MicroRNA-155 promotes bladder cancer growth by repressing the tumor suppressor DMTF1

Urinary extracellular vesicles-encapsulated miRNA signatures: A new paradigm for urinary bladder cancer diagnosis and classification

Bladder cancer (BCa) stands as prevalent malignancy of the urinary system globally, especially among men. The clinical classification of BCa into non-muscle invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) is crucial for prognosis and treatment decisions. However, challenges persist in current diagnostic methods like Urine cytopathology that shows poor sensitivity therefore compromising on accurately diagnosing and monitoring BCa. In recent years, research has emphasized the importance of identifying urine and blood-based specific biomarkers for BCa that can enable early and precise diagnosis, effective tumor classification, and monitoring. The convenient proximity of urine with the urinary bladder epithelium makes urine a good source of noninvasive biomarkers, in particular urinary EVs because of the packaged existence of tumor-associated molecules. Therefore, the review assesses the potential of urinary extracellular vesicles (uEVs) as noninvasive biomarkers for BCa. We have elaborately reviewed and discussed the research that delves into the role of urinary EVs in the context of BCa diagnosis and classification. Extensive research has been dedicated to investigating differential microRNA (miRNA) expressions, with the goal of establishing distinct, noninvasive biomarkers for BCa. The identification of such biomarkers has the potential to revolutionize early detection, risk stratification, therapeutic interventions, and ultimately, the long-term prognosis of BCa patients. Despite notable advancements, inconsistencies persist in the biomarkers identified, methodologies employed, and study populations. This review meticulously compiles reported miRNA biomarkers, critically assessing the variability and discrepancies observed in existing research. By synthesizing these findings, the article aims to direct future studies toward a more cohesive and dependable approach in BCa biomarker identification, fostering progress in patient care and management.

Targeting microRNAs as a promising anti-cancer therapeutic strategy against traffic-related air pollution-mediated lung cancer

Air pollutants are increasingly emitted into the atmosphere because of the high dependency of humans on fossil-derived fuels. Wind speed and direction assisted high dispersibility and uncontrolled nature of air pollution across geo-/demographical borders, making it one of the major global concerns. Besides climate change, air pollution has been found to be associated with various diseases, such as cancer. Lung cancer, which is the world's most common type of cancer, has been found to be associated with traffic-related air pollution. Research and political efforts have been taken to explore green/renewable energy sources. However, these efforts at the current intensity cannot cope with the increasing need for fossil fuels. More specifically, political tensions such as the Russian-Ukraine war, economic tension (e.g., China-USA economic tensions), and other issues (e.g., pandemic, higher inflation rate, and poverty) significantly hindered phasing out fossil fuels. In this context, an increasing global population will be exposed to traffic-related air pollution, which justifies the current uptrend in the number of lung cancer patients. To combat this health burden, novel treatments with higher efficiency and specificity must be designed. One of the potential "life changer" options is microRNA (miRNA)-based therapy to target the expression of oncogenic genes. That said, this review discusses the association of traffic-related air pollution with lung cancer, the changes in indigenous miRNAs in the body during lung cancer, and the current status of miRNA therapeutics for lung cancer treatment. We believe that the article will significantly appeal to a broad readership of oncologists, environmentalists, and those who work in the field of (bio)energy. It may also gain the policymakers' attention to establish better health policies and regulations about air pollution, for example, by promoting (bio)fuel exploration, production, and consumption.

The role of miR-155 in urologic malignancies

MicroRNAs (miRNAs) are a class of short non-coding RNAs that play a crucial role in regulating gene expression across multiple levels. They are involved in a wide range of physiological processes, including proliferation, differentiation, apoptosis, and cell cycle control. In recent years, miRNAs have emerged as pivotal regulatory molecules in the development and progression of tumors. Among these, miR-155 has garnered significant attention due to its high expression in various diseases, particularly urologic malignancies. Since an extensive corpus of studies having focused on the roles of miR-155 in various urologic malignancies, it is essential to summarize the current evidence on this topic through a comprehensive review. Altered miR-155 expression is related to various physiological and pathological processes, including immune response, inflammation, tumor development and treatment resistance. Notably, alterations in miR-155 expression have been observed in urologic malignancies as well. The up-regulation of miR-155 expression is commonly observed in urologic malignancies, contributing to their progression by targeting specific proteins and signaling pathways. This article provides a comprehensive review of the significant role played by miR-155 in the development of urologic malignancies. Furthermore, the potential of miR-155 as a biomarker and therapeutic target in urologic malignancies is also discussed.

Dysregulation of immunity by cigarette smoking promotes inflammation and cancer: A review

Smoking is a serious global health issue. Cigarette smoking contains over 7000 different chemicals. The main harmful components include nicotine, acrolein, aromatic hydrocarbons and heavy metals, which play the key role for cigarette-induced inflammation and carcinogenesis. Growing evidences show that cigarette smoking and its components exert a remarkable impact on regulation of immunity and dysregulated immunity promotes inflammation and cancer. Therefore, this comprehensive and up-to-date review covers four interrelated topics, including cigarette smoking, inflammation, cancer and immune system. The known harmful chemicals from cigarette smoking were summarized. Importantly, we discussed in depth the impact of cigarette smoking on the formation of inflammatory or tumor microenvironment, primarily by affecting immune effector cells, such as macrophages, neutrophils, and T lymphocytes. Furthermore, the main molecular mechanisms by which cigarette smoking induces inflammation and cancer, including changes in epigenetics, DNA damage and others were further summarized. This article will contribute to a better understanding of the impact of cigarette smoking on inducing inflammation and cancer.

Unraveling Therapeutic Opportunities and the Diagnostic Potential of microRNAs for Human Lung Cancer

Lung cancer is a major public health problem and a leading cause of cancer-related deaths worldwide. Despite advances in treatment options, the five-year survival rate for lung cancer patients remains low, emphasizing the urgent need for innovative diagnostic and therapeutic strategies. MicroRNAs (miRNAs) have emerged as potential biomarkers and therapeutic targets for lung cancer due to their crucial roles in regulating cell proliferation, differentiation, and apoptosis. For example, miR-34a and miR-150, once delivered to lung cancer via liposomes or nanoparticles, can inhibit tumor growth by downregulating critical cancer promoting genes. Conversely, miR-21 and miR-155, frequently overexpressed in lung cancer, are associated with increased cell proliferation, invasion, and chemotherapy resistance. In this review, we summarize the current knowledge of the roles of miRNAs in lung carcinogenesis, especially those induced by exposure to environmental pollutants, namely, arsenic and benzopyrene, which account for up to 1/10 of lung cancer cases. We then discuss the recent advances in miRNA-based cancer therapeutics and diagnostics. Such information will provide new insights into lung cancer pathogenesis and innovative diagnostic and therapeutic modalities based on miRNAs.

LANA regulates miR-155/GATA3 signaling axis by enhancing c-Jun/c-Fos interaction to promote the proliferation and migration of KSHV-infected cells

Kaposi's sarcoma (KS) is the second most common tumor in people infected with human immunodeficiency virus worldwide, but its pathogenesis is still unclear. In this study, we discovered that the expression of GATA-binding protein 3 (GATA3) was lowly expressed in KS tissues and KSHV-infected cells, while microRNA-155 (miR-155) was highly expressed in KS serum and KSHV-infected cells. miR-155 promoted the proliferation, migration and invasion of KSHV infection by targeting GATA3. Further, The KSHV-encoded protein, the Latency associated nuclear antigen (LANA), promotes the proliferation, migration and invasion of KSHV-infected cells by regulating the miR-155/GATA3 axis. Regarding the molecular mechanism, c-Jun and c-Fos interact to form a complex. LANA upregulates the expression of c-Jun and c-Fos and enhances the formation of c-Jun/c-Fos complex. The complex binds to the -95∼-100 bp site of miR-155 promoter and transcriptionally activates miR-155. All in all, LANA enhances the c-Jun/c-Fos interaction, resulting in enhanced transcriptional regulation of miR-155 by the c-Jun/c-Fos complex, thereby downregulating GATA3 and promoting the proliferation, migration and invasion of KSHV-infected cells. The discovery of LANA/c-Jun/c-Fos/miR-155/GATA3 further refines the pathogenesis of KS, potentially opening a new avenue for developing effective drugs against KS.

The MicroRNA Prediction Models as Ancillary Diagnosis Biomarkers for Urothelial Carcinoma in Patients With Chronic Kidney Disease

Urothelial carcinoma is a common urological cancer in chronic kidney disease patients. Cystoscopy and urine cytology are the clinical diagnostic tools for UC. However, cystoscopy is an invasive procedure, while urine cytology showed low sensitivity for low-grade urothelial tumors. High accuracy with non-invasive tools for UC is needed for CKD patients. Our study collected a total of 272 urine and 138 plasma samples to detect the miRNA expression levels for establishing UC signatures from CKD patients. Seventeen candidate miRNAs of biofluids were selected and confirmed by qRT-PCR. Our results showed that urinary miR-1274a and miR-30a-5p expression levels were significantly lower but miR-19a-5p expression levels were higher in UC when compared with CKD. In plasma samples, miR-155-5p, miR-19b-1-5p, miR-378, and miR-636 showed significantly lower expression in UC compared to those with CKD. The Kaplan-Meier curve showed that lower expression of miR-19a, miR-19b, miR-636 and miR-378, and higher expression of miR-708-5p were associated with poor prognosis in patients with bladder cancer. In addition, we produced classifiers for predicting UC by multiple logistic regression. The urine signature was developed with four miRNAs, and the AUC was 0.8211. Eight miRNA expression levels from both urine and plasma samples were examined, and the AUC was 0.8595. Two miRNA classifiers and the nomograms could improve the drawbacks of current UC biomarker screenings for patients with CKD.

SRSF5 regulates alternative splicing of DMTF1 pre-mRNA through modulating SF1 binding

ABBREVIATIONS

ARF: alternative reading frame, that is, p14ARF, or CDKN2A (cyclin-dependent kinase inhibitor 2A); β-gal: β-galactosidase; CLIP-seq: crosslinking and immunoprecipitation-sequencing; DMTF1: the cyclin D binding myb-like transcription factor 1; ESS/ESE: exonic splicing silencer/enhancer; Ex: exon; FBS: fetal bovine serum; Gluc: Gaussia luciferase; hnRNPs: heterogeneous nuclear ribonucleoproteins; In: intron; ISS/ISE: intronic splicing silencer/enhancer; PBS: phosphate-buffered saline; PCR: polymerase chain reaction; PSI: percent-splice-in; qPCR: quantitative real-time PCR; RIP: RNA immunoprecipitation; RNAseq: RNA sequencing; RT: reverse transcription; SF1: splicing factor 1; SR: serine/arginine-rich proteins; SRSF5: serine and arginine-rich splicing factor 5; TCGA: the cancer genome atlas; UCSC: University of California, Santa Cruz. WT: Wild type.

MiR-6838-5p facilitates the proliferation and invasion of renal cell carcinoma cells through inhibiting the DMTF1/ARF-p53 axis

Renal cell carcinoma (RCC) is one of the most common renal malignancies in the urinary system. Numerous studies have demonstrated that miRNAs can regulate tumorigenesis and progression. This study aims to investigate the role and regulatory mechanism of miR-6838-5p in RCC. Our study confirmed that miR-6838-5p was upregulated in human RCC tissues (30/42, 77.43%, P < 0.01) and RCC cell lines (P < 0.05) compared to adjacent non-neoplastic tissues and normal renal epithelial cells. In vitro, overexpression of miR-6838-5p enhanced cell proliferation and invasion in human RCC cell lines (ACHN and 786-O), which were detected by CCK-8, Transwell and Colony formation assays (P < 0.05), and knockdown of miR-6838-5p suppressed cell proliferation and invasion (P < 0.05). Results of Bioinformatics analysis combined with Dual-luciferase reporter gene assay demonstrated that miR-6838-5p could bind to Cyclin D binding myb-like transcription factor 1 (DMTF1). In addition, RT-qPCR and Western blotting confirmed that DMTF1 was downregulated in RCC tissues and cell lines. Meanwhile, it was demonstrated that overexpression of miR-6838-5p inhibited DMTF1 level in ACHN cells. Next, we confirmed that DMTF1 overexpression reversed the inhibitory effects of overexpression of miR-6838-5p on phosphatase and tensin homolog (PTEN), tumor protein 53(p53), murine double minute 2 (MDM2) and alternative reading frame (ARF) protein levels in the ARF-p53 signaling pathway. In conclusion, our research showed that miR-6838-5p enhanced the proliferation and invasion of RCC cells by inhibiting the DMTF1/ARF-p53 axis.

Comprehensive Analysis of Correlations in the Expression of miRNA Genes and Immune Checkpoint Genes in Bladder Cancer Cells

Personalised medicine is the future and hope for many patients, including those with cancers. Early detection, as well as rapid, well-selected treatment, are key factors leading to a good prognosis. MicroRNA mediated gene regulation is a promising area of development for new diagnostic and therapeutic methods, crucial for better prospects for patients. Bladder cancer is a frequent neoplasm, with high lethality and lacking modern, advanced therapeutic modalities, such as immunotherapy. MicroRNAs are involved in bladder cancer pathogenesis, proliferation, control and response to treatment, which we summarise in this perspective in response to lack of recent review publications in this field. We further performed a correlation-based analysis of microRNA and gene expression data in bladder cancer (BLCA) TCGA dataset. We identified 27 microRNAs hits with opposite expression profiles to genes involved in immune response in bladder cancer, and 24 microRNAs hits with similar expression profiles. We discuss previous studies linking the functions of these microRNAs to bladder cancer and assess if they are good candidates for personalised medicine therapeutics and diagnostics. The discussed functions include regulation of gene expression, interplay with transcription factors, response to treatment, apoptosis, cell proliferation and angiogenesis, initiation and development of cancer, genome instability and tumour-associated inflammatory reaction.

Mechanisms regulating DMTF1β/γ expression and their functional interplay with DMTF1α

The cyclin D binding myb-like transcription factor 1 (DMTF1), a haplo-insufficient tumor suppressor gene, has 3 alternatively spliced mRNA isoforms encoding DMTF1α, β and γ proteins. Previous studies have indicated a tumor suppressive role of DMTF1α and the oncogenic activity of DMTF1β, while the function of DMTF1γ remains largely undetermined. In the present study, the mechanisms regulating DMTF1 isoform expression were investigated and the functional interplay of DMTF1β and γ with DMTF1α was characterized. It was found that specific regions of DMTF1β and γ transcripts can impair their mRNA integrity or stability, and thus reduce protein expression levels. Additionally, DMTF1β and γ proteins exhibited a reduced stability compared to DMTF1α and all 3 DMTF1 isoforms were localized in the nuclei. Two basic residues, K52 and R53, in the DMTF1 isoforms determined their nuclear localization. Importantly, both DMTF1β and γ could associate with DMTF1α and antagonize its transactivation of the ARF promoter. Consistently, the ratios of both DMTF1β/α and γ/α were significantly associated with a poor prognoses of breast cancer patients, suggesting oncogenic roles of DMTF1β and γ isoforms in breast cancer development.

Expression profile of microRNAs in bladder cancer and their application as biomarkers

Bladder cancer (BC) comprises 3% of all cancers and is particularly common in the developed countries. Early diagnosis is an important necessity in improvement of BC prognosis, as patients' outcome is significantly different between muscle invasive BC (MIBC) and non-muscle invasive BC cases. This cancer is resulted from an intricate interaction between genetic and environmental factors. Recent studies have identified microRNAs (miRNAs) as potential modulators of carcinogenic potential of BC cells. These small transcripts regulate expression of target genes mostly through binding with their 3' untranslated regions. Expression of several oncomiRs has been increased in BC tissues, peripheral blood or urine samples of these patients. These miRNAs promote oncogenic potential of BC through modulation of epithelial-mesenchymal transition or PI3K/AKT, JAK/STAT and NF-κB/Snail signaling pathways. Besides, a number of tumor suppressive miRNAs have been down-regulated in BC samples leading to enhanced proliferation, invasiveness and metastasis of these cells. TGFβ1, Akt, MAPK, MET/SMAD3/SNAIL, MAPK1/Slug/vimentin and Wnt7a/β-catenin pathways and axes are among molecular targets of these miRNAs. Aberrant expressions of miRNAs in biofluids of patients with BC have potentiated them as molecular markers for prediction of disease course. In the current review, we provided a summary of studies which reported aberrant expression of miRNAs and their implications in the diagnosis or prognosis of patients with BC.

Comprehensive Analysis of Novel lncRNA-TF Regulatory Cross Talks and Identification of Core lncRNA-TF Feedback Loops in Sarcoma

Sarcomas are a broad family of cancers that arise from cells of mesenchymal origin in virtually every tissue of the body. Some transcription factors (TFs) have been reported to be involved in the pathogenesis and metastasis of sarcomas. The expression of certain long noncoding RNAs (lncRNAs) has been correlated with the degree of cancer prognosis. There is an urgent need to effectively integrate TFs and lncRNA/microRNA/mRNA regulatory axis and further identify more key regulators that play crucial roles in sarcomas. We performed a network-based computational analysis to investigate the lncRNA-TF cross talks via integrating lncRNA-TF ceRNA interactions and TF-TF protein-protein interactions. Multiple topology analyses were performed to the sarcomas-related global lncRNA-TF network. Several lncRNAs or TFs with central topology structures were identified as key regulators and used to locate a hub-associated lncRNA-TF subnetwork. Three functional modules were identified from the sarcomas-related global lncRNA-TF network, which have shown significant pathway enrichment and prognosis capability. The lncRNAs and TFs of these modules were shown to participate in sarcoma-related biological phenomena through involving in mitogen-activated protein kinases (MAPK), Jak-STAT, and transforming growth factor (TGF-beta) signaling pathways. More importantly, a subset of core lncRNA-TF cross talks that might form positive feedback loops to control biological processes of sarcomas was identified. These core lncRNA-TF positive feedback loops showed more TF binding affinity than other lncRNAs. All the results can help us uncover the molecular mechanism of sarcomas and provide a novel way for diagnosis biomarker and therapeutic target identification.

Current Concepts of Non-Coding RNAs in the Pathogenesis of Non-Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a relatively rare malignancy of the urinary tract system. RCC is a heterogenous disease in terms of underlying histology and its associated underlying pathobiology, prognosis and treatment schedule. The most prevalent histological RCC subtype is clear-cell renal cell carcinoma (ccRCC), accounting for about 70-80% of all RCCs. Though the pathobiology and treatment schedule for ccRCC are well-established, non-ccRCC subtypes account for 20%-30% of RCC altogether, and their underlying molecular biology and treatment options are poorly defined. The class of non-coding RNAs-molecules that are generally not translated into proteins-are new cancer drivers and suppressors in all types of cancer. Of these, small non-coding microRNAs (miRNAs) contribute to carcinogenesis by regulating posttranscriptional gene silencing. Additionally, a growing body of evidence supports the role of long non-coding RNAs (lncRNAs) in cancer development and progression. Most studies on non-coding RNAs in RCC focus on clear-cell histology, and there is a relatively limited number of studies on non-ccRCC subtypes. The aim of this review is to give an overview of the current knowledge regarding the role of non-coding RNAs (including short and long non-coding RNAs) in non-ccRCC and to highlight possible implications as diagnostic, prognostic and predictive biomarkers.

MiR-155-5p modulates HSV-1 replication via the epigenetic regulation of SRSF2 gene expression

A previous study reported that miR-155-5p knockout mice were more resistant to herpes simplex virus type I (HSV-1) infection. However, the exact underlying molecular mechanism remains to be elucidated. Here, we demonstrated that HSV-1 infection upregulates miR-155-5p expression. By binding to the promoter of serine/arginine-rich splicing factor 2 (SRSF2), which is an important transcriptional activator of HSV-1 genes that was previously reported by our group, and altering the histone modification located near the transcription start site (TSS) of the SRSF2 gene, miR-155-5p promotes the transcription of the SRSF2 gene, ultimately increasing viral replication and viral gene expression. Our results provide insight for an understanding of the roles and molecular mechanism of miR-155-5p in HSV-1 replication and the epigenetic control of SRSF2 gene expression.

Identifying Disease-Gene Associations With Graph-Regularized Manifold Learning

Complex diseases are known to be associated with disease genes. Uncovering disease-gene associations is critical for diagnosis, treatment, and prevention of diseases. Computational algorithms which effectively predict candidate disease-gene associations prior to experimental proof can greatly reduce the associated cost and time. Most existing methods are disease-specific which can only predict genes associated with a specific disease at a time. Similarities among diseases are not used during the prediction. Meanwhile, most methods predict new disease genes based on known associations, making them unable to predict disease genes for diseases without known associated genes.In this study, a manifold learning-based method is proposed for predicting disease-gene associations by assuming that the geodesic distance between any disease and its associated genes should be shorter than that of other non-associated disease-gene pairs. The model maps the diseases and genes into a lower dimensional manifold based on the known disease-gene associations, disease similarity and gene similarity to predict new associations in terms of the geodesic distance between disease-gene pairs. In the 3-fold cross-validation experiments, our method achieves scores of 0.882 and 0.854 in terms of the area under of the receiver operating characteristic (ROC) curve (AUC) for diseases with more than one known associated genes and diseases with only one known associated gene, respectively. Further de novo studies on Lung Cancer and Bladder Cancer also show that our model is capable of identifying new disease-gene associations.

miR-155 in cancer drug resistance and as target for miRNA-based therapeutics

Small non-coding microRNAs (miRNAs) are instrumental in physiological processes, such as proliferation, cell cycle, apoptosis, and differentiation, processes which are often disrupted in diseases like cancer. miR-155 is one of the best conserved and multifunctional miRNAs, which is mainly characterized by overexpression in multiple diseases including malignant tumors. Altered expression of miR-155 is found to be associated with various physiological and pathological processes, including hematopoietic lineage differentiation, immune response, inflammation, and tumorigenesis. Furthermore, miR-155 drives therapy resistance mechanisms in various tumor types. Therefore, miR-155-mediated signaling pathways became a potential target for the molecular treatment of cancer. In this review, we summarize the current findings of miR-155 in hematopoietic lineage differentiation, the immune response, inflammation, and cancer therapy resistance. Furthermore, we discuss the potential of miR-155-based therapeutic approaches for the treatment of cancer.

Plasma miRNA profile is a biomarker associated with urothelial carcinoma in chronic hemodialysis patients

The incidence of urothelial carcinoma (UC) is higher in patients undergoing chronic dialysis than in the general population. This study investigated plasma miRNA profiling as the ancillary diagnosis biomarker associated with UC in patients undergoing chronic hemodialysis. We successfully screened out and detected miRNA expression from plasma in eight patients undergoing dialysis through quantitative real-time PCR array analysis and identified eight candidate miRNAs. The candidate miRNAs were then validated using single quantitative RT-PCR assays from 52 plasma samples. The miRNA classifier for ancillary UC detection was developed by multiple logistic regression analyses. Moreover, we validated the classifier by testing another nine samples. Expression levels of miR-150-5p, miR-150-5p/miR-155-5p, miR-378a-3p/miR-150-5p, miR-636/miR-150-5p, miR-150-5p/miR-210-3p, and miR-19b-1-5p/miR-378a-3p were shown to be significantly different between UC and non-UC samples (P = 0.035, 0.0048, 0.016, 0.024, 0.038, and 0.048). Kaplan-Meier curve analysis also showed that low miR-19b-1-5p expression was associated with a worse prognosis (P = 0.0382). We also developed a miRNA classifier based on five miRNA expression levels to predict UC and found that the area under curve was 0.882. The classifier had a sensitivity of 80% (95% confidence interval: 0.5191% to 0.9567%) and a specificity of 83.7% (95% confidence interval: 0.6799% to 0.9381%). This classifier was tested by nine samples with 100% accuracy. The miRNA classifier offers higher sensitivity and specificity than the existing makers. Thus, this approach will improve the prospective diagnosis of UC in patients undergoing chronic hemodialysis.

miR‑675 promotes colorectal cancer cell growth dependent on tumor suppressor DMTF1

Colorectal cancer (CRC) has become a worldwide health concern, particularly in developing countries. Therefore, the present study focuses on the investigation of oncogenic microRNA (miR)-675-3p, and its role in colorectal carcinogenesis. miR-675-3p expression was either overexpressed or inhibited in SW480 CRC cells in order to demonstrate its positive effect on the cell proliferation, as determined by MTS and flow cytometry. Then the present study utilized a luciferase assay to demonstrate that cyclin D binding myb like transcription factor 1 (DMTF1) was modulated by miR-675-3p directly at its 3′untranslated region. Overexpression or inhibition of miR-675-3p affected the expression of DMTF1, as determined by reverse transcription-quantitative polymerase chain reaction and western blotting. In addition, the overexpression of miR-675-3p promoted cell proliferation, whereas the additional introduction of DMTF1 rescued the overgrowth of the SW480 cells. These results were also confirmed in HT29 CRC cells. In summary, the results of the study demonstrated that miR-675-3p directly regulated the expression of DMTF1, which contributed to the further regulation of CRC cell proliferation.

Prognostic role of microRNA-155 expression in gliomas: A meta-analysis

Recent studies have reported that microRNA-155 (miR-155) is linked to the clinical outcomes of many tumors. However, its role in prognosis of gliomas remains unclear. This meta-analysis aims to evaluate the prognostic value of miR-155 in the survival of patients with gliomas. Hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) were pooled with random effects or fixed effects models on the basis of heterogeneity. Subgroup analysis and sensitivity analysis were performed to elucidate the possible confounding factors and investigate the source of heterogeneity. In addition, we assessed publication bias using the Begg's funnel plots, Egger's test, and Begg's test. Only non-laboratory studies were considered for our analysis. 9 studies from 6 articles containing 1259 glioma patients were included. The pooled HR of elevated miR-155 for OS in patients with gliomas was 1.40 (95%CI [1.19-1.63], P < 0.001) (I-squared = 52.4%, P = 0.032) suggesting that miR-155 might be a promising biomarker for the prognosis of gliomas in future clinical applications.

Tumor suppression by the EGR1, DMP1, ARF, p53, and PTEN Network

Recent studies have indicated that EGR1 is a direct regulator of tumor suppressors including TGFβ1, PTEN, and p53. The Myb-like transcription factor Dmp1 is a physiological regulator of the Arf-p53 pathway through transactivation of the Arf promoter and physical interaction of p53. The Dmp1 promoter has binding sites for Egr proteins, and Egr1 is a target for Dmp1. Crosstalks between p53 and PTEN have been reported. The Egr1-Dmp1-Arf-p53-Pten pathway displays multiple modes of interaction with each other, suggesting the existence of a functional network of tumor suppressors that maintain normal cell growth and prevent the emergence of incipient cancer cells.

Identifying a panel of genes/proteins/miRNAs modulated by arsenicals in bladder, prostate, kidney cancers

Arsenic and arsenic-derivative compounds, named as arsenicals, represent a worldwide problem for their effect on the human health and, in particular, for their capability to increase the risk of developing cancer such as kidney, bladder and prostate cancer. The main source of arsenical exposure is drinking water. Nowadays, it is well known that the chronic exposure to arsenicals leads to a series of epigenetic alterations that have a role in arsenic-induced effects on human health including cancer. Based on these observations, the aim of our study was to select by network analysis the genes/proteins/miRNAs implicated in kidney, bladder and prostate cancer development upon arsenical exposure. From this analysis we identified: (i) the nodes linking the three molecular networks specific for kidney, bladder and prostate cancer; (ii) the relative HUB nodes (RXRA, MAP3K7, NR3C1, PABPC1, NDRG1, RELA and CTNNB1) that link the three cancer networks; (iii) the miRNAs able to target these HUB nodes. In conclusion, we highlighted a panel of potential molecules related to the molecular mechanisms of arsenical-induced cancerogenesis and suggest their utility as biomarkers or therapeutic targets.

Network-based analysis of oligodendrogliomas predicts novel cancer gene candidates within the region of the 1p/19q co-deletion

Oligodendrogliomas are primary human brain tumors with a characteristic 1p/19q co-deletion of important prognostic relevance, but little is known about the pathology of this chromosomal mutation. We developed a network-based approach to identify novel cancer gene candidates in the region of the 1p/19q co-deletion. Gene regulatory networks were learned from gene expression and copy number data of 178 oligodendrogliomas and further used to quantify putative impacts of differentially expressed genes of the 1p/19q region on cancer-relevant pathways. We predicted 8 genes with strong impact on signaling pathways and 14 genes with strong impact on metabolic pathways widespread across the region of the 1p/19 co-deletion. Many of these candidates (e.g. ELTD1, SDHB, SEPW1, SLC17A7, SZRD1, THAP3, ZBTB17) are likely to push, whereas others (e.g. CAP1, HBXIP, KLK6, PARK7, PTAFR) might counteract oligodendroglioma development. For example, ELTD1, a functionally validated glioblastoma oncogene located on 1p, was overexpressed. Further, the known glioblastoma tumor suppressor SLC17A7 located on 19q was underexpressed. Moreover, known epigenetic alterations triggered by mutated SDHB in paragangliomas suggest that underexpressed SDHB in oligodendrogliomas may support and possibly enhance the epigenetic reprogramming induced by the IDH-mutation. We further analyzed rarely observed deletions and duplications of chromosomal arms within oligodendroglioma subcohorts identifying putative oncogenes and tumor suppressors that possibly influence the development of oligodendroglioma subgroups. Our in-depth computational study contributes to a better understanding of the pathology of the 1p/19q co-deletion and other chromosomal arm mutations. This might open opportunities for functional validations and new therapeutic strategies.

MiR-155 promotes epithelial-mesenchymal transition in hepatocellular carcinoma cells through the activation of PI3K/SGK3/β-catenin signaling pathways

Oncogenic mutations in PIK3CA, the gene encoding the catalytic subunit of phosphoinositide 3-kinase (PI3K), occur with high frequency in hepatocellular carcinoma (HCC). The protein kinase Akt is considered to be the primary effector of PI3K, but there is evidence to suggest that serum and glucocorticoid kinase 3 (SGK3) acts in an Akt-independent manner downstream of PI3K. In this report, we found that SGK3 promotes epithelial-mesenchymal transition (EMT) and reduces phosphorylation-dependent degradation of β-catenin in HCC cells. We determined that miR-155, previously shown to promote EMT, stimulates the expression of SGK3 by targeting and repressing P85α, thereby removing its inhibitory effect on PI3K-AKT signaling. These findings suggest that miR-155 promotes EMT and metastatic properties in HCC cells through activation of PI3K/SGK3/β-catenin signaling pathways.

Dysregulation of miRNAs in bladder cancer: altered expression with aberrant biogenesis procedure

Aberrant expression profiles of miRNAs are widely observed in the clinical tissue specimens and urine samples as well as the blood samples of bladder cancer patients. These profiles are closely related to the pathological features of bladder cancer, such as the tumour stage/grade, metastasis, recurrence and chemo-sensitivity. MiRNA biogenesis forms the basis of miRNA expression and function, and its dysregulation has been shown to be essential for variations in miRNA expression profiles as well as tumourigenesis and cancer progression. In this review, we summarize the up-to-date and widely reported miRNAs in bladder cancer that display significantly altered expression. We then compare the miRNA expression profiles among three different sample types (tissue, urine and blood) from patients with bladder cancer. Moreover, for the first time, we outline the dysregulated miRNA biogenesis network in bladder cancer from different levels and analyse its possible relationship with aberrant miRNA expression and the pathological characteristics of the disease.

Selenium targets resistance biomarkers enhancing efficacy while reducing toxicity of anti-cancer drugs: preclinical and clinical development

Selenium (Se)-containing molecules exert antioxidant properties and modulate targets associated with tumor growth, metastasis, angiogenesis, and drug resistance. Prevention clinical trials with low-dose supplementation of different types of Se molecules have yielded conflicting results. Utilizing several xenograft models, we earlier reported that the enhanced antitumor activity of various chemotherapeutic agents by selenomethione and Se-methylselenocysteine in several human tumor xenografts is highly dose- and schedule-dependent. Further, Se pretreament offered selective protection of normal tissues from drug-induced toxicity, thereby allowing higher dosing than maximum tolerated doses. These enhanced therapeutic effects were associated with inhibition of hypoxia-inducible factor 1- and 2-alpha (HIF1α, HIF2α) protein, nuclear factor (erythyroid-derived 2)-like 2 (Nrf2) and pair-related homeobox-1 (Prx1) transcription factors, downregulation of oncogenic- and upregulation of tumor suppressor miRNAs. This review provides: 1) a brief update of clinical prevention trials with Se; 2) advances in the use of specific types, doses, and schedules of Se that selectively modulate antitumor activity and toxicity of anti-cancer drugs; 3) identification of targets selectively modulated by Se; 4) plasma and tumor tissue Se levels achieved after oral administration of Se in xenograft models and cancer patients; 5) development of a phase 1 clinical trial with escalating doses of orally administered selenomethionine in sequential combination with axitinib to patients with advanced clear cell renal cell carcinoma; and 6) clinical prospects for future therapeutic use of Se in combination with anticancer drugs.

miR-155-5p inhibition promotes the transition of bone marrow mesenchymal stem cells to gastric cancer tissue derived MSC-like cells via NF-κB p65 activation

Gastric cancer tissue-derived MSC-like cells (GC-MSC) share similar characteristics to bone marrow MSC (BM-MSC); however, the phenotypical and functional differences and the molecular mechanism of transition between the two cell types remain unclear. Compared to BM-MSC, GC-MSC exhibited the classic phenotype of reactive stroma cells, a stronger gastric cancer promoting capacity and lower expression of miR-155-5p. Inhibition of miR-155-5p by transfecting miRNA inhibitor induced a phenotypical and functional transition of BM-MSC into GC-MSC-like cells, and the reverse experiment deprived GC-MSC of tumor-promoting phenotype and function. NF-kappa B p65 (NF-κB p65) and inhibitor of NF-kappa B kinase subunit epsilon (IKBKE/IKKε) were identified as targets of miR-155-5p and important for miRNA inhibitor activating NF-κB p65 in the transition. Inactivation of NF-κB by pyrrolidine dithiocarbamic acid (PDTC) significantly blocked the effect of miR-155-5p inhibitor on BM-MSC. IKBKE, NF-κB p65 and phospho-NF-κB p65 proteins were highly enriched in MSC-like cells of gastric cancer tissues, and the latter two were correlated with the pathological progression of gastric cancer. In GC-MSC, the expression of miR-155-5p was downregulated and NF-κB p65 protein was increased and activated. NF-κB inactivation by PDTC or knockdown of its downstream cytokines reversed the phenotype and function of GC-MSC. Taken together, our findings revealed that miR-155-5p downregulation induces BM-MSC to acquire a GC-MSC-like phenotype and function depending on NF-κB p65 activation, which suggests a novel mechanism underlying the cancer associated MSC remodeling in the tumor microenvironment and offers an effective target and approach for gastric cancer therapy.

Crosstalk between liver-related microRNAs and Wnt/β-catenin pathway in hepatocellular carcinoma patients

BACKGROUND AND STUDY AIMS

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide with highest incidence in Asia and Africa. MicroRNAs (miRNAs), a class of non-coding single stranded RNA, which not only post transcriptionally regulate gene expression but also respond to signaling molecules to affect cell functions such as Wnt/β-catenin signaling specifically in HCC. The goal of this study is to investigate the crosstalk between Wnt/β-catenin signaling proteins and microRNAs expression in HCC patients.

PATIENTS AND METHODS

Fresh tissue samples of 30 primary HCC patients and 10 control subjects were included. Expression level of 13 different miRNAs (miR-10a- miR-106b- miR-99a- miR-148a- miR-125b- miR-30e- miR-183- miR-155- miR-199a- miR-199a3p- miR-24- miR-122 and miR-215) were examined using real-time PCR assay. Five proteins involved in the Wnt/β-catenin pathway (β-catenin, APC, c-myc, survivin and cyclin D1) were analysed by immunohistochemistry technique. The correlation between miRNAs expression levels with protein expressions was assessed.

RESULTS

Up-regulation of miR-155 and miR-183 was reported in HCC patients compared to normal controls and this up-regulation was significantly correlated with liver cirrhosis in the case of miR-155 (p<0.05) referring to their oncogenic activity. Down-regulation was observed for 11 miRNAs in HCC indicating their tumour suppression activity. MiRNA-10a, miR-30e, miR-215, miR-125b and miR-148a were significantly correlated with the expression of important players in Wnt/β-catenin pathway including β-catenin, APC and c-myc (p<0.05). Detailed analysis revealed that miR-215 is associated with the grade of the disease and miR-125b is associated with HCV infection.

CONCLUSION

Collectively, our data showed potential role of miR-10a, miR-30e, miR-215, miR-125b and miR-148a as important mediators in HCC progression. Furthermore, their association with Wnt/β-catenin cascade proteins could be exploited to develop new therapeutic target strategies in HCC.

MicroRNAs with prognostic significance in bladder cancer: a systematic review and meta-analysis

The aim of this study was to systematically review articles that investigated the prognostic significance of different microRNAs in bladder cancer (BC). We systematically searched PubMed, Web of Science, and Embase to identify relevant studies until March 2016. After screening, 26 studies that involved 2753 patients were included. Results suggested that many miRs expression aberration may predict prognosis in patients with BC. There are six miRs (miR-21, miR-143, miR-155, miR-200, miR-214, and miR-222) were reported by at least two studies, and we performed meta-analysis in the corresponding studies. Accordingly, we found that high miR-21 expression was associated with poor overall survival [OS; hazard ratio (HR) = 3.94, 95% CI 2.08–7.44]. High miR-143 expression was associated with poor progression-free survival (PFS; HR = 3.78, 95% CI 1.61–8.89). High miR-155 expression was associated with poor PFS (HR = 8.10, 95% CI 2.92–22.48). High miR-222 expression was associated with poor OS (HR = 3.39, 95% CI 1.10–10.41). Meanwhile, low miR-214 expression was correlated with poor RFS(HR = 0.34, 95% CI 0.22–0.53). Our comprehensive systematic review concluded that microRNAs, particularly miR-21, miR-143, miR-155, miR-214, and miR-222, could serve as meticulous follow-up markers for early detection of progression or recurrence and even useful therapeutic targets for the treatment in patients with BC.

Understanding the Role of Non-Coding RNAs in Bladder Cancer: From Dark Matter to Valuable Therapeutic Targets

The mortality and morbidity that characterize bladder cancer compel this malignancy into the category of hot topics in terms of biomolecular research. Therefore, a better knowledge of the specific molecular mechanisms that underlie the development and progression of bladder cancer is demanded. Tumor heterogeneity among patients with similar diagnosis, as well as intratumor heterogeneity, generates difficulties in terms of targeted therapy. Furthermore, late diagnosis represents an ongoing issue, significantly reducing the response to therapy and, inevitably, the overall survival. The role of non-coding RNAs in bladder cancer emerged in the last decade, revealing that microRNAs (miRNAs) may act as tumor suppressor genes, respectively oncogenes, but also as biomarkers for early diagnosis. Regarding other types of non-coding RNAs, especially long non-coding RNAs (lncRNAs) which are extensively reviewed in this article, their exact roles in tumorigenesis are—for the time being—not as evident as in the case of miRNAs, but, still, clearly suggested. Therefore, this review covers the non-coding RNA expression profile of bladder cancer patients and their validated target genes in bladder cancer cell lines, with repercussions on processes such as proliferation, invasiveness, apoptosis, cell cycle arrest, and other molecular pathways which are specific for the malignant transformation of cells.

Identification and profiling of growth-related microRNAs in Chinese perch (Siniperca chuatsi)

Background

MicroRNAs (miRNAs) are endogenous small non-coding RNAs that play important roles in the regulation of diverse biological processes in eukaryotes. Chinese perch (Siniperca chuatsi) is one of the most economically important fish species widely cultured in China. Growth is an extremely important characteristic in fish. Individual differences in body size are common in Siniperca chuatsi, which significantly influence the aquaculture production of Siniperca chuatsi. However, the underline growth-related regulatory factors, such as miRNAs, are still unknown.

Results

To investigate the growth-related miRNAs in Siniperca chuatsi, two RNA libraries from four growth-related tissues (brain, pituitary, liver, and muscle) of Siniperca chuatsi at 6-month stage with relatively high or low growth rates (big-size group or small-size group) were obtained and sequenced using Solexa sequencing. A total of 252 known miRNAs and 12 novel miRNAs were identified. The expression patterns of these miRNAs in big-size group and small-size group were compared, and the results showed that 31 known and 5 novel miRNAs were differently expressed (DE). Furthermore, to verify the Solexa sequencing, five DE miRNAs were randomly selected and quantified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The results showed that their expression patterns were consistent with those of Solexa sequencing. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of target genes of DE miRNAs was performed. It showed that the target genes were involved in multiple biological processes including metabolic process, suggesting that metabolic process played an important role in growth of fish.

Conclusions

Siniperca chuatsi is a popular and economically important species in aquaculture. In this study, miRNAs in Siniperca chuatsi with different growth rates were identified, and their expression profiles were compared. The data provides the first large-scale miRNA profiles related to growth of Siniperca chuatsi, which is expected to contribute to a better understanding of the role of miRNAs in regulating the biological processes of growth and possibly useful for Siniperca chuatsi breeding.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3851-y) contains supplementary material, which is available to authorized users.

Direct quantitative detection for cell-free miR-155 in urine: a potential role in diagnosis and prognosis for non-muscle invasive bladder cancer

High recurrence rates of non-muscle invasive bladder cancer (NMIBC) in patients require lifelong testing and monitoring. The aim of this study is to develop a simplified RT-qPCR method (RT-qPCR-D) which directly quantifies cell-free miR-155 in urine without RNA extraction, and assess it as a potential tool in NMIBC detection. A pilot study including 60 urine samples was used to investigate the feasibility of RT-qPCR-D in detecting cell-free miR-155. Then, miR-155 levels were quantified in a large independent cohort of urine from 162 NIMBC patients, 76 cystitis patients, and 86 healthy donors using the RT-qPCR-D method. Changes of cell-free miR-155 before and after operation were also analyzed in 32 NIMBC patients. In pilot study, we found a significant linear association between RT-qPCR and RT-qPCR-D in urinary miR-155 detection. Both methods showed cell-free miR-155 were significantly increased in NMIBC patients, and could reflect their expression in tissues. Then, the increased expression of cell-free miR-155 was successfully validated in 162 NIMBC patients when compared with cystitis patients and healthy donors. Moreover, it distinguished NMIBC patients from others with 80.2% sensitivity and 84.6% specificity, which was superior to urine cytology. Cell-free miR-155 correlated with NMIBC stage and grade, and was an independent factor for predicting recurrence and progression to muscle invasion. In addition, cell-free miR-155 was significantly decreased after NMIBC patients underwent transurethral bladder resection. In conclusion, detection of cell-free miR-155 in urine using RT-qPCR-D is a simple and noninvasive approach which may be used for NMIBC diagnosis and prognosis prediction.

Clinical applications of mouse models for breast cancer engaging HER2/neu

Human c-ErbB2 (HER2) has long been used as a marker of breast cancer (BC) for sub-categorization for the prediction of prognosis, and determination of therapeutic strategies. HER2 overexpressing BCs are more invasive/metastatic; but patients respond to monoclonal antibody therapy with trastuzumab or tyrosine kinase inhibitors, at least at early stages. To date, numerous mouse models that faithfully reproduce HER2(+) BCs have been created in mice. We recently reviewed different mouse models of BC overexpressing wild type or mutant neu driven by MMTV, neu, or doxycycline-inducible promoters. These mice have been used to demonstrate the histopathology, oncogenic signaling pathways initiated by aberrant overexpression of HER2 in the mammary epithelium, and interaction between oncogenes and tumor suppressor genes at molecular levels. In this review, we focus on their clinical applications. They can be used to test the efficacy of HER(2) inhibitors before starting clinical trials, characterize the tumor-initiating cells that could be the cause of relapse after therapy as well as to analyze the molecular mechanisms of therapeutic resistance targeting HER2. MMTV-human ErbB2 (HER2) mouse models have recently been established since the monoclonal antibody to HER2 (trastuzumab; Herceptin®) does not recognize the rat neu protein. It has been reported that early intervention with HER2 monoclonal antibody would be beneficial for preventing mammary carcinogenesis. MDA-7/IL-24 as well as naturally-occurring chemicals have also been tested using MMTV-neu models. Recent studies have shown that MMTV-neu models are useful to develop vaccines to HER2 for immunotherapy. The mouse models employing HER2/neu will be essential for future antibody or drug screenings to overcome resistance to trastuzumab or HER(2)-specific tyrosine kinase inhibitors.

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.

The role of microRNAs in gallbladder cancer

MicroRNAs (also referred to as miRNAs or miRs) play a crucial role in post-transcriptional gene regulation and serve as negative gene regulators by controlling a variety of target genes and regulating diverse biological processes, such as cell proliferation, invasion, migration and apoptosis. Aberrant expression of miRNAs is associated with the development and progression of cancer. Recent studies have reported that miRNAs may repress or promote the expression of cancer-related genes via several different signaling pathways in gallbladder cancer (GBC) patients and may function as tumor suppressors or oncogenes, thus providing a promising tool for the diagnosis and therapeutics of GBCs. In this review, we summarize the role of dysregulawted miRNA expression in the signaling pathways implicated in GBC and discuss the significant role of circulating miRNAs in GBC. Therefore, miRNAs may serve as novel therapeutic targets as well as diagnostic or prognostic markers in GBC.

miR-155 regulates the proliferation and invasion of clear cell renal cell carcinoma cells by targeting E2F2

MicroRNAs (miRNAs) have emerged as critical modulators of carcinogenesis and tumor progression. In the present work, we sought to identify the biological function of miR-155 as well as its underlying mechanism in clear cell renal cell carcinoma (ccRCC). We examined the expression of miR-155 in clear cell RCC (ccRCC) and adjacent normal tissues and then explored the roles of miR-155 both in vitro and in vivo. The results of this analysis indicated that miR-155 activity was significantly upregulated in ccRCC tissues compared with the corresponding normal tissues. miR-155 was associated with ccRCC aggressiveness in both cell lines and clinical specimens, and a specific and inverse correlation between miR-155 and E2F2 expression was found in human ccRCC samples. Overexpression of miR-155 in 786-O cells decreased E2F2 expression while reduction of miR-155 by anti-miR-155 in ACHN cells elevated E2F2 expression. Re-expression of E2F2 in 786-O cells repressed the cell migration/invasion abilities elevated by miR-155, whereas knockdown of E2F2 in ACHN cells restored these cellular functions hampered by the miR-155 inhibitor. Using Western blot and luciferase reporter assays, we determined that E2F2 was a direct target of miR-155. Taken together, the in vitro and in vivo results demonstrate that miR-155 functions as a tumor-promoting miRNA by targeting E2F2 in ccRCC.

Preliminary Analysis of the Expression of Selected Proangiogenic and Antioxidant Genes and MicroRNAs in Patients with Non-Muscle-Invasive Bladder Cancer

Heme oxygenase-1 (HO-1) is an enzyme contributing to the development and progression of different cancer types. HO-1 plays a role in pathological angiogenesis in bladder cancer and contributes to the resistance of this cancer to therapy. It also regulates the expression of microRNAs in rhabdomyosarcoma and non-small cell lung cancer. The expression of HO-1 may be regulated by hypoxia inducible factors (HIFs) and Nrf2 transcription factor. The expression of HO-1 has not so far been examined in relation to Nrf2, HIF-1α, and potential mediators of angiogenesis in human bladder cancer. We measured the concentration of proinflammatory and proangiogenic cytokines and the expression of cytoprotective and proangiogenic mRNAs and miRNAs in healthy subjects and patients with bladder cancer. HO-1 expression was upregulated together with HIF-1α, HIF-2α, and Nrf2 in bladder cancer in comparison to healthy tissue. VEGF was elevated both at mRNA and protein level in the tumor and in sera, respectively. Additionally, IL-6 and IL-8 were increased in sera of patients affected with urothelial bladder cancer. Moreover, miR-155 was downregulated whereas miR-200c was elevated in cancer biopsies in comparison to healthy tissue. The results indicate that the increased expression of HO-1 in bladder cancer is paralleled by changes in the expression of other potentially interacting genes, like Nrf2, HIF-1α, HIF-2α, IL-6, IL-8, and VEGF. Further studies are necessary to also elucidate the potential links with miR-155 and miR-200c.

Overexpression of MicroRNA-221 is associated with poor prognosis in non-small cell lung cancer patients

The abnormal expression of microRNA-221 was detected in several cancers and some studies had indicated that microRNA-221 was associated with cancer prognosis. This study was aimed to evaluate the prognostic significance of microRNA-221 in non-small cell lung cancer (NSCLC). Quantitative real-time polymerase chain reaction (qRT-PCR) was used for detecting the relative expression levels of microRNA-221 in the pathological tissues and corresponding normal tissues of 104 NSCLC patients. The relationship between the expression levels and the clinical features was estimated by Chi-square method and the overall survival of patients at different expression levels was demonstrated by Kaplan-Meier method. Cox regression analysis was used to evaluate the prognostic significance of microRNA-221. The relative expression levels of microRNA-221 in the pathological tissues were remarkably higher than that in the corresponding normal tissues (1.71 vs 1.07, P = 0.000). The expression level was associated with lymph node metastasis (P = 0.001). The results of Kaplan-Meier method indicated that patients with high expression level of microRNA-221 had shorter overall survival time than those with low expression level (36.8 vs 45.2 months, P = 0.001). Moreover, Cox regression analysis suggested that microRNA-221 was a useful independent biomarker for NSCLC prognosis (HR = 1.873, 95 % CI = 1.267-2.768, P = 0.002). The aberrant expression of microRNA-221 is associated with NSCLC progression and it might be a potential biomarker for NSCLC prognosis.

MicroRNA-155 expression as a prognostic factor in patients with gallbladder carcinoma after surgical resection

BACKGROUND

MicroRNA-155 (miR-155) is over-expressed in both hematopoietic malignancies and solid tumors. In the present study, we investigated the clinical significance of miR-155 in gallbladder carcinoma among Chinese population.

METHODS

Tissue specimens were collected from 133 patients who had undergone surgical resection at Shandong Provincial Hospital, Shandong University between May 2008 and April 2014. We profiled miR- 155 expression in the gallbladder carcinoma tissues and normal gallbladder tissues by qRT-PCR. The Kaplan-Meier method was used to analyze the 5-year survival rate.

RESULTS

The expression levels of miR-155 were significantly higher in gallbladder carcinoma tissues than that in normal gallbladder tissues (P<0.001). High miR-155 expression was significantly associated with TNM stage (P=0.003), lymph node status (P=0.042), liver metastasis (P=0.010), and differentiated degree (P<0.001). We found that gallbladder carcinoma patients with high miR-155 expression level had distinctly shorter overall survival than patients with low miR-155 expression level (P=0.03). Multivariate analysis revealed that miR-155 expression level was independent prognostic factors for overall survival (HR=2.394, 95% CI: 1.568-10.034; P=0.009).

CONCLUSION

High miR-155 expression is a prognostic indicator for poor prognosis of patients with gallbladder carcinoma among Chinese population.

Small molecules targeting microRNA for cancer therapy: Promises and obstacles

Aberrant expression of miRNAs is critically implicated in cancer initiation and progression. Therapeutic approaches focused on regulating miRNAs are therefore a promising approach for treating cancer. Antisense oligonucleotides, miRNA sponges, and CRISPR/Cas9 genome editing systems are being investigated as tools for regulating miRNAs. Despite the accruing insights in the use of these tools, delivery concerns have mitigated clinical application of such systems. In contrast, little attention has been given to the potential of small molecules to modulate miRNA expression for cancer therapy. In these years, many researches proved that small molecules targeting cancer-related miRNAs might have greater potential for cancer treatment. Small molecules targeting cancer related miRNAs showed significantly promising results in different cancer models. However, there are still several obstacles hindering the progress and clinical application in this area. This review discusses the development, mechanisms and application of small molecules for modulating oncogenic miRNAs (oncomiRs). Attention has also been given to screening technologies and perspectives aimed to facilitate clinical translation for small molecule-based miRNA therapeutics.