MicroRNA-191 targets N-deacetylase/N-sulfotransferase 1 and promotes cell growth in human gastric carcinoma cell line MGC803

Novel insights into the roles of migrasome in cancer

Cell migration, a hallmark of cancer malignancy, plays a critical role in cancers. Improperly initiated or misdirected cell migration can lead to invasive metastatic cancer. Migrasomes are newly discovered vesicular cellular organelles produced by migrating cells and depending on cell migration. Four marker proteins [NDST1 (bifunctionalheparan sulfate N-deacetylase/N-sulfotransferase 1), EOGT (Epidermal growth factor domains pecific O-linked N-acetylglucosaminetransferase), CPQ (carboxypeptidase Q), and PIGK (phosphatidylinositol glycan anchor biosynthesis, class K)] of migrasomes were successfully identified. There are three marker proteins (NDST1, PIGK, and EOGT) of migrasome expressed in cancer. In this review, we will discuss the process of migrasome discovery, the formation of migrasome, the possible functions of migrasome, and the differences between migrasomes and exosomes, especially, the biological functions of migrasome marker proteins in cancer, and discuss some possible roles of migrasomes in cancer. We speculate that migrasomes and migracytosis can play key roles in regulating the development of cancer.

Insilco prediction of the role of the FriZZled5 gene in colorectal cancer

INTRODUCTION

In this study, we aimed to elucidate the crosstalk between the Wnt/β-catenin signaling pathway and colorectal cancer (CRC) associated with inflammatory bowel disease (IBD) using a bioinformatics analysis of putative common biomarkers and a systems biology approach.

MATERIALS AND METHODS

The following criteria were used to search the GEO and ArrayExpress databases for terms related to CRC and IBD: 1. The dataset containing the transcriptomic data, and 2. Untreated samples by medications or drugs. A total of 42 datasets were selected for additional analysis. The GEO2R identified the differentially expressed genes. The genes involved in the Wnt signaling pathway were extracted from the KEGG database. Enrichment analysis and miRNA target prediction were conducted through the ToppGene online tool.

RESULTS

In CRC datasets, there were 1168 up- and 998 down-regulated probes, whereas, in IBD datasets, there were 256 up- and 200 down-regulated probes. There were 65 upregulated and 57 downregulated genes shared by CRC and IBD. According to KEGG, there were 166 genes in the Wnt pathway. FriZZled5 (FZD5) was a down-regulated gene in both CRC and IBD, as determined by the intersection of CRC- and IBD-related DEGs with the Wnt pathway. It was also demonstrated that miR-191, miR-885-5p, miR-378a-3p, and miR-396-3p affect the FriZZled5 gene expression.

CONCLUSION

It is possible that increased expression of miR-191 and miR-885-5p, or decreased expression of miR-378a -3p and miR396-3, in IBD and CRC results in decreased expression of the FZD5 gene. Based on the function of this gene, FZD5 may be a potential therapeutic target in IBD that progresses to CRC.

MicroRNAs as Biomarkers of Active Pulmonary TB Course

The spread of drug-resistant forms of TB dictates the need for surgical treatment in the complex of anti-tuberculosis measures in Russia. Most often, surgical intervention is performed in the case of pulmonary tuberculoma or fibrotic cavitary tuberculosis (FCT). This study is devoted to the search for biomarkers that characterize the course of disease in surgical TB patients. It is assumed that such biomarkers will help the surgeon decide on the timing of the planned operation. A number of serum microRNAs, potential regulators of inflammation and fibrosis in TB, selected on the basis of PCR-Array analysis, were considered as biomarkers. Quantitative real time polymerase chain reaction and receiver operating curves (ROC) were used to verify Array data and to estimate the ability of microRNAs (miRNAs) to discriminate between healthy controls, tuberculoma patients, and FCT patients. The study showed that miR-155, miR-191 and miR-223 were differentially expressed in serum of tuberculoma with “decay” and tuberculoma without “decay” patients. Another combination (miR-26a, miR-191, miR-222 and miR-320) forms a set to differentiate between tuberculoma with “decay” and FCT. Patients with tuberculoma without “decay” diagnosis differ from those with FCT in serum expression of miR-26a, miR-155, miR-191, miR-222 and miR-223. Further investigations are required to evaluate these sets on a larger population so as to set cut-off values that could be applied in laboratory diagnosis.

Heparan sulfate proteoglycans in cancer: Pathogenesis and therapeutic potential

The heparan sulfate proteoglycans (HSPGs) are glycoproteins that consist of a proteoglycan "core" protein and covalently attached heparan sulfate (HS) chain. HSPGs are ubiquitously expressed in mammalian cells on the cell surface and in the extracellular matrix (ECM) and secretory vesicles. Within HSPGs, the protein cores determine when and where HSPG expression takes place, and the HS chains mediate most of HSPG's biological roles through binding various protein ligands, including cytokines, chemokines, growth factors and receptors, morphogens, proteases, protease inhibitors, and ECM proteins. Through these interactions, HSPGs modulate cell proliferation, adhesion, migration, invasion, and angiogenesis to display essential functions in physiology and pathology. Under physiological conditions, the expression and localization of HSPGs are finely regulated to orchestrate their physiological functions, and this is disrupted in cancer. The HSPG dysregulation elicits multiple oncogenic signaling, including growth factor signaling, ECM and Integrin signaling, chemokine and immune signaling, cancer stem cell, cell differentiation, apoptosis, and senescence, to prompt cell transformation, proliferation, tumor invasion and metastasis, tumor angiogenesis and inflammation, and immunotolerance. These oncogenic roles make HSPGs an attractive pharmacological target for anti-cancer therapy. Several therapeutic strategies have been under development, including anti-HSPG antibodies, peptides and HS mimetics, synthetic xylosides, and heparinase inhibitors, and shown promising anti-cancer efficacy. Therefore, much progress has been made in this line of study. However, it needs to bear in mind that the roles of HSPGs in cancer can be either oncogenic or tumor-suppressive, depending on the HSPG and the cancer cell type with the underlying mechanisms that remain obscure. Further studies need to address these to fill the knowledge gap and rationalize more efficient therapeutic targeting.

Glycosyltransferases EXTL2 and EXTL3 cellular balance dictates Heparan Sulfate biosynthesis and shapes gastric cancer cell motility and invasion

Heparan Sulfate Proteoglycans (HSPGs) are abundant glycoconjugates in cells' glycocalyx and Extracellular Matrix (ECM). By acting as scaffolds for protein-protein interactions, HSPGs modulate extracellular ligand gradients, cell signaling networks, and cell-ECM crosstalk. Aberrant expression of HSPGs and enzymes involved in HSPG biosynthesis and processing has been reported in tumors, with impact in cancer cell behavior and tumor microenvironment properties. However, the roles of specific glycosyltransferases in the deregulated biosynthesis of HSPGs are not fully understood. In this study, we established glycoengineered gastric cancer cell models lacking either Exostosin Like glycosyltransferase 2 (EXTL2) or EXTL3, and revealed their regulatory roles in both Heparan Sulfate (HS) and Chondroitin Sulfate (CS) biosynthesis and structural features. We showed that EXTL3 is key for initiating the synthesis of HS chains in detriment of CS biosynthesis, intervening in the fine-tuned balance of the HS/CS ratio in cells, while EXTL2 functions as a negative regulator of HS biosynthesis, with impact over the glycoproteome of gastric cancer cells. We demonstrated that knock-out of EXTL2 enhanced HS levels along with concomitant upregulation of Syndecan-4, which is a major cell-surface carrier of HS. This aberrant HS expression profile promoted a more aggressive phenotype, characterized by higher cellular motility and invasion, and impaired activation of Ephrin type-A 4 cell surface receptor tyrosine kinase. Our findings uncover the biosynthetic roles of EXTL2 and EXTL3 in the regulation of cancer cell GAGosylation and proteoglycans expression, and unravel the functional consequences of aberrant HS/CS balance in cellular malignant features.

miR-155, miR-191, and miR-494 as diagnostic biomarkers for oral squamous cell carcinoma and the effects of Avastin on these biomarkers

Objectives

Oral squamous cell carcinoma (OSCC) is one of the most common types of head and neck cancer. MicroRNAs, as new biomarkers, are recommended for diagnosis and treatment of different types of cancers. Bevacizumab, sold under the trade name Avastin, is a humanized whole monoclonal antibody that targets and blocks VEGF-A (vascular endothelial growth factor A; angiogenesis) and oncogenic signaling pathways.

Materials and Methods

This study comprised 50 cases suffering from OSCC and 50 healthy participants. Peripheral blood samples were collected in glass test tubes, and RNA extraction was started immediately. Expression levels of miR-155, miR-191, and miR-494 biomarkers in the peripheral blood of OSCC-affected individuals and healthy volunteers in vivo were evaluated using real-time PCR. The influence of Avastin on the expression levels of the aforementioned biomarkers in vitro and in the HN5 cell line was also investigated.

Results

Expression levels of miR-155, miR-191, and miR-494 in the peripheral blood of individuals affected by OSCC were higher than in those who were healthy. Moreover, Avastin at a concentration of 400 µM caused a decrease in the expression levels of the three biomarkers and a 1.5-fold, 3.5-fold, and 4-fold increase in apoptosis in the test samples compared to the controls in the HN5 cell line after 24, 48, and 72 hours, respectively.

Conclusion

The findings of this study demonstrate that overexpression of miR-155, miR-191, and miR-494 is associated with OSCC, and Avastin is able to regulate and downregulate the expression of those biomarkers and increase apoptosis in cancerous cells in the HN5 cell line

Sweet Control: MicroRNA Regulation of the Glycome

Glycosylation is a sophisticated informational system that controls specific biological functions at the cellular and organismal level. Dysregulation of glycosylation may underlie some of the most complex and common diseases of the modern era. In the past 5 years, microRNAs have come to the forefront as a critical regulator of the glycome. Herein, we review the current literature on miRNA regulation of glycosylation and how this work may point to a new way to identify the biological importance of glycosylation enzymes.

Serum miR-191 and miR-425 as Diagnostic and Prognostic Markers of Advanced Gastric Cancer Can Predict the Sensitivity of FOLFOX Chemotherapy Regimen

Purpose

miR-191 and miR-425 have been proved to be highly expressed in gastric carcinoma (GC). However, little research has been done on their clinical value in serum of patients with advanced GC. In addition, it is not clear whether they can be used as markers for the response and prognosis of GC patients treated with oxaliplatin combined with 5-fluorouracil and FOLFOX chemotherapy.

Patients and Methods

A total of 230 patients with advanced GC admitted to our hospital were selected as the study objects, all of whom received FOLFOX chemotherapy regimen. Another 100 cases of healthy subjects were included. QRT-PCR was employed to detect the serum expression of miR-191 and miR-425 in patients.

Results

Compared with the healthy subjects, the serum expressions of miR-191 and miR-425 in GC patients were significantly upregulated, which were correlated with differentiation degree and TNM staging, respectively. According to the ROC curve, the AUC of miR-191 and miR-425 for GC diagnosis was 0.937 and 0.901, respectively, while the AUC for differentiation degree diagnosis was 0.854 and 0.822, and that for TNM staging diagnosis was 0.860 and 0.829, respectively. The predictive AUC of miR-191 and miR-425 for chemosensitivity was 0.868 and 0.835, respectively, with a combined predictive AUC of 0.935. Low differentiation degree, high TNM staging, high miR-191 and high miR-425 expressions were independent risk factors for chemotherapy insensitivity. Differentiation degree, TNM staging, chemotherapy effect, miR-191 and miR-425 were independent influencing factors for the prognosis of GC patients.

Conclusion

Up-regulated expression of miR-191 and miR-425 in the serum of patients with advanced GC are effective biomarkers for the diagnosis, chemotherapy and prognosis evaluation of GC.

MicroRNA-191 targets CCAAT/enhanced binding protein β and functions as an oncogenic molecule in human non-small cell lung carcinoma cells

The aberrant expression of microRNAs (miRs) may be involved in tumor growth and progression in human non-small cell lung carcinoma (NSCLC). The present study aimed to investigate the potential roles of miR-191 in NSCLC. Western blotting and reverse transcription-quantitative polymerase chain reaction were performed to assess protein and/or mRNA levels. Scratch wound healing and transwell assays were performed to determine the NSCLC cell migration and invasion. A luciferase demonstrated that CCAAT/enhanced binding protein β (C/EBPβ) was a target of miR-191. Previously, miR-191 has been reported to act as an oncogenic player in multiple human cancers. C/EBPβ has been identified as a target gene of miR-191; however, the roles and underlying mechanisms of miR-191 associated with the regulation of tumor invasion in NSCLC remain unknown. In the present study, it was demonstrated that miR-191 expression levels were higher in human NSCLC tumors compared with in normal adjacent tissue and elevated miR-191 expression levels were closely associated with tumor node metastasis stage in patients with NSCLC. Furthermore, transfection with miR-191 mimic inhibited C/EBPβ expression at the mRNA and protein levels and promoted A549 cell migration and invasion. C/EBPβ was reported to be the direct target gene of miR-191 using a dual luciferase reporter assay. Finally, C/EBPβ siRNA can mimic the effects of miR-191. These findings indicated that miR-191 may function as an oncogene in NSCLC, at least partially due to its negative regulatory on C/EBPβ.

Upregulation of microRNA-191 can serve as an independent prognostic marker for poor survival in prostate cancer

MicroRNA-191 (miR-191) has been identified as being upregulated in several types of cancers, and plays the role of oncogene. The expression of miR-191 has been found to be upregulated in prostate cancer tissues as well as cell lines. In this study, we analyzed the correlation of miR-191 expression with clinicopathologic factors and prognosis in prostate cancer.Prostate cancer tissue samples and adjacent normal prostate tissue samples were collected from 146 patients who underwent laparoscopic radical prostatectomy between April 2013 and March 2018. Student two-tailed t-test was used for comparisons of 2 independent groups. The relationships between miR-191 expression and different clinicopathological characteristics were evaluated using the Chi-squared test. Kaplan-Meier survival plots and log-rank tests were used to assess the differences in overall survival of the different subgroups of prostate cancer patients.miR-191 expression was significantly higher in prostate cancer tissues compared with normal adjacent prostate tissues (P < .001). miR-191 expression was observed to be significantly correlated with Gleason score (P < .001), pelvic lymph node metastasis (P = .006), bone metastases (P < .001), and T stage (P = .005). Kaplan-Meier analysis showed that patients with higher levels of miR-191 had significantly poorer survival than those with lower expression of this miRNA in prostate cancer patients (log rank test, P = .011). Multivariate analysis revealed that miR-191 expression (hazard ratio [HR] = 2.311, 95% confidence interval, [CI]: 1.666-9.006; P = .027) was independently associated with the overall survival of prostate cancer patients.Our results demonstrated that miR-191 might serve as an independent prognostic indicator for prostate cancer patients.

MicroRNA-191-5p exerts a tumor suppressive role in renal cell carcinoma

Renal cell carcinoma (RCC) is a common tumor of the urinary system. Previously, miR-191-5p has been reported to be associated with various types of cancer; however, its specific functions in RCC have not been investigated to date. In the present study, the expression of miR-191-5p in the 786-O and ACHN cell lines was detected in vitro by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The results of RT-qPCR revealed that miR-191-5p was significantly downregulated in the two cell lines compared with the 293T cell line. miR-191-5p was also significantly downregulated in RCC tissue compared with paired normal tissue. In addition, the effects of miR-191-5p on cell proliferation, migration, invasion and apoptosis were examined by CCK-8, MTT, wound scratch, Transwell and flow cytometry assays. Downregulation of miR-191-5p was observed to promote cell proliferation, migration and invasion, as well as to repress the cell apoptosis of 786-O and ACHN cells. Therefore, the current study suggests that miR-191-5p functions as a tumor suppressor in RCC. Further studies are required to uncover the underlying signaling pathway of miR-191-5p and its potential role as a biomarker for early detection and prognosis prediction, and as a therapeutic target of RCC.

P53-miR-191-SOX4 regulatory loop affects apoptosis in breast cancer

miRNAs have emerged as key participants of p53 signaling pathways because they regulate or are regulated by p53. Here, we provide the first study demonstrating direct regulation of an oncogenic miRNA, miR-191-5p, by p53 and existence of a regulatory feedback loop. Using a combination of qRT-PCR, promoter-luciferase, and chromatin-immunoprecipitation assays, we show that p53 brings about down-regulation of miR-191-5p in breast cancer. miR-191-5p overexpression brought about inhibition of apoptosis in breast cancer cell lines (MCF7 and ZR-75) as demonstrated by reduction in annexin-V stained cells and caspase 3/7 activity, whereas miR-191-5p down-regulation showed the opposite. We further unveiled that SOX4 was a direct target of miR-191-5p. SOX4 overexpression was shown to increase p53 protein levels in MCF7 cells. miR-191-5p overexpression brought about down-regulation of SOX4 and thus p53 levels, suggesting the existence of a regulatory feedback loop. Breast cancer treatment by doxorubicin, an anti-cancer drug, involves induction of apoptosis by p53; we thus wanted to check whether miR-191-5p affects doxorubicin sensitivity. Interestingly, Anti-miR-191 treatment significantly decreased the IC50 of the doxorubicin drug and thus sensitized breast cancer cells to doxorubicin treatment by promoting apoptosis. Overall, this work highlights the importance of the p53-miR-191-SOX4 axis in the regulation of apoptosis and drug resistance in breast cancer and offers a preclinical proof-of-concept for use of an Anti-miR-191 and doxorubicin combination as a rational approach to pursue for better breast cancer treatment.

Epigenetic Regulation of the Biosynthesis & Enzymatic Modification of Heparan Sulfate Proteoglycans: Implications for Tumorigenesis and Cancer Biomarkers

Emerging evidence suggests that the enzymes in the biosynthetic pathway for the synthesis of heparan sulfate moieties of heparan sulfate proteoglycans (HSPGs) are epigenetically regulated at many levels. As the exact composition of the heparan sulfate portion of the resulting HSPG molecules is critical to the broad spectrum of biological processes involved in oncogenesis, the epigenetic regulation of heparan sulfate biosynthesis has far-reaching effects on many cellular activities related to cancer progression. Given the current focus on developing new anti-cancer therapeutics focused on epigenetic targets, it is important to understand the effects that these emerging therapeutics may have on the synthesis of HSPGs as alterations in HSPG composition may have profound and unanticipated effects. As an introduction, this review will briefly summarize the variety of important roles which HSPGs play in a wide-spectrum of cancer-related cellular and physiological functions and then describe the biosynthesis of the heparan sulfate chains of HSPGs, including how alterations observed in cancer cells serve as potential biomarkers. This review will then focus on detailing the multiple levels of epigenetic regulation of the enzymes in the heparan sulfate synthesis pathway with a particular focus on regulation by miRNA and effects of epigenetic therapies on HSPGs. We will also explore the use of lectins to detect differences in heparan sulfate composition and preview their potential diagnostic and prognostic use in the clinic.

[Expression of microRNA-191 in T lymphoblastic leukemia/lymphoma and its underlying mechanism]

OBJECTIVE

To evaluate the correlation between MicroRNA-191 (miR-191) and T lymphoblastic leukemia/lymphoma (T-ALL/LBL) to probe its underlying molecular mechanism.

METHODS

The expression of miR-191 was examined by real-time PCR (RT-PCR) in 20 T-ALL/LBL tissue samples and 20 lymphoid reactive hyperplasia (LRH) tissue samples. The correlation between miR-191 and the clinicopathological feature of T-ALL/LBL was analyzed. Antisense miR-191 lentiviral vectors was constructed and transfected into T-ALL/LBL Jukat cells. After transfection, the expression of miR-191 was examined by RT-PCR. The cell activity was evaluated by CCK-8 asssy. The cell cycle and apoptosis were determined by flow cytometry.

RESULTS

Compared with LRH samples, the results of RT-PCR showed significant upregulation of miR-191 in 20 T-ALL/LBL tissue samples (1.875±0.079 vs 1.000, P<0.05). The expression level of miR-191 was negatively associated with prognosis. Compared with LV-NC-GFP and control groups, the expression of miR-191 significantly decreased after transfection of antisense miR-191 lentiviral vectors (0.578±0.012 vs 1.011±0.053 and 1.000, P<0.05), the percentages of apoptotic cells and the cell in G0/G1 phase significantly increased (P<0.05).

CONCLUSIONS

miR-191 might play a significant role in the development of T-ALL/LBL, implicating a new target for therapy.

Deciphering the microRNA transcriptome of skeletal muscle during porcine development

MicroRNAs (miRNAs) play critical roles in many important biological processes, such as growth and development in mammals. Various studies of porcine muscle development have mainly focused on identifying miRNAs that are important for fetal and adult muscle development; however, little is known about the role of miRNAs in middle-aged muscle development. Here, we present a comprehensive investigation of miRNA transcriptomes across five porcine muscle development stages, including one prenatal and four postnatal stages. We identified 404 known porcine miRNAs, 118 novel miRNAs, and 101 miRNAs that are conserved in other mammals. A set of universally abundant miRNAs was found across the distinct muscle development stages. This set of miRNAs may play important housekeeping roles that are involved in myogenesis. A short time-series expression miner analysis indicated significant variations in miRNA expression across distinct muscle development stages. We also found enhanced differentiation- and morphogenesis-related miRNA levels in the embryonic stage; conversely, apoptosis-related miRNA levels increased relatively later in muscle development. These results provide integral insight into miRNA function throughout pig muscle development stages. Our findings will promote further development of the pig as a model organism for human age-related muscle disease research.

Combinations of gene ontology and pathway characterize and predict prognosis genes for recurrence of gastric cancer after surgery

Gastric cancer (GC) is the second leading cause of death from cancer globally. The most common cause of GC is the infection of Helicobacter pylori, but ∼11% of cases are caused by genetic factors. However, recurrences occur in approximately one-third of stage II GC patients, even if they are treated with adjuvant chemotherapy or chemoradiotherapy. This is potentially due to expression variation of genes; some candidate prognostic genes were identified in patients with high-risk recurrences. The objective of this study was to develop an effective computational method for meaningfully interpreting these GC-related genes and accurately predicting novel prognostic genes for high-risk recurrence patients. We employed properties of genes (gene ontology [GO] and KEGG pathway information) as features to characterize GC-related genes. We obtained an optimal set of features for interpreting these genes. By applying the minimum redundancy maximum relevance algorithm, we predicted the GC-related genes. With the same approach, we further predicted the genes for the prognostic of high-risk recurrence. We obtained 1104 GO terms and KEGG pathways and 530 GO terms and KEGG pathways, respectively, that characterized GC-related genes and recurrence-related genes well. Finally, three novel prognostic genes were predicted to help supplement genetic markers of high-risk GC patients for recurrence after surgery. An in-depth text mining indicated that the results are quite consistent with previous knowledge. Survival analysis of patients confirmed the novel prognostic genes as markers. By analyzing the related genes, we developed a systematic method to interpret the possible underlying mechanism of GC. The novel prognostic genes facilitate the understanding and therapy of GC recurrences after surgery.

MiR-191 Regulates Primary Human Fibroblast Proliferation and Directly Targets Multiple Oncogenes

miRNAs play a central role in numerous pathologies including multiple cancer types. miR-191 has predominantly been studied as an oncogene, but the role of miR-191 in the proliferation of primary cells is not well characterized, and the miR-191 targetome has not been experimentally profiled. Here we utilized RNA induced silencing complex immunoprecipitations as well as gene expression profiling to construct a genome wide miR-191 target profile. We show that miR-191 represses proliferation in primary human fibroblasts, identify multiple proto-oncogenes as novel miR-191 targets, including CDK9, NOTCH2, and RPS6KA3, and present evidence that miR-191 extensively mediates target expression through coding sequence (CDS) pairing. Our results provide a comprehensive genome wide miR-191 target profile, and demonstrate miR-191’s regulation of primary human fibroblast proliferation.

Methylation-regulated miR-149 modulates chemoresistance by targeting GlcNAc N-deacetylase/N-sulfotransferase-1 in human breast cancer

Dysregulation of microRNA is strongly implicated in the chemoresistance of cancer. In this study, we found that miR-149 was downregulated and involved in chemoresistance in adriamycin (ADM)-resistant human breast cancer cells (MCF-7/ADM). Downregulation of miR-149 was related to hypermethylation of its 5'-UTR; this methylation also affected the expression of the glypican 1 gene, which is both the host and the target gene of miR-149. Furthermore, we found that miR-149 modulated chemoresistance through targeting the expression of GlcNAc N-deacetylase/N-sulfotransferase-1 (NDST1). With downregulated miR-149, NDST1 expression was increased in chemoresistant MCF-7/ADM cells versus control MCF-7 wild-type cells. The increased NDST1 then activated a heparan sulfate-related pathway involving activation of heparanase. Finally, expression of miR-149 and NDST1 was confirmed in clinical chemoresistant samples of breast cancers receiving anthracycline/taxane-based chemotherapies. The high expression of NDST1 was also an unfavorable predictor for distant relapse-free survival in Her2 and basal breast cancers. Taken together, our findings demonstrate that miR-149 is regulated by methylation, and is a modulator of cancer chemoresistance by targeting NDST1.

The clinical significance and regulation mechanism of hypoxia-inducible factor-1 and miR-191 expression in pancreatic cancer

The aim of study was to discuss the correlation and regulatory mechanism of HIF-1 and miR-191 expression in pancreatic tumor. The association between the miR-191 and the clinicopathologic characteristics and the prognosis of pancreatic cancer was further explored. After hypoxic cultured for 6 and 12 h, qRT-PCR and Western blot were practiced to analyze the miR-191 and HIF-1 expression of MIA PaCa-2 and Aspac1 cells. We regulated the HIF-1 expression via plasmid and siRNA transfection to observe the alteration of HIF-1 and miR-191 expression. ChIP sequencing identified the binding sites of HIF-1 and miR-191. Dual luciferase assays were practiced to verify the binding sites. Immunohistochemical staining was practiced to analyze the expression of HIF-1, while qRT-PCR were done for investigating miR-191 in tumor tissues. Then, the association between the expression of them and the clinicopathologic characteristics and prognosis of pancreatic cancer were analyzed. After hypoxic cultured 12 h, the expression of HIF-1 protein, HIF-1mRNA and miR-191 of MIA PaCa-2 and AsPC-1 cells increased significantly (P < 0.05). After HIF-1 overexpressing plasmid transfected to the MIA PaCa-2 and AsPC-1 cells for 48 h, the expression of HIF-1 protein, HIF-1mRNA, and miR-191 upregulated significantly (P < 0.05). While after transfected the MIA PaCa-2 cells by HIF-1 siRNA, the significant decreasing of HIF-1 protein, HIF-1mRNA, and miR-191 expression were observed (P < 0.05). ChIP sequencing showed the protein synthesis of HIF-1 increased in hypoxia situation. Only the HRE5 (-1,169 bp, ChIP4) were significantly brighter in hypoxia in comparing with normoxic cells. In dual luciferase assays, after pGL3-miR-191 and HIF-1 overexpressing plasmid co-transfect the MIAPaCa-2 cells for 48 h, its relative expression of bioluminescence was higher than those co-transfected by mutant miR-191 vectors and HIF-1 overexpressing plasmid or by pGL3-miR-191 and HIF-1 empty plasmid. The expression of miR-191 closely associated with the tumor size, pTNM stage, lymph node metastasis, and perineural invasion (P < 0.05). Patients with higher expression of miR-191 were a risk factor for prognosis of pancreatic cancers. Expression of HIF-1 in pancreatic cancer cells increased under the condition of chronic hypoxia, which may bind to HRE2 in 5'flanking region of miR-191 and initiate transcription of miR-191. Expression of miR-191 was significantly higher in pancreatic tumor tissues. The expression of miR-191 closely associated with the tumor size, pTNM stage, lymph node metastasis and perineural invasion and poor prognosis of pancreatic cancer.

MicroRNA and signaling pathways in gastric cancer

MicroRNAs (miRNAs) function as either oncogenes or tumor suppressors by inhibiting the expression of target genes, some of which are either directly or indirectly involved with canonical signaling pathways. The relationship between miRNAs and signaling pathways in gastric cancer is extremely complicated. In this paper, we determined the pathogenic mechanism of gastric cancer related to miRNA expression based on recent high-quality studies and then clarified the regulation network of miRNA expression and the correlated functions of these miRNAs during the progression of gastric cancer. We try to illustrate the correlation between the expression of miRNAs and outcomes of patients with gastric cancer. Understanding this will allow us to take a big step forward in the treatment of gastric cancer.

miR-191: an emerging player in disease biology

Specific microRNAs have emerged as key players in disease biology by playing crucial role in disease development and progression. This review draws attention to one such microRNA, miR-191 that has been recently reported to be abnormally expressed in several cancers (>20) and various other diseases like diabetes-type 2, Crohn' s, pulmonary hypertension, and Alzheimer' s. It regulates important cellular processes such as cell proliferation, differentiation, apoptosis, and migration by targeting important transcription factors, chromatin remodelers, and cell cycle associated genes. Several studies have demonstrated it to be an excellent biomarker for cancer diagnosis and prognosis leading to two patents already in its kitty. In this first review we summarize the current knowledge of the regulation, functions and targets of miR-191 and discuss its potential as a promising disease biomarker and therapeutic target.

MicroRNA-24 suppression of N-deacetylase/N-sulfotransferase-1 (NDST1) reduces endothelial cell responsiveness to vascular endothelial growth factor A (VEGFA)

Heparan sulfate (HS) proteoglycans, present at the plasma membrane of vascular endothelial cells, bind to the angiogenic growth factor VEGFA to modulate its signaling through VEGFR2. The interactions between VEGFA and proteoglycan co-receptors require sulfated domains in the HS chains. To date, it is essentially unknown how the formation of sulfated protein-binding domains in HS can be regulated by microRNAs. In the present study, we show that microRNA-24 (miR-24) targets NDST1 to reduce HS sulfation and thereby the binding affinity of HS for VEGFA. Elevated levels of miR-24 also resulted in reduced levels of VEGFR2 and blunted VEGFA signaling. Similarly, suppression of NDST1 using siRNA led to a reduction in VEGFR2 expression. Consequently, not only VEGFA binding, but also VEGFR2 protein expression is dependent on NDST1 function. Furthermore, overexpression of miR-24, or siRNA-mediated reduction of NDST1, reduced endothelial cell chemotaxis in response to VEGFA. These findings establish NDST1 as a target of miR-24 and demonstrate how such NDST1 suppression in endothelial cells results in reduced responsiveness to VEGFA.

MicroRNA-191, an estrogen-responsive microRNA, functions as an oncogenic regulator in human breast cancer

Estrogen- and microRNA-mediated gene regulation play a crucial role in breast cancer biology. However, a functional link between the two major players remains unclear. This study reveals miR-191 as an estrogen-inducible onco-miR in breast cancer, which promotes several hallmarks of cancer including enhanced cell proliferation, migration, chemoresistance and survival in tumor microenvironment. miR-191 is a direct estrogen receptor (ER) target and our results suggest existence of a positive regulatory feedback loop. We show miR-191 as critical mediator of estrogen-mediated cell proliferation. Investigations of mechanistic details of miR-191 functions identify several cancer-related genes like BDNF, CDK6 and SATB1 as miR-191 targets. miR-191 and SATB1 show inverse correlation of expression. miR-191-mediated enhanced cell proliferation and migration are partly dependent on targeted downregulation of SATB1. Further, functional validation of estrogen:miR-191:SATB1 link suggests a cascade initiated by estrogen that induces miR-191 in ER-dependent manner to target SATB1, a global chromatin remodeler, thereby contributing to estrogen-specific gene signature to regulate genes like ANXA1, PIWIL2, CASP4, ESR1/ESR2, PLAC1 and SOCS2 involved in breast cancer progression and migration. Overall, the identification of estrogen/ER/miR-191/SATB1 cascade seems to be a significant pathway in estrogen signaling in breast cancer with miR-191 as oncogenic player.

Estrogen mediated-activation of miR-191/425 cluster modulates tumorigenicity of breast cancer cells depending on estrogen receptor status

MicroRNAs (miRNAs), single-stranded non-coding RNAs, influence myriad biological processes that can contribute to cancer. Although tumor-suppressive and oncogenic functions have been characterized for some miRNAs, the majority of microRNAs have not been investigated for their ability to promote and modulate tumorigenesis. Here, we established that the miR-191/425 cluster is transcriptionally dependent on the host gene, DALRD3, and that the hormone 17β-estradiol (estrogen or E2) controls expression of both miR-191/425 and DALRD3. MiR-191/425 locus characterization revealed that the recruitment of estrogen receptor α (ERα) to the regulatory region of the miR-191/425-DALRD3 unit resulted in the accumulation of miR-191 and miR-425 and subsequent decrease in DALRD3 expression levels. We demonstrated that miR-191 protects ERα positive breast cancer cells from hormone starvation-induced apoptosis through the suppression of tumor-suppressor EGR1. Furthermore, enforced expression of the miR-191/425 cluster in aggressive breast cancer cells altered global gene expression profiles and enabled us to identify important tumor promoting genes, including SATB1, CCND2, and FSCN1, as targets of miR-191 and miR-425. Finally, in vitro and in vivo experiments demonstrated that miR-191 and miR-425 reduced proliferation, impaired tumorigenesis and metastasis, and increased expression of epithelial markers in aggressive breast cancer cells. Our data provide compelling evidence for the transcriptional regulation of the miR-191/425 cluster and for its context-specific biological determinants in breast cancers. Importantly, we demonstrated that the miR-191/425 cluster, by reducing the expression of an extensive network of genes, has a fundamental impact on cancer initiation and progression of breast cancer cells.

MicroRNAs are small noncoding RNAs that act as posttranscriptional repressors of gene expression. A pivotal role for miRNAs in all the molecular processes driving initiation and progression of various malignancies, including breast cancer, has been described. Divergent miRNA expression between normal and neoplastic breast tissues has been demonstrated, as well as differential miRNA expression among the molecular subtypes of breast cancer. Over half of all breast cancers overexpress ERα, and several studies have shown that miRNA expression is controlled by ERα. We assessed the global change in microRNA expression after estrogen starvation and stimulation in breast cancer cells and identified that miR-191/425 and the host gene DALRD3 are positively associated to ERα-positive tumors. We demonstrated that ERα regulates the miR-191/425 cluster and verified the existence of a transcriptional network that allows a dual effect of estrogen on miR-191/425 and their host gene. We show that estrogen induction of miR-191/425 supports in vitro and in vivo the estrogen-dependent proliferation of ERα positive breast cancer cells. On the contrary, miR-191/425 cluster reprograms gene expression to impair tumorigenicity and metastatic potential of highly aggressive ERα negative breast cancer cells.

The role of microRNAs in cancers of the upper gastrointestinal tract

Cancers of the oesophagus, gastro-oesophageal junction and stomach (upper gastrointestinal tract cancers; UGICs) pose a major health risk around the world. Collectively, the 5-year survival rate has remained <15%, and therapeutic improvements have been very slow and small. Novel molecules for early diagnosis, prognosis and therapy are, therefore, urgently needed. The role that microRNA (miRNA) molecules have in UGICs are worth pursuing to this end. miRNAs are small noncoding RNA molecules that regulate ∼60% of coding genes in humans and, therefore, are pivotal in mediating and regulating many physiologic processes. miRNAs are deregulated in many disease states, particularly in cancer, making them important targets. Here, we review the growing body of evidence regarding the alterations of miRNAs in UGICs. By suppressing translation and/or promoting degradation of mRNAs, miRNAs can contribute to carcinogenesis and progression of UGICs. In-depth studies of miRNAs in UGICs might yield novel insights and potential novel therapeutic strategies.

Loss of SNAIL regulated miR-128-2 on chromosome 3p22.3 targets multiple stem cell factors to promote transformation of mammary epithelial cells

A discontinuous pattern of LOH at chromosome 3p has been reported in 87% of primary breast cancers. Despite the identification of several tumor suppressor genes in this region, there has yet to be a detailed analysis of noncoding RNAs including miRNAs in this region. In this study, we identified 16 aberrant miRNAs in this region and determined several that are frequently lost or amplified in breast cancer. miR-128-2 was the most commonly deleted miRNA. Embedded in the intron of the ARPP21 gene at chromosome 3p22.3, miR-128-2 was frequently downregulated along with ARPP21 in breast cancer, where it was negatively associated with clinicopathologic characteristics and survival outcome. Forced expression of miR-128 impeded several oncogenic traits of mammary carcinoma cells, whereas depleting miR-128-2 expression was sufficient for oncogenic transformation and stem cell-like behaviors in immortalized nontumorigenic mammary epithelial cells, both in vitro and in vivo. miR-128-2 silencing enabled transforming capacity partly by derepressing a cohort of direct targets (BMI1, CSF1, KLF4, LIN28A, NANOG, and SNAIL), which together acted to stimulate the PI3K/AKT and STAT3 signaling pathways. We also found that miR-128-2 was directly downregulated by SNAIL and repressed by TGF-β signaling, adding 2 additional negative feedback loops to this network. In summary, we have identified a novel TGF-β/SNAIL/miR-128 axis that provides a new avenue to understand the basis for oncogenic transformation of mammary epithelial cells.

Expression of miR-191 and its potential target genes in gastric carcinoma

AIM: To investigate the expression of miR-191 and its predicted target genes in gastric carcinoma.

METHODS: The relative expression of miR-191 in gastric carcinoma and tumor-adjacent tissue was quantified by qRT-PCR. The potential target genes of miR-191 were predicted using bioinformatic software. Expression of target genes in gastric carcinoma and tumor-adjacent tissue was detected by immunohistochemistry. The association between miR-191 expression and target gene expression was analyzed.

RESULTS: The expression of miR-191 was significantly higher in gastric carcinoma than in tumor-adjacent tissue [0.0314 (0.0037-0.4924) vs 0.0240 (0.0037-0.1593), P < 0.05]. MiR-191 expression was not related with age, gender, histological type, lymph node metastasis or clinical stage. Nine target genes were predicted, including SOX4 and NDST1, both of which had been confirmed as direct targets of miR-191. The expression of phospholipase C-delta 1 (PLCD1) was significantly up-regulated in gastric carcinoma compared to tumor-adjacent tissue (56.7% vs 96.7%, P < 0.01). MiR-191 expression was significantly inversely correlated with PLCD1 expression in gastric carcinoma (90% vs 30%, r = -0.639, P < 0.01).

CONCLUSION: The expression of miR-191 is up-regulated in gastric carcinoma. MiR-191 may play a pivotal role in the pathogenesis of gastric carcinoma by regulating PLCD1 expression.

Identification of serum microRNAs as novel non-invasive biomarkers for early detection of gastric cancer

BACKGROUND

To investigate the potential of serum miRNAs as biomarkers for early detection of gastric cancer (GC), a population-based study was conducted in Linqu, a high-risk area of GC in China.

METHODOLOGY/PRINCIPAL FINDINGS

All subjects were selected from two large cohort studies. Differential miRNAs were identified in serum pools of GC and control using TaqMan low density array, and validated in individual from 82 pairs of GC and control, and 46 pairs of dysplasia and control by real-time quantitative reverse transcription-polymerase chain reaction. The temporal trends of identified serum miRNA expression were further explored in a retrospective study on 58 GC patients who had at least one pre-GC diagnosis serum sample based on the long-term follow-up population. The miRNA profiling results demonstrated that 16 miRNAs were markedly upregulated in GC patients compared to controls. Further validation identified a panel of three serum miRNAs (miR-221, miR-744, and miR-376c) as potential biomarkers for GC detection, and receiver operating characteristic (ROC) curve-based risk assessment analysis revealed that this panel could distinguish GCs from controls with 82.4% sensitivity and 58.8% specificity. MiR-221 and miR-376c demonstrated significantly positive correlation with poor differentiation of GC, and miR-221 displayed higher level in dysplasia than in control. Furthermore, the retrospective study revealed an increasing trend of these three miRNA levels during GC development (P for trend<0.05), and this panel could classify serum samples collected up to 5 years ahead of clinical GC diagnosis with 79.3% overall accuracy.

CONCLUSIONS/SIGNIFICANCE

These data suggest that serum miR-221, miR-376c and miR-744 have strong potential as novel non-invasive biomarkers for early detection of GC.

The role of microRNAs in Helicobacter pylori pathogenesis and gastric carcinogenesis

Gastric carcinogenesis is a multistep process orchestrated by aberrancies in the genetic and epigenetic regulation of oncogenes and tumor suppressor genes. Chronic infection with Helicobacter pylori is the strongest known risk factor for the development of gastric cancer. H. pylori expresses a spectrum of virulence factors that dysregulate host intracellular signaling pathways that lower the threshold for neoplastic transformation. In addition to bacterial determinants, numerous host and environmental factors increase the risk of gastric carcinogenesis. Recent discoveries have shed new light on the involvement of microRNAs (miRNAs) in gastric carcinogenesis. miRNAs represent an abundant class of small, non-coding RNAs involved in global post-transcriptional regulation and, consequently, play an integral role at multiple steps in carcinogenesis, including cell cycle progression, proliferation, apoptosis, invasion, and metastasis. Expression levels of miRNAs are frequently altered in malignancies, where they function as either oncogenic miRNAs or tumor suppressor miRNAs. This review focuses on miRNAs dysregulated by H. pylori and potential etiologic roles they play in H. pylori-mediated gastric carcinogenesis.