signature that may serve as an underlying prognostic indicator for those patients suffering from STAD has been identified and described here.

Identification of prognosis biomarkers of prostatic cancer in a cohort of 498 patients from TCGA

OBJECTIVE

Prostatic cancer (PCa) is the first common cancer in male, and the prognostic variables are beneficial for clinical trial design and treatment strategies for PCa. This study was performed to identify more potential biomarkers for the prognosis of patients with PCa.

METHODS AND RESULTS

The transcriptome data and survival information of a cohort including 498 subjects with PCa were downloaded from TCGA. A total of 4293 differentially expressed genes (DEGs), including 1362 prognosis-related DEGs, were identified in PCa tissues compared with normal tissues. Upregulated genes, including serine/arginine-rich splicing factors (SRSFs; such as SRSF2, SRSF5, SRSF7 and SRSF8), and ubiquitin conjugating enzyme E2 (UBE2) members (such as UBE2D2, UBE2G2, UBE2J1 and UBE2E1), were identified as negative prognostic biomarkers of PCa, as the high expression of them correlated with poor overall survival of PCa patients. Several downregulated Golgi-ER traffic mediators (such as SEC31A, TMED2, and TMED10) were identified as positive prognostic biomarkers of PCa, as the high expression of them correlated with good overall survival of PCa patients.

CONCLUSIONS

These genes were of great interests in prognosis of PCa, and some of them may be constructive for the augmentation of clinical trial design and treatment strategies for PCa.

Genetic associations between the miRNA polymorphisms miR-130b (rs373001), miR-200b (rs7549819), and miR-495 (rs2281611) and colorectal cancer susceptibility

BACKGROUND

Recent studies have extensively investigated the role of miRNAs in colorectal cancer (CRC), and several associations have been reported. In addition, single nucleotide polymorphisms (SNPs) in promoter regions of miRNAs have been shown to affect miRNA expression. Therefore, we aimed to analyze the effect of miRNA polymorphisms on CRC susceptibility.

METHODS

We conducted association studies on the relationships between the miRNA polymorphisms miR-130bT > C rs373001, miR-200bT > C rs7549819, and miR-495A > C rs2281611 and CRC with 472 CRC patients and 399 control subjects in Korea.

RESULTS

Multivariate logistic regressions of the CRC subgroups showed that the miR-495CC genotype associated with rectal cancer (AA+AC vs. CC; adjusted odds ratio (AOR) for CC, 1.592; 95% confidence interval (CI), 1.071-2.368; P = 0.022). The gene-environment combinatorial analysis showed that the combination of miR-495A > C and low plasma folate contributed to an increased risk of rectal cancer (AA+AC vs. CC; AOR for CC, 3.829; 95% CI, 1.577-9.300; P = 0.003). In the survival analysis, miR-200bT > C associated with CRC patient mortality (TT vs TC + CC; adjusted hazard ratio for TC + CC, 0.592; 95% CI, 0.373-0.940; P = 0.026).

CONCLUSION

In this study, we found that miR-200b and miR-495 polymorphisms are involved in CRC susceptibility and prognosis.

miRNA-766 induces apoptosis of human colon cancer cells through the p53/Bax signaling pathway by MDM4

miRNAs are closely associated with tumor genesis and development. The present study investigated the role of the expression of miRNA-766 in the survival of patients with colon cancer and the underlying molecular mechanisms. Reverse transcription-quantitative polymerase chain reaction analysis and microarray analysis were used to analyze the expression of miRNA-766. The results revealed that the expression of miRNA-766 was decreased in patients with colon cancer. The overall survival and disease-free survival rates of patients with colon cancer with a high expression of miRNA-766 were prolonged, compared with those with a low expression of miRNA-766. The overexpression of miRNA-766 reduced cell growth and induced apoptosis in colon cancer cells through suppression of the MDM4/p53 pathway. By contrast, the downregulation of miRNA-766 promoted cell growth and reduced apoptosis in colon cancer cells through activation of the MDM4/p53 pathway. The promotion of MDM4 attenuated the anticancer effect of miRNA-766 in colon cancer cells. These results demonstrated that miRNA-766 induced cell apoptosis in human colon cancer through MDM4/p53.

MicroRNA‑25/ATXN3 interaction regulates human colon cancer cell growth and migration

The present study aimed to investigate the function of microRNA-25 (miR-25) in human colon cancer cell viability and migration in addition to the underlying possible mechanisms. miR-25 expression was upregulated in patients with colon cancer compared with the control group. Reverse transcription-quantitative polymerase chain reaction and gene chip technology were used to analyze the alterations of miR-25 in patients with colon cancer. Cell viability and cell migration were analyzed using MTT and wound healing assays, respectively, apoptosis was analyzed using flow cytometry, and western blot analysis was conducted to determine the protein expression of ataxin-3 (ATXN3), apoptosis regulator Bax (Bax) and cyclin D1. Overexpression of miR-25 increased cell viability and migration, decreased apoptosis, decreased caspase-3/9 activity level in addition to decreased Bax protein expression, and increased cyclin D1 protein expression in colon cancer cells. Furthermore, miR-25 was demonstrated to target ATXN3 and suppress ATXN3 protein expression. Downregulation of miR-25 induced apoptosis of colon cancer cells via increased expression ATXN3. Small interfering-ATXN3 inhibited the anti-cancer effects of miR-25 downregulation in colon cancer. Collectively, the present results demonstrated that miR-25 promoted human colon cancer cell viability and migration by regulating ATXN3 expression.

Dysregulation of ncRNAs located at the DLK1‑DIO3 imprinted domain: involvement in urological cancers

Genomic imprinting has been found to be involved in human physical development and several diseases. The DLK1-DIO3 imprinted domain is located on human chromosome 14 and contains paternally expressed protein-coding genes (DLK1, RTL1, DIO3) and numerous maternally expressed ncRNA genes (MEG3, MEG8, antisense RTL1, miRNAs, piRNAs, and snoRNAs). Emerging evidence has implicated that dysregulation of the DLK1-DIO3 imprinted domain especially the imprinted ncRNAs is critical for tumor progressions. Multiple miRNAs and lncRNAs have been investigated in urological cancers, of which several are transcribed from this domain. In this review, we present current data about the associated miRNAs, lncRNAs, and piRNAs and the regulation of differentially methylated regions methylation status in the progression of urological cancers and preliminarily propose certain concepts about the potential regulatory networks involved in DLK1-DIO3 imprinted domain.

MicroRNA replacement therapy in cancer

Despite the recent progress in cancer management approaches, the mortality rate of cancer is still growing and there are lots of challenges in the clinics in terms of novel therapeutics. MicroRNAs (miRNA) are regulatory small noncoding RNAs and are already confirmed to have a great role in regulating gene expression level by targeting multiple molecules that affect cell physiology and disease development. Recently, miRNAs have been introduced as promising therapeutic targets for cancer treatment. Regulatory potential of tumor suppressor miRNAs, which enables regulation of entire signaling networks within the cells, makes them an interesting option for developing cancer therapeutics. In this regard, over recent decades, scientists have aimed at developing powerful and safe targeting approaches to restore these suppressive miRNAs in cancerous cells. The present review summarizes the function of miRNAs in tumor development and presents recent findings on how miRNAs have served as therapeutic agents against cancer, with a special focus on tumor suppressor miRNAs (mimics). Moreover, the latest investigations on the therapeutic strategies of miRNA delivery have been presented.

MicroRNA‑495 targets Notch1 to prohibit cell proliferation and invasion in oral squamous cell carcinoma

MicroRNAs (miRNAs) are associated with the initiation and progression of oral squamous cell carcinoma (OSCC) by regulating a variety of cancer‑associated behaviors. Fully understanding the regulatory mechanism of miRNAs in the pathogenesis of OSCC may provide novel promising approaches for the identification of prognostic biomarkers and therapeutic targets for this particular malignancy. In the present study, reverse transcription‑quantitative polymerase chain reaction analysis was performed to detect miRNA (miR)‑495 expression in OSCC tissues and cell lines. The effects of miR‑495 on the proliferation and invasion of OSCC cells were determined using Cell Counting Kit‑8 and Matrigel invasion assays, respectively. The mechanisms underlying the action of miR‑495 in OSCC cells were also investigated. Results from the present study revealed that miR‑495 expression was downregulated in OSCC tissues and cell lines compare with in adjacent normal tissues and human oral keratinocytes, respectively. Exogenous expression of miR‑495 restricted cell proliferation and invasion of OSCC cells in vitro. Notch1 was identified as a direct functional target of miR‑495 in OSCC. Furthermore, Notch1 knockdown exhibited inhibitory effects, similar to those induced by miR‑495 overexpression in OSCC cells. Restoration of Notch1 expression rescued the suppressive effects of miR‑495 on OSCC cell proliferation and invasion. These findings suggested an important role for miR‑495 in the regulation of OSCC cell growth and metastasis, at least partly by directly targeting Notch1. In addition, the findings of the present study revealed the potential of miR‑495 as a novel therapeutic target for the treatment of patients with OSCC.

MicroRNA-495 suppresses cell proliferation and invasion of hepatocellular carcinoma by directly targeting insulin-like growth factor receptor-1

Hepatocellular carcinoma (HCC) is the fifth most common malignancy and second-most frequent cause of cancer-associated deaths worldwide. Previously, increasing studies report that microRNAs (miRNAs/miRs) are abnormally expressed in various types of human cancers and may participate in the tumourigenesis and tumour development of HCC. miRNA-based targeted therapy is effective against different molecular targets and may increase the sensitisation of cancer cells to therapy by several folds. Therefore, further validation of potentially important miRNAs involved in HCC initiation and progression may provide valuable insights into the treatment of patients with HCC. miR-495 is abnormally expressed in multiple types of human cancers. However, the expression level and roles of miR-495 in HCC have yet to be completely elucidated. In the present study, miR-495 expression was frequently downregulated in HCC tissues and cell lines, and miR-495 expression levels were significantly correlated with tumour size, tumor-node-metastasis (TNM) stage and lymph node metastasis in patients with HCC. Functional assays revealed that miR-495 overexpression inhibited cell proliferation and invasion in HCC. Insulin-like growth factor receptor-1 (IGF1R) was identified as a direct target gene of miR-495 in HCC. IGF1R was upregulated in HCC tissues and negatively correlated with miR-495 expression level. The upregulation of IGF1R rescued the miR-495-induced tumour-suppressive roles in HCC cell proliferation and invasion, and the restored miR-495 expression inactivated the protein kinase B and extracellular regulated protein kinase signalling pathways in HCC. These results provide novel insights into the molecular mechanism underlying HCC progression, and suggest that miR-495 may be investigated as a novel therapeutic target for patients with this disease.

MiRNA-target network analysis identifies potential biomarkers for Traditional Chinese Medicine (TCM) syndrome development evaluation in hepatitis B caused liver cirrhosis

Hepatitis B is one of most etiologies of Liver cirrhosis in China, and clinically lacks the effective strategy for Hepatitis B caused cirrhosis (HBC) therapy. As a complementary and alternative medicine, Chinese Traditional Medicine (TCM) has special therapeutic effects for HBC. Here, we focus on the evolution process of HBC TCM syndromes, which was from Excessive (Liver-Gallbladder Dampness-Heat Syndrome, LGDHS) to Deficient (Liver-Kidney Deficiency Syndrome, LKYDS) via Excessive-Deficient syndrome (Liver-Depression and Spleen-Deficiency Syndrome, LDSDS). Using R package, 16 miRNAs in LGDHS/Normal, 48 miRNAs in LDSDS/LGDHS, and 16 miRNAs in LKYDS/LDSDS were identified, respectively. The miRNA-target networks show that the LDSDS was most stability and complicated. Subsequently, 4 kernel miRNAs with LGDHS-LDSDS process, and 5 kernel miRNAs with LDSDS-LKYDS process were screened. Using RT-qPCR data, p1 (hsa-miR-17-3p, -377-3p, -410-3p and -495) and p2 miRNA panel (hsa-miR-377-3p, -410-3p, -27a-3p, 149-5p and 940) were identified by Logistic Regression Model, which clearly improve the accuracy of TCM syndrome classification. The rebuilt miRNA-target network shows that the LDSDS is a critical point and might determine the evolution directions of HBC TCM syndrome. This study suggests that the identified kernel miRNAs act as potential biomarkers and benefit to evaluate the evolution tendency of HBC TCM syndromes.

miR-495 sensitizes MDR cancer cells to the combination of doxorubicin and taxol by inhibiting MDR1 expression

MDR1 is highly expressed in MDR A2780DX5 ovarian cancer cells, MDR SGC7901R gastric cancer cells and recurrent tumours. It pumps cytoplasmic agents out of cells, leading to decreased drug accumulation in cells and making cancer cells susceptible to multidrug resistance. Here, we identified that miR-495 was predicted to target ABCB1, which encodes protein MDR1. To reduce the drug efflux and reverse MDR in cancer cells, we overexpressed a miR-495 mimic in SGC7901R and A2780DX cells and in transplanted MDR ovarian tumours in vivo. The results indicated that the expression of MDR1 in the above cells or tumours was suppressed and that subsequently the drug accumulation in the MDR cells was decreased, cell death was increased, and tumour growth was inhibited after treatment with taxol-doxorubicin, demonstrating increased drug sensitivity. This study suggests that pre-treatment with miR-495 before chemotherapy could improve the curative effect on MDR1-based MDR cancer.

Demethylation of miR-495 inhibits cell proliferation, migration and promotes apoptosis by targeting STAT-3 in breast cancer

In breast cancer (BC), silencing of miRNA genes due to miRNA gene promoter methylation are the important mechanisms directly contributing to tumorigenesis and tumor progression. miRNA-495 (miR-495) has been reported to be a tumor suppressor gene in various cancers, but its role and regulation in BC remains unclear. In the present study, the level of miR-495 was inversely correlated with the expression of STAT-3 in BC tissues and cell lines. miR-495 can directly target 3'-UTR of STAT-3 mRNA and thereby decrease the expression of STAT-3 in MCF-7 and HCC1973 cells by Targetscan and Dual-luciferase assay. We further analyzed miR-495 promoter methylation by sodium bisulfite sequencing method (BSP), and found DNA methyltransferase inhibitor, 5-AzaC concomitantly upregulated expression of miR-495 and downregulated its target gene STAT-3 and its downstream target VEGF. Furthermore, we further observed that 5-AzaC treatment, miR-495 mimics and STAT-3 knockdown significantly inhibited cell function in breast cancer by Transwell assay, EdU flow cytometry, Annexin V-FITC/PI combined with flow cytometry and Hoechst staining. Taken together, our data are first to demonstrate that the miR-495 is silenced due to promoter methylation in breast cancer. DNA methyltransferase inhibitor 5-AzaC could reverse miR‑495 (suppressor gene) and STAT-3 (oncogene). The anticancer properties of 5-AzaC were preliminarily confirmed in breast cancer.

Targeting MicroRNAs in Cancer Gene Therapy

MicroRNAs (miRNAs) are a kind of conserved small non-coding RNAs that participate in regulating gene expression by targeting multiple molecules. Early studies have shown that the expression of miRNAs changes significantly in different tumor tissues and cancer cell lines. It is well acknowledged that such variation is involved in almost all biological processes, including cell proliferation, mobility, survival and differentiation. Increasing experimental data indicate that miRNA dysregulation is a biomarker of several pathological conditions including cancer, and that miRNA can exert a causal role, as oncogenes or tumor suppressor genes, in different steps of the tumorigenic process. Anticancer therapies based on miRNAs are currently being developed with a goal to improve outcomes of cancer treatment. In our present study, we review the function of miRNAs in tumorigenesis and development, and discuss the latest clinical applications and strategies of therapy targeting miRNAs in cancer.