miR-145 induces caspase-dependent and -independent cell death in urothelial cancer cell lines with targeting of an expression signature present in Ta bladder tumors

The Suppression of the Epithelial to Mesenchymal Transition in Prostate Cancer through the Targeting of MYO6 Using MiR-145-5p

Aberrant expression of miR-145-5p has been observed in prostate cancer where is has been suggested to play a tumor suppressor role. In other cancers, miR-145-5p acts as an inhibitor of epithelial-to-mesenchymal transition (EMT), a key molecular process for tumor progression. However, the interaction between miR-145-5p and EMT remains to be elucidated in prostate cancer. In this paper the link between miR-145-5p and EMT in prostate cancer was investigated using a combination of in silico and in vitro analyses. miR-145-5p expression was significantly lower in prostate cancer cell lines compared to normal prostate cells. Bioinformatic analysis of The Cancer Genome Atlas prostate adenocarcinoma (TCGA PRAD) data showed significant downregulation of miR-145-5p in prostate cancer, correlating with disease progression. Functional enrichment analysis significantly associated miR-145-5p and its target genes with EMT. MYO6, an EMT-associated gene, was identified and validated as a novel target of miR-145-5p in prostate cancer cells. In vitro manipulation of miR-145-5p levels significantly altered cell proliferation, clonogenicity, migration and expression of EMT-associated markers. Additional TCGA PRAD analysis suggested miR-145-5p tumor expression may be useful predictor of disease recurrence. In summary, this is the first study to report that miR-145-5p may inhibit EMT by targeting MYO6 in prostate cancer cells. The findings suggest miR-145-5p could be a useful diagnostic and prognostic biomarker for prostate cancer.

The Simultaneous Effects of miR-145-5p and hsa-let-7a-3p on Colorectal Tumorigenesis: In Vitro Evidence

Purpose

MicroRNAs (miRNAs) are a group of small regulatory non-coding RNAs, which are dysregulated through tumor progression. let-7 and MIR-145 are both tumor suppressor microRNAs that are downregulated in a wide array of cancers including colorectal cancer (CRC).

Methods

This study was aimed to investigate the effect of simultaneous replacement of these two tumor suppressor miRNAs on proliferation, apoptosis, and migration of CRC cells. HCT-116 with lower expression levels of hsa-let-7a-3p and MIR-145-5p was selected for functional investigations. The cells were cultured and transfected with hsa-let-7a and MIR-145, separately and in combination. Cell viability and apoptosis rates were assessed by MTT assay and flow cytometry, respectively. Cell cycle status was further evaluated using flow cytometry and qRT-PCR was employed to evaluate gene expression.

Results

The obtained results showed that exogenous overexpression of MIR-145 and hsa-let-7a in HCT-116 cells could cooperatively decrease CRC cell proliferation and induce sub-G1 cell cycle arrest. Moreover, hsa-let-7a and MIR-145 co-transfection significantly increased apoptosis induction compared to separate transfected cells and control through modulating the expression levels of apoptosis-related genes including Bax, Bcl-2, P53, Caspase-3, Caspase-8, and Caspase-9. Furthermore, qRT-PCR results illustrated that hsa-let-7a and MIR-145 combination more effectively downregulated MMP-9 and MMP-2 expression, as the important modulators of metastasis, compared to the controls.

Conclusion

Taken together, considering that exogenous overexpression of MIR-145 and hsa-let-7a showed cooperative anti-cancer effects on CRC cells, their combination may be considered as a novel therapeutic strategy for the treatment of CRC.

Multiple roles of LncRNA-BMNCR on cell proliferation and apoptosis by targeting miR-145/CBFB axis in BMECs

Bovine mastitis is one of the most serious and costly disease affecting dairy cattle production. The present study explored the inflammatory response and autoprotective mechanism of a novel specific high expression BMNCR (bovine mastitis related long non-coding RNA) in S. aureus induced mastitis by miR-145/CBFB axis in dairy cows from the perspective of molecular genetics. In bovine mammary epithelial cells, we preformed loss of function experiments to detect changes in cytokine, proliferation and apoptosis by qRT-PCR, western blot, flow cytometry and EdU staining. The results demonstrated that BMNCR significantly increased cell apoptosis, and inhibited cell proliferation. However, the secretion of IL-1α, IL-2, IL-6, IL-8 and IL-12 were enhanced after knock-down BMNCR. Bioinformatics analysis demonstrated that BMNCR could target 8 miRNAs, in-depth analyses indicated that BMNCR acts as a molecular sponge for bta-miR-145 and CBFB was one of 23 target gene of bta-miR-145 . The results of the present study demonstrated that the role of BMNCR in S. aureus induced mastitis can be mediated by sponge bta-miR-145 activating CBFB expression. BMNCR could be a potential target for mastitis diagnosis and therapy, which may enrich the theoretical research of therapeutic intervention, and further increase milk yield and improve milk quality.

Expression of miR-145 and miR-18b in Peripheral Blood Samples of Head and Neck Cancer Patients

Head and neck squamous cell carcinomas (HNSCC) is one of the most prevalent type of cancer known in Indian population. Studies are needed to identify the early biomarkers for HNSCC. MicroRNAs (miRNAs) are non-coding RNA molecules, expression of which can be used as biomarker for early diagnosis of HNSCC. For miRNA profiling total RNA, which also contained small RNAs were isolated from ten HNSCC tissue samples and adjacent control. Purity and concentration of eluted RNA was assessed using the NanoDrop1000® spectrophotometer, Reverse Transcription reaction was carried out with megaplex RT primers of pool A and pool B and the expression of selected miRNAs (miR-143/145 and miR-18a/b) was measured using TaqMan primers specific for mature miRNAs. Our study showed dramatic downregulation in expression of two miRNAs, miR-18b and miR-145 in blood samples of HNSCC patients, which are inhibitor of tumorigenesis and can be targeted as biomarker of HNSCC pathogenesis therefore developing avenues for miRNA role in prognosis and therapeutics.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-023-01119-2.

Targeting microRNA-145-mediated progressive phenotypes of early bladder cancer in a molecularly defined in vivo model

A progressive subclass of early-stage non-muscle-invasive bladder cancer (NMIBC) frequently recurs and progress into invasive carcinoma, thus decreasing the overall survival rate of NMIBC. However, therapeutic development for progressive NMIBC has been challenging due to the lack of molecularly validated in vivo models and agents targeting its genetic vulnerability. We herein molecularly characterized an interventional model of progressive NMIBC and revealed the principal functions and therapeutic potential of microRNA-145 (miR-145) in early bladder tumorigenesis. N-butyl-N-(4-hydroxybutyl)nitrosamine-induced premalignant lesions (BiPLs) in rats exhibited downregulated expression of miR-145 as well as highly similar mutation/expression profiles to those of the human progressive NMIBC subclass with the worst prognosis. The expression patterns of miR-145 inversely correlated with those of BC-related oncogenes in BiPLs. We also demonstrated that miR-145 dominantly regulated interferon pathways and c-Myc expression, which play a crucial role in the pathogenesis of progressive NMIBC. Furthermore, we demonstrated that miR-145 replacement with a novel miR-145-based intravesical agent (miR-145S1) significantly inhibited the progression of BiPLs in vivo. These results provide insights into the essential role of miR-145 as the earliest-acting oncogenic driver of bladder tumorigenesis as well as a validated interventional model and novel miR-145-based nucleic acid therapeutic agent for progressive NMIBC.

Epigenetic and Immunological Features of Bladder Cancer

Bladder cancer (BLCA) is one of the most common types of malignant tumors of the urogenital system in adults. Globally, the incidence of BLCA is more than 500,000 new cases worldwide annually, and every year, the number of registered cases of BLCA increases noticeably. Currently, the diagnosis of BLCA is based on cystoscopy and cytological examination of urine and additional laboratory and instrumental studies. However, cystoscopy is an invasive study, and voided urine cytology has a low level of sensitivity, so there is a clear need to develop more reliable markers and test systems for detecting the disease with high sensitivity and specificity. Human body fluids (urine, serum, and plasma) are known to contain significant amounts of tumorigenic nucleic acids, circulating immune cells and proinflammatory mediators that can serve as noninvasive biomarkers, particularly useful for early cancer detection, follow-up of patients, and personalization of their treatment. The review describes the most significant advances in epigenetics of BLCA.

Molecular switch in human diseases-disintegrin and metalloproteinases, ADAM17

The ADAMs (a disintegrin and metalloproteinase) are a family of cell surface proteins with crucial roles in the regulation of cell adhesion, cell proliferation to migration, proteolysis and cell signaling transduction pathways. Among these enzymes, the ADAM17 shows significant effects in the “ectodomain shedding” of its substrates such as cytokines (e.g., tumor necrosis factor α, TNFα), growth factors (e.g., epidermal growth factor, EGF), adhesion proteins (e.g., L-selectin), and their receptors (e.g., IL-6R and TNFα). Several studies focus on the underlying molecular mechanisms of ADAM17 in diseased conditions. Here, we took several different approaches to elucidate the function of ADAM17, the participation of ADAM17 in several human diseases, and the potential as targeted therapy reagents. As more and more studies verify the miRNA-mediated expression variation of ADAM17, the specific regulation network of miRNAs and ADAM17 was exploited in this review as well.

The p53/miR-145a Axis Promotes Cellular Senescence and Inhibits Osteogenic Differentiation by Targeting Cbfb in Mesenchymal Stem Cells

The osteogenic differentiation capacity of senescent bone marrow mesenchymal stem cells (MSCs) is reduced. p53 not only regulates cellular senescence but also functions as a negative regulator in bone formation. However, the role of p53 in MSCs senescence and differentiation has not been extensively explored. In the present study, we investigated the molecular mechanism of p53 in MSCs senescence and osteogenic differentiation. We found that p53 was upregulated during cellular senescence and osteogenic differentiation of MSCs respectively induced by H2O2 and BMP9. Similarly, the expression of p53-induced miR-145a was increased significantly. Furthermore, Overexpression of miR-145a in MSCs promoted cellular senescence and inhibited osteogenic differentiation. Then, we identified that p53-induced miR-145a inhibited osteogenic differentiation by targeting core binding factor beta (Cbfb), and the restoration of Cbfb expression rescued the inhibitory effects of miRNA-145a. In summary, our results indicate that p53/miR-145a axis exert its functions both in promoting senescence and inhibiting osteogenesis of MSCs, and the novel p53/miR-145a/Cbfb axis in osteogenic differentiation of MSCs may represent new targets in the treatment of osteoporosis.

MicroRNA-145 targets in cancer and the cardiovascular system: evidence for common signaling pathways

miRNAs are small regulatory RNAs which govern gene expression post-transcriptionally by primarily binding to the 3'-UTR of mRNA target genes. miR-145 is a well-studied miRNA that has been implicated in controlling a range of biological processes. miR-145 is expressed in a variety of tissues and cell types and acts as a tumor-suppressor by regulating target gene signaling pathways involved in different aspects of tumor growth and progression. There is also strong evidence that highlights the important functions of miR-145 in the cardiovascular system. Here, we review the mechanisms of miR-145 in tumorigenesis and cancer progression and compare and contrast with the roles of miR-145 in cardiovascular development and disease. We discuss the important targets of miR-145 in cancer and their possible link to the cardiovascular system.

MicroRNAs and target molecules in bladder cancer

Bladder cancer (BC) is considered as one of the most common malignant tumors in humans with complex pathogenesis including gene expression variation, protein degradation, and changes in signaling pathways. Many studies on involved miRNAs in BC have demonstrated that they could be used as potential biomarkers in the prognosis, response to treatment, and screening before the cancerous phenotype onset. MicroRNAs (miRNAs) regulate many cellular processes through their different effects on special targets along with modifying signaling pathways, apoptosis, cell growth, and differentiation. The diverse expression of miRNAs in cancerous tissues could mediate procedures leading to the oncogenic or suppressor behavior of certain genes in cancer cells. Since a specific miRNA may have multiple targets, an mRNA could also be regulated by multiple miRNAs which further demonstrates the actual role of miRNAs in cancer. In addition, miRNAs can be utilized as biomarkers in some cancers that cannot be screened in the early stages. Hence, finding blood, urine, or tissue miRNA biomarkers by novel or routine gene expression method could be an essential step in the prognosis and control of cancer. In the present review, we have thoroughly evaluated the recent findings on different miRNAs in BC which can provide comprehensive information on better understanding the role of diverse miRNAs and better decision making regarding the new approaches in the diagnosis, prognosis, prevention, and treatment of BC.

The immunomodulatory effects of mesenchymal stromal cell-based therapy in human and animal models of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune inflammatory disease with no absolute cure. Although the exact etiopathogenesis of SLE is still enigmatic, it has been well demonstrated that a combination of genetic predisposition and environmental factors trigger a disturbance in immune responses and thereby participate in the development of this condition. Almost all available therapeutic strategies in SLE are primarily based on the administration of immunosuppressive drugs and are not curative. Mesenchymal stromal cells (MSCs) are a subset of non-hematopoietic adult stem cells that can be isolated from many adult tissues and are increasingly recognized as immune response modulating agents. MSC-mediated inhibition of immune responses is a complex mechanism that involves almost every aspect of the immune response. MSCs suppress the maturation of antigen-presenting cells (DC and MQ), proliferation of T cells (Th1, T17, and Th2), proliferation and immunoglobulin production of B cells, the cytotoxic activity of CTL and NK cells in addition to increasing regulatory cytokines (TGF-β and IL10), and decreasing inflammatory cytokines (IL17, INF-ϒ, TNF-α, and IL12) levels. MSCs have shown encouraging results in the treatment of several autoimmune diseases, in particular SLE. This report aims to review the beneficial and therapeutic properties of MSCs; it also focuses on the results of animal model studies, preclinical studies, and clinical trials of MSC therapy in SLE from the immunoregulatory aspect.

Non-coding RNA in bladder cancer

Bladder cancer is the tenth most common cancer worldwide and has been associated with high mortality and morbidity. Although the treatment of bladder cancer is based on well-defined tumor classifications and gradings, patients still experience different clinical response. The heterogeneity of this disease calls for substantial research with more in-depth molecular characterization, with the hope of identifying new diagnostic and treatment options. In recent years, non-coding RNAs (ncRNAs), particularly, microRNAs (miRNAs), long non-coding RNA (lncRNAs), and circular RNAs (circRNAs) were found to be associated with bladder cancer occurrence and development. This review highlights the recent findings concerning ncRNAs and their relevance to the pathogenesis of bladder cancer. This may provide a foundation for developing highly specific diagnostic tools and more robust therapeutic strategies in the future.

Exploration of bladder cancer-associated methylated miRNAs by methylated DNA immunoprecipitation sequencing

BACKGROUND

The current study aimed to explore the association between two epigenomic components, miRNA and DNA methylation, in bladder cancer (BC).

METHODS

Eight paired samples of tumor tissue and matched adjacent normal tissues from BC patients were subjected to methylated DNA immunoprecipitation sequencing and sRNA-Seq for differentially methylated miRNA genes and differential miRNA analysis. The miRNAs regulated by DNA methylation were screened and their functions involved in BC were analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) as well as a miRNA-mRNA interaction network.

RESULTS

The methylation levels of 212 genes were different between tumors and normal tissues with specific enrichment at transcription initiation and termination sites. Among these genes, 154 were hypermethylated and 58 were hypomethylated. GO and KEGG pathway enrichment analysis indicated that differentially methylated miRNA genes were mainly enriched in tumor-associated GO terms and signaling pathways. Pairwise statistical analysis of MeDIP-Seq and sRNA-Seq data showed that there are 154 and 165 candidate methylation-regulated genes in tumors and normal tissues, respectively. Notably, an interaction network indicated that the miRNAs regulated by methylation regulated a broad range of mRNAs associated with cancer development and progression. In particular, the most differentially expressed miRNAs were validated by qRT-PCR, such that miR-145-5p was downregulated and miR-182-5p was upregulated in patients with bladder cancer.

CONCLUSION

A large number of miRNA genes were modified by methylation in BC. Identification of changes in the expression of these miRNAs provides a great deal of important information for BC diagnosis.

Integrative Analysis of Genomic and Clinical Data Reveals Intrinsic Characteristics of Bladder Urothelial Carcinoma Progression

The progression of bladder cancer is generally a complex and dynamic process, involving a variety of biological factors. Here, we aimed to identify a set of survival-related genes that play an important role in the progression of bladder cancer and uncover their synergistic patterns. Based on the large-scale genomic profiling data and clinical information of 404 bladder cancer patients derived from The Cancer Genome Atlas (TCGA) database, we first discovered 1078 survival-related genes related to their survival states using univariate and multivariate Cox proportional hazardous regression. We then investigated the dynamic changes of the cooperative behaviors of these 1078 genes by analyzing their respective genomic features, including copy number variations, DNA methylations, somatic mutations, and microRNA regulatory networks. Our analyses showed that during the progression of bladder cancer, the biological disorder involving the identified survival-related genes can be reflected by multiple levels of abnormal gene regulation, ranging from genomic alteration to post-transcriptional dysregulation. In particular, the stage-specific co-expression networks of these genes undergo a series of structural variations. Our findings provide useful hints on understanding the underlying complex molecular mechanisms related to the evolution of bladder cancer and offer a new perspective on clinical diagnosis and treatment of bladder cancer.

Celecoxib inhibits the epithelial-to-mesenchymal transition in bladder cancer via the miRNA-145/TGFBR2/Smad3 axis

Celecoxib, a selective cyclooxygenase-2 inhibitor, has chemo-preventive activity against different cancer types, including bladder cancer (BC). However, the mechanisms by which celecoxib exerts its cancer preventative effects have yet to be completely understood. In the present study, the effect of celecoxib on the epithelial-to-mesenchymal transition (EMT) of BC cells and its potential molecular mechanisms were investigated. The results of the present study demonstrated that celecoxib inhibited the proliferation, migration, invasion and EMT of BC cells. Further investigation of the underlying mechanism revealed that celecoxib inhibited EMT by upregulating microRNA (miR)-145 and downregulating the expression of transforming growth factor β receptor 2 and SMAD family member 3. Furthermore, the combination of celecoxib with miR-145 mimics demonstrated an additive migration and invasion-inhibitory effect in BC cell lines.

MicroRNA-145 inhibits growth of laryngeal squamous cell carcinoma by targeting the PI3K/Akt signaling pathway

Purpose: In this study, we used a nude mouse model of human laryngeal squamous cell carcinoma (LSCC) to investigate inhibition of tumor growth by microRNA-145 (miR-145) and the mechanisms underlying this inhibition. Methods: Tumors were established in nude mice by transplantation of the LSCC AMC-HN-8 cell line. Forty-eight nude mice were randomly divided into groups of eight mice each and treated with high (1.0 optical density [OD]) or low (0.5 OD) doses of miR-145, or relevant control treatments. Tumor growth was observed in each group and used to calculate the inhibition rate. Routine pathological and electron microscopic examinations were used to determine tumor apoptosis and proliferation. Changes in levels of miR-145 and PI3K and Akt protein levels were also analyzed. Results: MiR-145 inhibited LSCC growth in a dose-dependent manner, as tumor growth was significantly inhibited in mice injected intratumorally with high-dose miR-145 compared with both the untreated and low-dose miR-145 groups (p<0.05). Pathological examination showed increased tumor necrotic and apoptotic changes in treated mice, which was confirmed by electron microscopy. PI3K and Akt protein expression were significantly lower in tumors treated with high-dose miR-145 group compared with those in the untreated and low-dose miR-145 groups (p<0.05). Conclusions: MiR-145 was associated with inhibited tumor growth in a nude mouse model of LSCC. The underlying mechanism may be inhibition of the PI3K/Akt signaling pathway, which regulates tumor growth, invasion, and metastasis and also plays an important role in tumor angiogenesis and proliferation of tumor stem cells. MiR-145 may act as a tumor suppressor gene and is a promising candidate for cancer treatment.

A Genome-Wide Analysis of the Penumbral Volume in Inbred Mice following Middle Cerebral Artery Occlusion

Following ischemic stroke, the penumbra, at-risk neural tissue surrounding the core infarct, survives for a variable period of time before progressing to infarction. We investigated genetic determinants of the size of penumbra in mice subjected to middle cerebral artery occlusion (MCAO) using a genome-wide approach. 449 male mice from 33 inbred strains underwent MCAO for 6 hours (215 mice) or 24 hours (234 mice). A genome-wide association study using genetic data from the Mouse HapMap project was performed to examine the effects of genetic variants on the penumbra ratio, defined as the ratio of the infarct volume after 6 hours to the infarct volume after 24 hours of MCAO. Efficient mixed model analysis was used to account for strain interrelatedness. Penumbra ratio differed significantly by strain (F = 2.7, P < 0.001) and was associated with 18 significant SNPs, including 6 protein coding genes. We have identified 6 candidate genes for penumbra ratio: Clint1, Nbea, Smtnl2, Rin3, Dclk1, and Slc24a4.

Function of microRNA-145 and mechanisms underlying its role in malignant tumor diagnosis and treatment

miRNAs are single-stranded small RNAs that do not encode proteins. They can combine complementarily with the 3′-UTRs of target gene mRNA molecules to promote targeted mRNA degradation or inhibit mRNA translation, thereby regulating gene expression at the post-transcriptional level. MiRNAs participate in regulation of cell cycling, growth, apoptosis, differentiation, and stress responses. MiRNA-145 (miR-145) is a tumor suppressor that targets various tumor-specific genes and proteins, thereby influencing related signaling pathways. MiR-145 not only regulates tumor growth, invasion, and metastasis, but is also important for tumor angiogenesis and tumor stem cell proliferation. Here, we review the roles and mechanisms of miR-145 in the diagnosis and treatment of malignant tumors. Published data confirm that miR-145 expression in various tumors is significantly lower than that in normal tissues and that overexpression of miR-145 inhibits the growth of different tumor cells, significantly reduces the ability of tumors to spread, and improves sensitivity to chemotherapeutic drugs. We conclude that miR-145 is a potential marker for use in the early diagnosis and prognostic evaluation of patients with cancer, has a role as a tumor suppressor, and is a promising cancer treatment target candidate.

MiR-145-modulated SOX9-mediated hypospadias through acting on mitogen-activated protein kinase signaling pathway

This study primarily explored how miR-145, mitogen-activated protein kinase (MAPK) signaling and a downstream transcription factor (i.e., SOX9) mediated development of hypospadias. The hypospadias tissues and preputial tissues were isolated from pediatric inpatients postoperatively. Simultaneously, the rat models of hypospadias were established, and spermatogonial stem cells were separated. The expressions of proteins that symbolized cell apoptosis and oxidative stress were quantified via western blot analysis. Furthermore, the apoptosis, proliferation, and viability of cells were evaluated by means of flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays. The results of microarray indicated miR-145 as a differentially expressed biomarker between hypospadias tissues and normal tissues (p < 0.05). Moreover, rat models of hypospadias were observed with markedly lower vitamins A and E levels, reduced expressions of proteins relevant to oxidative stress (i.e., Nrf2, HO-1, Gpx, and SOD-1), as well as enhanced Bax and cleaved caspase-3 expressions ( p < 0.05). Furthermore, SOX9 was found to be targeted by miR-145, and it was also modified by phosphorylated extracellular-regulated kinase (p-ERK), a portion of MAPK signaling ( p < 0.05). The p-ERK was significantly regulated after altering the expression of miR-145 ( p < 0.05). Moreover, activation of p-ERK and transfection of pcDNA-SOX9 could cause higher expression of apoptins and larger apoptotic proportion of cells ( p < 0.05), yet transfection of miR-145 mimic led to improved cell apoptosis and depressed cell viability ( p < 0.05). In conclusion, SOX9, which was regulated by both miR-145 and miR-145/MAPK signaling, could be involved in the pathogenesis of hypospadias.

Expression of microRNA-99a-3p in Prostate Cancer Based on Bioinformatics Data and Meta-Analysis of a Literature Review of 965 Cases

BACKGROUND microRNAs (miRNAs) have a role as biomarkers in human cancer. The aim of this study was to use bioinformatics data, and review of cases identified from the literature, to investigate the role of microRNA-99a-3p (miR-99a-3p) in prostate cancer, including the identification of its target genes and signaling pathways. MATERIAL AND METHODS Meta-analysis from a literature review included 965 cases of prostate cancer. Bioinformatics databases interrogated for miR-99a-3p in prostate cancer included The Cancer Genome Atlas (TCGA), the Gene Expression Omnibus (GEO), and ArrayExpress. Twelve computational predictive algorithms were developed to integrate miR-99a-3p target gene prediction data. Bioinformatics analysis data from Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) network analysis were used investigate the possible pathways and target genes for miR-99a-3p in prostate cancer. RESULTS TCGA data showed that miR-99a was down-regulated in prostate cancer when compared with normal prostate tissue. Receiver-operating characteristic (ROC) curve area under the curve (AUC) for miR-99a-3p was 0.660 (95% CI, 0.587-0.732) or a moderate level of discriminations. Pathway analysis showed that miR-99a-3p was associated with the Wnt and vascular endothelial growth factor (VEGF) signaling pathways. The PPP3CA and HYOU1 genes, selected from the PPI network, were highly expressed in prostate cancer tissue compared with normal prostate tissue, and negatively correlated with the expression of miR-99a-3p. CONCLUSIONS In prostate cancer, miR-99a-3p expression was associated with the Wnt and VEGF signaling pathways, which might inhibit the expression of PPP3CA or HYOU1.

MicroRNAs Targeting Caspase-3 and -7 in PANC-1 Cells

MicroRNAs (miRNAs), a critical part of the RNA silencing machinery, are known to play important regulatory roles in cancer. However, the consequence of miRNA deregulation in cancer is unknown for many miRNAs. Here, we define that miRNAs, miR-17-5p, miR-132-3p/-212-3p, and miR-337-3p are significantly up-regulated in the pancreatic ductal adenocarcinomas (PDAC) compared to the normal and benign tissues. Furthermore, by using PANC-1 cells, we demonstrate that overexpressed miR-337-3p and miR-17-5p/miR-132-3p/-212-3p can regulate executioner caspases-3 and -7, respectively. In addition, over-expression of miRNAs, especially miR-337-3p, attenuates tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) cytotoxicity in PANC-1 cells. Our findings unveil an important biological function for miRNAs up-regulated in PDAC in coordinately regulating caspases, potentially contributing to the malignant progression of PDAC.

miR-145 Antagonizes SNAI1-Mediated Stemness and Radiation Resistance in Colorectal Cancer

Epithelial-to-mesenchymal transition (EMT) has been closely linked with therapy resistance and cancer stem cells (CSCs). However, EMT pathways have proven challenging to therapeutically target. MicroRNA 145 (miR-145) targets multiple stem cell transcription factors and its expression is inversely correlated with EMT. Therefore, we hypothesized that miR-145 represents a therapeutic target to reverse snail family transcriptional repressor 1 (SNAI1)-mediated stemness and radiation resistance (RT). Stable expression of SNAI1 in DLD1 and HCT116 cells (DLD1-SNAI1; HCT116-SNAI1) increased expression of Nanog and decreased miR-145 expression compared to control cells. Using a miR-145 luciferase reporter assay, we determined that ectopic SNAI1 expression significantly repressed the miR-145 promoter. DLD1-SNAI1 and HCT116-SNAI1 cells demonstrated decreased RT sensitivity and, conversely, miR-145 replacement significantly enhanced RT sensitivity. Of the five parental colon cancer cell lines, SW620 cells demonstrated relatively high endogenous SNAI1 and low miR-145 levels. In the SW620 cells, miR-145 replacement decreased CSC-related transcription factor expression, spheroid formation, and radiation resistance. In rectal cancer patient-derived xenografts, CSC identified by EpCAM+/aldehyde dehydrogenase (ALDH)+ demonstrated high expression of SNAI1, c-Myc, and Nanog compared with non-CSCs (EpCAM+/ALDH-). Conversely, patient-derived CSCs demonstrated low miR-145 expression levels relative to non-CSCs. These results suggest that the SNAI1:miR-145 pathway represents a novel therapeutic target in colorectal cancer to overcome RT resistance.

Stroma-derived extracellular vesicles deliver tumor-suppressive miRNAs to pancreatic cancer cells

The biology of tumor-associated stroma (TAS) in pancreatic ductal adenocarcinoma (PDAC) is not well understood. The paradoxical observation that stroma-depletion strategies lead to progression of PDAC reinforced the need to critically evaluate the functional contribution of TAS in the initiation and progression of PDAC. PDAC and TAS cells are unique in their expression of specific miRNAs, and this specific miRNA expression pattern alters host to tumor microenvironment interactions. Using primary human pancreatic TAS cells and primary xenograft PDAC cells co-culture, we provide evidence of miRNA trafficking and exchanging between TAS and PDAC cells, in a two-way, cell-contact independent fashion, via extracellular vesicles (EVs) transportation. Selective packaging of miRNAs into EVs led to enrichment of stromal specific miR-145 in EVs secreted by TAS cells. Exosomes, but not microvesicles, derived from human TAS cells demonstrated a tumor suppressive role by inducing PDAC cell apoptosis. This effect was mitigated by anti-miR-145 sequences. Our data suggest that TAS-derived miRNAs are delivered to adjacent PDAC cells via exosomes and suppress tumor cell growth. These data highlight that TAS cells secrete exosomes carrying tumor suppressive genetic materials, a possible anti-tumor capacity. Future work of the development of patient-derived exosomes could have therapeutic implications for unresectable PDAC.

Analysis of gene expression profiling variations induced by hsa‑miR‑145‑5p‑overexpression in laryngeal squamous cell carcinoma cell line Tu‑177

The present study aimed to investigate the variations of the gene network and biological functions induced by hsa‑miR‑145‑5p in the laryngeal squamous cell carcinoma (LSCC) cell line Tu‑177. A hsa‑miR‑145‑5p‑overexpressed Tu‑177 cell model was established, and the gene expression microarray data of miR‑145‑5p‑overexpressed cells and negative control (NC) cells were analyzed. The differentially expressed genes (DEGs) between two groups were identified, and their potential functions were predicted by functional enrichment analysis. Furthermore, the targets of miR‑145‑5p were identified from the DEGs, and their potential functions and protein‑protein interactions (PPIs) were analyzed. The mRNA expressions of acetyl‑CoA carboxylase β (ACACB), fibroblast growth factor receptor 1 (FGFR1), protein phosphatase 3 catalytic subunit a (PPP3CA) and spleen associated tyrosine kinase (SYK), were analyzed via quantitative polymerase chain reaction. A total of 1,501 upregulated and 887 downregulated genes were identified in the hsa‑miR‑145‑5p‑overexpressed Tu‑177 cells, compared with the NC cells. Of these DEGs, 164 upregulated and 221 downregulated genes were predicted to be targeted by hsa‑miR‑145‑5p. The upregulated target genes were primarily associated with functions of immunity, whereas the downregulated target genes were significantly enriched in the p53 signaling pathway. In the PPI network consisting of 267 target genes, the upregulated ACACB had the greatest degree and interacted with downregulated genes including PPP3CA and SYK, in addition to upregulated genes, including FGFR1. The mRNA expressions of ACACB and FGFR1were markedly enhanced in miR‑145‑5p‑overexpressed Tu‑177 cells, whereas overexpressing miR‑145‑5p significantly reduced mRNA expression of PPP3CA and SYK. hsa‑miR‑145‑5p may exhibit an anticancer role in LSCC via regulating multiple cell processes, including cell proliferation and invasion, fatty acid metabolism, immunity and p53 signaling pathway. These findings provide novel information for the future investigation of miR‑145‑5p functions in LSCC.

MicroRNA‑663 suppresses the proliferation and invasion of colorectal cancer cells by directly targeting FSCN1

Colorectal cancer (CRC) is the most frequently diagnosed malignancy of the gastrointestinal tract. The dysregulation of microRNAs (miRNAs/miRs) has been reported in the majority of types of human cancer, and is correlated with tumorigenesis and tumor development. Abnormal expression of miR‑663 has been observed in various types of human cancer. However, little is known about its role in CRC. Therefore, the aim of the present study was to clarify the expression and potential role of miR‑663, and its underlying molecular mechanism in CRC. It was observed that miR‑663 was markedly downregulated in CRC tissues and cell lines. Decreased miR‑663 expression levels in CRC tissues were correlated with tumor, node, metastasis stage and lymph node metastasis. Functional assays revealed that upregulation of miR‑663 inhibited cell proliferation and invasion in CRC. Further molecular mechanism assays demonstrated the fascin (FSCN1) was a target gene of miR‑663. In addition, FSCN1 was increased and negatively correlated with miR‑663 expression in CRC tissues. FSCN1 underexpression mimicked the tumor suppressive functions induced by miR‑663 overexpression on CRC cell proliferation and invasion. Collectively, the present study presented evidence that miR‑663 may act as a tumor suppressor in CRC by directly targeting FSCN1, which may lead to a potential therapeutic strategy focusing on miR‑663 and FSCN1 for patients with this disease.

MicroRNA-145 protects follicular granulosa cells against oxidative stress-induced apoptosis by targeting Krüppel-like factor 4

Oxidative stress-induced follicular granulosa cell (GC) apoptosis plays an essential role in abnormal follicular atresia, which may trigger ovarian dysfunction. To investigate the role of microRNA (miR)-145 in the regulation of GC apoptosis and modulation of the apoptotic pathway in the setting of oxidative stress, we employed an H2O2-induced in vitro model and a 3-nitropropionic acid (NP)-induced in vivo model of ovarian oxidative stress. We demonstrated in vitro that miR-145 expression was significantly down-regulated in KGN cells and mouse granulosa cells (mGCs) treated with H2O2, whereas miR-145 over-expression attenuated H2O2-induced apoptosis in GCs. Moreover, miR-145 protected GCs against H2O2-induced apoptosis by targeting KLF4, which promoted H2O2-induced GC apoptosis via the BAX/BCL-2 pathway. Importantly, decreased miR-145 expression in the in vivo ovarian oxidative stress model promoted apoptosis by up-regulating KLF4 expression, whereas GC-specific miR-145 over-expression attenuated apoptosis by targeting KLF4. In conclusion, miR-145 protects GCs against oxidative stress-induced apoptosis by targeting KLF4.

The Cardiotoxic Mechanism of Doxorubicin (DOX) and Pegylated Liposomal DOX in Mice Bearing C-26 Colon Carcinoma: a Study Focused on microRNA Role for Toxicity Assessment of New Formulations

PURPOSE

MicroRNAs (miRs) are a group of small non-coding RNAs that regulate transcriptional or post-transcriptional gene expression. The aim of the present study was to investigate the role of miR -1, -21 and -145 and their targets in cardiotoxicity-induced by DOX and pegylated liposomal DOX.

METHODS

BALB/c mice subjected to subcutaneous injection of C-26 tumor cells. Eight days after tumor inoculation, animals were divided into 6 groups: control, liposome, DOX (6 and 9 mg/kg) and PL-DOX (6 and 9 mg/kg). The formulations were administered one time per week for four weeks. 24 h after the last injection, mice were sacrificed; blood and heart samples were taken. Western blot analysis was done on protein extracts to investigate the expression of cardiac caspase-3, -8, Bax, Bcl2, Programmed cell death 4 (PDCD4) and BCL2/Adenovirus E1B 19 kDa Interacting Protein 3 (BNIP3). The expression levels of miR -1, -21 and -145 were also evaluated by quantitative real-time PCR.

RESULTS

Mice treated with both DOX formulations showed a marked inhibition in tumor growth. Western blot analysis indicated that the expression level of cardiac caspase-3, caspase-8, Bax and BNIP3 were up-regulated due to DOX injection (9 mg/kg). Exposure of mice with DOX resulted in a significant increase in cardiac miR-1 and miR-21 expression level. PL-DOX treatment did not change the proteins and miRs expression.

CONCLUSION

The results suggest that miR -1, -21 and -145 may involve in cardiotoxicity induced by DOX. Evaluation of miRs signaling pathways might be of potential value for toxicity assessment of new formulations. Graphical Abstract The cardiotoxic mechanism of doxorubicin (DOX) and pegylated liposomal DOX (PL-DOX).

MTDH and MAP3K1 are direct targets of apoptosis-regulating miRNAs in colorectal carcinoma

Artificially designed miRNAs mimics and inhibitors that specifically target known oncogenes have attracted significant research attention. Herein, we aimed to explore whether MIR-375, MIR-145, and MIR-224 are involved in induction of apoptosis of CRC cells by regulating apoptosis-mediating genes MTDH, MAP3K1, PDK1, BAX, and BCL-XL. MTT assay was used to assess cell growth. Apoptosis was determined in terms of caspase activity measurement and phosphatidylserine detection using annexin V staining by flow cytometry. Quantitative real time PCR, Western blotting, and luciferase reporter assay were carried out to validate genes regulation and targeting by miRNAs. We found that ectopic expression of MIR-375 and MIR-145, and inhibition of MIR-224 can decrease cell growth and induce cell ability to undergo early apoptosis. At mRNA level, transfected cells displayed down-regulation of MTDH, PDK1 and BCL-XL, while BAX and MAP3K1 were up-regulated. Protein expression of MTDH was decreased in cells transfected with MIR-145 mimic and MIR-224 inhibitor but remained unchanged in MIR-375 mimic-transfected cells. Furthermore, MAP3K1 protein expression exibited a decreased level after MIR-375 transient expression with no significant change after MIR-145 mimic or MIR-224 inhibitor transfection. Luciferase reporter assay revealed that MIR-375 and MIR-145 can bind to 3'UTR of MTDH, supporting that MTDH is directly targeted by both miRNAs. Similarly, MAP3K1 was found to be directly regulated by MIR-375. The study concluded that the expression modulation of tumor suppressors MIR-375 and MIR-145, and oncomiR MIR-224 have the ability to induce apoptosis of CRC cells through regulation of apoptosis mediating genes MTDH, MAP3K1, PDK1, BCL-XL and BAX.

Profiling of long non-coding RNAs identifies LINC00958 and LINC01296 as candidate oncogenes in bladder cancer

Aberrant expression of long non-coding RNAs (lncRNAs) has been regarded as a critical component in bladder cancer (BC) and lncRNAs have been associated with BC development and progression although their overall expression and functional significance is still unclear. The aim of our study was to identify novel lncRNAs with a functional role in BC carcinogenesis. RNA-sequencing was used to identify aberrantly expressed lncRNAs in 8 normal and 72 BC samples. We identified 89 lncRNAs that were significantly dys-regulated in BC. Five lncRNAs; LINC00958, LINC01296, LINC00355, LNC-CMC1-1 and LNC-ALX1-2 were selected for further analyses. Silencing of LINC00958 or LINC01296 in vitro reduced both cell viability and migration. Knock-down of LINC00958 also affected invasion and resistance to anoikis. These cellular effects could be linked to direct/indirect regulation of protein coding mRNAs involved in cell death/survival, proliferation and cellular movement. Finally, we showed that LINC00958 binds proteins involved in regulation and initiation of translation and in post-transcriptional modification of RNA, including Metadherin, which has previously been associated with BC. Our analyses identified novel lncRNAs in BC that likely act as oncogenic drivers contributing to an aggressive cancerous phenotype likely through interaction with proteins involved in initiation of translation and/or post-transcriptional modification of RNA.

Targeting oncogenic PLCE1 by miR-145 impairs tumor proliferation and metastasis of esophageal squamous cell carcinoma

Phospholipase C epsilon 1 (PLCE1) is a susceptibility gene in esophageal squamous cell carcinoma (ESCC). Nevertheless, the role of PLCE1 in ESCC tumorigenesis has not been elucidated. In this study, we determined the function of PLCE1 and its regulatory microRNA (miRNA) in ESCC. PLCE1 protein was excessively expressed in ESCC and precancerous lesions compared with that in normal tissues. High PLCE1 expression levels in ESCC were significantly linked with poor overall survival. Knockdown of PLCE1 promoted the apoptosis, cytokine-induced apoptosis, and sensitivity of cancer cells to chemotherapeutic drugs but abrogated the proliferation and EMT phenotype of ESCC in vitro. Notably, miR-145 was newly identified as a potent repressor of PLCE1 expression by directly targeting the 3′UTR of PLCE1. MiR-145 also inhibited cell proliferation, migration, and metastasis, as well as controlled the cytoskeleton dynamics of esophageal cancer. Moreover, miR-145 was expressed at low levels in a large cohort of patients with ESCC and was inversely correlated with PLCE1 protein expression in cancer cells and tissues. These findings demonstrate that PLCE1 functions as tumor promoter in ESCC and can be suppressed by miR-145 through inhibition of PLCE1 translation. Hence, delivery of PLCE1-targeting miR-145 is a potential therapeutic approach for esophageal cancer.

MicroRNA-26b Enhances the Radiosensitivity of Hepatocellular Carcinoma Cells by Targeting EphA2

Sensitizing hepatocellular carcinoma (HCC) cells to irradiation is important to achieve satisfactory therapeutic effect with low-dose radiotherapy. Erythropoietin-producing hepatocellular carcinoma A2 (EphA2) is a member of the Eph receptor family that constitutes the largest family of tyrosine kinase receptors. EphA2 overexpression is one of the poor prognostic factors in many progressive cancers. Importantly, EphA2 is a potential target of microRNA-26b (miR-26b), and miR-26b expression is down-regulated in several types of cancer. In this study, we measured the expression levels of miR-26b and EphA2 protein in seven human HCC cell lines by quantitative PCR and western blot analysis, respectively. Overall, lower miR-26b expression levels tended to be associated with higher EphA2 levels in HCC cell lines. Among the cell lines examined, 97H HCC cells expressed the lowest level of miR-26b and highest level of EphA2 protein. Thus, using 97H HCC cells, EphA2 mRNA was verified as the target of miR-26b by the luciferase reporter assay. Accordingly, a synthetic miR-26b, miR-26b mimics, was used to mimic the function of endogenous miR-26b. In 97H HCC cells transfected with miR-26b mimics or short-hairpin RNA targeting EphA2 mRNA, expression of EphA2 protein was reduced, which was associated with significantly lower proliferation rate and invasion ability and with higher apoptosis rate in response to low-dose irradiation, compared to control cells. In contrast, 97H HCC cells over-expressing EphA2 showed higher proliferation rate and invasion ability and lower apoptosis rate upon irradiation. These data suggest that miR-26b enhances the radiosensitivity of 97H HCC cells by targeting EphA2 protein.

Retinal expression of small non-coding RNAs in a murine model of proliferative retinopathy

Ocular neovascularization is a leading cause of blindness in proliferative retinopathy. Small non-coding RNAs (sncRNAs) play critical roles in both vascular and neuronal development of the retina through post-transcriptional regulation of target gene expression. To identify the function and therapeutic potential of sncRNAs in retinopathy, we assessed the expression profile of retinal sncRNAs in a mouse model of oxygen-induced retinopathy (OIR) with pathologic proliferation of neovessels. Approximately 2% of all analyzed sncRNAs were significantly altered in OIR retinas compared with normoxic controls. Twenty three microRNAs with substantial up- or down-regulation were identified, including miR-351, -762, -210, 145, -155, -129-5p, -150, -203, and -375, which were further analyzed for their potential target genes in angiogenic, hypoxic, and immune response-related pathways. In addition, nineteen small nucleolar RNAs also revealed differential expression in OIR retinas compared with control retinas. A decrease of overall microRNA expression in OIR retinas was consistent with reduced microRNA processing enzyme Dicer, and increased expression of Alu element in OIR. Together, our findings elucidated a group of differentially expressed sncRNAs in a murine model of proliferative retinopathy. These sncRNAs may exert critical post-transcriptional regulatory roles in regulating pathological neovascularization in eye diseases.

MicroRNA-145 sensitizes cervical cancer cells to low-dose irradiation by downregulating OCT4 expression

Poor elucidation of the mechanisms involved in regulating the radiosensitivity of cancers prevents the extensive application of low-dose radiotherapy in clinical settings. The present study was conducted to investigate the role of microRNA-145 (miR-145) in the modulation of cervical cancer cell radiosensitivity, as well as to identify the underlying target of miR-145 during this process. Cervical cancer tera cells were initially exposed to doses of radiation between 1 and 6 Gy before the assessments of the cell viability and apoptosis rate. Irradiation at dose of 1 Gy was screened as optimum dose and used in subsequent experiments. A dual luciferase reporter assay was performed to demonstrate that octamer-binding transcription factor 4 (OCT4) is a target of miR-145 in cervical cancer. Consequently, OCT4 was suggested to be a target of miR-145, as a dual luciferase vector that was ligated to a fragment corresponding to the predicted target site of miR-145 in OCT4 3'-UTR showed an 83% reduction in fluorescence. Following exposure to 1 Gy irradiation, tera cells transfected with miR-145 mimics, which showed downregulation of OCT4 and cyclin D1, had lower cell viability and cell migration rate and higher apoptosis rate compared to non-transfected cells. However, the co-transfection of miR-145 mimics and OCT4 expression vector restored OCT4 and cyclin D1 expression levels and made no significant difference in terms of cell viability, cell migration rate and apoptosis rate. The present results indicate that miR-145 increases the radiosensitivity of cervical cancer cells by silencing OCT4, that cyclin D1 is putatively under the positive regulation of OCT4 and mediates miR-145 function.

Androgen receptor (AR) suppresses miRNA-145 to promote renal cell carcinoma (RCC) progression independent of VHL status

Mutational inactivation of the VHL tumor suppressor plays key roles in the development of renal cell carcinoma (RCC), and mutated VHL-mediated VEGF induction has become the main target for the current RCC therapy. Here we identified a signal pathway of VEGF induction by androgen receptor (AR)/miRNA-145 as a new target to suppress RCC progression. Mechanism dissection revealed that AR might function through binding to the androgen receptor element (ARE) located on the promoter region of miRNA-145 to suppress p53's ability to induce expression of miRNA-145 that normally suppresses expression of HIF2α/VEGF/MMP9/CCND1. Suppressing AR with AR-shRNA or introducing exogenous miRNA-145 mimic can attenuate RCC progression independent of VHL status. MiR-145 mimic in preclinical RCC orthotopic xenograft mouse model revealed its efficacy in suppression of RCC progression. These results together identified signals by AR-suppressed miRNA-145 as a key player in the RCC progression via regulating HIF2α/VEGF/MMP9/CCND1 expression levels. Blockade of the newly identified signal by AR inhibition or miRNA-145 mimics has promising therapeutic benefit to suppress RCC progression.

Cooperative Effect of miR-141-3p and miR-145-5p in the Regulation of Targets in Clear Cell Renal Cell Carcinoma

Background

Due to the poor prognosis for advanced renal cell carcinoma (RCC), there is an urgent need for new therapeutic targets and for prognostic markers to identify high risk tumors. MicroRNAs (miRNAs) are frequently dysregulated in tumors, play a crucial role during carcinogenesis and therefore might be promising new biomarkers. In previous studies, we identified miR-141-3p and miR-145-5p to be downregulated in clear cell RCC (ccRCC). Our objective was to investigate the functional association of these miRNAs, focusing on the cooperative regulation of new specific targets and their role in ccRCC progression.

Methods

The effect of miR-141-3p and miR-145-5p on cell migration was examined by overexpression in 786-O cells. New targets of both miRNAs were identified by miRWalk, validated in 786-O and ACHN cells and additionally characterized in ccRCC tissue on mRNA and protein level.

Results

In functional analysis, a tumor suppressive effect of miR-141-3p and miR-145-5p by decreasing migration and invasion of RCC cells could be shown. Furthermore, co-overexpression of the miRNAs seemed to result in an increased inhibition of cell migration. Both miRNAs were recognized as post-transcriptional regulators of the targets EAPP, HS6ST2, LOX, TGFB2 and VRK2. Additionally, they showed a cooperative effect again as demonstrated by a significantly increased inhibition of HS6ST2 and LOX expression after simultaneous overexpression of both miRNAs. In ccRCC tissue, LOX mRNA expression was strongly increased compared to normal tissue, allowing also to distinguish between non-metastatic and already metastasized primary tumors. Finally, in subsequent tissue microarray analysis LOX protein expression showed a prognostic relevance for the overall survival of ccRCC patients.

Conclusion

These results illustrate a jointly strengthening effect of the dysregulated miR-141-3p and miR-145-5p in various tumor associated processes. Focusing on the cooperative effect of miRNAs provides new opportunities for the development of therapeutic strategies and offers novel prognostic and diagnostic capabilities.

The role of microRNAs in bladder cancer

Bladder cancer (BC) is the fifth most common cancer worldwide and is associated with significant morbidity and mortality. The prognosis of muscle invasive BC is poor, and recurrence is common after radical surgery or chemotherapy. Therefore, new diagnostic methods and treatment modalities are critical. MicroRNAs (miRNAs), a class of small noncoding RNAs, regulate the expression of protein-coding genes by repressing translation or cleaving RNA transcripts in a sequence-specific manner. miRNAs have important roles in the regulation of genes involved in cancer development, progression, and metastasis. The availability of genomewide miRNA expression profiles by deep sequencing technology has facilitated rapid and precise identification of aberrant miRNA expression in BC. Indeed, several miRNAs that are either upregulated or downregulated have been shown to have associations with significant cancer pathways. Furthermore, many miRNAs, including those that can be detected in urine and blood, have been studied as potential noninvasive tumor markers for diagnostic and prognostic purposes. Here, we searched PubMed for publications describing the role of miRNAs in BC by using the keywords "bladder cancer" and "microRNA" on March 1, 2016. We found 374 papers and selected articles written in English in which the level of scientific detail and reporting were sufficient and in which novel findings were demonstrated. In this review, we summarize these studies from the point of view of miRNA-related molecular networks (specific miRNAs and their targets) and miRNAs as tumor markers in BC. We also discuss future directions of miRNA studies in the context of therapeutic modalities.

A Tumor-specific MicroRNA Recognition System Facilitates the Accurate Targeting to Tumor Cells by Magnetic Nanoparticles

Targeted therapy for cancer is a research area of great interest, and magnetic nanoparticles (MNPs) show great potential as targeted carriers for therapeutics. One important class of cancer biomarkers is microRNAs (miRNAs), which play a significant role in tumor initiation and progression. In this study, a cascade recognition system containing multiple plasmids, including a Tet activator, a lacI repressor gene driven by the TetOn promoter, and a reporter gene repressed by the lacI repressor and influenced by multiple endogenous miRNAs, was used to recognize cells that display miRNA signals that are characteristic of cancer. For this purpose, three types of signal miRNAs with high proliferation and metastasis abilities were chosen (miR-21, miR-145, and miR-9). The response of this system to the human breast cancer MCF-7 cell line was 3.2-fold higher than that to the human breast epithelial HBL100 cell line and almost 7.5-fold higher than that to human embryonic kidney HEK293T cells. In combination with polyethyleneimine-modified MNPs, this recognition system targeted the tumor location in situ in an animal model, and an ~42% repression of tumor growth was achieved. Our study provides a new combination of magnetic nanocarrier and gene therapy based on miRNAs that are active in vivo, which has potential for use in future cancer therapies.

Circulating microRNAs, miR-92a, miR-100 and miR-143, as non-invasive biomarkers for bladder cancer diagnosis

The application of microRNAs (miRNAs) as potential biomarkers and therapy targets has been widely investigated in many kinds of cancers. Recent advantages of serum miRNAs open a new realm of possibilities for non-invasive diagnosis and prognosis of bladder cancer (BC). The aim of our study was to identify plasma miR-92a, miR-100 and miR-143 expression signatures in patients with BC to introduce new markers for establishing BC diagnosis and prognosis. Blood samples were collected from 70 BC patients and 62 controls. An expression of three target miRNAs (miR-92a, miR-100 and miR-143) was measured using quantitative real-time PCR method. Results were correlated with clinicopathological data and analysed. Plasma levels of miR-92a, miR-100 and miR-143 were significantly lower in BC patients than in control group. Receiver operator characteristic analysis revealed that the sensitivity and specificity values of miR-92a were 97·1% and 76·7%, respectively, with a cut-off value of 0·573. The sensitivity and specificity values of miR-100 were 90% and 66·7%, respectively, with a cut-off value of 0·644. The sensitivity and specificity values of miR-143 were 78·6% and 93·3%, respectively, with a cut-off value of 0·164. This study explores the existence of specific plasma miRNAs as early diagnostic biomarkers for BC in Egyptian patients; and these findings suggest that plasma miR-92a, miR-100 and miR-143 could be promising novel circulating biomarkers in clinical detection of BC.

Cisplatin and Paclitaxel Alter the Expression Pattern of miR-143/145 and miR-183/96/182 Clusters in T24 Bladder Cancer Cells

Although cisplatin-based chemotherapy is considered to be the treatment of choice for metastatic bladder cancer, its efficacy and tolerability has proven to be limited. MicroRNAs are small noncoding RNAs, whose genes are frequently organized in clusters. These molecules constitute posttranscriptional regulators of mRNA expression and are claimed to be deregulated in cancer. miR-143/145 and miR-183/96/182 clusters have been extensively studied in bladder cancer cells. Herein, we tried to add up to this knowledge by assessing the expression levels of the five mature microRNAs derived from the aforementioned clusters in T24 bladder cancer cells exposed to either cisplatin or paclitaxel. For both compounds, the viability of treated T24 cells was estimated via the MTT colorimetric assay and the Trypan Blue exclusion method, while a fraction of the cells was left to recover. The expression levels of all mature microRNAs were finally quantified both in treated and in recovered cells by performing real-time PCR. According to our data, cisplatin and paclitaxel strongly decreased T24 cells' viability, showing in parallel the ability to significantly down-regulate miR-143 levels, and up-regulate the expression levels of miR-145, miR-183, miR-96, and miR-182, which, in their total, demonstrated case-specific variations after recovery period.

Implications of miR cluster 143/145 as universal anti-oncomiRs and their dysregulation during tumorigenesis

Tumorigenesis is a multistep process, de-regulated due to the imbalance of oncogenes as well as anti-oncogenes, resulting in disruption of tissue homeostasis. In many cases the effect of oncogenes and anti-oncogenes are mediated by various other molecules such as microRNAs. microRNAs are small non-coding RNAs established to post-transcriptionally regulate more than half of the protein coding genes. miR cluster 143/145 is one such cancer-related microRNA cluster which is down-regulated in most of the cancers and is able to hinder tumorigenesis by targeting tumor-associated genes. The fact that they could sensitize drug-resistant cancer cells by targeting multidrug resistant genes makes them potent tools to target cancer cells. Their low levels precede events which lead to cancer progression and therefore could be considered also as biomarkers to stage the disease. Interestingly, evidence suggests the existence of several in vivo mechanisms by which this cluster is differentially regulated at the molecular level to keep their levels low in cancer. In this review, we summarize the roles of miR cluster 143/145 in cancer, their potential prognostic applications and also their regulation during tumorigenesis.

MiR-145, a microRNA targeting ADAM17, inhibits the invasion and migration of nasopharyngeal carcinoma cells

MiR-145 is downregulated and functions as a tumor suppressor in many malignancies. In this study, the biological function, molecular mechanism, and direct target genes of miR-145 in nasopharyngeal carcinoma (NPC) cells were investigated. Cell survival was detected by cell viability assay, and cell cycle was determined through flow cytometry. Invasion and migration of NPC cells were examined using cell invasion and wound healing assays, respectively. A disintegrin and metalloproteinase 17 (ADAM17) was verified as the target of miR-145 through luciferase reporter assay, qRT-PCR, and Western blot analysis. In NPC cell lines, miR-145 expression was significantly downregulated and ADAM17 protein expression was upregulated. ADAM17 was downregulated at the post-transcriptional level by miR-145 via the binding site of ADAM17-3'UTR. Transfection with miR-145 mimic suppressed cell growth and induced cell cycle arrest in the G0/G1 phase by upregulating key G0/G1 phase regulators, namely, p53 and p21. MiR-145 also inhibited cellular migration and invasion through targeting ADAM17 involving the regulation of EGFR and E-cadherin. Knockdown of ADAM17 elicited similar effects to that of miR-145 on NPC cells. This study reveals that miR-145 suppressed the invasion and migration of NPC cells by targeting ADAM17. Thus, miR-145 could be a therapeutic target for NPC.

Identification of apoptosis-related microRNAs and their target genes in myocardial infarction post-transplantation with skeletal myoblasts

Background

Skeletal myoblasts (SkMs) has provided a promising treatment for myocardial infarction (MI). Functioning as posttranscriptional regulators, microRNAs (miRNAs) play important roles in cardiac repairment and stem cell regulation. However, the correlation between miRNAs and their targeted genes in SkM cell therapy for MI was not fully understood.

Methods

We explored the cardioprotection by SkMs in infracted rats and determined cardiac functions at 4 weeks. In addition, we compared the expression profiles of miRNAs and mRNAs in post-MI rats with or without SkM cell therapy using microarray. The concordance between miRNA expression and mRNA levels of potential target genes was confirmed by quantitative real-time PCR.

Results

Quantitative echocardiography and histology showed improved cardiac function, attenuated heart infarcted area and inhibited cardiomyocyte apoptosis in the SkM group, compared with MI group. We identified that 160 miRNAs were differentially expressed in MI group as compared to the control group and 78 miRNAs were differentially expressed in the SkM treated group as compared to the untreated post-MI. We focused on a novel set of apoptosis-associated miRNAs and their target genes, among which 4 miRNAs (miR-30a-5p, miR-30c-5p, miR-145-5p, miR-140-3p), except one (miR-143-3p), were downregulated in the SkM treated group as compared to the untreated group. Furthermore, we found seven genes including Angptl4, Dpep1, Egr1, Eif5a, Tsc22d3, Irs2 and Cebpb that showed a linear correlation with which miRNAs.

Conclusions

The downregulation of apoptosis-regulatory miRNAs and in turn upregulation of target genes may partially account for rescue effect of SKM therapy for MI.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0603-0) contains supplementary material, which is available to authorized users.

Identification of a hypoxia-regulated miRNA signature in bladder cancer and a role for miR-145 in hypoxia-dependent apoptosis

BACKGROUND

Hypoxia leads to the stabilisation of the hypoxia-inducible factor (HIF) transcription factor that drives the expression of target genes including microRNAs (miRNAs). MicroRNAs are known to regulate many genes involved in tumourigenesis. The aim of this study was to identify hypoxia-regulated miRNAs (HRMs) in bladder cancer and investigate their functional significance.

METHODS

Bladder cancer cell lines were exposed to normoxic and hypoxic conditions and interrogated for the expression of 384 miRNAs by qPCR. Functional studies were carried out using siRNA-mediated gene knockdown and chromatin immunoprecipitations. Apoptosis was quantified by annexin V staining and flow cytometry.

RESULTS

The HRM signature for NMI bladder cancer lines includes miR-210, miR-193b, miR-145, miR-125-3p, miR-708 and miR-517a. The most hypoxia-upregulated miRNA was miR-145. The miR-145 was a direct target of HIF-1α and two hypoxia response elements were identified within the promoter region of the gene. Finally, the hypoxic upregulation of miR-145 contributed to increased apoptosis in RT4 cells.

CONCLUSIONS

We have demonstrated the hypoxic regulation of a number of miRNAs in bladder cancer. We have shown that miR-145 is a novel, robust and direct HIF target gene that in turn leads to increased cell death in NMI bladder cancer cell lines.

miR-9 promotes cell proliferation and inhibits apoptosis by targeting LASS2 in bladder cancer

MicroRNA-9 upregulation was reported in several tumors. However, its function and mechanism in human bladder cancer remains obscure. The present study aims to identify the expression pattern, biological roles and potential mechanism of miR-9 in human bladder cancers. We found that expression level of miR-9 in bladder cancer tissues was higher than normal tissues. miR-9 mimic transfection was performed in T24 and 5637 cells with low miR-9 expression, and miR-9 inhibitor was employed in BIU-87 cell line with high endogenous expression. miR-9 increased cell proliferation, cell cycle progression, invasion and chemoresistance, with upregulation of cyclin D1, MMP9, Bcl-2, and survivin and downregulation of E-cadherin. Using luciferase reporter assay, we confirmed that LASS2 was a direct target of miR-9 in bladder cancer cells. Transfection of miR-9 mimic downregulated LASS2 expression. LASS2 transfection downregulated Bcl-2 and survivin expression, which were induced by miR-9 mimic in both cell lines. In conclusion, these results indicate that miR-9 upregulation might be associated with malignant phenotype of bladder cancer. miR-9 promotes chemoresistance of bladder cancer cells by target LASS2.

Low miR-145 silenced by DNA methylation promotes NSCLC cell proliferation, migration and invasion by targeting mucin 1

MiR-145 has been implicated in the progression of non-small cell lung cancer (NSCLC); however, its exact mechanism is not well established. Here, we report that miR-145 expression is decreased in NSCLC cell lines and tumor tissues and that this low level of expression is associated with DNA methylation. MiR-145 methylation in NSCLC was correlated with a more aggressive tumor phenotype and was associated with poor survival time, as shown by Kaplan-Meier analysis. Additional multivariate Cox regression analysis indicated that miR-145 methylation was an independent prognostic factor for poor survival in patients with NSCLC. Furthermore, we found that restoration of miR-145 expression inhibited proliferation, migration and invasion of NSCLC by the direct targeting of mucin 1 by miR-145. Our results indicate that low miR-145 expression, due to methylation, promotes NSCLC cell proliferation, migration and invasion by targeting mucin 1. Therefore, miR-145 may be a valuable therapeutic target for NSCLC.

Salivary microRNAs in oral cancer

OBJECTIVE

This study investigated the use of three salivary microRNAs (miRNA-21, miRNA-184, and miRNA-145) as possible markers for malignant transformation in oral mucosal lesions.

MATERIALS AND METHODS

Salivary whole unstimulated samples were collected from a study group of 100 subjects, consisting of 20 clinically healthy controls, 40 patients with oral potentially malignant disorders (PMDs) [20 with dysplastic lesions and 20 without dysplasia], 20 with biopsy-confirmed oral squamous cell carcinoma (OSCC), and 20 with recurrent aphthous stomatitis (RAS) as disease controls. Total RNA was isolated and purified from saliva samples using the microRNA Isolation Kit (Qiagen, UL). miRNA expression analysis was performed using qRT-PCR (Applied Biosystems).

RESULTS

There was a highly significant increase in salivary miRNA-21 and miRNA-184 in OSCC and PMD (with and without dysplasia) when compared to healthy and disease controls (P < 0.001). Conversely, miRNA-145 levels showed a highly significant decrease in OSCC and PMD overall (P < 0.001). RAS cases showed no significant difference from normal controls in any measured miRNA (P > 0.05). The only microRNA to discriminate between OSCC and PMD with dysplasia was miRNA-184. When receiver operating characteristic curves were designed for the three miRNAs, cutoff points delineating the occurrence of malignant change were a fourfold increase in miRNA-21 with specificity 65% and sensitivity 65%, a 0.6 decrease in miRNA-145, with specificity 70% and sensitivity 60%, and a threefold increase of miRNA-184, with specificity 75% and sensitivity 80%. Calculating the area under the curve revealed that miRNA-184 was the only one among the studied miRNAs that provided good diagnostic value.

CONCLUSION

Salivary determination of the miRNAs tested might furnish a noninvasive, rapid adjunctive aid for revealing malignant transformation in oral mucosal lesions, particularly miRNA-184.

Gemcitabine impacts differentially on bladder and kidney cancer cells: distinct modulations in the expression patterns of apoptosis-related microRNAs and BCL2 family genes

Bladder and renal cancer are two representative cases of tumors that respond differentially to gemcitabine. Previous studies have shown that gemcitabine can trigger apoptosis in various cancer cells. Herein, we sought to investigate the impact of gemcitabine on the expression levels of the BCL2 family members BCL2, BAX, and BCL2L12 and the apoptosis-related microRNAs miR-182, miR-96, miR-145, and miR-16 in the human bladder and kidney cancer cell lines T24 and Caki-1, respectively. Cancer cells' viability as well as the IC50 doses of gemcitabine were estimated by the MTT assay, while the detection of cleaved PARP via Western blotting was used as an indicator of apoptosis. Furthermore, T24 and Caki-1 cells' ability to recover from treatment was also monitored. Two different highly sensitive quantitative real-time RT-PCR methodologies were developed in order to assess the expression levels of BCL2 family genes and microRNAs. Exposure of cancer cells to gemcitabine produced the IC50 values of 30 and 3 nM for Caki-1 and T24 cells, correspondingly, while cleaved PARP was detected only in Caki-1 cells. T24 cells demonstrated the ability to recover from gemcitabine treatment, whereas Caki-1 cells' recovery capability was dependent on the initial time of exposure. BCL2 and BAX were significantly modulated in treated Caki-1 cells. Instead, T24 cells exhibited alterations only in the latter, as well as in all studied microRNAs. Therefore, according to our data, bladder and renal cancer cells' response to gemcitabine is accompanied by distinct alterations in the expression levels of their apoptosis-related genes and microRNAs.