A Panel of MicroRNA Signature as a Tool for Predicting Survival of Patients with Urothelial Carcinoma of the Bladder

2'-Hydroxyflavanone inhibits bladder cancer cell proliferation and angiogenesis via regulating miR-99a-5p/mTOR signaling

OBJECTIVES

2'-Hydroxyflavanone (2HF) has been recognized for its antitumor potential in recent years. In the past decade, the role of miRNAs in tumors has been gradually explored. Since natural compounds may regulate miRNA networks, our objective is to investigate the potential effects and mechanisms of 2HF in the treatment of bladder cancer (BCa) by targeting miRNAs.

METHODS

Cell viability, tube formation, Transwell, western blotting and colony formation assays were used to evaluate the effects of 2HF on the viability and angiogenesis of BCa cells. The expression of miR-99a-5p and mTOR was detected via RT-qPCR and western blotting. A subcutaneous xenograft animal experiment was used to evaluate the tumor inhibition of 2HF in vivo. The binding of miR-99a-5p to mTOR was demonstrated via dual-luciferase reporting and RNA pull-down assays.

RESULTS

2HF inhibited the cell viability, angiogenesis, protein expression of VEGFa and Ki67 in T24 and 253J cells and protein expression of CD31 in HUVEC cells. Also, 2HF induced the upregulation of miR-99a-5p but the downregulation of mTOR expression. Additionally, the inhibitory effect of 2HF on tumor cells can be effectively rescued by silencing miR-99a-5p or overexpressing mTOR in vitro. Moreover, 2HF inhibited tumor growth in nude mice, in which it upregulated miR-99a-5p but suppressed mTOR expression in xenograft tissues. Mechanistically, miR-99a-5p can directly target the mRNA of mTOR by binding to its 3' untranslated region (3'-UTR) and then inhibiting the expression of mTOR.

CONCLUSIONS

2HF inhibited BCa cell proliferation and angiogenesis by regulating the miR-99a-5p/mTOR/VEGFa axis, which may provide a novel treatment strategy and molecular mechanism for BCa treatment.

The identification of biomarkers for Alzheimer's disease using a systems biology approach based on lncRNA-circRNA-miRNA-mRNA ceRNA networks

In addition to being the most prevalent form of neurodegeneration among the elderly, AD is a devastating multifactorial disease. Currently, treatments address only its symptoms. Several clinical studies have shown that the disease begins to manifest decades before the first symptoms appear, indicating that studying early changes is crucial to improving early diagnosis and discovering novel treatments. Our study used bioinformatics and systems biology to identify biomarkers in AD that could be used for diagnosis and prognosis. The procedure was performed on data from the GEO database, and GO and KEGG enrichment analysis were performed. Then, we set up a network of interactions between proteins. Several miRNA prediction tools including miRDB, miRWalk, and TargetScan were used. The ceRNA network led to the identification of eight mRNAs, four circRNAs, seven miRNAs, and seven lncRNAs. Multiple mechanisms, including the cell cycle and DNA replication, have been linked to the promotion of AD development by the ceRNA network. By using the ceRNA network, it should be possible to extract prospective biomarkers and therapeutic targets for the treatment of AD. It is possible that the processes involved in DNA cell cycle and the replication of DNA contribute to the development of Alzheimer's disease.

The Role of miRNAs to Detect Progression, Stratify, and Predict Relevant Clinical Outcomes in Bladder Cancer

Bladder cancer (BC) is one of the most common types of cancer worldwide, with significant differences in survival depending on the degree of muscle and surrounding tissue invasion. For this reason, the timely detection and monitoring of the disease are important. Surveillance cystoscopy is an invasive, costly, and uncomfortable procedure to monitor BC, raising the need for new, less invasive alternatives. In this scenario, microRNAs (miRNAs) represent attractive prognostic tools given their role as gene regulators in different biological processes, tissue expression, and their ease of evaluation in liquid samples. In cancer, miRNA expression is dynamically modified depending on the tumor type and cancer staging, making them potential biomarkers. This review describes the most recent studies in the last five years exploring the utility of miRNA-based strategies to monitor progression, stratify, and predict relevant clinical outcomes of bladder cancer. Several studies have shown that multimarker miRNA models can better predict overall survival, recurrence, and progression in BC patients than traditional strategies, especially when combining miRNA expression with clinicopathological variables. Future studies should focus on validating their use in different cohorts and liquid samples.

Investigating miR-9 as a mediator in laryngeal cancer health disparities

Background

For several decades, Black patients have carried a higher burden of laryngeal cancer among all races. Even when accounting for sociodemographics, a disparity remains. Differentially expressed microRNAs have been linked to racially disparate clinical outcomes in breast and prostate cancers, yet an association in laryngeal cancer has not been addressed. In this study, we present our computational analysis of differentially expressed miRNAs in Black compared with White laryngeal cancer and further validate microRNA-9-5p (miR-9-5p) as a potential mediator of cancer phenotype and chemoresistance.

Methods

Bioinformatic analysis of 111 (92 Whites, 19 Black) laryngeal squamous cell carcinoma (LSCC) specimens from the TCGA revealed miRNAs were significantly differentially expressed in Black compared with White LSCC. We focused on miR-9-5 p which had a significant 4-fold lower expression in Black compared with White LSCC (p<0.05). After transient transfection with either miR-9 mimic or inhibitor in cell lines derived from Black (UM-SCC-12) or White LSCC patients (UM-SCC-10A), cellular migration and cell proliferation was assessed. Alterations in cisplatin sensitivity was evaluated in transient transfected cells via IC50 analysis. qPCR was performed on transfected cells to evaluate miR-9 targets and chemoresistance predictors, ABCC1 and MAP1B.

Results

Northern blot analysis revealed mature miR-9-5p was inherently lower in cell line UM-SCC-12 compared with UM-SCC-10A. UM -SCC-12 had baseline increase in cellular migration (p < 0.01), proliferation (p < 0.0001) and chemosensitivity (p < 0.01) compared to UM-SCC-10A. Increasing miR-9 in UM-SCC-12 cells resulted in decreased cellular migration (p < 0.05), decreased proliferation (p < 0.0001) and increased sensitivity to cisplatin (p < 0.001). Reducing miR-9 in UM-SCC-10A cells resulted in increased cellular migration (p < 0.05), increased proliferation (p < 0.05) and decreased sensitivity to cisplatin (p < 0.01). A significant inverse relationship in ABCC1 and MAP1B gene expression was observed when miR-9 levels were transiently elevated or reduced in either UM-SCC-12 or UM-SCC-10A cell lines, respectively, suggesting modulation by miR-9.

Conclusion

Collectively, these studies introduce differential miRNA expression in LSCC cancer health disparities and propose a role for low miR-9-5p as a mediator in LSCC tumorigenesis and chemoresistance.

Development of Ferroptosis-Associated ceRNA Network in Periodontitis

OBJECTIVES

Periodontitis is a chronic inflammatory illness that may lead to tooth loosening and even loss, and its pathogenesis is not fully understood. Ferroptosis is an iron-dependent, regulated cell death. The present study aims to find the key ferroptosis-related genes (FRGs) in periodontitis and develop an mRNA-miRNA-lncRNA network to deeply explore the pathogenesis of periodontitis.

METHODS

Data from the Gene Expression Omnibus (GEO) database and FerrDb database were downloaded to discover the differentially expressed mRNA, miRNA, and FRGs. Functional enrichment analysis was conducted for the differentially expressed FRGs (DE-FRGs), including gene ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein-protein interaction (PPI) network analysis. Targetscan and miRtarbase were used to estimate the miRNAs that DE-FRGs may interact with, whilst StarBase v3.0 was used for lncRNA-miRNA interaction.

RESULTS

Seven DE-FRGs were identified through differential expression analysis. Interleukin 1 beta (IL1B) interacted with XBP1 and MMP13 in the PPI network. After taking the intersection between DE-miRNAs and predicted miRNAs, a ceRNA network containing IL1B, has-miR-185, has-miR-204, has-miR-211, has-miR-4306, and 28 lncRNAs was established.

CONCLUSIONS

Seven FRGs in periodontitis were identified, which might promote deeper understanding of ferroptosis in periodontitis.

The Roles of miRNAs in Predicting Bladder Cancer Recurrence and Resistance to Treatment

Bladder cancer (BCa) is associated with significant morbidity, with development linked to environmental, lifestyle, and genetic causes. Recurrence presents a significant issue and is managed in the clinical setting with intravesical chemotherapy or immunotherapy. In order to address challenges such as a limited supply of BCG and identifying cases likely to recur, it would be advantageous to use molecular biomarkers to determine likelihood of recurrence and treatment response. Here, we review microRNAs (miRNAs) that have shown promise as predictors of BCa recurrence. MiRNAs are also discussed in the context of predicting resistance or susceptibility to BCa treatment.

Role of microRNA-34b-5p in cancer and injury: how does it work?

MicroRNAs (miRNAs or miRs) are a class of noncoding single-stranded RNAs that can regulate gene expression by binding to the untranslated sequences at the 3 ' end of messenger RNAs. The microRNA-34 family is dysregulated in various human diseases. It is considered as a tumor-suppressive microRNA because of its synergistic effect with the well-known tumor suppressor p53. As a member of the miRNA-34 family, miR-34b-5p serves as a powerful regulator of a suite of cellular activities, including cell growth, multiplication, development, differentiation, and apoptosis. It promotes or represses disease occurrence and progression by participating in some important signaling pathways. This review aimed to provide an overview and update on the differential expression and function of miR-34b-5p in pathophysiologic processes, especially cancer and injury. Additionally, miR-34b-5p-mediated clinical trials have indicated promising consequences for the therapies of carcinomatosis and injury. With the application of the first tumor-targeted microRNA drug based on miR-34a mimics, it can be inferred that miR-34b-5p may become a crucial factor in the therapy of various diseases. However, further studies on miR-34b-5p should shed light on its involvement in disease pathogenesis and treatment options.

Biomarkers of Bladder Cancer: Cell-Free DNA, Epigenetic Modifications and Non-Coding RNAs

Bladder cancer (BC) is the 10th most frequent cancer in the world. The initial diagnosis and surveillance of BC require a combination of invasive and non-invasive methods, which are costly and suffer from several limitations. Cystoscopy with urine cytology and histological examination presents the standard diagnostic approach. Various biomarkers (e.g., proteins, genes, and RNAs) have been extensively studied in relation to BC. However, the new trend of liquid biopsy slowly proves to be almost equally effective. Cell-free DNA, non-coding RNA, and other subcellular structures are now being tested for the best predictive and diagnostic value. In this review, we focused on published gene mutations, especially in DNA fragments, but also epigenetic modifications, and non-coding RNA (ncRNA) molecules acquired by liquid biopsy. We performed an online search in PubMed/Medline, Scopus, and Web of Science databases using the terms "bladder cancer", in combination with "markers" or "biomarkers" published until August 2022. If applicable, we set the sensitivity and specificity threshold to 80%. In the era of precision medicine, the development of complex laboratory techniques fuels the search and development of more sensitive and specific biomarkers for diagnosis, follow-up, and screening of BC. Future efforts will be focused on the validation of their sensitivity, specificity, predictive value, and their utility in everyday clinical practice.

Non-coding RNAs as potential biomarkers in osteosarcoma

Osteosarcoma (OS) is a primary solid malignant tumor that occurs most frequently in the metaphysis of long bones. More likely to happen to children and adolescents. OS has high mortality and disability rate. However, the etiology and pathogenesis of OS have not been fully understood till now. Due to the lack of effective biomarkers, OS cannot be precisely detected in the early stage. With the application of next-generation and high-throughput sequencing, more and more abnormally expressed non-coding RNAs(ncRNAs) have been identified in OS. Growing evidences have suggested the ncRNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), have played an important role in the tumorigenesis and progression of OS. Thus, they can be served as novel biomarkers for diagnosis, treatment and prognosis. This review summarized the application of ncRNA as biomarkers in OS in detail, and discussed the limitation and future improvement of the potential biomarkers.

Non-coding RNA-mediated high expression of SFXN3 as a prognostic biomarker associated with paclitaxel resistance and immunosuppressive microenvironment in head and neck cancer

Chemoresistance is the leading cause of poor prognosis in head and neck squamous cell carcinoma (HNSC); however, promising biomarkers to identify patients for stratified chemotherapy are lacking. Sideroflexin 3 (SFXN3) is an important mitochondrial serine transporter during one-carbon metabolism, which is involved in the proliferation of cancer cells. However, the specific role of SFXN3 in HNSC remains unknown. In this study, we performed expression and survival analysis for SFXN3 in pan-cancer using data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) and found that SFXN3 served as a potential oncogene in HNSC. Notably, SFXN3 expression was found to be positively associated with enriched tumor-infiltrating macrophages, other immune suppressive cells, and immune checkpoint expression and resistance to paclitaxel. Gene, clinical, and immune variables included in the univariate and multivariate analyses showed that SFXN3 expression was an independent risk factor. Moreover, the LINC01270/hsa-miR-29c-3p/SFXN3 axis was identified as the most likely upstream non-coding RNA-related pathway of SFXN3 in HNSC using bioinformatic analysis, expression analysis, correlation analysis, and survival analysis. Taken together, our findings demonstrated that a non-coding RNA-mediated high expression of SFXN3 is a prognostic biomarker and is associated with the immunosuppressive microenvironment in HNSC.

Diagnostic Strategies for Urologic Cancer Using Expression Analysis of Various Oncogenic Surveillance Molecules—From Non-Coding Small RNAs to Cancer-Specific Proteins

Urinary-tract-related tumors are prone to simultaneous or heterogeneous multiple tumor development within the primary organ. Urologic tumors have a very high risk of recurrence in the long and short term. This may be related to the disruption of homeostasis on the genetic level, such as the induction of genetic mutations due to exposure to various carcinogenic factors and the disruption of cancer suppressor gene functions. It is essential to detect the cancer progression signals caused by genetic abnormalities and find treatment therapies. In this review, we discuss the usefulness of tumor-expressing clinical biomarkers for predicting cancer progression. Furthermore, we discuss various factors associated with disturbed intracellular signals and those targeted by microRNAs, which are representative of non-coding small RNAs.

A Novel M7G-Related MicroRNAs Risk Signature Predicts the Prognosis and Tumor Microenvironment of Kidney Renal Clear Cell Carcinoma

Background: M7G modification is extremely vital for the development of many cancers, especially tumor immunity. M7G modification is a novel functional regulator of miRNA, and the researches on m7G-related miRNAs in kidney renal clear cell carcinoma (KIRC) are still insufficient. This research aims to establish a risk signature on the foundation of m7G-associated miRNAs, which can precisely forecast the prognosis of KIRC patients.

Methods: Transcriptome data and clinical data used in this study come from The Cancer Genome Atlas database. Our team utilized univariable Cox, Lasso and multivariable Cox analyses to construct a m7G-associated miRNAs risk signature that can forecast the prognosis of KIRC patients. Kaplan-Meier method, time-dependent receiver operating characteristic (ROC) curve, and the independent analysis of risk signatures were employed to verify the predictability and accuracy of the risk signature. Subsequently, based on CIBERSORT, ESTIMATE and ssGSEA algorithms, we speculated the potential impact of the proposed risk signature on tumor immune microenvironment. Ultimately, by virtue of the risk signature and tumor immunity, the hub genes affecting the prognosis of KIRC patients were screened out.

Results: Our team established and verified a prognostic signature comprising 7 m7G-associated miRNAs (miR-342-3p, miR-221-3p, miR-222-3p, miR-1277-3p, miR-6718-5p, miR-1251-5p, and miR-486-5p). The results of the Kaplan-Meier survival analysis revealed that the prognosis of KIRC sufferers in the high-risk group was often unsatisfactory. The accuracy of the prediction ability of the risk signature was verified by calculating the area under the ROC curve. Univariate-multivariate Cox analyses further showed that this risk signature could be utilized as an independent prognosis-related biomarker for KIRC sufferers. The results of the immune analysis revealed that remarkable diversities existed in immune status and tumor microenvironment between high-risk and low-risk groups. On the foundation of the proposed risk signature and other clinical factors, a nomogram was established to quantitatively forecast the survival of KIRC sufferers at 1, 3 and 5 years.

Conclusion: Based on m7G-related miRNAs, a risk signature was successfully constructed, which could precisely forecast the prognosis of sufferers and guide personalized immunotherapy for KIRC patients.

Identification of Five N6-Methylandenosine-Related ncRNA Signatures to Predict the Overall Survival of Patients with Gastric Cancer

Noncoding ribonucleic acids (ncRNAs) are involved in various functions in the formation and progression of different tumors. However, the association between N6-methyladenosine-related ncRNAs (m6A-related ncRNAs) and gastric cancer (GC) prognosis remains elusive. As such, this research was aimed at identifying m6A-related ncRNAs (lncRNAs and miRNAs) in GC and developing prognostic models of relevant m6A-related ncRNAs and identifying potential biomarkers regulated by m6A. In this study, the m6A2Target database, Starbase database, and The Cancer Genome Atlas (TCGA) were used to screen m6A-related ncRNAs. And then, we performed integrated bioinformatics analyses to determine prognosis-associated ncRNAs and to develop the m6A-related ncRNA prognostic signature (m6A-NPS) for GC patients. Finally, five m6A-related ncRNAs (including lnc-ARHGAP12, lnc-HYPM-1, lnc-WDR7-11, LINC02266, and lnc-PRIM2-7) were identified to establish m6A-NPS. The predictive power of m6A-NPS was better in the receiver operating characteristic (ROC) curve analysis of the training set (area under the curve (AUC), >0.6). The m6A-NPS could be utilized to classify patients into high- and low-risk cohorts, and the Kaplan-Meier analysis indicated that participants in the high-risk cohort had a poorer prognosis. The entire TCGA dataset substantiated the predictive value of m6A-NPS. Significant differences in TCGA molecular GC subtypes were observed between high- and low-risk cohorts. The ROC curve analysis indicated that m6A-NPS had better predictive power than other clinical characteristics of GC prognosis. Uni- and multivariate regression analyses indicated m6A-NPS as an independent prognostic factor. Furthermore, the m6A status between the low-risk cohort and high-risk cohort was significantly different. Differential genes between them were enriched in multiple tumor-associated signaling pathways. In summary, five m6A-related ncRNA signatures that could forecast the overall survival of patients with GC were identified.

Identification of Novel Biomarkers for Predicting Prognosis and Immunotherapy Response in Head and Neck Squamous Cell Carcinoma Based on ceRNA Network and Immune Infiltration Analysis

Objectives

Patients with head and neck squamous cell carcinoma (HNSCC) have poor prognosis and show poor responses to immune checkpoint (IC) inhibitor (ICI) therapy. Competing endogenous RNA (ceRNA) networks, tumor-infiltrating immune cells (TIICs), and ICIs may influence tumor prognosis and response rates to ICI therapy. This study is aimed at identifying prognostic and IC-related biomarkers and key TIIC signatures to improve prognosis and ICI therapy response in HNSCC patients.

Methods and Results

Ninety-five long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and 1746 mRNAs were identified using three independent methods. We constructed a ceRNA network and estimated the proportions of 22 immune cell subtypes. Ten ceRNAs were related to prognosis according to Kaplan–Meier analysis. Two risk signatures based, respectively, on nine ceRNAs (ANLN, CFL2, ITGA5, KDELC1, KIF23, NFIA, PTX3, RELT, and TMC7) and three immune cell types (naïve B cells, neutrophils, and regulatory T cells) via univariate Cox regression, least absolute shrinkage and selection operator, and multivariate Cox regression analyses could accurately and independently predict the prognosis of HNSCC patients. Key mRNAs in the ceRNA network were significantly correlated with naïve B cells and regulatory T cells and with stage, grade, and immune and molecular subtype. Eight IC genes exhibited higher expression in tumor tissues and were correlated with eight key mRNAs in the ceRNA network in HNSCC patients with different HPV statuses according to coexpression and TIMER 2.0 analyses. Most drugs were effective in association with expression of these key signatures (ANLN, CFL2, ITGA5, KIF23, NFIA, PTX3, RELT, and TMC7) based on GSCALite analysis. The prognostic value of key biomarkers and associations between key ceRNAs and IC genes were validated using online databases. Eight key ceRNAs were confirmed to predict response to ICI in other cancers based on TIDE analysis.

Conclusions

We constructed two risk signatures to accurately predict prognosis in HNSCC. Key IC-related signatures may be associated with response to ICI therapy. Combinations of ICIs with inhibitors of eight key mRNAs may improve survival outcomes of HNSCC patients.

Hsa_circ_0001806 promotes glycolysis and cell progression in hepatocellular carcinoma through miR-125b/HK2

OBJECTIVE

Hepatocellular carcinoma (HCC) is one of the most common malignant tumours and a leading cause of cancer death. Circular RNA (circRNA) has been demonstrated to play an important role in regulating tumour development. The current study aims to explore the specific role of hsa_circ_0001806 during HCC progression.

METHODS

The expression of hsa_circ_0001806 in HCC tissues and cells was measured through qRT-PCR. Cell proliferation, apoptosis and migration were measured using CCK-8 and Annexin V/PI staining kits, and Transwell assay. Bioinformatics prediction and dual-luciferase reporter assay were adopted to explore the mechanism underlying the cell function of hsa_circ_0001806 in HCC cells. In addition, glycolysis was assessed by measuring the glucose uptake, lactate production and ATP level using a glucose assay kit, fluorometric lactate assay kit and ATP detection assay kit.

RESULTS

Hsa_circ_0001806 was up-regulated in HCC tissues and cells and positively associated with the advanced TNM stage, metastasis and poor overall survival. The overexpression of hsa_circ_0001806 promoted HCC cell proliferation, migration and glycolysis and inhibited cell apoptosis, while the silence of hsa_circ_0001806 showed an opposite effect. Furthermore, hsa_circ_0001806 acted as a sponge of miR-125b to up-regulate hexokinase II (HK2) expression. In addition, the inhibition of miR-125b and HK2 overexpression partly reversed the inhibitory effect of hsa_circ_0001806 silencing on HCC cell proliferation, migration and glycolysis.

CONCLUSION

The inhibition of hsa_circ_0001806 suppressed HCC cell proliferation, migration and glycolysis through mediating miR-125b/HK2 axis.

miR-33b-3p Acts as a Tumor Suppressor by Targeting DOCK4 in Prostate Cancer

Despite that androgen-deprivation therapy results in long-lasting responses, the disease inevitably progresses to metastatic castration-resistant prostate cancer. In this study, we identified miR-33b-3p as a tumor suppressor in prostate cancer. miR-33b-3p was significantly reduced in prostate cancer tissues, and the low expression of miR-33b-3p was correlated with poor overall survival of prostate cancer patients. Overexpression of miR-33b-3p inhibited both migration and invasion of highly metastatic prostate cancer cells whereas inhibition of miR-33b-3p promoted those processes in lowly metastatic cells. The in vivo results demonstrate that miR-33b-3p suppresses metastasis of tail vein inoculated prostate cancer cells to lung and lymph nodes in mice. DOCK4 was validated as the direct target of miR-33b-3p. miR-33b-3p decreased the expression of DOCK4 and restoration of DOCK4 could rescue miR-33b-3p inhibition on cell migration and invasion. Moreover, downregulation of miR-33b-3p was induced by bortezomib, the clinically used proteasome inhibitor, and overexpression of miR-33b-3p enhanced the insufficient inhibition of bortezomib on migration and invasion as well as metastasis of prostate cancer cells. In summary, our findings demonstrate that miR-33b-3p suppresses metastasis by targeting DOCK4 in prostate cancer. Our results suggest that enhancing miR-33b-3p expression may provide a promising therapeutic strategy for overcoming that proteasome inhibitor’s poor efficacy against metastatic prostate cancer.

In Vitro Investigations of miR-33a Expression in Estrogen Receptor-Targeting Therapies in Breast Cancer Cells

(1) Background: Increased fatty acid synthesis leads to the aggressive phenotype of breast cancer and renders efficiency of therapeutics. Regulatory microRNAs (miRNAs) on lipid biosynthesis pathways as miR-33a have potential to clarify the exact mechanism. (2) Methods: We determined miR-33a expression levels following exposure of MCF-7 and MDA-MB-231 breast cancer cells to estrogen receptor (ER) activator (estradiol-17β, E2) or anti-estrogens (ICI 182,780, Fulvestrant, FUL) at non-cytotoxic concentrations. We related miR-33a expression levels in the cells to cellular lipid biosynthesis-related pathways through immunoblotting. (3) Results: miR-33a mimic treatment led to significantly downregulation of fatty acid synthase (FASN) in MCF-7 cells but not in MDA-MB-231 cells in the presence of estradiol-17β (E2) or Fulvestrant (FUL). In contrast to the miR-33a inhibitor effect, miR-33a mimic co-transfection with E2 or FUL led to diminished AMP-activated protein kinase α (AMPKα) activity in MCF-7 cells. E2 increases FASN levels in MDA-MB-231 cells regardless of miR-33a cellular levels. miR-33a inhibitor co-treatment suppressed E2-mediated AMPKα activity in MDA-MB-231 cells. (4) Conclusions: The cellular expression levels of miR-33a are critical to understanding differential responses which include cellular energy sensors such as AMPKα activation status in breast cancer cells.

Genome-Wide Expression Difference of MicroRNAs in Basal Cell Carcinoma

Distinct expression of the miRNAs has rarely been explored in basal cell carcinoma (BCC) of skin, and the regulatory role of miRNAs in BCC development remains quite opaque. Here, we collected control tissues from adjacent noncancerous skin (n = 15; control group) and tissues at tumor centers from patients with cheek BCC (n = 15; BCC group) using punch biopsies. After six small RNA sequencing- (sRNA-seq-) based miRNA expression profiles were generated for both BCC and controls, including three biological replicates, we conducted comparative analysis on the sRNA-seq dataset, discovering 181 differentially expressed miRNAs (DEMs) out of the 1,873 miRNAs in BCCs. In order to validate the sRNA-seq data, expression of 15 randomly selected DEMs was measured using the TaqMan probe-based quantitative real-time PCR. Functional analysis of predicted target genes of DEMs in BCCs shows that these miRNAs are primarily involved in various types of cancers, immune response, epithelial growth, and morphogenesis, as well as energy production and metabolism, indicating that BCC development is caused, at least in part, by changes in miRNA regulation for biological and disease processes. In particular, the “basal cell carcinoma pathways” were found to be enriched by predicted DEM targets, and regulatory relationships between DEMs and their targeted genes in this pathway were further uncovered. These results revealed the association between BCCs and abundant miRNA molecules that regulate target genes, functional modules, and signaling pathways in carcinogenesis.

Circulating microRNA‑135a‑3p in serum extracellular vesicles as a potential biological marker of non‑alcoholic fatty liver disease

Non‑alcoholic fatty liver disease (NAFLD) is a widespread threat to human health. However, the present screening methods for NAFLD are time‑consuming or invasive. The present study aimed to assess the potential of microRNAs (miRNAs/miRs) in serum extracellular vesicles (EVs) as a biomarker of NAFLD. C57BL/6J mice were fed either a 12‑week high‑fat diet (HFD) or standard chow to establish NAFLD and control groups, respectively. Serum samples were obtained from the mouse model of NAFLD, as well as 50 patients with NAFLD and 50 healthy individuals, and EVs were extracted and verified. Using reverse transcription‑quantitative PCR, the mRNA expression level of selected miRNAs in the serum and EVs was analyzed. In order to determine the diagnostic value, receiver operating characteristic (ROC) curves were used. The mice treated with HFD showed notable hepatic steatosis and higher concentrations of serum alanine aminotransferase (ALT). There was also a significant decrease in the expression levels of miR‑135a‑3p, miR‑129b‑5p and miR‑504‑3p, and an increase in miR‑122‑5p expression levels in circulating EVs in mice treated with HFD and patients with NAFLD. There were also similar miR‑135a‑3p and miR‑122‑5p expression patterns in the serum. ROC analysis demonstrated that miR‑135a‑3p in circulating EVs was highly accurate in diagnosing NAFLD, with the area under the curve value being 0.849 (95% CI, 0.777‑0.921; P<0.0001). Bioinformatics analysis indicated that dysregulated miR‑135a‑3p was associated with 'platelet‑derived growth factor receptor signaling pathway' and 'AMP‑activated protein kinase signaling pathway'. In summary, circulating miR‑135a‑3p in EVs may serve as a potential non‑invasive biomarker to diagnose NAFLD. This miRNA was a more sensitive and specific biological marker for NAFLD compared with ALT.

The Novel Target of Liver Cancer: MicroRNA-4324 Regulates Cell Proliferation and Migration via Targeting Neuraminidase 3

Background: MicroRNA-4324 has been reported to regulate various biological malignant cancer. Nonetheless, the expression and molecular mechanism of miR-4324 in liver cancer remain rarely known. This study aimed to investigate the effect miR-4324 on the proliferation, invasion and migration of hepatoma cells. Methods: The mRNA level of miR-4324 was assessed in four hepatoma cell lines (HepG2, Huh7, MHCC97, HB611) and human embryonic liver cell, HHL5. MiR-4324 was over-expressed in hepatoma cells. Subsequently, the effects of miR-4324 on cell proliferation, migration and invasion and the underlying molecular mechanisms were detected. Results: Our data indicated that miR-4324 was down-regulation in hepatoma cell lines compared with HHL5. Overexpression of miR-4324 inhibits cellular proliferation, colony-formation, migration and invasion abilities of hepatoma cells. However, the biological effects of miR-4324 overexpression on hepatoma cells were reversed after overexpressing NEU3. Conclusions: Our findings concluded that miR-4324 inhibits biological functions of hepatoma cells by targeting NEU3 and it might be a potential target for the treatment of liver cancer.

Exosomal LINC00355 derived from cancer-associated fibroblasts promotes bladder cancer cell resistance to cisplatin by regulating miR-34b-5p/ABCB1 axis

Cisplatin resistance is a major challenge for bladder cancer (BC). Evidence indicates that exosome derived from cancer-associated fibroblasts (CAF-Exo) can promote chemotherapy resistance in various human tumors by delivering bioactive molecules. We have previously demonstrated that CAF-derived exosomal LINC00355 promotes BC cell proliferation and invasion. However, the underlying mechanisms are still unclear. In this study, we aimed to investigate the role and mechanisms of CAF-derived exosomal LINC00355 in BC cell resistance to cisplatin. Exosomes were isolated from normal fibroblasts (NFs) and BC tumor-derived CAFs, namely, NF-Exo and CAF-Exo. CAFs were transfected with si-Ctrl or si-LINC00355 and then different exosomes were isolated, namely, CAFsi-Ctrl-Exo and CAFsi-LINC00355-Exo. The human BC cell lines (T24 and 5367) were incubated with NF-Exo, CAF-Exo, CAFsi-Ctrl-Exo, and CAFsi-LINC00355-Exo in the presence of cisplatin. MTT proliferation assay and flow cytometric analysis showed that CAF-Exo promoted BC cell resistance to cisplatin and upregulated ABCB1 expression in BC cells by transferring LINC00355 to BC cells. Luciferase activity assay confirmed the interaction between miR-34b-5p and LINC00355 or ABCB1. qRT-PCR and western blot analysis further showed that LINC00355 sponged miR-34b-5p to upregulate ABCB1 expression. However, the promoting effects of CAF-Exo on BC cell resistance to cisplatin were abolished by miR-34b-5p overexpression and ABCB1 silencing. In conclusion, exosomal LINC00355 derived from CAFs promotes BC cell resistance to cisplatin by regulating the miR-34b-5p/ABCB1 axis.

The Construction and Analysis of Tumor-Infiltrating Immune Cells and ceRNA Networks in Bladder Cancer

Background

Bladder cancer (BLCA) is the 11th most common malignancy worldwide. Although significant improvements have been made in screening, diagnosis, and precise management in recent years, the prognosis of BLCA remains bleak.

Objectives

This study aimed to investigate the prognostic significance of tumor-infiltrating immune cells and construct ceRNA networks in BLCA patients.

Methods

The expression data of BLCA patients were obtained from The Cancer Genome Atlas (TCGA) database. A competing endogenous RNA (ceRNA) network was constructed to identify the hub genes involved in the prognosis of BLCA. The CIBERSORT algorithm was utilized to investigate the infiltration levels of 22 subsets of immune cells. Ultimately, the nomogram was generated to visualize the survival probability of each patient, with the calibration curve being performed to assess its performance. Furthermore, the Pearson correlation test was used to explore the correlation between the identified hub genes in the ceRNA network and the prognostic-related immune cells.

Results

A total of eight elements in the ceRNA network were considered as key members and correlated with the prognosis of BLCA, including ELN, SREBF1, DSC2, TTLL7, DIP2C, SATB1, hsa-miR-20a-5p, and hsa-miR-29c-3p. T cells CD8, T cells follicular helper (Tfh), and neutrophils were identified as independent prognostic factors in BLCA. The co-expression analysis showed that there was a significant correlation between the identified hub genes and immune cells.

Conclusion

Our results suggest that the mechanism of hsa-miR-29c-3p regulates the expression of ELN and DSC2, and the infiltration of Tfh and neutrophils might play pivotal roles in the progression of BLCA.

Potential therapeutic approaches of microRNAs for COVID-19: Challenges and opportunities

The coronavirus disease 2019 (COVID-19) emerges as current outbreak cause by Novel Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2). This infection affects respiratory system and provides uncontrolled systemic inflammatory response as cytokine storm. The main concern about SARS-CoV-2 pandemic is high viral pathogenicity with no specific drugs. MicroRNAs (miRs) as small non-coding RNAs (21–25 ​nt) regulate gene expression. The SARS-CoV-2 encoded-miRs affect human genes that involved in transcription, translation, apoptosis, immune response and inflammation. Also, they alter self-gene regulation and hijacked host miRs that provide protective environment to maintain its latency. On the other hand, Host miRs play critical role in viral gene expression to restrict infection. Over expression/inhibition of miRs might result in cell cycle irregularity, impaired immune response or cancer. In this manner, exact role of each miR should be specified. Mimic encoded-miRs like antagomirs showed successful result in phases of clinical trial prevent from negative effects of viral encoded-miRs. Products of mimic miRs are inexpensive corresponds to synthesis of primer; they are short and nanoscale in size. Although SARS-CoV-2 genome is undergoing evaluation, detection of exact molecular pathogenesis open up opportunities to for vaccine development. Salivaomics can evaluate SARS-CoV-2 genome, transcriptome, proteome and biomarkers like miRs in oral related and cancer disease. In this review, we studied the challenge and opportunities of miRs in therapeutic approach for SARS-CoV-2 infection, then overviewed the role of miRs in saliva droplet during SARS-CoV-2 infection and related cancer.

miRNA biomarkers for predicting overall survival outcomes for head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a malignant tumor of the upper aerodigestive tract. The loss and gain of miRNA function promote cancer development through various mechanisms. RNA sequencing (RNA-seq) and miRNAs sequencing data from the Cancer Genome Atlas (TCGA) was used to show the dysfunctional miRNAs microenvironment and to provide useful biomarkers for miRNAs therapy. Seven miRNAs were found to be independent prognostic factors of HNSCC patients in the training cohort. A total of 60 target genes for these miRNAs were predicted. Nine target genes (CDCA4, CXCL14, FLNC, KLF7, NBEAL2, P4HA1, PFKM, PFN2 and SEPPINE1) were correlated with patient's overall survival (OS) outcomes. We identified novel miRNAs markers for the prognosis of head and neck squamous cell carcinoma.

Integrated analysis of circRNA-miRNA-mRNA network reveals potential prognostic biomarkers for radiotherapies with X-rays and carbon ions in non-small cell lung cancer

Background

This work was aimed at exploring the regulatory network of non-coding RNA (ncRNA) especially circular RNA (circRNA) and microRNA (miRNA), in the sensitivity of non-small cell lung cancer (NSCLC) cells to low linear energy transfer (LET) X-ray and high-LET carbon ion irradiations.

Methods

The radioresistant NSCLC cell line A549-R11 was obtained from its parental cell line A549 through irradiation with X-rays of 2.0 Gy per fraction for 30 times. The sensitivities of A549, A549-R11 and H1299 cells exposed to X-rays and carbon ions were verified using the colony formation assay. A comprehensive circRNA-miRNA-mRNA network was constructed through the sequencing data in parental A549, acquired radioresistant A549-R11 and intrinsic radioresistant H1299 cells, and the network was further optimized according to the prognostic results from the TCGA and GEO databases.

Results

Based on high-throughput sequencing of circRNAs, we found that 40 circRNAs were up-regulated while 184 circRNAs were down-regulated in the intersection of the sets of A549-R11 and H1299 cells. Subsequently, a circRNA- miRNA-mRNA network, including 14 interactive pairs and 8 circRNAs, 4 overall survival-associated miRNAs, and 4 mRNAs, was constructed through the high-throughput data screening and bioinformatics methods.

Conclusions

Our results provide a complete understanding to the regulatory mechanism of the sensitivities to low-LET X-ray and high-LET carbon ion irradiations, and might be helpful to screen potential biomarkers for predicting the Carbon-ion radiotherapy (CIRT) and X-ray radiotherapy responses in NSCLC.

Clinical value of microRNA-19a-3p and microRNA-99a-5p in bladder cancer

INTRODUCTION

MicroRNAs (miRNA) are small (approximately 17 to 25 nucleotides in length), single stranded, non-coding RNAs that play an important role in the control of gene expression at the post-transcriptional stage, by inhibiting protein translation or promoting mRNA degradation. The main aim of the study was to evaluate the clinical utility of the tested markers (miRNAs 19a-3p and 99a-5p), which might be important in the diagnostics of non-invasive bladder cancer (BC).

MATERIAL AND METHODS

The study involved a group of 60 patients suffering from BC (histopathologically confirmed), in which 20 patients were diagnosed with muscle invasive BC (INBC) and 40 patients with non-muscle invasive BC (NINBC). The control group consisted of 20 samples of normal urothelium, which did not show any cancerous changes during histopathological examination. We assessed the expression of microRNA, using real-time PCR and the miRCURY LNA Universal RT microRNA PCR Kit by Exiqon, Denmark.

RESULTS

Reduced expression of both analyzed markers was observed in most cases: miR-19a-3p in 51.8% and miR-99a-5p in 65.5% (as follows Mann-Whitney U test p < 0.000001 and Student's t test p = 0.034262). Moreover, miR-19a-3p in our tested group was useful to differentiate between low and high grade disease in non-invasive stages (t test p = 0.0315435). Furthermore, miR-19a-3p and miR-99a-5p were able to discriminate patients in low grade for groups with or without recurrence.

CONCLUSIONS

Our data indicated that miR-19a-3p and miR-99a-5p were significantly altered in bladder cancer samples and useful as diagnostic markers.

MicroRNA: Another Pharmacological Avenue for Colorectal Cancer?

MicroRNAs (miR) are single-stranded RNA of 21-23 nucleotides in length that repress mRNA translation and induces mRNA degradation. miR acts as an endogenous factor of gene expression and plays a crucial part in cancer biology such as cell development, proliferation, differentiation, and apoptosis. Numerous research has indicated that dysregulation of miR associates with colorectal carcinogenesis. In this review article, we firstly introduce the background of miR and colorectal cancer, and the mechanisms of miR in colorectal cancer, such as the proliferation, apoptosis, and progression. Then, we summarize the theranostic value of miR in colorectal cancer. Eventually, we discuss the potential directions and perspectives of miR. This article serves as a guide for further studies and implicate miR as a potent theranostic target for colorectal cancer.

An RNA-sequencing-based transcriptome for a significantly prognostic novel driver signature identification in bladder urothelial carcinoma

Bladder cancer (BC) is the ninth most common malignancy worldwide. Bladder urothelial carcinoma (BLCA) constitutes more than 90% of bladder cancer (BC). The five-year survival rate is 5–70%, and patients with BLCA have a poor clinical outcome. The identification of novel clinical molecular markers in BLCA is still urgent to allow for predicting clinical outcomes. This study aimed to identify a novel signature integrating the three-dimension transcriptome of protein coding genes, long non-coding RNAs, microRNAs that is related to the overall survival of patients with BLCA, contributing to earlier prediction and effective treatment selection, as well as to the verification of the established model in the subtypes identified. Gene expression profiling and the clinical information of 400 patients diagnosed with BLCA were retrieved from The Cancer Genome Atlas (TCGA) database. A univariate Cox regression analysis, robust likelihood-based survival modelling analysis and random forests for survival regression and classification algorithms were used to identify the critical biomarkers. A multivariate Cox regression analysis was utilized to construct a risk score formula with a maximum area under the curve (AUC = 0.7669 in the training set). The significant signature could classify patients into high-risk and low-risk groups with significant differences in overall survival time. Similar results were confirmed in the test set (AUC = 0.645) and in the entire set (AUC = 0.710). The multivariate Cox regression analysis indicated that the five-RNA signature was an independent predictive factor for patients with BLCA. Non-negative matrix factorization and a similarity network fusion algorithm were applied for identifying three molecular subtypes. The signature could separate patients in every subtype into high- and low- groups with a distinct difference. Gene set variation analysis of protein-coding genes associated with the five prognostic RNAs demonstrated that the co-expressed protein-coding genes were involved in the pathways and biological process of tumourigenesis. The five-RNA signature could serve as to some degree a reliable independent signature for predicting outcome in patients with BLCA.

ExoceRNA atlas: A database of cancer ceRNAs in human blood exosomes

AIMS

Competing endogenous RNAs (ceRNAs) play essential roles in cancer pathogenesis and those in exosomes have been the promising biomarkers for cancer diagnose and therapy. We aim to identify potential active ceRNA pairs in cancer blood exosomes by combining TCGA and exoRBase.

MAIN METHODS

Two strict screening criteria were implemented, including hypergeometric test on the targets predicted by RNA22 for differential miRNAs and Pearson test on the candidate mRNAs and lncRNAs for each cancer. Then2638292, 4925485 and 70669 ceRNAs in blood exosomes are available for colorectal cancer (CRC), hepatocellular carcinoma (HCC) and pancreatic adenocarcinoma (PAAD), respectively.

KEY FINDINGS

A comprehensive functional analysis on differential miRNAs in cancer blood exosomes indicates that they play important roles in development of cancer by degrading or inhibiting the post-transcription translation level of mRNA or by acting as mediators to regulate the expression of mRNA. Topological and biological functional analysis of ceRNA networks demonstrate that hub ceRNAs involve in cancer-related biological pathways and processes, so as to influence the occurrence and development of cancer and would be the potential biomarkers for three cancers. Finally, we designed a web-accessible database, ExoceRNA Atlas (https://www.exocerna-atlas.com/exoceRNA#/) as a repository of ceRNAs in blood exosomes. It can friendly search, browse and visualize ceRNA networks of the query genes along with giving the detailed functional analysis results. The entire ceRNA data can also be freely downloaded.

SIGNIFICANCE

ExoceRNA Atlas will serve as a powerful public resource for identifying ceRNAs and greatly deepen our understanding their functions in cancer exosomes.

Molecular Mechanisms of the Anti-Cancer Effects of Isothiocyanates from Cruciferous Vegetables in Bladder Cancer

Bladder cancer (BC) is a representative of urological cancer with a high recurrence and metastasis potential. Currently, cisplatin-based chemotherapy and immune checkpoint inhibitors are used as standard therapy in patients with advanced/metastatic BC. However, these therapies often show severe adverse events, and prolongation of survival is unsatisfactory. Therefore, a treatment strategy using natural compounds is of great interest. In this review, we focused on the anti-cancer effects of isothiocyanates (ITCs) derived from cruciferous vegetables, which are widely cultivated and consumed in many regions worldwide. Specifically, we discuss the anti-cancer effects of four ITC compounds—allyl isothiocyanate, benzyl isothiocyanate, sulforaphane, and phenethyl isothiocyanate—in BC; the molecular mechanisms underlying their anti-cancer effects; current trends and future direction of ITC-based treatment strategies; and the carcinogenic potential of ITCs. We also discuss the advantages and limitations of each ITC in BC treatment, furthering the consideration of ITCs in treatment strategies and for improving the prognosis of patients with BC.

miR-4324 functions as a tumor suppressor in colorectal cancer by targeting HOXB2

Objective

MicroRNAs (miRNAs) are reported to have crucial roles in human cancers; however, their role in colorectal cancer (CRC) remains largely unknown.

Methods

In this study, we analyzed the expression of miR-4324 in CRC cell lines using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We also examined miR-4324 expression in CRC tumor tissues using a miRNA expression dataset obtained from the Gene Expression Omnibus. We validated the connection between miR-4324 and homeobox B2 (HOXB2) using a luciferase activity reporter assay and western blotting. The effects of miR-4324 and HOXB2 on CRC cell malignant behaviors in vitro were further investigated.

Results

miR-4324 expression was significantly decreased in both CRC tumor tissues and cell lines. Overexpression of miR-4324 suppressed CRC cell proliferation, migration, and invasion. In contrast, overexpression of HOXB2 promoted CRC malignant cell behaviors. Furthermore, we validated HOXB2 as a direct target of miR-4324.

Conclusions

miR-4324 expression was decreased in CRC. miR-4324 regulates CRC cell proliferation, migration, and invasion by targeting HOXB2.

MicroRNAs Which Can Prognosticate Aggressiveness of Bladder Cancer

Bladder cancer (BC) is still characterized by a very high death rate in patients with this disease. One of the reasons for this is the lack of adequate markers which could help determine the biological potential of the tumor to develop into its invasive stage. It has been found that some microRNAs (miRNAs) correlate with disease progression. The purpose of this study was to identify which miRNAs can accurately predict the presence of BC and can differentiate low grade (LG) tumors from high grade (HG) tumors. The study included 55 patients with diagnosed bladder cancer and 30 persons belonging to the control group. The expression of seven selected miRNAs was estimated with the real-time PCR technique according to miR-103-5p (for the normalization of the results). Receiver operating characteristics (ROC) curves and the area under the curve (AUC) were used to evaluate the feasibility of using selected markers as biomarkers for detecting BC and discriminating non-muscle invasive BC (NMIBC) from muscle invasive BC (MIBC). For HG tumors, the relevant classifiers are miR-205-5p and miR-20a-5p, whereas miR-205-5p and miR-182-5p are for LG (AUC = 0.964 and AUC = 0.992, respectively). NMIBC patients with LG disease are characterized by significantly higher miR-130b-3p expression values compared to patients in HG tumors.

MiR-125b-5p suppresses the bladder cancer progression via targeting HK2 and suppressing PI3K/AKT pathway

Bladder cancer (BCa) is identified as the most common malignant solid cancer in the urogenital tract. Recently, dysregulation of miRNAs has received more attention because of its extensive role in the carcinogenesis of BCa. This research was designed to verify how miR-125b-5p be involved in BCa development. The expression of miR-125b-5p was detected in 52 pairs of BCa specimens and adjacent normal bladder specimens. The effects of miR-125b-5p on BCa viability, migration, and apoptosis in vitro were examined. We then examined directly target gene(s) of miR-125b-5p in BCa cells. Our data demonstrated that miR-125b-5p was decreased in BCa tissues and cell lines. Patients with low miR-125b-5p expression had obviously shorter 5-year survival time. Lower miR-125b-5p expression was significant correlated with distant metastasis, tumor size and lymph node metastasis. Ectopic expression of miR-125b-5p inhibited the BCa cell viability and migration and induced cell apoptosis. Furthermore, HK2 was confirmed regulated by miR-125b-5p. HK2 recovered miR-125b-5p-mediated suppression of BCa cell viability and migration. In addition, miR-125b-5p also exhibited suppressive effect on PI3K/AKT pathway. Overall, these data indicate that miR-125b-5p played a role in the suppressive effect on BCa by targeting HK2 through suppressing PI3K/AKT pathway and offer a potential therapeutic target for BCa.

MiRNA-217 accelerates the proliferation and migration of bladder cancer via inhibiting KMT2D

To uncover the biological function of miRNA-217 in the progression of bladder cancer and the underlying mechanism. Potential miRNAs binding KMT2D were predicted through online bioinformatics. Their expression levels in bladder cancer tissues and adjacent ones were determined. Through Pearson correlation analysis and survival analysis, the most potential miRNA candidate (miRNA-217) that targets and regulates KMT2D in bladder cancer was selected. Subsequently, expression levels of miRNA-217 and KMT2D in non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC) were detected. MiRNA-217 level in bladder cancer cell lines was determined as well. The interaction between KMT2D and miRNA-217 was verified by dual-luciferase reporter gene assay. Finally, regulatory effect of miRNA-217 on viability and migration in T24 and UMUC-3 cells were investigated. Five potential candidates that were upstream genes binding KMT2D were searched by bioinformatics. Among them, miRNA-217 was remarkably upregulated in bladder cancer tissues and closely linked to poor prognosis of affected patients. Moreover, dual-luciferase reporter gene assay verified the interaction between miRNA-217 and KMT2D. MiRNA-217 was able to downregulate mRNA and protein levels of KMT2D. Furthermore, knockdown of miRNA-217 attenuated viability and migration in bladder cancer cells. MiRNA-217 accelerates proliferative and migratory abilities in bladder cancer via inhibiting the level of tumor suppressor KMT2D, thereafter leading to the poor prognosis in bladder cancer patients.

The functions of microRNA-124 on bladder cancer

Background: To detect the expression of miR-124 in bladder cancer (BC) cell lines and tissue specimens and to analyze its association with the growth of the BC cells.

Methods: Quantitative real-time polymerase chain reaction (qPCR) was applied to examine the expression of miR-124 in BC cell lines and tissues. The function of miR-124 in modulating cell proliferation was assessed in BC cells with miRNA-124 overexpression; the cell viability was identified by Cell Count Kit-8; flow cytometry was employed to detect the cell cycle; the expressions of E2F3, cyclin-dependent kinase 4 (CDK4), Ki-67 and vascular endothelial growth factor (VEGF) were tested by qPCR and Western blot; angiogenesis experiment was performed to analysis changes in angiogenesis rate; and bioinformatics prediction and dual luciferase reporter system were employed to identify the target of miR-124.

Results: Survival curve data showed that the expression of MicroRNA-124 was positively correlated with survival. MicroRNA-124 expression was significantly decreased in BC cell lines and tissues. Bioinformatics prediction and dual luciferase reporter system verified CDK4 as a direct target of miR-124, which regulated the proliferation of BC cells by directly inhibiting CDK4. BC cells over-expressing miR-124 showed significantly inhibited cell viability, decreased angiogenesis rate, prevented cell proliferation and diminished the expression of E2F3, CDK4, Ki-67 and VEGF. All of these changes were reversed by over-expressing CDK4.

Conclusion: MicroRNA-124 suppressed the proliferation of CRC cells by directly targeting CDK4, which provides a target for improving the therapeutic effect of BC.