MicroRNA-1826 targets VEGFC, beta-catenin (CTNNB1) and MEK1 (MAP2K1) in human bladder cancer

Natural compounds as modulators of miRNAs: a new frontier in bladder cancer treatment

Bladder cancer (BC) is a major global health issue with a high recurrence rate and limited effective treatments. Over the past few years, it has become evident that miRNAs play a role in the carcinogenesis process, particularly in regulating genes that promote cancer cell proliferation and invasion. This review focuses on the extent to which natural products can act as potential miRNA modulators for the management of bladder cancer. Polyphenols, flavonoids, and other phytochemicals are natural compounds found to have inherent potential to modulate miRNAs and reform the oncogenic properties of bladder cancer cells regulating cell growth and death. In integration with the current cancer treatment regimes, such natural agents may safely substitute for the traditional chemical chemotherapeutic agents of the conventional approaches. To this end, this review presents the existing knowledge of natural compounds as regulators of miRNA, their mechanisms for the management of BC, the role of their nanoparticles, and future novel therapies. The use of these compounds is not only a therapeutic practice for the conditions of bladder cancer, but it also upholds new avenues for creativity.

Effect of Herniarin on Cell Viability, Cell Cycle, and Erk Protein Levels in Different Stages of Bladder Cancer Cells

This study examines the potential of herniarin from tarragon, as an agent with multifaceted effects on bladder cancer cells and investigates herniarin's impact on cell viability, migration, cell cycle regulation, apoptosis induction, and Erk signaling pathways in bladder cancer cell lines, including RT-112 (grade 1, non-invasive), HTB9 (grade 2, invasive), and HT1376 (grade 3, invasive), through comprehensive in vitro experiments. The compound causes cell cycle arrest at distinct phases in different cell lines: G1/S arrest in RT112 cells, G2/M arrest in HTB9 cells, and S phase arrest in HT1376 cells. Furthermore, herniarin induces caspase-mediated apoptosis in various cell lines and simultaneously modulates protein levels of apoptotic and anti-apoptotic proteins, indicating its potential as a therapeutic agent. Herniarin's influence also extends to Erk signaling, a crucial pathway that regulates cell growth and differentiation. In conclusion, this study reveals herniarin's potential as a versatile agent in the treatment of bladder cancer.

miRNAs role in bladder cancer pathogenesis and targeted therapy: Signaling pathways interplay - A review

Bladder cancer (BC) is the 11th most popular cancer in females and 4th in males. A lot of efforts have been exerted to improve BC patients' care. Besides, new approaches have been developed to enhance the efficiency of BC diagnosis, prognosis, therapeutics, and monitoring. MicroRNAs (miRNAs, miRs) are small chain nucleic acids that can regulate wide networks of cellular events. They can inhibit or degrade their target protein-encoding genes. The miRNAs are either downregulated or upregulated in BC due to epigenetic alterations or biogenesis machinery abnormalities. In BC, dysregulation of miRNAs is associated with cell cycle arrest, apoptosis, proliferation, metastasis, treatment resistance, and other activities. A variety of miRNAs have been related to tumor kind, stage, or patient survival. Besides, although new approaches for using miRNAs in the diagnosis, prognosis, and treatment of BC have been developed, it still needs further investigations. In the next words, we illustrate the recent advances in the role of miRNAs in BC aspects. They include the role of miRNAs in BC pathogenesis and therapy. Besides, the clinical applications of miRNAs in BC diagnosis, prognosis, and treatment are also discussed.

Role of microRNAs in regulation of WNT signaling pathway in urothelial and prostate cancers

Background

Urothelial cancer (UC) and prostate cancer (PCa) are the most common cancers among men with a high ratio of mortality in advanced-stages. The higher risk of these malignancies among men can be associated with higher carcinogens exposure. Molecular pathology of UC and PCa is related to the specific mutations and aberrations in some signaling pathways. WNT signaling is a highly regulated pathway that has a pivotal role during urothelial and prostate development and homeostasis. This pathway also plays a vital role in adult stem cell niches to maintain a balance between stemness and differentiation. Deregulation of the WNT pathway is frequently correlated with tumor progression and metastasis in urothelial and prostate tumors. Therefore, regulatory factors of WNT pathways are being investigated as diagnostic or prognostic markers and novel therapeutic targets during urothelial and prostate tumorigenesis. MicroRNAs (miRNAs) have a pivotal role in WNT signaling regulation in which there are interactions between miRNAs and WNT signaling pathway during tumor progression. Since, the miRNAs are sensitive, specific, and noninvasive, they can be introduced as efficient biomarkers of tumor progression.

Main body

In present review, we have summarized all of the miRNAs that have been involved in regulation of WNT signaling pathway in urothelial and prostate cancers.

Conclusions

It was observed that miRNAs were mainly involved in regulation of WNT signaling in bladder cancer cells through targeting the WNT ligands and cytoplasmic WNT components such as WNT5A, WNT7A, CTNNB1, GSK3β, and AXIN. Whereas, miRNAs were mainly involved in regulation of WNT signaling in prostate tumor cells via targeting the cytoplasmic WNT components and WNT related transcription factors such as CTNNB1, GSK3β, AXIN, TCF7, and LEF1. MiRNAs mainly functioned as tumor suppressors in bladder and prostate cancers through the WNT signaling inhibition. This review paves the way of introducing a noninvasive diagnostic panel of WNT related miRNAs in urothelial and prostate tumors.

MicroRNAs as the critical regulators of protein kinases in prostate and bladder cancers

Background

Bladder cancer (BCa) and prostate cancer (PCa) are frequent urothelial and genital malignancies with a high ratio of morbidity and mortality which are more common among males. Since BCa and PCa cases are mainly diagnosed in advanced stages with clinical complications, it is required to introduce the efficient early detection markers. Protein kinases are critical factors involved in various cellular processes such as cell growth, motility, differentiation, and metabolism. Deregulation of protein kinases can be frequently observed through the neoplastic transformation and tumor progression. Therefore, kinases are required to be regulated via different genetic and epigenetic processes. MicroRNAs (miRNAs) are among the critical factors involved in epigenetic regulation of protein kinases. Since miRNAs are noninvasive and more stable factors in serum and tissues compared with mRNAs, they can be used as efficient diagnostic markers for the early detection of PCa and BCa.

Main body

In present review, we have summarized all of the reported miRNAs that have been associated with regulation of protein kinases in bladder and prostate cancers.

Conclusions

For the first time, this review highlights the miRNAs as critical factors in regulation of protein kinases during prostate and bladder cancers which paves the way of introducing a noninvasive kinase-specific panel of miRNAs for the early detection of these malignancies. It was observed that the class VIII receptors of tyrosine kinases and non-receptor tyrosine kinases were the most frequent targets for the miRNAs in bladder and prostate cancers, respectively.

Hyperactivation of MEK/ERK pathway by Ca2+ /calmodulin-dependent protein kinase kinase 2 promotes cellular proliferation by activating cyclin-dependent kinases and minichromosome maintenance protein in gastric cancer cells

Although CAMKK2 is overexpressed in several cancers, its role and relevant downstream signaling pathways in gastric cancer (GC) are poorly understood. Treatment of AGS GC cells with a CAMKK2 inhibitor, STO-609, resulted in decreased cell proliferation, cell migration, invasion, colony-forming ability, and G1/S-phase arrest. Quantitative phosphoproteomics in AGS cells with the CAMKK2 inhibitor led to the identification of 9603 unique phosphosites mapping to 3120 proteins. We observed decreased phosphorylation of 1101 phosphopeptides (1.5-fold) corresponding to 752 proteins upon CAMKK2 inhibition. Bioinformatics analysis of hypo-phosphorylated proteins revealed enrichment of MAPK1/MAPK3 signaling. Kinase enrichment analysis of hypo-phosphorylated proteins using the X2K Web tool identified ERK1, cyclin-dependant kinase 1 (CDK1), and CDK2 as downstream substrates of CAMKK2. Moreover, inhibition of CAMKK2 and MEK1 resulted in decreased phosphorylation of ERK1, CDK1, MCM2, and MCM3. Immunofluorescence results were in concordance with our mass spectroscopy data and Western blot analysis results. Taken together, our data reveal the essential role of CAMKK2 in the pathobiology of GC through the activation of the MEK/ERK1 signaling cascade.

Prognostic Value of miR-1826 in Prostate Cancer and Its Regulatory Effect on Tumor Progression

Purpose

miRNAs can act as oncogenes or tumor suppressors and participate in the development and progression of tumors, thus affecting the prognosis and survival of cancer patients. In this paper, we mainly studied the role of miR-1826 in prostate cancer.

Patients and Methods

The expression of miR-1826 was studied by quantitative real-time PCR (qRT-PCR). Kaplan–Meier curves were used to analyze the relationship between the expression of miR-1826 and the survival rate of PC patients. Cox regression analysis was used to study the risk factors affecting the prognosis of PC patients. PC cells were transfected with miR-1826 mimic, mimic negative control (mimic NC), miR-1826 inhibitor, or inhibitor NC. The effect of miR-1826 on the proliferation of PC cells was studied by the CCK-8 method and colony formation assay. Transwell assays were used to detect the effect of miR-1826 on the migratory and invasive abilities of tumor cells.

Results

The expression of miR-1826 in PC tissues was lower than that in adjacent normal tissues, and that the expression levels of miR-1826 in four PC cell lines were all lower than normal human prostate epithelial cell lines. Patients with low expression of miR-1826 had shorter overall survival compared with those with high expression. The downregulation of miR-1826 promoted PC cell proliferation, migration, and invasion.

Conclusion

In summary, the low expression of miR-1826 may promote the progression of PC, and the low expression of miR-1826 is also associated with a poor prognosis in PC patients.

TEAD4 is an Immune Regulating-Related Prognostic Biomarker for Bladder Cancer and Possesses Generalization Value in Pan-Cancer

Recent studies have revealed the significant role of TEA domain family member 4 (TEAD4) in the development and progression of cancer. However, the potential role of TEAD4 in the progression of bladder cancer (BC) remains to be explored. The aim of this study was to determine whether TEAD4 could serve as a pan-cancer predictor of the prognosis for BC. Based on data mined from public databases, expression levels and clinical value of TEAD4 were identified in BC and human pan-cancers. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was performed to detect the TEAD4 expression levels in BC cell lines. Gene Set Enrichment Analysis (GSEA) was carried out for functional analysis in BC, and the relationship between infiltrating immune cells and TEAD4 expression was evaluated by the CIBERSORT algorithm in BC and pan-cancer data. TEAD4 was overexpressed and associated with poor prognosis in BC and several types of cancers. GSEA and CIBERSORT algorithm suggested that various pathways including immune-related pathways were enriched in TEAD4 high expression group and several immunocytes infiltrated were correlated with the expression of TEAD4. This study revealed TEAD4 is an immune regulating-related predictor of prognosis for BC and has generalization value in pan-cancer.

The impact of microRNAs on myeloid-derived suppressor cells in cancer

Inflammation promotes cancer development. To a large extent, this can be attributed to the recruitment of myeloid-derived suppressor cells (MDSCs) to tumors. These cells are known for establishing an immunosuppressive tumor microenvironment by suppressing T cell activities. However, MDSCs also promote metastasis and angiogenesis. Critically, as small non-coding RNAs that regulate gene expression, microRNAs (miRNAs) control MDSC activities. In this review, we discuss how miRNA networks regulate key MDSC signaling pathways, how they shape MDSC development, differentiation and activation, and how this impacts tumor development. By targeting the expression of miRNAs in MDSCs, we can alter their main signaling pathways. In turn, this can compromise their ability to promote multiple hallmarks of cancer. Therefore, this may represent a new powerful strategy for cancer immunotherapy.

Wnt signalling pathway in bladder cancer

Bladder cancer (BC) is one of the most common tumours of the urinary system and is also known as a highly malignant tumour. In addition to conventional diagnosis and treatment methods, recent research has focused on studying the molecular mechanisms related to BC, in the hope that new, less toxic and effective targeted anticancer drugs and new diagnostic markers can be discovered. It is known that the Wingless (Wnt) signalling pathway and its related genes, proteins and other substances are involved in multiple biological processes of various tumours. Clarifying the contribution of the Wnt signalling pathway in bladder tumours will help establish early diagnosis indicators, develop new therapeutic drugs and evaluate the prognosis for BC. This review aims to summarise previous studies related to BC and the Wnt signalling pathway, with a focus on exploring the participating substances and their mechanisms in the regulation of the Wnt signalling pathway to better determine how to promote new chemotherapeutic drugs, potential therapeutic targets and diagnostic biomarkers.

A 3-MicroRNA Signature Identified From Serum Predicts Clinical Outcome of the Locally Advanced Gastric Cancer

Background: Current staging systems are inadequate for evaluating the prognosis of patients with locally advanced gastric cancer (LAGC, stages II–III). Therefore, we developed a serum microRNA (miRNA) signature to facilitate individualized management of these patients.

Methods: Using microarray analysis, we analyzed 12 serum specimens based on different prognoses (good survival group, n = 7; poor survival group, n = 5). We identified and confirmed differential expression of these miRNAs using quantitative reverse transcription PCR (qRT-PCR) of serum from 51 patients with LAGC. A three miRNA-based classifier was established as a training set by Cox proportional hazard regression and risk-score analysis. We validated the prognostic accuracy of this model in an internal validation cohort (Sun Yat-Sen University Cancer Center, SYSUCC validation cohort, n = 50) and an external independent cohort (Beijing Cancer Hospital, BJCH cohort, n = 67).

Results: Three miRNAs were found to be associated with survival of LAGC (P < 0.001 for miR-132, P = 0.011 for miR-548a-3p, and P < 0.001 for miR-1826). A three-miRNA signature was developed for the training set, and a significant difference was found between the survival of low- and high-risk score patients (P < 0.01). The combination of the miRNA signature and tumor–node–metastasis (TNM) stage exhibited superior discrimination. Consistent results were obtained by further validation of the internal set and the BJCH set, which confirmed the predictive value of the model.

Conclusions: We built an easy-to-use prognostic signature using three serum miRNAs as markers. Our miRNA signature may improve postoperative risk stratification and serve as a complement to the TNM staging system.

miR-214-3p Targets β-Catenin to Regulate Depressive-like Behaviors Induced by Chronic Social Defeat Stress in Mice

β-Catenin has been implicated in major depressive disorder (MDD), which is associated with synaptic plasticity and dendritic arborization. MicroRNAs (miRNA) are small noncoding RNAs containing about 22 nucleotides and involved in a variety of physiological and pathophysiological process, but their roles in MDD remain largely unknown. Here, we investigated the expression and function of miRNAs in the mouse model of chronic social defeat stress (CSDS). The regulation of β-catenin by selected miRNA was validated by silico prediction, target gene luciferase reporter assay, and transfection experiment in neurons. We demonstrated that the levels of miR-214-3p, which targets β-catenin transcripts were significantly increased in the medial prefrontal cortex (mPFC) of CSDS mice. Antagomir-214-3p, a neutralizing inhibitor of miR-214-3p, increased the levels of β-catenin and reversed the depressive-like behavior in CSDS mice. Meanwhile, antagomir-214-3p increased the amplitude of miniature excitatory postsynaptic current (mEPSC) and the number of dendritic spines in mPFC of CSDS mice, which may be related to the elevated expression of cldn1. Furthermore, intranasal administered antagomir-214-3p also significantly increased the level of β-catenin and reversed the depressive-like behaviors in CSDS mice. These results may represent a new therapeutic target for MDD.

Bisphenol A triggers the malignancy of nasopharyngeal carcinoma cells via activation of Wnt/β-catenin pathway

It is critical to understand the risk factors responsible for the tumorigenesis and progression of nasopharyngeal carcinoma (NPC). Bisphenol A (BPA) can regulate the estrogenic signals to modulate cancer progression, while its roles in NC were not investigated. Our present study revealed that the BPA can increase proliferation and migration of NPC cells while decrease the chemosensitivity to doxorubicin (Dox). The inhibitor of GSK-3β/β-catenin (LiCl) can restore BPA-induced cell proliferation of NPC cells, which is due to that BPA can decrease phosphorylation while increase expression and nucleus localization of β-catenin. Mechanistically, BPA can increase the mRNA stability of β-catenin (encoded by CTNNB1) via suppressing the expression of miR-214-3p, which can direct target the 3'UTR of β-catenin mRNA. Further, BPA can decrease phosphorylation of β-catenin via repressing the expression of CK1α. Collectively, our data showed that BPA can trigger the proliferation and malignancy of NPC cells via activation of Wnt/β-catenin pathway. It indicated that body accumulation and inhalation exposure of BPA might be a risk factor for NPC development.

Downregulation of miR-1826 Indicates a Poor Prognosis for Osteosarcoma Patients and Regulates Tumor Cell Proliferation, Migration, and Invasion

Background

Osteosarcoma (OS) is the most frequent bone tumor with high metastasis. This study is aimed at assessing the expression and prognostic significance of microRNA-1826 (miR-1826) in OS patients, as well as its biological function in tumor progression.

Methods

Quantitative Real-Time PCR was employed to measure the expression of miR-1826 in OS tissues and cell lines. Kaplan-Meier survival analysis and Cox regression model were used to evaluate the prognostic value of miR-1826. CCK-8 and Transwell assay were conducted to investigate the effect of miR-1826 on OS cell proliferation, migration, and invasion.

Results

miR-1826 expression was downregulated in OS tissues and cell lines and associated with OS patients' clinical stage and distant metastasis. Low levels of miR-1826 were related with shorter survival time and determined as an independent prognostic indicator for the overall survival of OS patients. The overexpression of miR-1826 in OS cells led to inhibited cell proliferation, migration, and invasion.

Conclusion

The decreased expression of miR-1826 predicts a poor prognosis in OS patients, and its overexpression inhibits OS cell proliferation, migration, and invasion. This newly identified miR-1826 provides a novel sight into the pathogenesis of OS and offers a candidate prognostic biomarker and therapeutic target for OS treatment.

Plasma miR-200c-3p, miR-100-5p, and miR-1826 serve as potential diagnostic biomarkers for knee osteoarthritis: Randomized controlled trials

OBJECTIVE

To study the potential diagnostic value of plasma miR-200c-3p, miR-100-5p, and miR-1826 levels in knee osteoarthritis (KOA).

METHODS

Real-time quantitative PCR (RT-PCR) was used to measure the expression levels of serum miR-200c-3p, miR-100-5p, and miR-1826 in 150 KOA patients and 150 control controls. In addition, the levels of DNMT3A, ZEB1, MMP13, and CTNNB1 mRNAs in the synovial fluid were also measured by RT-PCR.

RESULTS

The expression levels of miR-100-5p, miR-200c-3p, and miR-1826 in the synovial fluid of 150 KOA patients were significantly lower than those in 54 controls (P < .001). In the synovial fluid, the miR-100-5p and DNMT3A mRNA levels, miR-100-5p and ZEB1 mRNA levels, miR-200c-3p and MMP13 mRNA levels, and miR-1826 and CTNNB1 mRNA levels were all negatively correlated (r = -0.83, -0.81, -0.83, -0.58, respectively). The AUCs of the diagnosis for KOA using the plasma levels of miR-200c-3p, miR-100-5p, and miR-1826 were 0.755, 0.845, and 0.749, respectively.

CONCLUSION

The plasma levels of miR-200c-3p, miR-100-5p, and miR-1826 are of potentially high value in the diagnosis of KOA.

Identification of Targetable Pathways in Oral Cancer Patients via Random Forest and Chemical Informatics

Treatment of head and neck cancer has been slow to change with epidermal growth factor receptor (EGFR) inhibitors, PD1 inhibitors, and taxane-/plant-alkaloid-derived chemotherapies being the only therapies approved by the U.S. Food and Drug Administration (FDA) in the last 10 years for the treatment of head and neck cancers. Head and neck cancer is a relatively rare cancer compared to breast or lung cancers. However, it is possible that existing therapies for more common solid tumors or for the treatment of other diseases could also prove effective against oral cancers. Many therapies have molecular targets that could be appropriate in oral cancer as well as the cancer in which the drug gained initial FDA approval. Also, there may be targets in oral cancer for which existing FDA-approved drugs could be applied. This study describes informatics methods that use machine learning to identify influential gene targets in patients receiving platinum-based chemotherapy, non-platinum-based chemotherapy, and genes influential in both groups of patients. This analysis yielded 6 small molecules that had a high Tanimoto similarity (>50%) to ligands binding genes shown to be highly influential in determining treatment response in oral cancer patients. In addition to influencing treatment response, these genes were also found to act as gene hubs connected to more than 100 other genes in pathways enriched with genes determined to be influential in treatment response by a random forest classifier with 20 000 trees trying 320 variables at each tree node. This analysis validates the use of multiple informatics methods to identify small molecules that have a greater likelihood of efficacy in a given cancer of interest.

The Importance of microRNAs in RAS Oncogenic Activation in Human Cancer

microRNAs (miRNAs) regulate gene expression by modulating the translation of protein-coding RNAs. Their aberrant expression is involved in various human diseases, including cancer. Here, we summarize the experimental pieces of evidence that proved how dysregulated miRNA expression can lead to RAS (HRAS, KRAS, or NRAS) activation irrespective of their oncogenic mutations. These findings revealed relevant pathogenic mechanisms as well as mechanisms of resistance to target therapies. Based on this knowledge, potential approaches for the control of RAS oncogenic activation can be envisioned.

WNT/β-catenin signaling in urothelial carcinoma of bladder

Urothelial carcinoma of bladder is the second most prevalent genitourinary disease. It is a highly heterogeneous disease as it represents a spectrum of neoplasms, including non-muscle invasive bladder cancer (NMIBC), muscle invasive bladder cancer (MIBC) and metastatic lesions. Genome-wide approaches and candidate gene analysis suggest that malignant transformation of the bladder is multifactorial and a multitude of genes are involved in the development of MIBC or NMIBC phenotypes. Wnt signaling is being examined to control and maintain balance between stemness and differentiation in adult stem cell niches. Owing to its participation in urothelial development and maintenance of adult urothelial tissue homeostasis, the components of Wnt signaling are reported as an important diagnostic and prognostic markers as well as novel therapeutic targets. Mutations/epigenetic alterations in the key molecules of Wnt/β-catenin canonical pathway have been linked with tumorigenesis, development of drug resistance and enhanced survival. Present review extends our understanding on the functions of key regulatory molecules of canonical Wnt/β-catenin pathway in urothelial tumorigenesis by inducing cancer stem cell phenotype (UCSCs). UCSCs may be responsible for tumor heterogeneity, high recurrence rates and complex biological behavior of bladder cancer. Therefore, understanding the role of UCSCs and the regulatory mechanisms that are responsible for high relapse rates and metastasis could help to develop pathway inhibitors and augment current therapies. Potential implications in the treatment of urothelial carcinoma of bladder by targeting this pathway primarily in UCSCs as well as in bulk tumor population that are responsible for high relapse rates and metastasis may facilitate potential therapeutic avenues and better prognosis.

Novel MicroRNA Biomarkers, miR-142-5p, miR-550a, miR-1826, and miR-1201, Were Identified for Primary Melanoma

This study was aimed to identify novel miRNA biomarkers and explore the cooperative function of multi-RNAs in the progress of primary melanoma. The miRNA expression profile GSE62370 generated from 9 congenital nevi and 92 primary melanoma samples was downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs between primary melanoma and congenital nevi were compared and the target genes of them were selected. Pathway enrichment analysis and protein/protein interaction (PPI) network of miRNA target genes were performed. In addition, the differential expression of miRNAs to identify the tumor stage-dependent differences in miRNA expression was analyzed. Differentially expressed miRNAs, including 6 upregulated and 23 downregulated, were found in primary melanoma. Besides, the miRNA-associated gene regulatory network revealed 274 nodes, including miR-142-5p and miR-125b, and 307 miRNA-target pairs. miRNA-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, such as melanoma, was found. Target genes in the PPI module were mainly enriched in cancer-related pathways. Finally, the melanoma stage-related overexpressed miR-142-5p and the downregulated miR-550, miR-1826, miR-1201, miR-205, and miR-125b were identified. Some validated miRNAs, including miR-125a/b, let-7a/b, and miR-205, were found and illustrated the reliability of our study. Four novel miRNAs, including miR-142-5p, miR-550a, miR-1826, and miR-1201, were considered to have potential prognostic values for primary melanoma.

MicroRNA-132 inhibits migration, invasion and epithelial-mesenchymal transition via TGFβ1/Smad2 signaling pathway in human bladder cancer

Background and aim: Increasing evidence shows that microRNAs play an important regulatory role in the development of several types of cancers. However, the role of microRNA-132 (miR-132) in human bladder cancer (BC) metastasis remains unclear. In this research, we aimed to investigate the effect of miR-132 on the cell migration and relate potential mechanism in BC.

Methods: miR-132 expression level was assessed by quantitative real-time PCR (qRT-PCR) in 32 BC tissues and BC cell lines (T24). The function of miR-132 was evaluated by Transwell assay. Gene expression was determined by using qRT-PCR or Western blot.

Results: The results showed that miR-132 had a lower expression in BC tissues than in adjacent normal tissues. At the same time, compared to human normal urethral epithelium cells, the expression level of miR-132 was downregulated in T24 cell lines. miR-132 overexpression significantly inhibited migration and invasion capacities in T24 cells, while downregulation of miR-132 expression strengthened such capacities. Compared with those transfected with miR-132 mimic, EMT-related markers and TGFβ1/Smad2 expression levels were higher in T24 cells transfected with miR-132 inhibitor. Moreover, EMT-related markers and Smad2 expression levels was obviously increased in BC tissues compared to the adjacent normal tissues. The correlation result indicated that the expression of miR-132 and Smad2 was reversed.

Conclusion: In short, our results suggest that miR-132 may play a suppressive role in the metastasis of BC cells via TGFβ1/Smad2 signaling pathway.

MicroRNAs: Key Players in Bladder Cancer

Bladder cancer (BC) is the second highest morbid malignancy of the urinary tract and the fifth most common cancer worldwide. BC is highly malignant with significant morbidity and mortality, especially muscle-invasive BC (MIBC), which has a poor prognosis and frequently recurs after the first resection. Therefore, more sensitive diagnostic tools and effective therapeutic methods are urgently needed. MicroRNAs (miRNAs) are small noncoding RNAs that regulate the expression of protein-coding genes by repressing their translation or cleaving RNA transcripts in a sequence-specific manner. miRNAs play very important roles in regulating genes related to tumorigenesis, tumor development, progression, metastasis and angiogenesis. With the rapid development of high-throughput sequencing technology, an increasing number of miRNAs with aberrant expression between either BC patients and healthy volunteers or between BC tumor tissues and matched peripheral control tissues have been recently examined. The tumor etiopathogenesis must be determined to promote the development of new markers as diagnostic and prognostic tools and targets for bladder tumor therapy, it is therefore vital to elucidate the function of miRNAs with aberrant expression in BC. In the present study, we examined the published data of BC-related miRNAs by reviewing their expression levels, possible functions, potential target genes, related molecular regulatory networks, candidate markers for prognosis and diagnosis, and prospective therapeutic cases, and we summarized the status of research on BC-related miRNAs in recent years.

Expression of miR-195 and MEK1 in patients with bladder cancer and their relationship to prognosis

OBJECTIVE

MAPK kinase 1 (MEK1) plays an important role in regulating cell proliferation and apoptosis through activation of the ERK/MAPK signaling pathway. It was found that the expression of miR-195 in bladder cancer was abnormally decreased, suggesting that miR-195 may affect the development of bladder cancer. In this study, we examined the expression of miR-195 and MEK1 in bladder cancer tissues and analyzed the relationship between miR-195 and MEK1 in cell proliferation and apoptosis in bladder cancer cells.

PATIENTS AND METHODS

The expression of MEK1 in bladder cancer tissues was detected by western blot, and the expression levels of miR-195 and MEK1 mRNA were detected by qRT-PCR. Log Rank test was used to compare the survival and prognosis of patients with low and high expression of miR-195 and MEK1 by using the median expression of miR-195 and MEK1. Bioinformatics analysis and double luciferase reporter gene test were used to verify the relationship between miR-195 and MEK1. Bladder cancer BIU-87 and 5637 cells were cultured in vitro and divided into two groups: miR-NC group and miR-195 mimic group. The expression of MEK1 and p-MEK1 protein was detected by western blot, apoptosis was detected by flow cytometry, and cell proliferation was detected by EdU staining.

RESULTS

Compared with normal bladder tissue, expression of miR-195 in bladder cancer tissue was significantly decreased, while the expression of MEK1 mRNA and protein was significantly increased. The prognosis of patients with low expression of miR-195 was worse than those with high expression of miR-195. The prognosis of patients with low expression of MEK1 was better than those with high expression of MEK1. Bioinformatics analysis showed that there was a target complementary binding site between miR-195 and MEK1. Double luciferase reporter gene experiments confirmed that there was a target regulatory relationship between miR-195 and MEK1. miR-195 mimic transfection could significantly down-regulate the expression of MEK1 and p-MEK1 proteins in BIU-87 and 5637 cells, weaken cell proliferation, and increase cell apoptosis.

CONCLUSION

Overexpression of miR-195 can inhibit the proliferation of bladder cancer cells by inhibiting MEK1, which provides further evidence for developing therapy against bladder cancer.

MicroRNAs in ovarian follicular atresia and granulosa cell apoptosis

MicroRNAs (miRNAs) are short, noncoding RNAs that posttranscriptionally regulate gene expression. In the past decade, studies on miRNAs in ovaries have revealed the key roles of miRNAs in ovarian development and function. In this review, we first introduce the development of follicular atresia research and then summarize genome-wide studies on the ovarian miRNA profiles of different mammalian species. Differentially expressed miRNA profiles during atresia and other biological processes are herein compared. In addition, current knowledge on confirmed functional miRNAs during the follicular atresia process, which is mostly indicated by granulosa cell (GC) apoptosis, is presented. The main miRNA families and clusters, including the let-7 family, miR-23-27-24 cluster, miR-183-96-182 cluster and miR-17-92 cluster, and related pathways that are involved in follicular atresia are thoroughly summarized. A deep understanding of the roles of miRNA networks will not only help elucidate the mechanisms of GC apoptosis, follicular development, atresia and their disorders but also offer new diagnostic and treatment strategies for infertility and other ovarian dysfunctions.

MicroRNA-3619-5p suppresses bladder carcinoma progression by directly targeting β-catenin and CDK2 and activating p21

Current studies indicate that microRNAs (miRNAs) are widely decreased in various tumors and function as tumor suppressors by inhibiting cancer cell proliferation, survival, invasion, and migration. The potential application of using miRNAs to predict therapeutic responses to multiple types of cancer treatment holds high promise. In current study, we demonstrate that miR-3619-5p is downregulated in bladder cancer (BCa) tissues and cells. Exogenous overexpression of miR-3619-5p in BCa cells inhibits proliferation, migration, and invasion. Moreover, a nude mouse xenograft model shows that miR-3619-5p inhibits BCa cell growth. We also demonstrate that miR-3619-5p leads to the activation of p21 by targeting its promoter in BCa cells. Enforced miR-3619-5p expression consistently leads to the downregulation of β-catenin and cyclin-dependent kinase 2 (CDK2) through predicted binding sites within the β-catenin and CDK2 3′-untranslated regions (UTRs), respectively. Moreover, β-catenin and CDK2 knockdown is able to mimic BCa cells growth and metastasis effects induced by overexpressing miR-3619-5p. We further confirm that miR-3619-5p inhibits Wnt-β-catenin signal pathway and EMT progression in BCa cells. We also found that miR-3619-5p-induced growth arrest and metastasis inhibition are p21-dependent in BCa cells. Taken together, these results confirm that miR-3619-5p plays a tumor suppressive role in BCa by interfering with cell growth and metastasis and may serve as a potential therapeutic target in BCa treatment.

MicroRNA-224 inhibits proliferation and migration of breast cancer cells by down-regulating Fizzled 5 expression

The Wnt/β-catenin signaling is crucial for the proliferation and migration of breast cancer cells. However, the expression of microRNA-224 (miR-224) in the different types of breast cancers and its role in the Wnt/β-catenin signaling and the proliferation and migration of breast cancer cells are poorly understood. In this study, the levels of miR-224 in different types of breast cancer tissues and cell lines were examined by quantitative RT-PCR and the potential targets of miR-224 in the Wnt/β-catenin signaling were investigated. The effects of altered miR-224 expression on the frequency of CD44⁺CD24⁻ cancer stem-like cells (CSC), proliferation and migration of MCF-7 and MDA-MB-231 cells were examined by flow cytometry, MTT and transwell migration. We found that the levels of miR-224 expression in different types of breast cancer tissues and cell lines were associated inversely with aggressiveness of breast cancers. Enhanced miR-224 expression significantly reduced the fizzled 5-regulated luciferase activity in 293T cells, fizzled 5 expression in MCF-7 and MDA-MB-231 cells, the β-dependent luciferase activity in MCF-7 cells, and the nuclear translocation of β-catenin in MDA-MB-231 cells. miR-224 inhibition significantly increased the percentages of CSC in MCF-7 cells and enhanced proliferation and migration of MCF-7 cells. Enhanced miR-224 expression inhibited proliferation and migration of MDA-MB-231 cells, and the growth of implanted breast cancers in vivo. Induction of frizzled 5 over-expression mitigated the miR-224-mediated inhibition of breast cancer cell proliferation. Collectively, these data indicated that miR-224 down-regulated the Wnt/β-catenin signaling possibly by binding to frizzled 5 and inhibited proliferation and migration of breast cancer cells.

Targeting XBP1-mediated β-catenin expression associated with bladder cancer with newly synthetic Oridonin analogues

Conventional chemotherapy is commonly used for advanced stages of transitional cell carcinoma (TCC) with modest success and high morbidity; however, TCC eventually develops resistance. Muscle invasive bladder cancer (MIBC) is recognized as a lethal disease due to its poor response to traditional chemotherapy. Numerous studies have implicated β-catenin, a critical effector in Wnt–mediated pathway associated with epithelial-mesenchymal transition and cancer stem cell, is involved in TCC progression, and furthermore closely associated with chemo-resistance. In this study, we discovered a novel natural product analogue CYD 6-17 that has a potent inhibitory effect on TCC cells exhibiting drug resistance to various chemotherapeutics, with an IC₅₀ at nM range. Delivery of CYD 6-17 significantly inhibited the tumor growth using xenograft model but without detectable side effects. Mechanistically, it targeted β-catenin gene transcription by decreasing the binding of XBP1 to the promoter region, which appeared to be a new regulatory mechanism for β-catenin gene expression. Clinically, XBP1 expression correlated with the poor overall survival of patients. Overall, this study unveils unique mechanism of β-catenin gene regulation in advanced TCC and also offers a potential rational therapeutic regimen to MIBC.

MEK1 signaling promotes self-renewal and tumorigenicity of liver cancer stem cells via maintaining SIRT1 protein stabilization

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death. This high mortality has been commonly attributed to the presence of residual cancer stem cells (CSCs). Meanwhile, MEK1 signaling is regarded as a key molecular in HCC maintenance and development. However, nobody has figured out the particular mechanisms that how MEK1 signaling regulates liver CSCs self-renewal. In this study, we show that inhibition or depletion of MEK1 can significantly decrease liver CSCs self-renewal and tumor growth both in vitro and vivo conditions. Furthermore, we demonstrate that MEK1 signaling promotes liver CSCs self-renewal and tumorigenicity by maintaining SIRT1 level. Mechanistically, MEK1 signaling keeps SIRT1 protein stabilization through activating SIRT1 ubiquitination, which inhibits proteasomal degradation. Clinical analysis shows that patients co-expression of MEK1 and SIRT1 are associated with poor survival. Our finding indicates that MEK1-SIRT1 can act as a novel diagnostic biomarker and inhibition of MEK1 may be a viable therapeutic option for targeting liver CSCs treatment.

RAS-MAPK pathway epigenetic activation in cancer: miRNAs in action

The highly conserved RAS-mitogen activated protein kinase (MAPK) signaling pathway is involved in a wide range of cellular processes including differentiation, proliferation, and survival. Somatic mutations in genes encoding RAS-MAPK components frequently occur in many tumors, making the RAS-MAPK a critical pathway in human cancer. Since the pioneering study reporting that let-7 miRNA acted as tumor suppressor by repressing the RAS oncogene, growing evidence has suggested the importance of miRNAs targeting the RAS-MAPK in oncogenesis. MiRNAs alterations in human cancers may act as a rheostat of the oncogenic RAS signal that is often amplified as cancers progress. However, specific mechanisms leading to miRNAs deregulation and their functional consequences in cancer are far from being fully elucidated. In this review, we provide an experimental-validated map of RAS-MAPK oncomiRs and tumor suppressor miRNAs from transmembrane receptor to downstream ERK proteins. MiRNAs could be further considered as potential genetic biomarkers for diagnosis, prognosis, or therapeutic purpose.

CCL5 promotes VEGF-C production and induces lymphangiogenesis by suppressing miR-507 in human chondrosarcoma cells

Chondrosarcoma is the second most frequently occurring type of bone malignancy that is characterized by the distant metastasis propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumor lymphangiogenesis and lymphatic metastasis. Chemokine CCL5 has been reported to facilitate angiogenesis and metastasis in chondrosarcoma. However, the effect of chemokine CCL5 on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has largely remained a mystery. In this study, we showed a clinical correlation between CCL5 and VEGF-C as well as tumor stage in human chondrosarcoma tissues. We further demonstrated that CCL5 promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium (CM) from CCL5-overexpressed cells significantly induced tube formation of human lymphatic endothelial cells (LECs). Mechanistic investigations showed that CCL5 activated VEGF-C-dependent lymphangiogenesis by down-regulating miR-507. Moreover, inhibiting CCL5 dramatically reduced VEGF-C and lymphangiogenesis in the chondrosarcoma xenograft animal model. Collectively, we document for the first time that CCL5 induces tumor lymphangiogenesis by the induction of VEGF-C in human cancer cells. Our present study reveals miR-507/VEGF-C signaling as a novel mechanism in CCL5-mediated tumor lymphangiogenesis. Targeting both CCL5 and VEGF-C pathways might serve as the potential therapeutic strategy to block cancer progression and metastasis in chondrosarcoma.

The crosstalk between microRNAs and the Wnt/β-catenin signaling pathway in cancer

Mounting evidence has indicated microRNA (miR) dysregulation and the Wnt/β-catenin signaling pathway jointly drive carcinogenesis, cancer metastasis, and drug-resistance. The current review will focus on the role of the crosstalk between miRs and the Wnt/β-catenin signaling pathway in cancer development. MiRs were found to activate or inhibit the canonical Wnt pathway at various steps. On the other hand, Wnt activation increases expression of miR by directly binding to its promoter and activating transcription. Moreover, there are mutual feedback loops between some miRs and the Wnt/β-catenin signaling pathway. Clinical trials of miR-based therapeutic agents are investigated for solid and hematological tumors, however, challenges concerning low bioavailability and possible side effects must be overcome before the final clinical application. This review will describe current understanding of miR crosstalk with the Wnt/β-catenin signaling cascade. Better understanding of the regulatory network will provide insight into miR-based therapeutic development.

Cancer Hallmarks and MicroRNAs: The Therapeutic Connection

Human cancers are characterized by a number of hallmarks, including sustained proliferative signaling, evasion of growth suppressors, activated invasion and metastasis, replicative immortality, angiogenesis, resistance to cell death, and evasion of immune destruction. As microRNAs (miRNAs) are deregulated in virtually all human cancers, they show involvement in each of the cancer hallmarks as well. In this chapter, we describe the involvement of miRNAs in cancer from a cancer hallmarks and targeted therapeutics point of view. As no miRNA-based cancer therapeutics are available to date, and the only clinical trial on miRNA-based cancer therapeutics (MRX34) was terminated prematurely due to serious adverse events, we are focusing on protein-coding miRNA targets for which targeted therapeutics in oncology are already approved by the FDA. For each of the cancer hallmarks, we selected major protein-coding players and describe the miRNAs that target them.

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.

miR-613 inhibits bladder cancer proliferation and migration through targeting SphK1

OBJECTIVES

Increasing evidence has suggested that microRNA (miRNA) dysregulation may contribute to tumor progression and metastasis. However, the role of miR-613 in bladder cancer was still unknown.

MATERIALS AND METHODS

qRT-PCR and Western blotting were performed to detect the expression of miR-613 and its direct target gene. CCK-8 analysis, qRT-PCR and cell invasion were performed to measure the cell function.

RESULTS

We demonstrated that the expression of miR-613 was downregulated in the bladder cancer cell lines. In addition, miR-613 expression was downregulated in the bladder cancer tissues compared to the adjacent normal tissues. Out of 35 bladder cancer tissues, miR-613 was downregulated in 27 cases compared to the adjacent tissues. Ectopic expression of miR-613 suppressed the bladder cancer cell proliferation and invasion. Moreover, miR-613 overexpression enhanced the expression of epithelial biomarker, Ecadherin, and suppressed the expression of mesenchymal biomarker, Vimentin, Snail and N-cadherin. Furthermore, we identified the Sphingosine kinase 1 (SphK1) as the direct target gene of miR-613 in the bladder cancer cell. Restoration of Sphk1 partially rescued miR-613-inhibited bladder cancer cell proliferation, invasion and EMT.

CONCLUSIONS

These data suggested that miR-613 acted a tumor suppressive role in bladder cancer through targeting SphK1 in bladder.

MicroRNA-1 down-regulates proliferation and migration of breast cancer stem cells by inhibiting the Wnt/β-catenin pathway

We investigated the miRNA profiles of breast cancer stem cells (CSCs) and non-CSC tumor cells by miRNA microarray and determined the effect of altered miR-1 expression on proliferation and migration of breast CSCs. The potential targets of miR-1 in the Wnt/β-catenin signaling were characterized by bioinformatics analysis and luciferase assay. We found that 14 miRNAs were up-regulated and 13 were down-regulated in the ESA⁺CD44⁺CD24⁻lineage⁻ CSCs, related to ESA⁺CD44⁻CD24⁺lineage⁻ non-CSC tumor cells. The miR-1 expression was associated inversely with aggressiveness of breast cancers. Furthermore, enhanced miR-1 expression decreased the percentages of SKBR3/CSCs and miR-1 inhibition increased the percentages of MCF-7/CSCs. Enhanced miR-1 expression significantly reduced the Frizzled 7 and Tankyrase-2 (TNKS2)-regulated luciferase activity in 293T cells and decreased Frizzled 7, TNKS2, c-Myc, octamer-binding transcription factor 4 (Oct4) and Nanog expression and the ratios of nuclear to cytoplasmic β-catenin as well as β-catenin-dependent luciferase activity in breast CSCs in vitro. miR-1 inhibited proliferation, migration and wound healing of breast CSCs in vitro. Enhanced miR-1 expression inhibited the growth of implanted MCF-7/CSCs while miR-1 inhibition promoted the growth of implanted MCF-7/CSCs in vivo. Our data indicate that miR-1 down-regulates breast CSC stemness, proliferation and migration by targeting the Frizzled 7 and TNKS2 to inhibit the Wnt/β-catenin signaling.

Leptin promotes VEGF-C production and induces lymphangiogenesis by suppressing miR-27b in human chondrosarcoma cells

Chondrosarcoma is the second most frequently occurring type of bone malignancy that is characterized by the distant metastasis propensity. Vascular endothelial growth factor-C (VEGF-C) is the chief lymphangiogenic mediator, and makes crucial contributions to tumor lymphangiogenesis. Leptin is an adipocytokine and has been indicated to facilitate tumorigenesis, angiogenesis and metastasis. However, the effect of leptin on VEGF-C regulation and lymphangiogenesis in human chondrosarcoma has hugely remained a mystery. Our results showed a clinical correlation between leptin and VEGF-C as well as tumor stage in human chondrosarcoma tissues. We further demonstrated that leptin promoted VEGF-C production and secretion in human chondrosarcoma cells. The conditioned medium from leptin-treated chondrosarcoma cells induced lymphangiogenesis of human lymphatic endothelial cells. We also found that leptin-induced VEGF-C is mediated by the FAK, PI3K and Akt signaling pathway. Furthermore, the expression of microRNA-27b was negatively regulated by leptin via the FAK, PI3K and Akt cascade. Our study is the first to describe the mechanism of leptin-promoted lymphangiogenesis by upregulating VEGF-C expression in chondrosarcomas. Thus, leptin could serve as a therapeutic target in chondrosarcoma metastasis and lymphangiogenesis.

Adiponectin promotes VEGF-C-dependent lymphangiogenesis by inhibiting miR-27b through a CaMKII/AMPK/p38 signaling pathway in human chondrosarcoma cells

Chondrosarcoma is the second most frequently occurring type of bone malignancy characterized by distant metastatic propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumour lymphangiogenesis and lymphatic metastasis. Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes. In recent years, adiponectin has also been indicated as facilitating tumorigenesis, angiogenesis and metastasis. However, the effect of adiponectin on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has remained largely a mystery. In the present study, we have shown a clinical correlation between adiponectin and VEGF-C, as well as tumour stage, in human chondrosarcoma tissues. We further demonstrated that adiponectin promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium from adiponectin-treated cells significantly induced tube formation and migration of human lymphatic endothelial cells. In addition, adiponectin knock down inhibited lymphangiogenesis in vitro and in vivo We also found that adiponectin-induced VEGF-C is mediated by the calmodulin-dependent protein kinase II (CaMKII), AMP-activated protein kinase (AMPK) and p38 signaling pathway. Furthermore, the expression of miR-27b was negatively regulated by adiponectin via the CaMKII, AMPK and p38 cascade. The present study is the first to describe the mechanism of adiponectin-promoted lymphangiogenesis by up-regulating VEGF-C expression in chondrosarcomas. Thus, adiponectin could serve as a therapeutic target in chondrosarcoma metastasis and lymphangiogenesis.

MiR-3162-3p Is a Novel MicroRNA That Exacerbates Asthma by Regulating β-Catenin

Asthma is a common chronic respiratory disease. In a previous study, we found several circulating microRNA signatures associated with childhood asthma and selected miR-3162-3p for subsequent studies. Since the target proteins and underlying molecular mechanisms of miR-3162-3p in asthma etiopathogenesis are not well characterized, we designed this study to clarify its role. We employed bioinformatics and quantitative PCR methods as a first step to determine the target of miR-3162-3p, and we elucidated β-catenin. Luciferase assays and western blot analysis confirmed β-catenin as a direct target of miR-3162-3p as the 3'-untranslated region of β-catenin mRNA possesses a specific miR-3162-3p pairing site. The correlation between the expression levels of miR-3162-3p and β-catenin is confirmed by quantitative PCR and western blot studies in A549, Beas-2B and H1299 cell lines and OVA-induced asthma mouse model. Of note, upregulation of the endogenous miR-3162-3p level is concomitant with the reduction of β-catenin mRNA and protein expression levels. MiR-3162-3p antagomir treatment antagonizes the endogenous miR-3162-3p and effectively rescues the attenuation of endogenous β-catenin in OVA-induced asthmatic mice, which alleviates airway hyperresponsiveness and ameliorates airway inflammation. Collectively, our findings suggest a novel relationship between miR-3162-3p and β-catenin and clarify their mechanistic role in asthma etiopathogenesis.

MicroRNAs in apoptosis, autophagy and necroptosis

MicroRNAs (miRNAs) are endogenous 22 nt non-coding RNAs that target mRNAs for cleavage or translational repression. Numerous miRNAs regulate programmed cell death including apoptosis, autophagy and necroptosis. We summarize how miRNAs regulate apoptotic, autophagic and necroptotic pathways and cancer progression. We also discuss how miRNAs link different types of cell death.

Copy number variants associated with 18p11.32, DCC and the promoter 1B region of APC in colorectal polyposis patients

Familial Adenomatous Polyposis (FAP) is the second most common inherited predisposition to colorectal cancer (CRC) associated with the development of hundreds to thousands of adenomas in the colon and rectum. Mutations in APC are found in ~ 80% polyposis patients with FAP. In the remaining 20% no genetic diagnosis can be provided suggesting other genes or mechanisms that render APC inactive may be responsible. Copy number variants (CNVs) remain to be investigated in FAP and may account for disease in a proportion of polyposis patients. A cohort of 56 polyposis patients and 40 controls were screened for CNVs using the 2.7M microarray (Affymetrix) with data analysed using ChAS (Affymetrix). A total of 142 CNVs were identified unique to the polyposis cohort suggesting their involvement in CRC risk. We specifically identified CNVs in four unrelated polyposis patients among CRC susceptibility genes APC, DCC, MLH1 and CTNNB1 which are likely to have contributed to disease development in these patients. A recurrent deletion was observed at position 18p11.32 in 9% of the patients screened that was of particular interest. Further investigation is necessary to fully understand the role of these variants in CRC risk given the high prevalence among the patients screened.

Epigenetic Regulation of Epidermal Stem Cell Biomarkers and Their Role in Wound Healing

As an actively renewable tissue, changes in skin architecture are subjected to the regulation of stem cells that maintain the population of cells responsible for the formation of epidermal layers. Stems cells retain their self-renewal property and express biomarkers that are unique to this population. However, differential regulation of the biomarkers can initiate the pathway of terminal cell differentiation. Although, pockets of non-clarity in stem cell maintenance and differentiation in skin still exist, the influence of epigenetics in epidermal stem cell functions and differentiation in skin homeostasis and wound healing is clearly evident. The focus of this review is to discuss the epigenetic regulation of confirmed and probable epidermal stem cell biomarkers in epidermal stratification of normal skin and in diseased states. The role of epigenetics in wound healing, especially in diseased states of diabetes and cancer, will also be conveyed.

SENP2 regulates MMP13 expression in a bladder cancer cell line through SUMOylation of TBL1/TBLR1

Bladder cancer (BC) is the most popular malignant urinary cancer in China. BC has the highest incidence and mortality among all genitourinary system tumors. Although the early-stage BC could be treated with advanced electron flexible systourethroscope, early metastasis of the BC occur frequently, and often results in poor prognosis. Recently, we reported that small ubiquitin related modifier (SUMO)-specific protease 2 (SENP2) was downregulated in BC specimen. SENP2 appeared to inhibit migration and invasion of bladder cancer cells in vitro, through suppressing MMP13 in BC cells. However, the exact underlying mechanisms remain unknown. Here, we reported that SENP2 inhibited nuclear translocation of β-catenin, which targeted the promotor of MMP13 to activate MMP13 to enhance BC cell metastasis. WNT ligands induced TBL1/TBLR1 SUMOylation to form complexes with β-catenin to facilitate β-catenin nuclear translocation, which could be efficiently inhibited through suppression of SUMOylation of TBL1/TBLR1. Together, our data suggest that SENP2 inhibits MMP13 expression in BC cells through de-SUMOylation of TBL1/TBLR1, which inhibits nuclear translocation of β-catenin. Thus, SENP2 may be a promising therapeutic target for BC.

microRNA regulation of Wnt signaling pathways in development and disease

Wnt signaling pathways and microRNAs (miRNAs) are critical regulators of development. Aberrant Wnt signaling pathways and miRNA levels lead to developmental defects and diverse human pathologies including but not limited to cancer. Wnt signaling pathways regulate a plethora of cellular processes during embryonic development and maintain homeostasis of adult tissues. A majority of Wnt signaling components are regulated by miRNAs which are small noncoding RNAs that are expressed in both animals and plants. In animal cells, miRNAs fine tune gene expression by pairing primarily to the 3'untranslated region of protein coding mRNAs to repress target mRNA translation and/or induce target degradation. miRNA-mediated regulation of signaling transduction pathways is important in modulating dose-sensitive response of cells to signaling molecules. This review discusses components of the Wnt signaling pathways that are regulated by miRNAs in the context of development and diseases. A fundamental understanding of miRNA functions in Wnt signaling transduction pathways may yield new insight into crosstalks of regulatory mechanisms essential for development and disease pathophysiology leading to novel therapeutics.

Zoledronic acid inhibits the pentose phosphate pathway through attenuating the Ras-TAp73-G6PD axis in bladder cancer cells

Zoledronic acid (ZA) is the current standard of care for the therapy of patients with bone metastasis or osteoporosis. ZA inhibits the prenylation of small guanosine‑5'-triphosphate (GTP)‑binding proteins, such as Ras, and thus inhibit Ras signaling. The present study demonstrated that ZA inhibited cell proliferation and the pentose phosphate pathway (PPP) in bladder cancer cells. In addition, the expression of glucose‑6‑phosphate dehydrogenase (G6PD, the rate‑limiting enzyme of the PPP) was found to be inhibited by ZA. Furthermore, the stability of TAp73, which activates the expression G6PD was decreased in zoledronic acid treated cells. Decreased levels of Ras‑GTP and phosphorylated‑extracellular signal-regulated kinase 1/2 were also observed following treatment with ZA. This may be due to the fact that activated Ras was reported to stabilize TAp73 inducing its accumulation. The inhibition of Ras activity by PT inhibitor II also significantly reduced the levels of TAp73 and G6PD and the PPP flux. Moreover, knockdown of TAp73, attenuated the PPP flux and eliminated the affection of ZA on the PPP flux. In conclusion, it was proposed that ZA can inhibit stability of TAp73 and attenuate the PPP via blocking Ras signaling in bladder cancer cells.

MicroRNA-490-5p is a novel tumor suppressor targeting c-FOS in human bladder cancer

INTRODUCTION

Recent studies have demonstrated the critical roles of micro-RNAs in tumorigenesis and tumor progression. Here, we describe the regulation and function of miR-490-5p in bladder cancer.

MATERIAL AND METHODS

Paired tissue samples were collected from bladder cancer patients (n = 20). Real-time PCR revealed that miR-490-5p expression was significantly down-regulated in human bladder cancer tissues and cells. Also there was an inverse relationship between the expression level of miR-490-5p and the pathological grade of bladder cancer. Western blotting was performed to detect the expression levels of c-FOS and TET1 in 6 matched tumor tissue samples and 4 bladder cell lines. Furthermore, to better understand the underlying mechanisms of miR-490-5p, we conducted gain and loss of function analysis by transfecting bladder cancer T24 cells with chemically synthesized miR-490-5p mimics and inhibitor, respectively.

RESULTS

We found that overexpression of miR-490-5p in T24 cells could inhibit cell proliferation and invasion and induce cell apoptosis. Conversely, suppression of miR-490-5p expression induced cell proliferation and invasion, while it inhibited cell apoptosis. In addition, our bioinformatics prediction and experimental data showed that c-FOS was a potential target of miR-490-5p. The expression level of c-FOS was significantly decreased after miR-490-5p overexpression and significantly increased after miR-490-5p suppression, indicating that c-FOS was a target of miR-490-5p.

CONCLUSIONS

These findings suggest that miR-490-5p is a novel tumor suppressor, contributing to the carcinogenesis of bladder cancer by targeting c-FOS.

The non-canonical role of vascular endothelial growth factor-C axis in cancer progression

It has been shown in many clinical studies that the level of vascular endothelial growth factor-C (VEGF-C) positively correlates with lymph node metastasis. Nevertheless, beyond the canonical role of VEGF-C in stimulating lymphangiogenesis and thus promoting lymph node/distant metastasis, emerging evidence indicates that expression of VEGF-C contributes to various aspects of carcinogenicity via autocrine regulation. The newly identified functions of VEGF-C include but are not limited to proliferation, migration, invasion, and chemo-resistance. Besides tumor cell autocrine regulation, VEGF-C can also modulate the immune system such that tumor cells more easily escape immune surveillance. Therefore, understanding the functional roles and regulatory mechanisms related to the VEGF-C axis may lead to alternative strategies for cancer treatment. This mini-review will focus on summarizing recent discoveries regarding the unconventional functions of VEGF-C in cancer progression.

MicroRNA-214 suppresses oncogenesis and exerts impact on prognosis by targeting PDRG1 in bladder cancer

MicroRNA-214 (miR-214) has been reported to be dysregulated in human bladder cancer tissues. We aimed to investigate the clinical correlation, biological significance and molecular network of miR-214 in bladder cancer. Our results showed miR-214 was down-regulated in bladder cancer tissues and significantly associated with tumor stage, lymph node status, grade, multifocality, history of non-muscle-invasive bladder cancer (NMIBC). Moreover, miR-214 could serve as an independent factor of recurrence-free survival (RFS) and overall survival (OS) for patients with muscle-invasive bladder cancer (MIBC). Restoration of miR-214 expression in bladder cancer cell lines inhibited cell proliferation, migration, invasion and markedly promoted apoptosis. Dual-luciferase reporter assay recognized PDRG1 as direct downstream target gene of miR-214. PDRG1 was significantly increased in tumors low of miR-214 and knockdown of PDRG1 mimicked the effects of miR-214 overexpression. Our findings manifest that miR-214 could exert tumor-suppressive effects in bladder cancer by directly down-regulating oncogene PDRG1 and suggest an appealing novel indicator for prognostic and therapeutic intervention of bladder cancer.

Regulation of breast cancer stem cell features

Cancer stem cells (CSCs) are rare, tumour-initiating cells that exhibit stem cell properties: capacity of self-renewal, pluripotency, highly tumorigenic potential, and resistance to therapy. Cancer stem cells have been characterised and isolated from many cancers, including breast cancer. Developmental pathways, such as the Wnt/β-catenin, Notch/γ-secretase/Jagged, Shh (sonic hedgehog), and BMP signalling pathways, which direct proliferation and differentiation of normal stem cells, have emerged as major signalling pathways that contribute to the self-renewal of stem and/or progenitor cells in a variety of organs and cancers. Deregulation of these signalling pathways is frequently linked to an epithelial-mesenchymal transition (EMT), and breast CSCs often possess properties of cells that have undergone the EMT process. Signalling networks mediated by microRNAs and EMT-inducing transcription factors tie the EMT process to regulatory networks that maintain "stemness". Recent studies have elucidated epigenetic mechanisms that control pluripotency and stemness, which allows an assessment on how embryonic and normal tissue stem cells are deregulated during cancerogenesis to give rise to CSCs. Epigenetic-based mechanisms are reversible, and the possibility of "resetting" the abnormal cancer epigenome by applying pharmacological compounds targeting epigenetic enzymes is a promising new therapeutic strategy. Chemoresistance of CSCs is frequently driven by various mechanisms, including aberrant expression/activity of ABC transporters, aldehyde dehydrogenase and anti-oncogenic proteins (i.e. BCL2, B-cell lymphoma-2), enhanced DNA damage response, activation of pro-survival signalling pathways, and epigenetic deregulations. Despite controversy surrounding the CSC hypothesis, there is substantial evidence for their role in cancer, and a number of drugs intended to specifically target CSCs have entered clinical trials.