MicroRNA-409-3p inhibits migration and invasion of bladder cancer cells via targeting c-Met

MicroRNA-409: Molecular functions and clinical applications in cancer

Late diagnosis is one of the main reasons for high mortality rates in cancer patients. Therefore, investigating the molecular mechanisms involved in tumor progression can improve the cancer diagnosis in the early stages of the tumor progression. MicroRNAs (miRNAs) have important roles in regulation of cell growth, proliferation, metabolism, and migration. Since, deregulation of miR-409 has been reported in a wide range of cancers, in the present review, we investigated the molecular mechanisms of miR-409 during tumor progression and invasion. It has been shown that miR-409 functions as a tumor suppressor in different tumor types. MiR-409 can reduce tumor cell proliferation, growth, and migration by regulation of signaling pathways, cellular metabolism, transcription factors, and cellular adhesion. This review can be an effective step in introducing miR-409 as a non-invasive marker in cancer patients.

Investigating the molecular mechanisms of microRNA‑409‑3p in tumor progression: Towards targeted therapeutics (Review)

MicroRNAs (miRNAs) are a group of non‑coding RNAs that exert master regulatory functions in post‑-transcriptional gene expression. Accumulating evidence shows that miRNAs can either promote or suppress tumorigenesis by regulating different target genes or pathways and may be involved in the occurrence of carcinoma. miR‑409‑3p is dysregulated in a variety of malignant cancers. It plays a fundamental role in numerous cellular biological processes, such as cell proliferation, apoptosis, migration, invasion, autophagy, angiogenesis and glycolysis. In addition, studies have shown that miR‑409‑3p is expected to become a non‑invasive biomarker. Identifying the molecular mechanisms underlying miR‑409‑3p‑mediated tumor progression will help investigate miR‑409‑3p‑based targeted therapy for human cancers. The present review comprehensively summarized the recently published literature on miR‑409‑3p, with a focus on the regulation and function of miR‑409‑3p in various types of cancer, and discussed the clinical implications of miR‑409‑3p, providing new insight for the diagnosis and treatment of cancers.

BRF2 is mediated by microRNA-409-3p and promotes invasion and metastasis of HCC through the Wnt/β-catenin pathway

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Its invasiveness and ability to metastasize contributes to an extremely high patient mortality. However, the molecular mechanisms that underlie the characteristics of HCC progression are not well understood. BRF2 has been shown to be an oncogene in a number of tumors; however, its role in HCC has not yet been thoroughly examined. In this study, we identified and validated BRF2 as an oncogene in HCC, providing a new insight into HCC pathogenesis and therapeutic possibilities. We showed that BRF2 expression was significantly upregulated in HCC cell lines and tissues, while BRF2 depletion suppressed HCC metastasis and invasion. We then examined the upstream regulation of BRF2 and identified miR-409-3p as being predicted to bind to the 3' UTR of BRF2. We used a luciferase activity assay and functional verification to show that BRF2 is downregulated by miR-409-3p. Finally, we used bioinformatic analysis to show that BRF2 may be related to early HCC development through the Wnt/β-catenin signaling pathway.

The Relationship between Serum miRNAs and Early Mortality in Multiple Myeloma Patients Treated with Bortezomib-Based Regimens

Multiple myeloma (MM) is a hematological malignancy characterized by the clonal proliferation of plasma cells in the bone marrow (BM) microenvironment. Despite the progress made in treatment, some MM patients still die within the first year of diagnosis. Numerous studies investigating microRNA (miRNA) expression patterns suggest they may be good prognostic markers. The primary aim of this study was to analyze the expression of selected miRNAs in the serum of MM patients who were later treated with bortezomib-based regimens, and to determine their potential to predict early mortality. The study was conducted in 70 prospectively recruited patients with newly diagnosed MM admitted to the Department of Hematology of the Copernicus Memorial Hospital, Lodz (Poland) between 2017 and 2021. Among them, 17 patients experienced death within 12 months of diagnosis. The expression of 31 selected miRNAs was determined using a miRCURY LNA miRNA Custom PCR Panel. The obtained clinical data included patient characteristics on diagnosis, treatment regimen, response to treatment, and follow-up. Differential expression analysis found two miRNAs to be significantly downregulated in the early mortality group: hsa-miR-328-3p (fold change-FC: 0.72, p = 0.0342) and hsa-miR-409-3p (FC: 0.49, p = 0.0357). Univariate and multivariate logistic regression analyses were performed to assess the early mortality rate. The final model consisted of hsa-miR-409-3p, hsa-miR-328-3p, age, and R-ISS 3. It yielded an area under the curve (AUC) of 0.863 (95%CI: 0.761-0.965) with 88.2% sensitivity and 77.5% specificity. Further external validation of our model is needed to confirm its clinical value.

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.

Targeting c-Met in the treatment of urologic neoplasms: Current status and challenges

At present, studies have found that c-Met is mainly involved in epithelial-mesenchymal transition (EMT) of tumor tissues in urologic neoplasms. Hepatocyte growth factor (HGF) combined with c-Met promotes the mitosis of tumor cells, and then induces motility, angiogenesis, migration, invasion and drug resistance. Therefore, c-Met targeting therapy may have great potential in urologic neoplasms. Many strategies targeting c-Met have been widely used in the study of urologic neoplasms. Although the use of targeting c-Met therapy has a strong biological basis for the treatment of urologic neoplasms, the results of current clinical trials have not yielded significant results. To promote the application of c-Met targeting drugs in the clinical treatment of urologic neoplasms, it is very important to study the detailed mechanism of c-Met in urologic neoplasms and innovate c-Met targeted drugs. This paper firstly discussed the value of c-Met targeted therapy in urologic neoplasms, then summarized the related research progress, and finally explored the potential targets related to the HGF/c-Met signaling pathway. It may provide a new concept for the treatment of middle and late urologic neoplasms.

c-Met: A Promising Therapeutic Target in Bladder Cancer

Mesenchymal-epithelial transition factor (c-Met) belongs to the tyrosine kinase receptor family and is overexpressed in various human cancers. Its ligand is hepatocyte growth factor (HGF), and the HGF/c-Met signaling pathway is involved in a wide range of cellular processes, including cell proliferation, migration, and metastasis. Emerging studies have indicated that c-Met expression is strongly associated with bladder cancer (BCa) development and prognosis. Therefore, c-Met is a potential therapeutic target for BCa treatment. Recently, the aberrant expression of noncoding RNAs was found to play a significant role in tumour progression. There is a close connection between c-Met and noncoding RNA. Herein, we summarized the biological function and prognostic value of c-Met in BCa, as well as its potential role as a drug target. The relation of c-Met and ncRNA was also described in the paper.

MicroRNA-409-5p inhibits cell proliferation, and induces G2/M phase arrest and apoptosis by targeting DLGAP5 in ovarian cancer cells

MicroRNA (miRNA/miR)-409-5p has been reported to be implicated in prostate and breast cancers; however, its functional role in ovarian cancer (OC) remains unclear. Therefore the aim of the present study was to investigate the clinical significance and biological function of miR-409-5p in OC. Here, reverse transcription-quantitative PCR analysis was performed to detect miR-409-5p expression in OC tissues and cell lines. The association between miR-409-5p expression and the clinicopathological characteristics of patients with OC was assessed using the Fisher's exact test. Furthermore, the Cell Counting Kit-8 assay was performed to assess cell proliferation. Cell cycle distribution and apoptosis were evaluated via flow cytometric analysis, and the target gene of miR-409-5p was validated via the dual-luciferase reporter assay. The results demonstrated that miR-409-5p expression was significantly downregulated in OC tissues and cell lines compared with adjacent normal tissues and epithelial cells, respectively. In addition, low miR-409-5p expression was significantly associated with tumor size (P=0.044) and the International Federation of Gynecology and Obstetrics staging system (P=0.005). Notably, overexpression of miR-409-5p suppressed cell proliferation, and induced G₂/M phase arrest and apoptosis of OC cells. Mechanistically, discs large-associated protein 5 (DLGAP5) was identified as a novel target of miR-409-5p, which was negatively regulated by miR-409-5p. DLGAP5 expression was significantly upregulated in OC tissues and cell lines compared with adjacent normal tissues and epithelial cells, respectively. Furthermore, overexpression of DLGAP5 reversed the effects of miR-409-5p on SKOV-3 cell proliferation, and G₂/M phase and apoptosis. Taken together, these results suggest that miR-409-5p acts as a tumor suppressor in OC by modulating DLGAP5 expression.

The clinical significance of microRNA-409 in pancreatic carcinoma and associated tumor cellular functions

In recent years, the increasing incidence of pancreatic carcinoma (PC) patients has become one of the hot issues in the world. microRNAs (miRNAs) can act as oncogenes or tumor suppressor genes and have unpredictable effects on tumors, thus affecting the prognosis and survival of cancer patients. In this paper, we mainly studied the role of microRNA (miR)-409 in PC. The expression levels of miR-409 were analyzed by qRT-PCR. Kaplan-Meier curve and Cox regression were used to analyze the relationship between miR-409 and patient prognosis. The effects of miR-409 on the abilities of proliferation, migration and invasion were detected by CCK-8 and Transwell. The expression levels of miR-409 were down-regulated in PC, compared with normal controls. The prognosis of patients with low miR-409 expression is significantly poor in comparison with those with high expression. The down-regulation of miR-409 was conducive to the proliferation, migration and invasion of PC cells. miR-409 is a tumor suppressor of PC, the clinical significance of miR-409 in pancreatic cancer and related tumor cell function was clarified.

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.

miR-665 inhibits epithelial-to-mesenchymal transition in bladder cancer via the SMAD3/SNAIL axis

Emerging research indicates that miRNAs can regulate cancer progression by influencing molecular pathways. Here, we studied miR-665, part of the DLK1-DIO3 miRNA cluster, which is downregulated by upstream methylation in bladder cancer. MiR-665 overexpression significantly downregulated the expression of SMAD3, phospho-SMAD3, and SNAIL, reversed epithelial-mesenchymal transition progression, and inhibited the migration of bladder cancer cells. To predict potential targets of miR-665, we used online databases and subsequently determined that miR-665 binds directly to the 3' untranslated region of SMAD3. Moreover, silencing of SMAD3 with small interfering RNAs phenocopied the effect of miR-665 overexpression, and overexpression of SMAD3 restored miR-665-overexpression-induced metastasis. This study revealed the role of the miR-665/SMAD3/SNAIL axis in bladder cancer, as well as the potential of miR-665 as a promising therapeutic target.

MicroRNA-409-3p regulates macrophage migration in polymyositis through targeting CXCR4

BACKGROUND

Macrophage migration and infiltration contribute to the pathogenesis of polymyositis (PM). This study aims to investigate the effect and underlying mechanism of miR-409-3p on macrophage migration in PM.

METHODS

The GSE143845 database was used to predict the altered expression of microRNAs (miRNAs) in PM. The quantitative real-time PCR (qRT-PCR), western blot and Transwell assay were performed to detect migration of macrophages and expressions of related molecules. A luciferase activity assay was conducted to confirm the binding of miR-409-3p and CXCR4 3'-UTR. Next, a mouse model of experimental autoimmune myositis (EAM) was established. Haematoxylin and eosin (HE) staining, immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA) were used to measure associated factors.

RESULTS

MiR-409-3p was downregulated in PM of GSE143845 database and patients. Differently, the serum creatine kinase (s-CK), TNF-α, and IL-6 in patients with PM were increased. Furthermore, miR-409-3p mimic transfection reduced the migration of macrophages and CXCR4 levels, while miR-409-3p inhibitor exerted the opposite effects. CXCR4 was a target of miR-409-3p, and the effect of CXCR4 on promoting macrophage migration was reversed by miR-409-3p mimic. In vivo, miR-409-3p agomir injection reduced inflammatory cells, macrophages, and TNFα and IL-6 levels in muscles and serum of EAM mouse models.

CONCLUSIONS

In conclusion, miR-409-3p reduces the migration of macrophages through negatively regulating CXCR4 expression in PM.

Precision hyperthermia-induced miRNA-409-3p upregulation inhibits migration, invasion, and EMT of gastric cancer cells by targeting KLF17

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is widely used for clinical treatment of advanced cancers. However, the regulatory mechanism underlying precise hyperthermia treatment in advanced gastric cancer (AGC) remains unclear. MiR-409-3p is reportedly downregulated in a variety of cancers, although its role in regulating treatment of AGC by precise hyperthermia remains unclear. The underlying mechanisms of miRNA-medicated regulation have been investigated using predicted and validated miRNA-gene targets, confirming the role of miRNA in HIPEC; METHODS: We used quantitative real time PCR (qRT-PCR) to detect miR-409-3p expression in gastric cancer (GC), as well as adjacent normal tissues, following exposure to varying temperatures. We detected miR-409-3p targets using dual-luciferase assay, then performed cell apoptosis, western blotting, invasion, and migration assays to detect GC functions; RESULTS: MiR-409-3p was upregulated and downregulated in precise hyperthermia and AGC, respectively. Moreover, miR-409-3p upregulated the Krüppel-like-factor 17 (KLF17), which subsequently inhibited migration, invasiveness, and epithelial-mesenchymal transition (EMT) but promoted apoptosis in GC cells; CONCLUSIONS: Precise hyperthermia upregulated miR-409-3p and KLF17 indirectly, thereby inhibiting invasion, migration, and EMT, and promoting apoptosis of gastric cancer cells.

Novel nanopolymer RNA therapeutics normalize human diabetic corneal wound healing and epithelial stem cells

Human diabetic corneas develop delayed wound healing, epithelial stem cell dysfunction, recurrent erosions, and keratitis. Adenoviral gene therapy modulating c-Met, cathepsin F and MMP-10 normalized wound healing and epithelial stem cells in organ-cultured diabetic corneas but showed toxicity in stem cell-enriched cultured limbal epithelial cells (LECs). For a safer treatment, we engineered a novel nanobiopolymer (NBC) that carried antisense oligonucleotide (AON) RNA therapeutics suppressing cathepsin F or MMP-10, and miR-409-3p that inhibits c-Met. NBC was internalized by LECs through transferrin receptor (TfR)-mediated endocytosis, inhibited cathepsin F or MMP-10 and upregulated c-Met. Non-toxic NBC modulating c-Met and cathepsin F accelerated wound healing in diabetic LECs and organ-cultured corneas vs. control NBC. NBC treatment normalized levels of stem cell markers (keratins 15 and 17, ABCG2, and ΔNp63), and signaling mediators (p-EGFR, p-Akt and p-p38). Non-toxic nano RNA therapeutics thus present a safe alternative to viral gene therapy for normalizing diabetic corneal cells.

Systematic review and meta-analysis of the prognostic significance of microRNAs related to metastatic and EMT process among prostate cancer patients

The ability of tumor cells to spread from their origin place and form secondary tumor foci is determined by the epithelial-mesenchymal transition process. In epithelial tumors such as prostate cancer (PCa), the loss of intercellular interactions can be observed as a change in expression of polarity proteins. Epithelial cells acquire ability to migrate, what leads to the formation of distal metastases. In recent years, the interest in miRNA molecules as potential future treatment options has increased. In tumor microenvironment, miRNAs have the ability to regulate signal transduction pathways, where they can act as suppressors or oncogenes. MiRNAs are secreted by cancer cells, and the changes in their expression levels are closely related to a cancer progression, including epithelial-mesenchymal transition. These molecules offer new diagnostic and therapeutic possibilities. Therapeutics which make use of synthesized RNA fragments and mimic or block miRNAs affected in PCa, may lead to inhibition of tumor progression and even disease re-emission. Based on appropriate qualification criteria, we conducted a selection process to identify scientific articles describing miRNAs and their relation to epithelial-mesenchymal transition in PCa patients. The studies were published in English on Pubmed, Scopus and the Web of Science before August 08, 2019. Hazard ratios (HRs) and 95% confidence intervals (CI) as well as total Gleason score were used to assess the concordance between miRNAs and presence of metastases. A total of 13 studies were included in our meta-analysis, representing 1608 PCa patients and 15 miRNA molecules. Our study clarifies a relationship between the clinicopathological features of PCa and the aberrant expression of several miRNA as well as the complex mechanism of miRNA molecules involvement in the induction and promotion of the metastatic mechanism in PCa.

MicroRNAs and target molecules in bladder cancer

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

Circ_0001023 Promotes Proliferation and Metastasis of Gastric Cancer Cells Through miR-409-3p/PHF10 Axis

Background

Circular RNAs (circRNAs) have been well documented to regulate the gene expression via sponging microRNA (miRNA) in diverse neoplasms including gastric cancer (GC).

Methods

In the present study, the expressions of circ_0001023, miR-409-3p, and plant homeodomain finger 10 (PHF10) in GC tissues were detected by qRT-PCR. Chi-square test was performed to analyze the associations between circ_0001023 and pathological parameters. Cell Counting Kit-8 assay, colony formation assay, flow cytometry, and transwell assay were adopted to detect the role of circ_0001023/miR-409-3p axis in the proliferation, apoptosis, and migration of GC cells, respectively. The targeting relationship between circ_0001023 and miR-409-3p was investigated by dual-luciferase gene reporter gene assay. Additionally, subcutaneous xenotransplanted tumor model in nude mice was established to detect the function of circ_0001023 on GC growth in vivo.

Results

Compared with adjacent tissues, the expression of circ_0001023 was significantly upregulated and correlated with lymph node invasion and higher T stage of GC patients. It has also been proved that circ_0001023 could target miR-409-3p. Silencing circ_0001023 can impede the proliferation of GC cells and promote apoptosis, while miR-409-3p inhibitors can partially reverse the biological behavior of GC cells mentioned above. Moreover, the expression of circ_0001023 was reversely associated with miR-409-3p expression but positively correlated with PHF10, a downstream oncogene of miR-409-3p.

Conclusion

Collectively, it is concluded that circ_0001023 promotes the progression of GC via regulating miR-409-3p/PHF10 axis.

SP1/AKT/FOXO3 Signaling Is Involved in miR-362-3p-Mediated Inhibition of Cell-Cycle Pathway and EMT Progression in Renal Cell Carcinoma

Emerging evidence has indicated that dysregulation of miR-362-3p is involved in the initiation and progression of several types of human cancers. However, the molecular mechanism of miR-362-3p in renal cell carcinoma (RCC) is still not completely clear. In this study, we found that miR-362-3p was frequently down-regulated in human RCC tissues. Overexpression of miR-362-3p in RCC cells significantly suppressed the proliferation, cell cycle and motility in vitro and in vivo via regulating AKT/FOXO3 signaling. We further confirmed that SP1 was a direct target of miR-362-3p. Knockdown of SP1 expression by a small interfering RNA (siRNA) phenocopied the effect of miR-362-3p overexpression in RCC cells. In conclusion, the current results provide evidence for the role of miR-362-3p in the pathogenesis of RCC and thus miR-362-3p may serve as an attractive candidate for RCC therapy.

CCND1, NOP14 and DNMT3B are involved in miR-502-5p-mediated inhibition of cell migration and proliferation in bladder cancer

OBJECTIVES

Downregulation of miR-502-5p has emerged as a critical factor in tumour progression in several cancers. Herein, we elucidated the role of miR-502-5p in bladder cancer.

MATERIALS AND METHODS

RT-qPCR was performed to examine the expression of miR-502-5p in bladder cancer. And DNA methylation analysis showed that epigenetic mechanisms may contribute to the downregulation of miR-502-5p. Then, wound-healing assay, transwell assay, colony formation assay, CCK8 assay and flow cytometry analysis were applied to evaluate the function of miR-502-5p in bladder cancer cell lines. Western blot was conducted to measure the protein levels of related genes. Furthermore, dual-luciferase reporter assay, in vivo tumorigenesis assay and immunohistochemical staining were also conducted as needed.

RESULTS

MiR-502-5p is frequently downregulated in BCa. Meanwhile, hypermethylation of CpG islands contributes to the downregulation of miR-502-5p. Functionally, overexpression of miR-502-5p inhibited cell proliferation and migration in vitro and repressed tumour growth in vivo. CCND1, DNMT3B and NOP14 were identified as direct targets of miR-502-5p. Interestingly, DNMT3B and miR-502-5p established a positive feedback loop in the regulation of bladder cancer. In addition, rescue experiments further validated the direct molecular interaction between miR-502-5p and its targets.

CONCLUSIONS

Our study proposed and demonstrated that the miR-502-5p-mediated regulatory network is critical in bladder cancer; this network may be useful in the development of more effective therapies against bladder cancer.

Crosstalk Mechanisms Between HGF/c-Met Axis and ncRNAs in Malignancy

Several lines of evidence have confirmed the magnitude of crosstalk between HGF/c-Met axis (hepatocyte growth factor and its high-affinity receptor c-mesenchymal-epithelial transition factor) and non-coding RNAs (ncRNAs) in tumorigenesis. Through activating canonical or non-canonical signaling pathways, the HGF/c-Met axis mediates a range of oncogenic processes such as cell proliferation, invasion, apoptosis, and angiogenesis and is increasingly becoming a promising target for cancer therapy. Meanwhile, ncRNAs are a cluster of functional RNA molecules that perform their biological roles at the RNA level and are essential regulators of gene expression. The expression of ncRNAs is cell/tissue/tumor-specific, which makes them excellent candidates for cancer research. Many studies have revealed that ncRNAs play a crucial role in cancer initiation and progression by regulating different downstream genes or signal transduction pathways, including HGF/c-Met axis. In this review, we discuss the regulatory association between ncRNAs and the HGF/c-Met axis by providing a comprehensive understanding of their potential mechanisms and roles in cancer development. These findings could reveal their possible clinical applications as biomarkers for therapeutic interventions.

Communication Of Cancer Cells And Lymphatic Vessels In Cancer: Focus On Bladder Cancer

Bladder cancer is one of the most commonly diagnosed cancers worldwide and causes the highest lifetime treatment costs per patient. Bladder cancer is most likely to metastasize through lymphatic ducts, and once the lymph nodes are involved, the prognosis is poorly and finitely improved by current modalities. The underlying metastatic mechanism for bladder cancer is thus becoming a research focus to date. To identify relevant published data, an online search of the PubMed/Medline archives was performed to locate original articles and review articles regarding lymphangiogenesis and lymphatic metastasis in urinary bladder cancer (UBC), and was limited to articles in English published between 1998 and 2018. A further search of the clinical trials.gov search engine was conducted to identify both trials with results available and those with results not yet available. Herein, we summarized the unique mechanisms and biomarkers involved in the malignant progression of bladder cancer as well as their emerging roles in therapeutics, and that current data suggests that lymphangiogenesis and lymph node invasion are important prognostic factors for UBC. The growing knowledge about their roles in bladder cancers provides the basis for novel therapeutic strategies. In addition, more basic and clinical research needs to be conducted in order to identify further accurate predictive molecules and relevant mechanisms.

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

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

Clinicopathological impacts of c-Met overexpression in bladder cancer: evidence from 1,336 cases

Background: The clinicopathological impacts of c-Met overexpression in bladder cancer have been investigated in several studies with conflicting results. We performed this systematic review and meta-analysis to assess the pathologic and prognostic roles of c-Met status in bladder cancer patients. Methods: Eligible studies were searched and identified from the PubMed and China National Knowledge Infrastructure (CNKI) databases (up until October 4, 2018). The DerSimonian-Laird random-effects model was used to calculate the pooled risk estimates. Results: Eight studies including 1,336 bladder cancer cases were eventually included in this meta-analysis. We detected a significantly increased risk of poor overall survival (OS) associated with the high expression of c-Met (HR=2.42, 95% CI 1.36-4.32). There was no association between c-Met status and nuclear grade (OR=0.82, 95% CI 0.29-2.31) or tumor stage (OR=1.42, 95% CI 0.41-4.89). Conclusion: This study shows that the overexpression of c-Met in primary cancer tissues is associated with a worse OS in human bladder cancer. However, larger studies using standardized methods and criteria are warranted to verify these findings.

Identification of potential biomarkers for diagnosis of pancreatic and biliary tract cancers by sequencing of serum microRNAs

BACKGROUND

Pancreatic and biliary tract cancer (PC and BTC, respectively) are difficult to diagnose because of their clinical characteristics; however, recent studies suggest that serum microRNAs (miRNAs) might be the key to developing more efficient diagnostic methods for these cancers.

METHODS

We analysed the genome-wide expression of serum miRNAs in PC and BTC patients to identify novel biomarker candidates using high-throughput sequencing and experimentally validated miRNAs on clinical samples.

RESULTS

Statistical and classification analysis of the serum miRNA-expression profiles of 55 patient samples showed distinguishable patterns between cancer patients and healthy controls; however, we were unable to distinguish the two cancers. We found that three of the highest performing miRNAs were capable of distinguishing cancer patients from controls, with an accuracy of 92.7%. Additionally, dysregulation of these three cancer-specific miRNAs was demonstrated in an independent sample group by quantitative reverse transcription polymerase chain reaction.

CONCLUSIONS

These results suggested three candidate serum miRNAs (mir-744-5p, mir-409-3p, and mir-128-3p) as potential biomarkers for PC and BTC diagnosis.

miR-758-3p suppresses human bladder cancer cell proliferation, migration and invasion by targeting NOTCH2

MicroRNAs (miRs) are widely involved in regulating tumor development and progression. miR-758-3p has been reported to suppress the progression of various cancer types, including hepatocellular carcinoma. However, whether miR-758-3p has a role in bladder cancer (BC) has not been previously reported, and was thus investigated in the present study. It was revealed that miR-758-3p was downregulated in BC tissues and cell lines. Transfection with miR-758-3p mimics suppressed the proliferation, migration and invasion of BC cells, and inhibition of miR-758-3p had the opposite effect. In terms of the underlying mechanisms, a luciferase reporter assay revealed that Notch receptor 2 (NOTCH2) is a direct target gene of miR-758-3p in BC cells. Transfection with miR-758-3p mimics decreased the mRNA and protein levels of NOTCH2. Furthermore, an inverse correlation between miR-758-3p and NOTCH2 levels was identified. Finally, overexpression of NOTCH2 significantly rescued the proliferation, migration and invasion of BC cells transfected with miR-758-3p mimics. Taken together, the present study indicated that miR-758-3p suppresses BC cell proliferation, migration and invasion by targeting NOTCH2.

MicroRNA-365 suppressed cell proliferation and migration via targeting PAX6 in glioblastoma

MicroRNAs (miRNAs) act an important role in the progression of tumor. In this study, we showed that the serum expression of miR-365 was downregulated in the glioblastoma compared with in the healthy controls. We also demonstrated that miR-365 expression was downregulated in glioblastoma tissues compared with the adjacent normal tissues. Overexpression of miR-365 suppressed the glioblastoma cell proliferation and migration. Moreover, ectopic expression of miR-365 promoted the expression of Ecadherin while inhibited the expression of N-cadherin and Vimentin in U87 cell. Furthermore, we identified PAX6 as a direct target gene of miR-365 in U87 cell. Overexpression of miR-365 suppressed glioblastoma cell proliferation and migration and epithelial-to-mesenchymal transition through inhibiting PAX6 expression. These results suggested that miR-365 played a tumor suppressor in glioblastoma.

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

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

MIR-300 in the imprinted DLK1-DIO3 domain suppresses the migration of bladder cancer by regulating the SP1/MMP9 pathway

Emerging research has suggested that miRNAs play a significant role in oncogenesis and tumor progression by regulating multiple molecular pathways. Here, we investigated miR-300, which inhibited bladder cancer (BCa) migration by regulating the SP1/MMP9 pathway. miR-300, belonging to the DLK1-DIO3 miRNA cluster, is frequently expressed at lower levels in BCa tissue than in adjacent normal tissue due to DNA methylation. Reinforced expression of miR-300 significantly suppressed the migration of BCa cells. We carried out a search of online databases to predict potential targets of miR-300. Further studies determined that miR-300 directly targeted SP1 and suppressed its expression by specifically binding to its 3'-untranslated region. Meanwhile, downregulated MMP9 may be the final effector of BCa cell mobility. Small interference RNAs silencing SP1 phenocopied the effects of miR-300 overexpression, while restoration of SP1 expression partially rescued the inhibition of metastasis induced by miR-300 overexpression in BCa cells. In conclusion, we unveiled a miR-300/SP1/MMP9 pathway in BCa. These findings demonstrate that miR-300 is a promising tumor suppressor in BCa.

HGF/c-MET: A Promising Therapeutic Target in the Digestive System Cancers

The HGF/c-MET pathway is active in the development of digestive system cancers, indicating that inhibition of HGF/c-MET signaling may have therapeutic potential. Various HGF/c-MET signaling inhibitors, mainly c-MET inhibitors, have been tested in clinical trials. The observed efficacy and adverse events of some c-MET inhibitors were not very suitable for treating digestive system cancers. The development of new HGF/c-MET inhibitors in preclinical studies may bring promising treatments and synergistic combination (traditional anticancer drugs and c-MET inhibitors) strategies provided anacceptable safety and tolerability. Insights into miRNA biology and miRNA therapeutics have made miRNAs attractive tools to inhibit HGF/c-MET signaling. Recent reports show that several microRNAs participate in inhibiting HGF/c-MET signaling networks through antagonizing c-MET or HGF in digestive system cancers, and the miRNAs-HGF/c-MET axis plays crucial and novel roles for cancer treatment. In the current review, we will discuss recent findings about inhibitors of HGF/c-MET signaling in treating digestive system cancers, and how miRNAs regulate digestive system cancers via mediating HGF/c-MET pathway.

Phosphoinositide-dependent kinase 1-associated glycolysis is regulated by miR-409-3p in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most popular kidney cancer in adults. Metabolic shift toward aerobic glycolysis is a fundamental factor for ccRCC therapy. MicroRNAs (miRNAs) are thought to be important regulators in ccRCC development and progression. Phosphoinositide-dependent kinase 1 (PDK1) is required for metabolic activation; however, the role of PDK1-induced glycolytic metabolism regulated by miRNAs is unclear in ccRCC. So, the purpose of the current study is to elucidate the underlying mechanism in ccRCC cell metabolism mediated by PDK1. Our results revealed that miR-409-3p inhibited glycolysis by regulating PDK1 expression in ccRCC cells. We also found that miR-409-3p was regulated by hypoxia. Our results indicated that PDK1 facilitated ccRCC cell glycolysis, regulated by miR-409-3p in hypoxia.

RNAa and Vector-Mediated Overexpression of DIRAS1 Suppresses Tumor Growth and Migration in Renal Cell Carcinoma

The downregulation of DIRAS1 has been suggested to potentially contribute to tumor development and progression in several human cancers. However, the role of DIRAS1 in renal cell carcinoma (RCC) remains elusive. In this study, we examined the DIRAS1 expression level in RCC cell lines and tissues. Both RNA activation (RNAa) and vector transfection methods were used to upregulate the expression of DIRAS1 in RCC cells. Expression analysis revealed that DIRAS1 was significantly downregulated in RCC cell lines and tissues compared with nontumorigenic renal cells and adjacent nontumor tissues individually. Promoter methylation analysis indicated that the reduced DIRAS1 expression might be partly mediated by epigenetic modulation. The RNAa-mediated overexpression of DIRAS1 inhibited cell proliferation and tumorigenicity in vitro and in vivo. The re-activation of DIRAS1 also promoted apoptosis and suppressed migration and invasion in RCC cells. The ectopic expression of DIRAS1 via an expression vector recapitulated the RNAa results. These results reveal that DIRAS1, functioning as a putative tumor suppressor in RCC cells, could potentially be a therapeutic target and RNAa could be a therapeutic strategy for RCC.

MicroRNA-409-3p suppresses cell proliferation and cell cycle progression by targeting cyclin D2 in papillary thyroid carcinoma

MicroRNAs (miRs) function as tumor suppressors or oncogenes in tumor development and progression. The present study reported that miR-409-3p was significantly downregulated in human papillary thyroid carcinoma (PTC) tissues and cell lines. Overexpression of miR-409-3p suppressed cell proliferation and induced cell cycle G₀/G₁ phase arrest in PTC cells. Further study revealed that the transcriptional regulator cyclin D2 was a target of miR-409-3p, as miR-409-3p bound directly to its 3'-untranslated region and the miR-409-3p mimic reduced the protein expression levels of cyclin D2. In addition, restoration of cyclin D2 expression reversed the inhibitive effect of miR-409-3p on PTC cells. To the best of our knowledge, these findings demonstrate for the first time that miR-409-3p functions as a tumor suppressor in PTC and could serve as an efficient agent for therapy of PTC.

Inhibition of miR-1247 on cell proliferation and invasion in bladder cancer through its downstream target of RAB36

Recently, microRNA-1247 (miR-1247) has been reported to function as tumour suppressor in several cancer types, including pancreatic cancer, hepatocellular cancer and lung cancer. However, the biological function of miR-1247 in bladder cancer and the underlying mechanisms have remained largely uncovered. In this study, the expression of miR-1247 was significantly downregulated, while RAB36 protein was remarkably upregulated in bladder cancer tissues and cell lines compared with that in paired adjacent normal tissues or normal cell line (SU-HUC-1). The function of miR-1247 and RAB36 in the cell viability, proliferation and invasion of bladder cancer cells (T24 and J82) was assessed by CCK-8, colony formation and Transwell assay, respectively. Gain of function studies showed that upregulation of miR-1247 significantly inhibited cell proliferation and invasion capacity of bladder cancer cells. Consistently, downregulation of RAB36 mimicked the suppressive effects of miR-1247 overexpression in bladder cancer cells. Importantly, miR-1247 was confirmed to target the 30untranslated region (UTR) of RAB36 and downregulated its expression using luciferase reporter assay and Western blot assays. In conclusion, these results provide the first clues regarding the role of miR-1247 might be a potential therapeutic agent and diagnostic marker of bladder cancer by inhibiting RAB36 expression.

miR-409-3p suppresses the proliferation, invasion and migration of tongue squamous cell carcinoma via targeting RDX

The aim of the present study is to investigate the role of microRNA (miRNA/miR)-409-3p in the proliferation, invasion and migration of tongue squamous cell carcinoma (TSCC) cells via targeting radixin (RDX) gene. The expression of miR-409-3p was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in TSCC tissue and cell lines. The binding of miR-409-3p to RDX was investigated by performing a dual-luciferase reporter gene assay. Tca8113 cells were selected to transfect with miR-409-3p mimic/inhibitor, small interfering (si)-RDX, and miR-409-3p inhibitor + si-RDX, as well as negative control (NC) respectively. The proliferative, migratory and invasive abilities of transfected Tca8113 cells were investigated by cell-counting-kit-8, wound-healing and Transwell assays, respectively. Additionally, a tumor xenograft model was constructed to examine the effects of miR-409-3p on the tumor growth and lymphatic metastasis in nude mice. A significant downregulation was detected in miR-409-3p expression in TSCC tissues and cells (all P<0.05) compared with normal tongue mucosa tissues and cell line, which was associated with lymph node metastasis and tumor-node metastasis staging (both P<0.05). The results from the dual-luciferase reporter gene assay indicated that RDX is a potential target gene of miR-409-3p. Compared with the blank group, a marked reduction in RDX expression, cell proliferation, migration and invasion was detected in the miR-409-3p mimic group and si-RDX group (all P<0.05). Conversely, the reverse was observed in cells that were transfected with the miR-409-3p inhibitor. Furthermore, si-RDX is able to reverse the effect of miR-409-3p inhibitor on cell proliferation, invasion and migration (all P<0.05). The results form the tumor xenograft model of nude mice verified that miR-409-3p mimic is able to inhibit the growth of Tca8113 tumor cells and lymph node metastasis in nude mice. miR-409-3p may delay the proliferation of TSCC cells by inhibiting of RDX so as to decrease its migratory and invasive abilities. Therefore, miR-409-3p may be a potential target for the clinical treatment of TSCC.

MiR-22 suppresses epithelial-mesenchymal transition in bladder cancer by inhibiting Snail and MAPK1/Slug/vimentin feedback loop

MicroRNAs (miRNAs) have been validated to play prominent roles in the occurrence and development of bladder cancer (BCa). MiR-22 was previously reported to act as a tumor suppressor or oncomiRNA in various types of cancer. However, its accurate expression, function, and mechanism in BCa remain unclear. Here, we find that miR-22 is frequently downregulated in BCa tissues compared with adjacent non-cancerous tissues. Overexpression of miR-22 significantly inhibits proliferation, migration, and invasion of BCa cells both in vitro and in vivo. Importantly, miR-22 is found to suppress cell proliferation/apoptosis by directly targeting MAPK1 (mitogen-activated protein kinase 1, ERK2) and inhibit cell motility by targeting both MAPK1 and Snail. Further statistical analysis shows that low-expression of MAPK1 or Snail is an independent prognostic factor for a better overall survival in patients with BCa (n = 401). Importantly, we describe an important regenerative feedback loop among vimentin, Slug and MAPK1 in BCa cells. MAPK1-induced Slug expression upregulates vimentin. Vimentin in turn activates MAPK1. By inhibiting Snail and MAPK1/Slug/vimentin feedback loop, miR-22 suppresses epithelial–mesenchymal transition (EMT) of BCa cells in vitro as well as in vivo. Taken together, this study reveals that miR-22 is critical to the proliferation, apoptosis and EMT progression in BCa cells. Targeting the pathway described here may be a novel approach for inhibiting proliferation and metastasis of BCa.

Serum microRNAs as predictors of risk for non-muscle invasive bladder cancer

MicroRNAs (miRNAs) are implicated in the development of nearly all cancers and may function as promising biomarkers for early detection, diagnosis and prognosis. We sought to investigate the role of serum miRNAs as potential diagnostic biomarkers or biomarkers of risk for early-stage bladder cancer. First, we profiled global serum miRNAs in a pilot set of 10 non-muscle invasive bladder cancer (NMIBC) cases and 10 healthy controls matched on age, gender and smoking status. Eighty nine stably detectable miRNAs were selected for further testing and quantification by high-throughput Taqman analysis using the Fluidigm BioMark HD System to assess their association with NMIBC risk in both discovery and validation sets totaling 280 cases and 278 controls. We found miR-409-3p and six miRNAs expression ratios were significantly associated with risk of bladder cancer in both discovery and validation sets. Interestingly, we identified expression of miR-409-3p and miR-342-3p inversely correlated with age and age of onset of NMIBC. A risk score was generated based on the combination of three miRNA ratios (miR-29a-3p/miR-222-3p, miR-150-5p/miR-331-3p, miR-409-3p/miR-423-5p). In dichotomized analysis, we found individuals with high risk score showed increased risk of bladder cancer in the discovery, validation, and combined sets. Pathway enrichment analyses suggested altered miRNAs and cognate target genes are linked to the retinoid acid receptor (RAR) signaling pathway. Overall, these results suggested specific serum miRNA signatures may serve as noninvasive predictors of NMIBC risk. Biological insights underlying bladder cancer development based on the pathway enrichment analysis may reveal novel therapeutic targets for personalized medicine.

miRNA array screening reveals cooperative MGMT-regulation between miR-181d-5p and miR-409-3p in glioblastoma

The levels of expression of O⁶-methylguanine-DNA methyltransferase (MGMT) are relevant in predicting the response to the alkylating chemotherapy in patients affected by glioblastoma. MGMT promoter methylation and the published MGMT regulating microRNAs (miRNAs) do not completely explain the expression pattern of MGMT in clinical glioblastoma specimens. Here we used a genome-wide microarray-based approach to identify MGMT regulating miRNAs. Our screen unveiled three novel MGMT regulating miRNAs, miR-127-3p, miR-409-3p, and miR-124-3p, in addition to the previously identified miR-181d-5p. Transfection of these three novel miRNAs into the T98G glioblastoma cell line suppressed MGMT mRNA and protein expression. However, their MGMT- suppressive effects are 30–50% relative that seen with miR-181d-5p transfection. In silico analyses of The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) revealed that miR-181d-5p is the only miRNA that consistently exhibited inverse correlation with MGMT mRNA expression. However, statistical models incorporating both miR-181d-5p and miR-409-3p expression better predict MGMT expression relative to models involving either miRNA alone. Our results confirmed miR-181d-5p as the key MGMT-regulating miRNA. Other MGMT regulating miRNAs, including the miR-409-3p identified in this report, modify the effect of miR-181d-5p on MGMT expression. MGMT expression is, thus, regulated by cooperative interaction between key MGMT-regulating miRNAs.

miR-203 Suppresses Bladder Cancer Cell Growth and Targets Twist1

miR-203 is an epigenetically silenced tumor-suppressive microRNA in tumors. This study was designed to investigate the effects of miR-203 on the proliferation, migration, invasion, and apoptosis of bladder cancer (BCa) cells. The expression levels of miR-203 in BCa tissues, normal adjacent tissues, and BCa cell lines were detected. BCa cells were transfected with miR-203 mimic and inhibitor to investigate the effect of miR-203 on cell functions and the epithelial–mesenchymal transition (EMT). Cotransfection with miR-203 inhibitor and shRNA of the predicted target gene Twist1 (si-Twist1) was performed to investigate the target relationship of miR-203 and Twist1. The effects of knockdown of Twist1 on cell functions were also investigated. The expression of miR-203 was significantly reduced in BCa tissues and cells, in comparison with the control. miR-203 mimic significantly reduced cell viability, invasion, migration, and EMT, and enhanced cell apoptosis. On the contrary, miR-203 inhibitor showed the opposite results. However, the administration of si-Twist1 cancelled the effect of miR-203 inhibitor on cell proliferation, apoptosis, invasion, and migration. These demonstrated that miR-203 may function as a tumor-suppressive microRNA in BCa by negatively targeting Twist1. Both Twist1 and miR-203 might be explored as potential targets for studying the mechanism related to BCa pathogenesis and therapy.

Genetic and epigenetic drivers of neuroendocrine tumours (NET)

Neuroendocrine tumours (NET) of the gastrointestinal tract and the lung are a rare and heterogeneous group of tumours. The molecular characterization and the clinical classification of these tumours have been evolving slowly and show differences according to organs of origin. Novel technologies such as next-generation sequencing revealed new molecular aspects of NET over the last years. Notably, whole-exome/genome sequencing (WES/WGS) approaches underlined the very low mutation rate of well-differentiated NET of all organs compared to other malignancies, while the engagement of epigenetic changes in driving NET evolution is emerging. Indeed, mutations in genes encoding for proteins directly involved in chromatin remodelling, such as DAXX and ATRX are a frequent event in NET. Epigenetic changes are reversible and targetable; therefore, an attractive target for treatment. The discovery of the mechanisms underlying the epigenetic changes and the implication on gene and miRNA expression in the different subgroups of NET may represent a crucial change in the diagnosis of this disease, reveal new therapy targets and identify predictive markers. Molecular profiles derived from omics data including DNA mutation, methylation, gene and miRNA expression have already shown promising results in distinguishing clinically and molecularly different subtypes of NET. In this review, we recapitulate the major genetic and epigenetic characteristics of pancreatic, lung and small intestinal NET and the affected pathways. We also discuss potential epigenetic mechanisms leading to NET development.

MET/SMAD3/SNAIL circuit mediated by miR-323a-3p is involved in regulating epithelial-mesenchymal transition progression in bladder cancer

Bladder cancer (BCa) is the one of the most common cancers with high incidence, occurrence and low 5-year survival rate. Emerging evidence indicates that DLK1-DIO3 genomic region especially the miRNA cluster in this region is involved in several pathologic processes and various cancers, and miR-323a-3p is a member of this miRNA cluster. In this study, we investigate the function and regulatory network of miR-323a-3p in BCa. miR-323a-3p is frequently downregulated in BCa tissues and three cell lines compared with adjacent non-tumorous tissues and bladder normal cell line (SV-HUC-1). Besides, downregulation of miR-323a-3p is significantly associated with poor overall survival rate of BCa. Methylation of DLK1-MEG3 intergenic DMR (IG-DMR) contributes to the reduction of miR-323a-3p. Overexpression of miR-323a-3p significantly inhibits the epithelial-mesenchymal transition (EMT) progression of BCa. Both upregulated MET and SMAD3 are direct targets of miR-323a-3p, and the knockdown of MET and SMAD3 also represses the EMT progression consistently with overexpression of miR-323a-3p. SNAIL is detected in the last targeted confocal protein of both MET and SMAD3 signaling that trigger EMT consequently. Hence, a miR-323a-3p/MET/SMAD3/SNAIL circuit is established to regulate the EMT progression of BCa. And a mutual regulatory mechanism between miR-323a-3p/miR-433/miR-409 and MET also participates in this circuit. In conclusion, our study demonstrates a novel regulatory mechanism of the miR-323a-3p/MET/SMAD3/SNAIL circuit that is involved in the EMT regulation of BCa, which may be a potential therapy target for BCa.

c-Met, CREB1 and EGFR are involved in miR-493-5p inhibition of EMT via AKT/GSK-3β/Snail signaling in prostate cancer

miR-493-5p downregulation has emerged as a critical player in cancer progression yet, the underlying mechanisms of miR-493-5p expression pattern and its function in prostate cancer remains to be elucidated. Here, we illustrate that miR-493-5p is frequently downregulated in prostate cancer, at least partially due to altered DNA methylation. miR-493-5p functions as a tumor suppressor in prostate cancer cells. c-Met, CREB1 and EGFR are downstream target genes of miR-493-5p. miR-493-5p inhibits EMT via AKT/GSK-3β/Snail signaling in prostate cancer. Taken together, our study identified c-Met, CREB1, EGFR and miR-493-5p establish a regulatory loop in prostate cancer, which could prove useful in the development of effective and therapies against prostate cancer.

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.

MicroRNA-294 Promotes Cellular Proliferation and Motility through the PI3K/AKT and JAK/STAT Pathways by Upregulation of NRAS in Bladder Cancer

In our study we examined the role of microRNA-294 (miR-294) in bladder cancer and related mechanisms. Real-time polymerase chain reaction (RT-PCR) was performed to determine the expression level of miR-294. Western blot was used to determine the expression of NRAS, mainly factors in the PI3K/AKT and JAK/STAT pathways. Cell counting kit-8 assay, clonogenic assay, wound-healing assay, transwell and flow cytometry were used to explore, respectively, cell proliferation, survival, migration, invasion, and apoptosis of bladder cancer cell line T24. The expressions of miR-294 in bladder cancer cells including J82, HT1376, T24, and SW780 were significantly increased compared to those in human bladder epithelium cells (both HCV29 and SV-HUC-1). The proliferation rate, surviving fraction, migration, and invasion of T24 cells in miR-294 mimetic transfected group were significantly increased, while they were significantly decreased by miR-294 inhibitor transfection. Moreover, miR-294 suppression could increase the apoptotic rate of T24 cells. In addition, drug resistance of T24 cells to cisplatin was increased in miR-294 mimetic-treated group, while it was decreased by miR-294 inhibitor compared to empty control. Overexpression of miR-294 could upregulate NRAS expression in T24 cells and activate PI3K/AKT and JAK/STAT pathways. We found that miR-294 expression was positively related with proliferation and motility of T24 cells. Moreover, miR-294 suppression could promote the sensitivity of T24 cells to cisplatin. We also found miR-294 could upregulate NRAS and activate the PI3K/AKT and JAK/STAT pathways in T24 cells.

MicroRNA-608 inhibits proliferation of bladder cancer via AKT/FOXO3a signaling pathway

BACKGROUND

Current evidence indicates that miR-608 is widely down-regulated in various malignant tumors including liver cancer, colon cancer, lung cancer and glioma, and acts as a tumor suppressor by inhibiting cell proliferation, invasion and migration or by promoting apoptosis. The specific biological function of miR-608 in bladder cancer is still unknown.

METHODS

qRT-PCR and Chromogenic in Situ Hybridization (CISH) was conducted to assess the expression of miR-608 in paired BCa tissues and adjacent non-tumor bladder urothelial tissues. Bisulfite sequencing PCR was used for DNA methylation analysis. CCK-8, colony formation and flow cytometry assays were performed, and a xenograft model was studied. Immunohistochemistry staining was performed with peroxidase and DAB. The target of miR-608 was validated with a dual-luciferase reporter assay, quantitative RT-PCR, and Western blotting.

RESULTS

miR-608 is frequently down-regulated in human BCa tissues. The methylation status of CpG islands is involved in the regulation of miR-608 expression. Overexpression of miR-608 inhibits the proliferation and tumorigenesis of BCa cells in vitro and in vivo. Additionally, up-regulation of miR-608 in BCa cells induces G1-phase arrest through AKT/FOXO3a signaling. In contrast, down-regulation of miR-608 promotes proliferation and cell cycle progression in BCa cells. Moreover, the expression of FLOT1 was directly inhibited by miR-608, the down-regulation of FLOT1 induced by siFLOT1 could be significantly reversed by miR-608 inhibitor. Similarly, the up-regulation of FLOT1 by FLOT1 overexpression plasmid (pFLOT1) could also reverse the suppressed cell proliferation caused by miR-608.

CONCLUSIONS

miR-608 is a potential tumor suppressor in BCa, and the restoration of miR-608 might be a promising therapeutic option for BCa.

CCL21/CCR7 interaction promotes cellular migration and invasion via modulation of the MEK/ERK1/2 signaling pathway and correlates with lymphatic metastatic spread and poor prognosis in urinary bladder cancer

Lymph node metastasis in patients with urinary bladder cancer (UBC) is always associated with poor prognosis and is the determinant for tumor staging and the development of treatment regimens; however, its underlying mechanisms remain to be studied. Immunohistochemical staining of tumor sections from 62 UBC patients was performed using CCR7, D2-40 and CD34 antibodies. We showed that increased CCR7 expression was significantly associated with positive lymph node status (P=0.008), pT3-T4 tumor stage (P=0.015), tumor grade (P=0.010) and worse overall survival (OS, P<0.001) and that both CCR7 expression and lymph node metastasis were independent prognostic factors for OS (P=0.031 and P=0.001, respectively) based on multivariate analysis. We found that there was a significant association between MLVD and lymph node status (P=0.006), but this relation was not observed for MVD. Furthermore, we showed that increased CCR7 expression correlated significantly with higher MLVD (P=0.014) and MVD (P=0.002). Wound-healing and Matrigel Transwell assays indicated that activation of CCR7 with CCL21 significantly enhanced the invasion and migration abilities of UM-UC-3 cells, and this enhanced effect was significantly abrogated by CCR7 knockdown using siRNA. Western blot analysis revealed that the phospho-ERK1/2 level was markedly increased when UM-UC-3 cells were treated with CCL21 and significantly decreased when the CCR7 gene was silenced. MEK/ERK1/2 inhibition with PD98059 significantly suppressed the migration and invasion abilities of UM-UC-3 cells and also significantly abrogated the effects of CCL21/CCR7 on cell migration and invasion. Based on these results, we conclude that activation of the CCL21/CCR7 chemoaxis promotes lymph node metastasis of UBC in at least two ways. Firstly, although CCR7 is a promoting factor that induces both lymphangiogenesis and angiogenesis, it may promote lymph node metastasis through its lymphangiogenic effect rather than through its angiogenic effect. Secondly, the CCL21/CCR7 chemoaxis promotes the migration and invasion of UBC cells via the MEK/ERK1/2 signaling pathway rather than the PI3K/AKT pathway.

Serum microRNA profiling and bioinformatics analysis of patients with type 2 diabetes mellitus in a Chinese population

Type 2 diabetes mellitus (T2DM) is characterized by islet β-cell dysfunction and insulin resistance, which leads to an inability to maintain blood glucose homeostasis. Circulating microRNAs (miRNAs) have been suggested as novel biomarkers for T2DM prediction or disease progression. However, miRNAs and their roles in the pathogenesis of T2DM remain to be fully elucidated. In the present study, the serum miRNA expression profiles of T2DM patients in Chinese cohorts were examined. Total RNA was extracted from serum samples of 10 patients with T2DM and five healthy controls, and these was used in reverse-transcription‑quantitative polymerase chain reaction analysis with the Exiqon PCR system of 384 serum/plasma miRNAs. A total of seven miRNAs were differentially expressed between the two groups (fold change >3 or <0.33; P<0.05). The serum expression levels of miR‑455‑5p, miR‑454‑3p, miR‑144‑3p and miR‑96‑5p were higher in patients with T2DM, compared with those of healthy subjects, however, the levels of miR‑409‑3p, miR‑665 and miR‑766‑3p were lower. Hierarchical cluster analysis indicated that it was possible to separate patients with T2DM and control individuals into their own similar categories by these differential miRNAs. Target prediction showed that 97 T2DM candidate genes were potentially modulated by these seven miRNAs. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that 24 pathways were enriched for these genes, and the majority of these pathways were enriched for the targets of induced and repressed miRNAs, among which insulin, adipocytokine and T2DM pathways, and several cancer‑associated pathways have been previously associated with T2DM. In conclusion, the present study demonstrated that serum miRNAs may be novel biomarkers for T2DM and provided novel insights into the pathogenesis of T2DM.

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.