miR-200 expression regulates epithelial-to-mesenchymal transition in bladder cancer cells and reverses resistance to epidermal growth factor receptor therapy

miR-9: From function to therapeutic potential in cancer

Malignant neoplasms are regarded as the main cause of death around the world; hence, many research studies were conducted to further perceive molecular mechanisms, treatment, and cancer prognosis. Cancer is known as a major factor for health-related problems in the world. The main challenges associated with these diseases are prompt diagnosis, disease remission classification and treatment status forecast. Therefore, progressing in such areas by developing new and optimized methods with the help of minimally invasive biological markers such as circular microRNAs (miRNAs) can be considered important. miRNA interactions with target genes have specified their role in development, apoptosis, differentiation, and proliferation and also, confirm direct miRNA function in cancer. Different miRNAs expression levels in various types of malignant neoplasms have been observed to be associated with prognosis of various carcinomas. miR-9 seems to implement opposite practices in different tissues or under various cancer incidences by influencing different genes. Aberrant miR-9 levels have been observed in many cancer types. Therefore, we intended to investigate the precise role of miR-9 in patients with malignant neoplasms. To this end, in this study, we attempted to examine different studies to clarify the overall role of miR-9 as a prognostic marker in several human tumors. The presented data in this study can help us to find the novel therapeutic avenues for treatment of human cancers.

The crucial role of ZEB2: From development to epithelial-to-mesenchymal transition and cancer complexity

Zinc finger E-box binding homeobox 2 (ZEB2) is a DNA-binding transcription factor, which is mainly involved in epithelial-to-mesenchymal transition (EMT). EMT is a conserved process during which mature and adherent epithelial-like state is converted into a mobile mesenchymal state. Emerging data indicate that ZEB2 plays a pivotal role in EMT-induced processes such as development, differentiation, and malignant mechanisms, for example, drug resistance, cancer stem cell-like traits, apoptosis, survival, cell cycle arrest, tumor recurrence, and metastasis. In this regard, the understanding of mentioned subjects in the development of normal and cancerous cells could be helpful in cancer complexity of diagnosis and therapy. In this study, we review recent findings about the biological properties of ZEB2 in healthy and cancerous states to find new approaches for cancer treatment.

The basics of epithelial-mesenchymal transition (EMT): A study from a structure, dynamics, and functional perspective

Epithelial-mesenchymal transition (EMT) is a key step in transdifferentiation process in solid cancer development. Forthcoming evidence suggest that the stratified program transforms polarized, immotile epithelial cells to migratory mesenchymal cells associated with enhancement of breast cancer stemness, metastasis, and drug resistance. It involves primarily several signaling pathways, such as transforming growth factor-β (TGF-β), cadherin, notch, plasminogen activator protein inhibitor, urokinase plasminogen activator, and WNT/beta catenin pathways. However, current understanding on the crosstalk of multisignaling pathways and assemblies of key transcription factors remain to be explored. In this review, we focus on the crosstalk of signal transduction pathways linked to the current therapeutic and drug development strategies. We have also performed the computational modeling on indepth the structure and conformational dynamic studies of regulatory proteins and analyze molecular interactions with their associate factors to understand the complicated process of EMT in breast cancer progression and metastasis. Electrostatic potential surfaces have been analyzed that help in optimization of electrostatic interactions between the protein and its ligand. Therefore, understanding the biological implications underlying the EMT process through molecular biology with biocomputation and structural biology approaches will enable the development of new therapeutic strategies to sensitize tumors to conventional therapy and suppress their metastatic phenotype.

Low microRNA-139 expression associates with poor prognosis in patients with tumors: A meta-analysis

BACKGROUND

microRNA-139 (miR-139) is dysregulated in various types of tumors and plays a key role in carcinogenesis. miR-139 may be used as a diagnostic and prognostic biomarker of cancers. However, the data from the literature are not consistent. The present study aimed to verify the prognostic and diagnostic values of miR-139 in solid tumors.

DATA SOURCES

PubMed, Web of Science and Embase databases were searched and publications from January 2011 to August 2017 were included. We used Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database to further validate this meta-analysis.

RESULTS

Eight individual studies from seven articles were included. Pooled analyses showed that low miR-139 expression was related to worse overall survival (OS) [hazard ratio (HR) = 2.27; 95% confidence intervals (CI): 1.74-2.95; P < 0.001] in solid tumors, including hepatocellular carcinoma (HCC) and glioblastoma multiforme (GBM), consisting with the results of TCGA. However, our results of CRC showed that low miR-139 expression was associated with poor OS which was contradictory with the results in TCGA database and need larger samples to validate the phenomenon; whereas for CRC patients, high miR-139 expression predicted poor RFS, which was in good accordance with TCGA results. The results of 27 microarrays from GEO database showed that miR-139 expression levels were lower in tumor tissues compared to adjacent non-tumor tissues or healthy tissues. Decreased miR-139 expression was also significantly correlated with poor differentiation grade (OR = 3.57; 95% CI: 1.44-8.85; P = 0.006). However, the combined data indicated that no associations between miR-139 expression and the following parameters such as age (pooled OR = 1.50; 95% CI: 0.69-3.24; P = 0.304), gender (pooled OR = 0.92; 95% CI: 0.56-1.51; P = 0.738), tumor size (pooled OR = 1.51; 95% CI: 0.69-3.31; P = 0.298), late tumor-node-metastasis stage (pooled OR = 1.63; 95% CI: 0.99-2.68; P = 0.057) and lymph-node-metastasis (pooled OR = 0.66; 95% CI: 0.34-1.28; P = 0.222).

CONCLUSIONS

Low miR-139 expression was related to poor prognosis in HCC and GBM, which could be regarded as a potential prognostic biomarker. However, its precise functional role in CRC still need to be further investigated through larger samples and multicenter studies.

miRNA profile obtained by next‑generation sequencing in metastatic breast cancer patients is able to predict the response to systemic treatments

Metastatic breast cancer (MBC) is a challenge for oncologists, and public efforts should focus on identifying additional molecular markers and therapeutic management to improve clinical outcomes. Among all diagnosed cases of breast cancer (BC; approximately 10%) involve metastatic disease; notably, approximately 40% of patients with early-stage BC develop metastasis within 5 years. The management of MBC consists of systemic therapy. Despite different treatment options, the 5-year survival rate is <20%, which may be due to a lack of response with de novo or acquired resistance. MicroRNAs (miRNAs or miRs) are promising biomarkers as they are readily detectable and have a broad spectrum and potential clinical applications. The aim of this study was to identify a miRNA profile for distinguishing patients with MBC who respond to systemic treatment. Patients with MBC were treated according to the National Comprehensive Cancer Network guidelines. We performed miRNA-Seq on 9 primary tumors using the Thermo Fisher Scientific Ion S5 system. To obtain global miRNA profiles, we carried out differentially expressed gene elimination strategy (DEGES) analysis between the responsive and non-responsive patients. The results identified a profile of 12 miRNAs associated with the response to systemic treatment. The data were validated in an independent cohort (TCGA database). Based on the results, the upregulation of miR-342-3p and miR-187-3p was associated with the response to systemic treatment, and with an increased progression-free survival (PFS) and overall survival (OS); by contrast, the downregulation of miR-301a-3p was associated with a higher PFS and OS. On the whole, the findings of this study indicate that these miRNAs may serve as biomarkers for the response to systemic treatment or the prognosis of patients with MBC. However, these data should be validated experimentally in other robust cohorts and using different specimens before implementing these miRNAs as biomarkers in clinical practice to benefit this group of patients.

MicroRNA targeting by quercetin in cancer treatment and chemoprotection

A growing number of evidences from clinical and preclinical studies have shown that dysregulation of microRNA (miRNA) function contributes to the progression of cancer and thus miRNA can be an effective target in therapy. Dietary phytochemicals, such as quercetin, are natural products that have potential anti-cancer properties due to their proven antioxidant, anti-inflammatory, and anti-proliferative effects. Available experimental studies indicate that quercetin could modulate multiple cancer-relevant miRNAs including let-7, miR-21, miR-146a and miR-155, thereby inhibiting cancer initiation and development. This paper reviews the data supporting the use of quercetin for miRNA-mediated chemopreventive and therapeutic strategies in various cancers, with the aim to comprehensively understand its health-promoting benefits and pharmacological potential. Integration of technology platforms for miRNAs biomarker and drug discovery is also presented.

The role of microRNAs in the healing of diabetic ulcers

MicroRNAs (miRNAs) are small protected molecules with a length of 18 to 25 nucleotides. Many studies have recently been conducted on miRNAs, illustrating their role in regulating many biological, physiological, and pathological activities, such as maintaining cellular signalling and regulating cellular pathways. The main role of miRNAs is to regulate the expression of genes after translation, which can lead to the destruction or suppression of translation by binding to mRNAs. As any change in the regulation of miRNAs is associated with several physiological abnormalities, such as type 2 diabetes and its complications, these molecules can be used for therapeutic purposes or as biomarkers for the diagnosis of diseases such as diabetes and its complications. In this review article, we will discuss important findings about the miRNAs and the role of these molecules in different phases of the wound-healing process of chronic wounds, especially diabetic ulcer.

MicroRNA-200c reverses drug resistance of human gastric cancer cells by targeting regulation of the NER-ERCC3/4 pathway

Gastric cancer (GC) is one of the most common types of malignant tumor. Due to the lack of effective drugs and the emergence of chemotherapy resistance, patients with GC exhibit a poor prognosis and low survival rate. MicroRNAs (miRNAs/miRs) serve an important role in drug resistance of different types of cancer. They may be suitable for use as biomarkers in the diagnosis, treatment and prognosis of tumors. The present study aimed to investigate the molecular mechanism underlying the ability of miR-200c-3p to reverse drug resistance in a SGC7901/DDP GC cell line, particularly its effects on the ERCC excision repair 3, TFIIH core complex helicase subunit (ERCC3) and ERCC excision repair 4, endonuclease catalytic subunit (ERCC4) proteins in the nucleotide excision repair (NER) pathway. Reverse transcription-quantitative polymerase chain reaction demonstrated that miR-200c-3p expression in cisplatin-resistant SGC7901/DDP cells was lower than in parental SGC7901 cells, whereas the protein expression levels of ERCC3 and ERCC4 in these cells were higher by western blot analysis. In SGC7901/DDP-derived miR-200c-3p overexpressing cells, ERCC3 expression, ERCC4 expression and cisplatin resistance were decreased compared with in parental SGC7901/DDP cells and SGC7901/DDP-derived vector control cells. In SGC7901-derived miR-200c-3p knockdown cells, ERCC3 expression, ERCC4 expression and cisplatin resistance were increased compared with in parental SGC7901 cells and SGC7901-derived vector control cells. In conclusion, overexpression of miR-200c-3p may reverse drug resistance in the SGC7901/DDP GC cell line via downregulation of ERCC3 and ERCC4, which suggested this may be part of a mechanism involving the NER pathway.

TWIST1, MMP-21, and HLAG-1 co-overexpression is associated with ESCC aggressiveness

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive types of cancer, requiring reliable biomarkers for prognosis and therapeutic responsiveness. TWIST1, as an important factor responsible for metastasis of several cancers, is involved in tumor invasion and metastasis through indirectly regulation of MMP-21 expression. On the other hand, NF-ĸβ which is a regulator of HLAG-1 has direct interaction with TWIST1 protein. In this retrospective study we investigated the clinical significance of TWIST1, MMP-21, and HLAG-1 expression in ESCC, and the possible correlation between these genes and progression of the disease. The gene expression analyses of TWIST1, MMP-21, and HLA-G1 were performed by relative comparative real-time polymerase chain reaction in 58 ESCCs compared with corresponding margin-normal esophageal tissues. Significant overexpression of HLAG-1, TWIST1, and MMP-21 messenger RNA was observed in 22.4%, 41.4%, and 60.3% of tumor samples, respectively. Concomitant overexpression of TWIST1/MMP-21 and TWIST1/HLAG-1 were significantly correlated to each other in various clinicopathological features, including depth of tumor invasion, stage of tumor progression, lymphatic invasion, and grade of tumor cell differentiation ( P < 0.05). The current study is the first report of coexpression of TWIST1, MMP-21, and HLAG-1 in ESCC. Such findings suggest an oncogenic role for concomitant expression of these genes in ESCC invasion and metastasis.

Role of miRNAs in Melanoma Metastasis

Tumour metastasis is a multistep process. Melanoma is a highly aggressive cancer and metastasis accounts for the majority of patient deaths. microRNAs (miRNAs) are non-coding RNAs that affect the expression of their target genes. When aberrantly expressed they contribute to the development of melanoma. While miRNAs can act locally in the cell where they are synthesized, they can also influence the phenotype of neighboring melanoma cells or execute their function in the direct tumour microenvironment by modulating ECM (extracellular matrix) and the activity of fibroblasts, endothelial cells, and immune cells. miRNAs are involved in all stages of melanoma metastasis, including intravasation into the lumina of vessels, survival during circulation in cardiovascular or lymphatic systems, extravasation, and formation of the pre-metastatic niche in distant organs. miRNAs contribute to metabolic alterations that provide a selective advantage during melanoma progression. They play an important role in the development of drug resistance, including resistance to targeted therapies and immunotherapies. Distinct profiles of miRNA expression are detected at each step of melanoma development. Since miRNAs can be detected in liquid biopsies, they are considered biomarkers of early disease stages or response to treatment. This review summarizes recent findings regarding the role of miRNAs in melanoma metastasis.

Long non-coding RNA ZEB1-AS1 regulates miR-200b/FSCN1 signaling and enhances migration and invasion induced by TGF-β1 in bladder cancer cells

Background

The effect of competing endogenous RNA (ceRNA) can regulate gene expression by competitively binding microRNAs. Fascin-1 (FSCN1) plays an important role in the regulation of cellular migration and invasion during tumor progression, but how its regulatory mechanism works through the ceRNA effect is still unclear in bladder cancer (BLCA).

Methods

The role of fascin-1, miR-200b, and ZEB1-AS1 in BLCA was investigated in vitro and in vivo. The interaction between fascin-1, miR-200b, and ZEB1-AS1 was identified using bioinformatics analysis, luciferase activity assays, RNA-binding protein immunoprecipitation (RIP), quantitative PCR, and western blotting. Loss (or gain)-of-function experiments were performed to investigate the biological roles of miR-200b and ZEB1-AS1 on migration, invasion, proliferation, cell apoptosis, and cell cycle.

Results

ZEB1-AS1 functions as a competing endogenous RNA in BLCA to regulate the expression of fascin-1 through miR-200b. Moreover, the oncogenic long non-coding RNA ZEB1-AS1 was highly expressed in BLCA and positively correlated with high tumor grade, high TNM stage, and reduced survival of patients with BLCA. Moreover, ZEB1-AS1 downregulated the expression of miR-200b, promoted migration, invasion, and proliferation, and inhibited apoptosis in BLCA. Furthermore, we found TGF-β1 induced migration and invasion in BLCA by regulating the ZEB1-AS1/miR-200b/FSCN1 axis.

Conclusion

The observations in this study identify an important regulatory mechanism of fascin-1 in BLCA, and the TGF-β1/ZEB1-AS1/miR-200b/FSCN1 axis may serve as a potential target for cancer therapeutic purposes.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1102-6) contains supplementary material, which is available to authorized users.

R, Maitra A, Goggins MG, Eshelman JR, Wolfgang CL, Rasheed ZA, Matsui W. Direct Interactions With Cancer-Associated Fibroblasts Lead to Enhanced Pancreatic Cancer Stem Cell Function

OBJECTIVE

Cancer-associated fibroblasts (CAFs) play an important role in the progression of pancreatic ductal adenocarcinoma (PDAC) by promoting tumor cell migration and drug resistance. We determined the impact of CAFs on PDAC cancer stem cells (CSCs).

METHODS

Fibroblast cell lines from patients' tumors were cocultured with PDAC cells and examined for clonogenic growth and self-renewal using colony-forming assays and migration in vitro. Changes in the frequency of CSCs was determined by flow cytometry. The effect of integrin-focal adhesion kinase (FAK) signaling on CAF-mediated clonogenic growth was evaluated using short hairpin RNAs against β1 integrin and FAK as well as a small-molecule FAK inhibitor.

RESULTS

Cancer-associated fibroblasts enhanced PDAC clonogenic growth, self-renewal, and migration that was associated with an increase in the frequency of CSCs. These fibroblast cells were activated by PDAC cells and increased collagen synthesis resulting in FAK activation in PDAC cells. Knockdown of β1-integrin and FAK or the inhibition of FAK kinase activity in PDAC cells abrogated the impact of CAFs on clonogenic growth.

CONCLUSION

Therefore, CAFs enhance PDAC clonogenic growth, self-renewal, and the frequency of CSCs through type I collagen production that enhances integrin-FAK signaling in PDAC cells.

LBX2-AS1 is activated by ZEB1 and promotes the development of esophageal squamous cell carcinoma by interacting with HNRNPC to enhance the stability of ZEB1 and ZEB2 mRNAs

Long non-coding RNAs (lncRNAs) are a group of transcripts, which can regulate the progression of esophageal squamous cell carcinoma (ESCC). According to the data of TCGA, Ladybird homeobox 2 antisense RNA 1 (LBX2-AS1) is a highly expressed lncRNA in ESCC samples. Herein, we chose it for further study. Furtherly, dysregulation of LBX2-AS1 was identified in ESCC tissues with metastasis. Loss-of function assays were conducted and revealed that LBX2-AS1 knockdown suppressed ESCC cell migration and epithelial-mesenchymal transition (EMT). Zinc finger E-box binding homeobox 1 (ZEB1) and zinc finger E-box binding homeobox 2 (ZEB2) are two EMT-related transcription factors. Since LBX2-AS1 promoted the EMT progress and simultaneously enhanced the level of ZEB1 and ZEB2, we further investigated whether LBX2-AS1 promoted cell migration and EMT in ESCC by regulating ZEB1 and ZEB2. Mechanism investigations revealed that RNA binding protein heterogeneous nuclear ribonucleoprotein C (HNRNPC) could interact with LBX2-AS1, ZEB1 and ZEB2, simultaneously. The similar function of HNRNPC in regulating migration and EMT process was demonstrated. ZEB1 has been reported as a positive transcriptional regulator of lncRNA. Therefore, further mechanism analysis was made to demonstrate whether ZEB1 could regulate the transcription of LBX2-AS1. Collectively, our data showed that ZEB1-induced upregulation of LBX2-AS1 promoted cell migration and EMT process in ESCC via enhancing the stability of ZEB1 and ZEB2.

Epigenetic Mechanisms Influencing Epithelial to Mesenchymal Transition in Bladder Cancer

Bladder cancer is one of the most incident neoplasms worldwide, and its treatment remains a significant challenge, since the mechanisms underlying disease progression are still poorly understood. The epithelial to mesenchymal transition (EMT) has been proven to play an important role in the tumorigenic process, particularly in cancer cell invasiveness and metastatic potential. Several studies have reported the importance of epigenetic mechanisms and enzymes, which orchestrate them in several features of cancer cells and, specifically, in EMT. In this paper, we discuss the epigenetic enzymes, protein-coding and non-coding genes, and mechanisms altered in the EMT process occurring in bladder cancer cells, as well as its implications, which allows for improved understanding of bladder cancer biology and for the development of novel targeted therapies.

MiR-139-5p is associated with poor prognosis and regulates glycolysis by repressing PKM2 in gallbladder carcinoma

OBJECTIVES

Gallbladder carcinoma (GBC) is the most highly aggressive cancer of biliary tract, but effective therapeutics are lacking. Emerging evidence has unveiled that miR-139-5p is aberrantly downregulated in cancers, including GBC. However, the functions and mechanisms of miR-139-5p in GBC remain unclear.

MATERIALS AND METHODS

MiR-139-5p-overexpression was established in GBC cell lines, after which cell proliferation, migration, invasion, colony formation, and glucose metabolism were assayed in vitro. Subsequently, bioinformatics prediction and dual-luciferase reporter were performed to confirm that pyruvate kinase M2 (PKM2) was a direct target of miRNA-139-5p. Xenograft mouse models were applied to investigate the role of miR-139-5p in GBC tumourigenicity in vivo. In situ hybridization and immunohistochemical assays were performed to determine the relationships among miR-139-5p, PKM2 expression and clinical malignancies in GBC samples.

RESULTS

We found that miR-139-5p was substantially downregulated in GBC tissues. Low expression of miR-139-5p was significantly associated with poor clinical outcomes. GBC cell proliferation, migration, and invasion could be inhibited by overexpression of miR-139-5p either in vitro or in vivo. In addition, miR-139-5p overexpression could directly inhibit PKM2 expression and lead to suppression of glucose consumption, lactate production, and cellular ATP levels. Moreover, PKM2 was frequently upregulated in GBC and correlated with poor prognosis. Mechanistically, miRNA-139-5p inhibited cell proliferation, migration, and glycolysis in GBC, at least in part, by repressing PKM2.

CONCLUSIONS

These results demonstrated a novel role for miR-139-5p/PKM2 in GBC progression and provided potential prognostic predictors for GBC patients.

Genetic dissection of the miR-200-Zeb1 axis reveals its importance in tumor differentiation and invasion

The epithelial-to-mesenchymal transition (EMT) is an important mechanism for cancer progression and metastasis. Numerous in vitro and tumor-profiling studies point to the miR-200-Zeb1 axis as crucial in regulating this process, yet in vivo studies involving its regulation within a physiological context are lacking. Here, we show that miR-200 ablation in the Rip-Tag2 insulinoma mouse model induces beta-cell dedifferentiation, initiates an EMT expression program, and promotes tumor invasion. Strikingly, disrupting the miR-200 sites of the endogenous Zeb1 locus causes a similar phenotype. Reexpressing members of the miR-200 superfamily in vitro reveals that the miR-200c family and not the co-expressed and closely related miR-141 family is responsible for regulation of Zeb1 and EMT. Our results thus show that disrupting the in vivo regulation of Zeb1 by miR-200c is sufficient to drive EMT, thus highlighting the importance of this axis in tumor progression and invasion and its potential as a therapeutic target.

Epigenetic Alterations in Bladder Cancer

PURPOSE OF REVIEW

Epigenetics refers to processes that alter gene expression without altering primary DNA. Over that past decade, there is a growing focus on epigenetic mechanisms in cancer research and its importance in cancer biology. This review summarizes epigenetic dysregulation in bladder cancer.

RECENT FINDINGS

Epigenetic alterations are overall shared across various grades and stages of bladder cancer. High grade invasive tumors demonstrate a greater degree and intensity of methylation and may have a unique methylation pattern. Environmental exposures may influence epigenetic alterations directly independent of genomic change. Non-coding RNAs play an important role in cancer phenotype, especially in the context of integrative genomic analyses. DNA hypermethylation and non-coding RNAs have potential as robust bladder cancer biomarkers; however, they require further study and validation. Changes in chromatin and histone modification are attractive targets for therapy and are currently in clinical trials. Epigenetic dysregulation may be an important key in improving the understanding of bladder cancer pathogenesis, especially through integrative genomic analyses. Deeper understanding of these pathways can help identify clinically relevant biomarkers and therapeutic targets to validate for diagnosis, monitoring, prognosis, and treatment for bladder cancer.

PRMT5 Circular RNA Promotes Metastasis of Urothelial Carcinoma of the Bladder through Sponging miR-30c to Induce Epithelial-Mesenchymal Transition

PURPOSE

Circular RNAs (circRNAs), a novel class of noncoding RNAs, have recently drawn lots of attention in the pathogenesis of human cancers. However, the role of circRNAs in cancer cells epithelial-mesenchymal transition (EMT) remains unclear. In this study, we aimed to identify novel circRNAs that regulate urothelial carcinoma of the bladder (UCB) cells' EMT and explored their regulatory mechanisms and clinical significance in UCBs.

EXPERIMENTAL DESIGN

We first screened circRNA expression profiles using a circRNA microarray in paired UCB and normal tissues, and then studied the clinical significance of an upregulated circRNA, circPRMT5, in a large cohort of patients with UCB. We further investigated the functions and underlying mechanisms of circPRMT5 in UCB cells' EMT. Moreover, we evaluated the regulation effect of circPRMT5 on miR-30c, and its target genes, SNAIL1 and E-cadherin, in two independent cohorts from our institute and The Cancer Genome Atlas (TCGA).

RESULTS

We demonstrated that upregulated expression of circPRMT5 was positively associated with advanced clinical stage and worse survival in patients with UCB. We further revealed that circPRMT5 promoted UCB cell's EMT via sponging miR-30c. Clinical analysis from two independent UCB cohorts showed that the circPRMT5/miR-30c/SNAIL1/E-cadherin pathway was essential in supporting UCB progression. Importantly, we identified that circPRMT5 was upregulated in serum and urine exosomes from patients with UCB, and significantly correlated with tumor metastasis.

CONCLUSIONS

CircPRMT5 exerts critical roles in promoting UCB cells' EMT and/or aggressiveness and is a prognostic biomarker of the disease, suggesting that circPRMT5 may serve as an exploitable therapeutic target for patients with UCB.

miR-205 mediates adaptive resistance to MET inhibition via ERRFI1 targeting and raised EGFR signaling

The onset of secondary resistance represents a major limitation to long-term efficacy of target therapies in cancer patients. Thus, the identification of mechanisms mediating secondary resistance is the key to the rational design of therapeutic strategies for resistant patients. MiRNA profiling combined with RNA-Seq in MET-addicted cancer cell lines led us to identify the miR-205/ERRFI1 (ERBB receptor feedback inhibitor-1) axis as a novel mediator of resistance to MET tyrosine kinase inhibitors (TKIs). In cells resistant to MET-TKIs, epigenetically induced miR-205 expression determined the downregulation of ERRFI1 which, in turn, caused EGFR activation, sustaining resistance to MET-TKIs. Anti-miR-205 transduction reverted crizotinib resistance in vivo, while miR-205 over-expression rendered wt cells refractory to TKI treatment. Importantly, in the absence of EGFR genetic alterations, miR-205/ERRFI1-driven EGFR activation rendered MET-TKI-resistant cells sensitive to combined MET/EGFR inhibition. As a proof of concept of the clinical relevance of this new mechanism of adaptive resistance, we report that a patient with a MET-amplified lung adenocarcinoma displayed deregulation of the miR-205/ERRFI1 axis in concomitance with onset of clinical resistance to anti-MET therapy.

miR-7-5p acts as a tumor suppressor in bladder cancer by regulating the hedgehog pathway factor Gli3

Although important progresses have been made in the diagnosis and treatment of bladder cancer (BCa), the overall survival for patients with advanced BCa remains poor. It is necessary to uncover the molecular mechanism underlying the initiation and progression of bladder cancer. According to previous reports, mircoRNAs (miRNAs) can regulate tumorigenesis by targeting their downstream mRNAs. This study aims to explore and analyze a novel miRNA-mRNA axis which can regulate the progression of bladder cancer. Based on the microarray analysis, 182 mRNAs were found to be upregulated in BCa tissues. Gene oncology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that these upregulated mRNAs are related with hedgehog pathway. Gli3, an important factor of hedgehog pathway, belongs to these 182 upregulated mRNAs. Therefore, Gli3 was chosen to do further study. Kaplan-Meier analysis revealed that highly expressed Gli3 predicted unfavorable prognosis for patients with BCa. Results of functional experiments indicated the inhibitory effects of silenced Gli3 on cell proliferation, migration and EMT progress. Mechanically, Gli3 was the target mRNA of miR-7-5p in BCa cells. Finally, rescue assays were performed to validate the specific function of miR-7-5p/Gli3 axis in BCa progression. According to all data, we concluded that miR-7-5p acts as a tumor suppressor in BCa by downregulating Gli3.

Integrated analysis of a competing endogenous RNA network reveals key lncRNAs as potential prognostic biomarkers for human bladder cancer

Human bladder cancer (BCa) is one of the most commonly diagnosed malignancies worldwide. It has high recurrence rates and low-grade malignancy, thus representing an important public health concern. An increasing number of studies suggest that long-noncoding RNAs (lncRNAs) play important roles in various biological processes and disease pathologies, including cancer.We analyzed the expression profiles of lncRNA, miRNA, and mRNA, along with the clinical information of BCa patients collected from the Cancer Genome Atlas database to identify lncRNA biomarkers for prognosis. We also constructed an lncRNA-miRNA-mRNA global triple network (competitive endogenous RNA network) by bioinformational approach.This BCa lncRNA-miRNA-mRNA network consisted of 23 miRNA nodes, 52 mRNA nodes, 59 lncRNA nodes, and 365 edges. Subsequent gene ontology (GO) and pathway analyses were performed using BinGO for Cytoscape and Database for Annotation, Visualization, and Integration Discovery, respectively, highlighting important GO terms and pathways that were enriched in the network. Subnetworks were created using 3 key lncRNAs (MAGI2-AS3, ADAMTS9-AS2, and LINC00330), revealing associations with BCa-linked mRNAs and miRNAs. Finally, an analysis of significantly differentiating RNAs found 6 DElncRNAs (AC112721.1, ADAMTS9-AS1, ADAMTS9-AS2, HCG22, MYO16-AS1, and SACS-AS1), 1 DEmiRNA (miRNA-195), and 6 DEmRNAs (CCNB1, FAM129A, MAP1B, TMEM100, AIFM3, and HOXB5) that correlated with BCa patient survival.Our results provide a novel perspective from which to study the lncRNA-related ceRNA network in BCa, contributing to the development of future diagnostic biomarkers and therapeutic targets.

miR-22/KAT6B axis is a chemotherapeutic determiner via regulation of PI3k-Akt-NF-kB pathway in tongue squamous cell carcinoma

BACKGROUND

Tongue squamous cell carcinoma (TSCC) is the most common oral cancer. Neoadjuvant systemic treatment before or after surgery for advanced TSCC is considered one of the most crucial factors in reducing mortality. However, the therapeutic benefits of chemotherapy are usually attenuated due to intrinsic and/or acquired drug resistance, and a large proportion of TSCC are resistant to chemotherapy, which may result in more aggressive tumor behavior and an even worse clinical outcome. Recently, the potential application of using miRNAs to predict therapeutic response to cancer treatment holds high promise, but miRNAs with predictive value remain to be identified and underlying mechanisms remain to be understood in TSCC.

METHODS

The expression of miR-22 in tissues from patients diagnosed with TSCC was analyzed using real-time PCR. The effects of miR-22 on cell proliferation and tumorigenesis in TSCC cells were analyzed by MTS assay, and flow cytometry. The tumor growth in vivo was observed in xenograft model. Luciferase reporter assay, real-time PCR and western blot were performed to validate a potential target of miR-22 in TC. The correlation between miR-22 expression and KAT6B expression, as well as the mechanisms by which miR-22 regulates PI3k-Akt-NF-kB pathway in TSCC were also addressed.

RESULTS

We found a strong correlation between miR-22 expression and chemosensitivity to cisplatin (CDDP) in TSCC patients. Ectopic overexpression of miR-22 enhanced TSCC cells apoptosis in response to CDDP in experimental models performed in vitro and in vivo. Moreover, we found that KAT6B is a direct functional target of miR-22. Ectopic expression of KAT6B attenuated the efficiency of miR-22 in TSCC cells upon CDDP treatment. Mechanistically, miR-22 overexpression or KAT6B knockdown inhibited PI3K/Akt/NF-κB signaling in TSCC cells, possibly via downregulating the activators of PI3K/Akt/NF-κB signaling, such as S100A8, PDGF and VEGF. Furthermore, the activation of miR-22 depended on the intensity of the stresses in the presence of p53 activation.

CONCLUSIONS

Our findings define miR-22 as an intrinsic molecular switch that determines p53-dependent cellular fate through KAT6B/ PI3K-Akt/ NF-kB pathway.

Epithelial-mesenchymal-transition-inducing transcription factors: new targets for tackling chemoresistance in cancer?

Chemoresistance remains a major complication of cancer treatments. Recent data provide strong evidence that chemoresistance is linked to epithelial-mesenchymal transition (EMT), a latent developmental process, which is re-activated during cancer progression. EMT involves transcriptional reprogramming and is driven by specific EMT transcription factors (EMT-TFs). In this review, we provide support for the idea that EMT-TFs contribute to the development of resistance against cancer therapy and discuss how EMT-TFs might be targeted to advance novel therapeutic approaches to the treatment of cancer.

Human HLA‑F adjacent transcript 10 promotes the formation of cancer initiating cells and cisplatin resistance in bladder cancer

Epithelial to mesenchymal transition (EMT) serves important roles in tumor invasion, metastasis, formation of cancer initiating cells (CICs) and drug resistance. HLA‑F adjacent transcript 10 (FAT10) has been proposed as an oncogene in bladder cancer. However, the functional contribution of FAT10 to EMT and the formation of CICs remains unclear in bladder cancer. The present study reports that FAT10 protein expression is upregulated in bladder cancer cell lines, and the overexpression of FAT10 promotes EMT and the formation of CICs in bladder cancer UMUC‑3 cells. In addition, increased expression of FAT10 in tumor tissue was associated with shorter overall survival and progression free survival in Chinese patients with bladder cancer. Overexpression of FAT10 promotes cisplatin‑resistant bladder cancer formation. These results indicated FAT10 may be a novel target for the treatment of bladder cancer.

Long non-coding RNA LINC00673 promotes breast cancer proliferation and metastasis through regulating B7-H6 and epithelial-mesenchymal transition

BACKGROUND

Long non-coding RNAs (LncRNAs) have been reported as key regulators of tumor progression in recent decades. However, the potential molecular mechanisms of breast cancer are still unclear. With the development of sequencing technology, we discovered that LINC00673 is upregulated in tumor tissues. But the main role of LINC00673 in breast cancer has yet to be confirmed.

MATERIALS AND METHODS

35 pairs of breast tumors and normal tissues were selected to real-time quantitative polymerase chain reaction (RT-qPCR) to validate LINC00673 is overexpressed in tumor tissues. We conducted proliferation, colony formation, migration, invasion assays, and EMT-related phenotype to determine the specific role of LINC00673 in breast cancer cell lines (MDA-MB-231, BT-549, and MCF-7) transfected with small interfering RNA. Gene expression profiling was conducted to found LINC00673-associated gene transcriptional changes.

RESULTS

We discovered that LINC00673 is significantly upregulated in breast cancer tissues compared to paired adjacent non-tumor tissues by RT-qPCR and highly expressed LINC00673 is positively correlated with lymph node metastasis and clinical stage in the validated cohort. Knocking down LINC00673 inhibited cell proliferation and metastasis, whereas upregulated LINC00673 had the opposite effect. Gene expression profiling results indicated that LINC00673 could influence NCR3LG1(B7-H6) expression in transcriptional level. Western Blot showed us that LINC00673 could regulate epithelial-mesenchymal transition (EMT) and B7-H6 in protein level. Then we demonstrated that knocking down B7-H6 could decrease breast cancer cell proliferation and metastasis.

CONCLUSION

In this study, we identified the role of LINC00673 in inducing proliferation and metastasis of breast cancer cell lines and it might act as an underlying therapeutic target for breast cancer.

The Kraken Wakes: induced EMT as a driver of tumour aggression and poor outcome

Epithelial mesenchymal transition (EMT) describes the shift of cells from an epithelial form to a contact independent, migratory, mesenchymal form. In cancer the change is linked to invasion and metastasis. Tumour conditions, including hypoxia, acidosis and a range of treatments can trigger EMT, which is implicated in the subsequent development of resistance to those same treatments. Consequently, the degree to which EMT occurs may underpin the entire course of tumour progression and treatment response in a patient. In this review we look past the protective effect of EMT against the initial treatment, to the role of the mesenchymal state, once triggered, in promoting disease growth, spread and future treatment insensitivity. In patients a correlation was found between the propensity of a treatment to induce EMT and failure of that treatment to provide a survival benefit, implicating EMT induction in accelerated tumour progression after treatment cessation. Looking to the mechanisms driving this detrimental effect; increased proliferation, suppressed apoptosis, stem cell induction, augmented angiogenesis, enhanced metastatic dissemination, and immune tolerance, can all result from treatment-induced EMT and could worsen outcome. Evidence also suggests EMT induction with earlier therapies attenuates benefits of later treatments. Looking beyond epithelial tumours, de-differentiation also has therapy-attenuating effects and reversal thereof may yield similar rewards. A range of potential therapies are in development that may address the diverse mechanisms and molecular control systems involved in EMT-induced accelerated progression. Considering the broad reaching effects of mesenchymal shift identified, successful deployment of such treatments could substantially improve patient outcomes.

A miRNA-200c/cathepsin L feedback loop determines paclitaxel resistance in human lung cancer A549 cells in vitro through regulating epithelial-mesenchymal transition

Cathepsin L (CTSL), a cysteine protease, is closely related to tumor occurrence, development, and metastasis, and possibly regulates cancer cell resistance to chemotherapy. miRNAs, especially the miR-200 family, have been implicated in drug-resistant tumors. In this study we explored the relationship of CTSL, miRNA-200c and drug resistance, and the potential regulatory mechanisms in human lung cancer A549 cells and A549/TAX cells in vitro. A549/TAX cells were paclitaxel-resistant A549 cells overexpressing CTSL and characterized by epithelial-mesenchymal transition (EMT). We showed that miRNA-200c and CTSL were reciprocally linked in a feedback loop in these cancer cells. Overexpression of miRNA-200c in A549/TAX cells decreased the expression of CTSL, and enhanced their sensitivity to paclitaxel and suppressed EMT, whereas knockdown of miRNA-200c in A549 cells significantly increased the expression of CTSL, and decreased their sensitivity to paclitaxel and induced EMT. Overexpression of CTSL in A549 cells significantly decreased the expression of miRNA-200c, and reduced their sensitivity to paclitaxel and induced EMT, but these effects were reversed by miRNA-200c, whereas knockdown of CTSL in A549/TAX cells attenuated paclitaxel resistance and remarkably inhibited EMT, but the inhibition of miRNA-200c could reverse these effects. Therefore, miRNA-200c may be involved in regulating paclitaxel resistance through CTSL-mediated EMT in A549 cells, and CTSL and miRNA-200c are reciprocally linked in a feedback loop.

Epidermal growth factor receptor (EGFR): A rising star in the era of precision medicine of lung cancer

Lung cancer is a leading cause of cancer mortality worldwide. In tumors, the important role of noncoding RNA regulatory networks has been more and more reveal. EGFR has been identified as an oncogenic driver of NSCLC, especially activating mutations EGFR and its inhibition with specific TKIs can generate dramatic tumor responses. Studies have shown that EGFR plays significant roles in the progression of NSCLC. Subset analysis of the small proportion of patients with EGFR-mutant lung cancer showed a disease-free survival benefit, but was underpowered to detect a survival advantage. Herein, we highlight the progression of EGFR, noncoding RNA, and their roles in carcinogenesis. We also focus on anti-lung cancer drug development and EGFR-related drug resistance.

Regulation of Cell Cycle Regulatory Proteins by MicroRNAs in Uterine Leiomyoma

The objective of this study was to determine whether miR-93, miR-29c, and miR-200c, which we previously reported to be downregulated in leiomyomas, target cell cycle regulatory proteins that influence cell proliferation. Based on TargetScan algorithm 3 cell cycle regulatory proteins namely, E2F transcription factor 1 (E2F1), Cyclin D1 (CCND1) and CDK2 which were predicted to be targets of these miRNAs were  further analyzed. In 30 hysterectomy specimens, we found the expression of E2F1 and CCND1 messenger RNA (mRNA) was increased in leiomyoma as compared to matched myometrium, with no significant changes in CDK2 mRNA levels. There was a significant increase in the abundance of all 3 proteins in leiomyoma in comparison with matched myometrium. Using luciferase reporter assay, we demonstrated E2F1 and CCND1 are targets of miR-93 and CDK2 is a target of miR-29c and miR-200c. We confirmed these findings through transfection studies in which transfection of primary leiomyoma cells with miR-93 resulted in a significant decrease in the expression of E2F1 and CCND1 mRNA and protein levels, whereas knockdown of miR-93 had the opposite effect. Similarly, overexpression of miR-29c and miR-200c in leiomyoma cells inhibited the expression of CDK2 protein and mRNA, whereas knockdown of this microRNAs (miRNA) had the opposite effect. Transfection of miR-29c, miR-200c, and miR-93 in primary leiomyoma cells resulted in a time-dependent inhibition of cell proliferation and cell motility. These results collectively indicate that the 3 miRNAs known to be downregulated in fibroid tumors are critical in regulation of cell proliferation because of their effects on 3 key cell cycle regulatory proteins, which are overexpressed in uterine leiomyomas.

Employing an orthotopic model to study the role of epithelial-mesenchymal transition in bladder cancer metastasis

Epithelial-to-mesenchymal transition (EMT) has been implicated in the progression of bladder cancer. To study its contribution to bladder cancer metastasis, we established new xenograft models derived from human bladder cancer cell lines utilizing an orthotopic “recycling” technique that allowed us to isolate and examine the primary tumor and its corresponding circulating tumor cells (CTC’s) and metastatic lesions. Using whole genome mRNA expression profiling, we found that a reversible epithelial-to-mesenchymal transition (EMT) characterized by TGFβ pathway activation and SNAIL expression was associated with the accumulation of CTCs. Finally, we observed that conditional silencing of SNAIL completely blocked CTC production and regional/distant metastasis. Using this unique bladder cancer xenograft model, we conclude that metastasis is dependent on a reversible EMT mediated by SNAIL.

miR-429 expression in bladder cancer and its correlation with tumor behavior and clinical outcome

We previously showed that microRNA-429 (miR-429) played an important role in epithelial-mesenchymal transition (EMT) of urothelial cell carcinoma of the bladder. We herein evaluated the expression of miR-429 in bladder cancer and its potential relevance to clinicopathological characteristics and patient survival. Relative expression levels of miR-429 in surgical bladder cancer tissue specimens obtained from 76 patients with bladder cancer were measured by chromogenic in situ hybridization. miR-429 expression was significantly higher in specimens from alive patients than expired patients in both of 5-year overall survival (OS) (0.59 ± 0.09 vs. 0.27 ± 0.12; p < 0.05) and 5-year recurrence-free survival (RFS) (0.63 ± 0.10 vs. 0.33 ± 0.10; p < 0.05). The univariate Cox proportional hazards analysis revealed that tumor grade, stage, and miR-429 expression were significantly associated with patient survival. In multivariate analysis, tumor stage and miR-429 expression were significantly associated with 5-year OS (hazard ratio [HR] 4.70, p < 0.001) and 5-year-RFS (HR 2.20, p < 0.05). The Kaplan-Meier analysis showed that patients with miR-429 expression had significantly better 5-year OS and 5-year RFS rates than those without miR-429 expression (84.4% vs. 61.4%, p < 0.05 and 71.9% vs. 45.5%, p < 0.05, respectively). miR-429 may be considered as an adjunctive prognostic marker in addition to tumor grade and stage in bladder cancer.

Specific micro-RNA expression patterns distinguish the basal and luminal subtypes of muscle-invasive bladder cancer

The roles of non-coding RNAs in controlling clinical and biological heterogeneity in bladder cancer remain unclear. We used TCGA's published dataset (n = 405 tumors) as a discovery cohort and created a new validation cohort to define the miRNA expression patterns in the basal and luminal molecular subtypes of muscle-invasive bladder cancer (MIBC). We identified 63 miRNAs by PAM, which optimally identified basal and luminal tumors. The targets of the top luminal miRNAs were activators of EMT (ZEB1, ZEB2) and basal subtype transcription (IL-6, EGFR, STAT3), whereas the targets of the top basal miRNAs were involved in adipogenesis pathways and luminal breast cancer (ERBB2, ERBB3). We also identified a 15-miRNA signature that identified stromally infiltrated basal and luminal MIBCs corresponding to the “cluster IV/immune undifferentiated/claudin-low” and “cluster II/luminal immune” subtypes identified previously, which likely contain samples with higher infiltration rates. Using the 63-miRNA signature, we accurately assigned MIBCs to the basal and luminal subtypes and confirmed that patients with basal tumors had shorter overall survival. The results strongly suggest that miRNAs contribute to the control of the gene expression patterns observed in basal and luminal MIBCs and that they can be used as biomarkers and candidate therapeutic targets.

Molecular Correlates of In Vitro Responses to Dacomitinib and Afatinib in Bladder Cancer

Background:

The HER family of proteins (EGFR, HER2, HER3 and HER4) have long been thought to be therapeutic targets for bladder cancer, but previous clinical trials targeting these proteins have been disappointing. Second generation agents may be more effective.

Objective:

The aim of this study was to evaluate responses to two second-generation irreversible tyrosine kinase inhibitors, dacomitinib and afatinib, in bladder cancer cell lines.

Methods:

Cell lines were characterized by targeted next generation DNA sequencing, RNA sequencing, western blotting and flow cytometry. Cell survival responses to dacomitinib or afatinib were determined using (3-[4,5-dimethylthioazol-2-yl]-2,5-diphenyl tetrazolium bromide) (MTT) or [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) and phenazine methosylfate (PMS) cell survival assays.

Results:

Only two cell lines of 12 tested were sensitive to afatinib. Sensitivity to afatinib was significantly associated with mutation in either HER2 or HER3 (p < 0.05). The two cell lines sensitive to afatinib were also responsive to dacomitinib ralong with an additional 4 other cell lines out of 16 tested. No characteristic was associated with dacomitinib sensitivity. Molecular profiling demonstrated that only two genes were high in both afatinib and dacomitinib sensitive cells. Further rhigher expression of RAS pathway genes was noted for dacomitinib responsive cells.

Conclusions:

This study confirms that cell line screening can be useful in pre-clinical evaluation of targeted small molecule inhibitors and suggests that compounds with similar structure(s) and target(s) may have distinct sensitivity profiles. Further rcombinational targeting of additional molecularly relevant pathways may be important in enhancing responses to HER targeted agents in bladder cancer.

miR-200b is a key regulator of tumor progression and metabolism targeting lactate dehydrogenase A in human malignant glioma

Lactate dehydrogenase A (LDHA) is involved in various cancers. In this study, we investigated the expression and function of LDHA in glioma. We found that LDHA was up-regulated in glioma samples. Furthermore, we found that overexpression of LDHA promoted proliferation, invasion and glycolysis in glioma cells. Luciferase reporter assays confirmed that LDHA was a direct target of miR-200b. miR-200b was found to be down-regulated in glioma samples, which was inversely correlated with LDHA expression. Repression of LDHA by miR-200b suppressed the glycolysis, cell proliferation and invasion of glioma cells. These results provide evidence that miR-200b acts as a tumor suppressor in glioma through the inhibition of LDHA both in vitro and in vivo. Targeting LDHA through miR-200b could be a potential therapeutic strategy in glioma.

MiR-429 reverses epithelial-mesenchymal transition by restoring E-cadherin expression in bladder cancer

Epithelial-mesenchymal transition (EMT) accompanying loss of E-cadherin is important for invasiveness and metastasis of bladder cancer. MicroRNAs (miRs) had been associated with cancer progression and differentiation in several cancers. Our goal is to find out the specific miR which modulates EMT in bladder cancer. Real-time quantitative polymerase chain reaction was used to measure the miRs expression in urothelial cell carcinoma (UCC) cell lines. MiR or siRNA mimics was used to regulate miR and mRNA level respectively. Migration and scratch assays were used to determine the migratory ability. Zymography assay was used to confirm the metalloproteinase activity. Western blotting was used to elucidate the mechanism which regulated by specific miR. MiR-429 was highly expressed in low grade UCC cell lines. Exogenous mimic of miR-429 treatment dramatically inhibited the migratory ability of T24 cells. MiR-429 downstream target ZEB1 was decreased, E-cadherin was restored, and β-catenin was contrarily decreased by exogenous mimic of miR-429 treatment in T24 cells. Cell invasive ability was also inhibited by exogenous mimic of miR-429 treatment through inactivating the MMP-2 activity in T24 cells. E-cadherin protein expression level was inhibited by E-cadherin siRNA accompanied with increasing cell migratory ability when compared with control group in low grade TSGH8301 cells. MiR-429 decreased the cell migratory and invasive abilities through reducing ZEB1 and β-catenin, restoring the E-cadherin expression and inactivation of MMP-2 of UCC cells. MiR-429 might be used as a progression marker of bladder cancer.

MicroRNA-429 decreases the invasion ability of gastric cancer cell line BGC-823 by downregulating the expression of heparanase

The present study aimed to measure the expression of microRNA (miRNA/miR) −429 in gastric cancer and investigate the associated mechanism of action. A total of 30 patients with gastric cancer who received radical or palliative resection at Jining No. 1 People's Hospital between January-October 2016 were included in the present study. Resected gastric cancer and tumor-adjacent tissues were resected. Gastric cancer BGC-823 cells were transfected with miR-429 mimics to induce the overexpression of miR-429, or transfected with small interfering (si)RNA of heparanase (HPSE) for the silencing of HPSE. Reverse transcription-quantitative polymerase chain reaction was used to measure the expression of miR-429 or HPSE mRNA. Western blotting was employed to determine the protein expression of HPSE. Cell-Counting Kit-8 assay was carried out to test cell proliferation and a Transwell assay was used to determine cell invasion ability. Expression of HPSE mRNA and protein in gastric cancer tissues was increased compared with tumor-adjacent tissues. Reduced expression of miR-429 in gastric cancer tissues may be associated with the targeting of HPSE mRNA by miR-429. Overexpression of miR-429 inhibited the transcription and translation of the HPSE gene. However, overexpression of miR-429 did not affect the proliferation of gastric cancer cells. Notably, overexpression of miR-429 reduced the invasion ability of gastric cancer cells. Transfection with HPSE siRNA decreased the expression of the HPSE protein in BGC-823 cells and inhibited the occurrence and development of gastric cancer by reducing the invasion ability of the cells. The present study demonstrated that expression of miR-429 in gastric cancer tissues was significantly reduced compared with tumor-adjacent tissues. As a tumor-suppressor gene, miR-429 decreases the invasion ability of gastric cancer cells by downregulating the expression of HSPE.

The role of small adaptor proteins in the control of oncogenic signalingr driven by tyrosine kinases in human cancer

Protein phosphorylation on tyrosine (Tyr) residues has evolved as an important mechanism to coordinate cell communication in multicellular organisms. The importance of this process has been revealed by the discovery of the prominent oncogenic properties of tyrosine kinases (TK) upon deregulation of their physiological activities, often due to protein overexpression and/or somatic mutation. Recent reports suggest that TK oncogenic signaling is also under the control of small adaptor proteins. These cytosolic proteins lack intrinsic catalytic activity and signal by linking two functional members of a catalytic pathway. While most adaptors display positive regulatory functions, a small group of this family exerts negative regulatory functions by targeting several components of the TK signaling cascade. Here, we review how these less studied adaptor proteins negatively control TK activities and how their loss of function induces abnormal TK signaling, promoting tumor formation. We also discuss the therapeutic consequences of this novel regulatory mechanism in human oncology.

Increased Expression of a MicroRNA Correlates with Anthelmintic Resistance in Parasitic Nematodes

Resistance to anthelmintic drugs is a major problem in the global fight against parasitic nematodes infecting humans and animals. While previous studies have identified mutations in drug target genes in resistant parasites, changes in the expression levels of both targets and transporters have also been reported. The mechanisms underlying these changes in gene expression are unresolved. Here, we take a novel approach to this problem by investigating the role of small regulatory RNAs in drug resistant strains of the important parasite Haemonchus contortus. microRNAs (miRNAs) are small (22 nt) non-coding RNAs that regulate gene expression by binding predominantly to the 3′ UTR of mRNAs. Changes in miRNA expression have been implicated in drug resistance in a variety of tumor cells. In this study, we focused on two geographically distinct ivermectin resistant strains of H. contortus and two lines generated by multiple rounds of backcrossing between susceptible and resistant parents, with ivermectin selection. All four resistant strains showed significantly increased expression of a single miRNA, hco-miR-9551, compared to the susceptible strain. This same miRNA is also upregulated in a multi-drug-resistant strain of the related nematode Teladorsagia circumcincta. hco-miR-9551 is enriched in female worms, is likely to be located on the X chromosome and is restricted to clade V parasitic nematodes. Genes containing predicted binding sites for hco-miR-9551 were identified computationally and refined based on differential expression in a transcriptomic dataset prepared from the same drug resistant and susceptible strains. This analysis identified three putative target mRNAs, one of which, a CHAC domain containing protein, is located in a region of the H. contortus genome introgressed from the resistant parent. hco-miR-9551 was shown to interact with the 3′ UTR of this gene by dual luciferase assay. This study is the first to suggest a role for miRNAs and the genes they regulate in drug resistant parasitic nematodes. miR-9551 also has potential as a biomarker of resistance in different nematode species.

Identification and functional analysis of risk-related microRNAs for the prognosis of patients with bladder urothelial carcinoma

The aim of the present study was to investigate risk-related microRNAs (miRs) for bladder urothelial carcinoma (BUC) prognosis. Clinical and microRNA expression data downloaded from the Cancer Genome Atlas were utilized for survival analysis. Risk factor estimation was performed using Cox's proportional regression analysis. A microRNA-regulated target gene network was constructed and presented using Cytoscape. In addition, the Database for Annotation, Visualization and Integrated Discovery was used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment, followed by protein-protein interaction (PPI) network analysis. Finally, the K-clique method was applied to analyze sub-pathways. A total of 16 significant microRNAs, including hsa-miR-3622a and hsa-miR-29a, were identified (P<0.05). Following Cox's proportional regression analysis, hsa-miR-29a was screened as a prognostic marker of BUC risk (P=0.0449). A regulation network of hsa-miR-29a comprising 417 target genes was constructed. These target genes were primarily enriched in GO terms, including collagen fibril organization, extracellular matrix (ECM) organization and pathways, such as focal adhesion (P<0.05). A PPI network including 197 genes and 510 interactions, was constructed. The top 21 genes in the network module were enriched in GO terms, including collagen fibril organization and pathways, such as ECM receptor interaction (P<0.05). Finally, 4 sub-pathways of cysteine and methionine metabolism, including paths 00270_4, 00270_1, 00270_2 and 00270_5, were obtained (P<0.01) and identified to be enriched through DNA (cytosine-5)-methyltransferase (DNMT)3A, DNMT3B, methionine adenosyltransferase 2α (MAT2A) and spermine synthase (SMS). The identified microRNAs, particularly hsa-miR-29a and its 4 associated target genes DNMT3A, DNMT3B, MAT2A and SMS, may participate in the prognostic risk mechanism of BUC.

Epithelial plasticity and cancer stem cells: Major mechanisms of cancer pathogenesis and therapy resistance

Epithelial-mesenchymal transition (EMT) has been linked with aggressive tumor biology and therapy resistance. It plays central role not only in the generation of cancer stem cells (CSCs) but also direct them across the multiple organ systems to promote tumor recurrence and metastasis. CSCs are reported to express stem cell genes as well as specific cell surface markers and allow aberrant differentiation of progenies. It facilitates cancer cells to leave primary tumor, acquire migratory characteristics, grow into new environment and develop radio-chemo-resistance. Based on the current information, present review discusses and summarizes the recent advancements on the molecular mechanisms that derive epithelial plasticity and its major role in generating a subset of tumor cells with stemness properties and pathophysiological spread of tumor. This paper further highlights the critical need to examine the regulation of EMT and CSC pathways in identifying the novel probable therapeutic targets. These improved therapeutic strategies based on the co-administration of inhibitors of EMT, CSCs as well as differentiated tumor cells may provide improved anti-neoplastic response with no tumor relapse.

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.

MicroRNA-200c inhibits epithelial-mesenchymal transition, invasion, and migration of lung cancer by targeting HMGB1

MicroRNAs (miRs) play critical roles in cancer development, proliferation, epithelial-mesenchymal transition (EMT), invasion, and migration through regulating the expression of oncogenes and tumour suppressor genes. Previous studies have indicated that miR-200c acts as a tumour suppressor in various cancers by downregulating high-mobility group box 1 (HMGB1) and thereby suppressing EMT and metastasis. In addition, miR-200c was reported to be downregulated and correlated with poor outcomes in non-small cell lung cancer (NSCLC). However, its functional role in HMGB1 regulation in NSCLC is still unclear. This study aimed to clarify whether miR-200c acts as a tumour suppressor in NSCLC by downregulating HMGB1, which is associated with EMT, invasion, cytoskeleton rearrangement, and migration in vitro and in vivo. In order to demonstrate HMGB1 downregulation by miR-200c, the NSCLC cell line A549 was transfected with miR-200c mimic or inhibitor. The mimic significantly reduced HMGB1 expression and suppressed EMT, invasion, and migration, while the inhibitor generated the opposite effects. Additionally, using xenograft mouse models, we confirmed that HMGB1 overexpression increased tumour EMT. In summary, our results demonstrated that miR-200c could suppress EMT, invasion, and migration of NSCLC cells by downregulating HMGB1.

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.

Cancer stem cells and epithelial-mesenchymal transition in urothelial carcinoma: Possible pathways and potential therapeutic approaches

There is growing evidence of the presence of cancer stem cells in urothelial carcinoma. Cancer stem cells have the ability to self-renew and to differentiate into all cell types of the original heterogeneous tumor. A panel of diverse cancer stem cell markers might be suitable for simulation studies of urothelial cancer stem cells and for the development of optimized treatment protocols. The present review focuses on the advances in recognizing the markers of urothelial cancer stem cells and possible therapeutic targets. The commonly reported markers and pathways that were evaluated include CD44, CD133, ALDH1, SOX2 & SOX4, BMI1, EZH1, PD-L1, MAGE-A3, COX2/PGE2/STAT3, AR, and autophagy. Studies on the epithelial-mesenchymal transition-related pathways (Shh, Wnt/β-catenin, Notch, PI3K/Akt, TGF-β, miRNA) are also reviewed. Most of these markers were recognized through the expression patterns of cancer stem cell-rich side populations. Their regulative role in the development and differentiation of urothelial cancer stem cells was confirmed in vitro by functional analyses (e.g. cell migration, colony formation, sphere formation), and in vivo in xenograft experiments. Although a small number of these pathways are targeted by currently available drugs or drugs that are the currently being tested in clinical trials, a clear treatment approach has not been developed for most pathways. A greater understanding of the mechanisms that control the proliferation and differentiation of cancer stem cells is expected to lead to improvements in targeted therapy.