Decreased miR-204 in H. pylori-associated gastric cancer promotes cancer cell proliferation and invasion by targeting SOX4. PLoS One. 2014;9:e101457. [PMID: 24984017 PMCID: PMC4077842 DOI: 10.1371/journal.pone.0101457]

Inhibitory role of LINC00332 in gastric cancer progression through regulating cell EMT and stemness

OBJECTIVE

Gastric cancer (GC) is one of the most common lethal malignancies worldwide. The molecular mechanisms underlying GC early detection are poorly understood. Identifying potential coding and non-coding markers and related pathways in the GC progression is essential. Some Long non-coding RNAs (lncRNAs) reportedly play vital roles during gastric GC development. However, the clinical significance and biological function of LINC00332 in GC remain largely unclear.

METHODS

The gene expression patterns of GC from an RNAseq dataset (GSE122401) were retrieved from the Gene Expression Omnibus (GEO) database to recognize differentially expressed genes (DEGs) and lncRNAs (DELs) between normal and GC samples through several bioinformatic analysis. The expression of LINC00332 and MMP-13 as a target gene was quantified in fresh frozen tissues obtained from GC patients. In addition, we investigated the potential function of LINC00332 in silico and in vitro.

RESULTS

The expressions of LINC00332 and MMP-13 were significantly downregulated and upregulated in GC tissues, respectively. A significant inverse correlation between LINC00332 and MMP-13 mRNA expression was observed in tumor samples. The mRNA expression level of mesenchymal markers, stem cell factors, and MMP genes were significantly decreased after the LINC00332 ectopic expression, while epithelial markers expression was significantly increased. The LINC00332 overexpression markedly repressed proliferation, migration, and invasion and did not induce apoptosis in AGS cells. In addition, LINC00332 overexpression notably promoted the E-cadherin protein expression. Moreover, LINC00332 significantly decreased the cisplatin resistance.

CONCLUSION

Our findings indicated that LINC00332 may be a critical anti-EMT factor and provided a new efficient therapeutic strategy for GC treatment.

Function of Non-coding RNA in Helicobacter pylori-Infected Gastric Cancer

Gastric cancer is a common malignant tumor of the digestive system. Its occurrence and development are the result of a combination of genetic, environmental, and microbial factors. Helicobacter pylori infection is a chronic infection that is closely related to the occurrence of gastric tumorigenesis. Non-coding RNA has been demonstrated to play a very important role in the organism, exerting a prominent role in the carcinogenesis, proliferation, apoptosis, invasion, metastasis, and chemoresistance of tumor progression. H. pylori infection affects the expression of non-coding RNA at multiple levels such as genetic polymorphisms and signaling pathways, thereby promoting or inhibiting tumor progression or chemoresistance. This paper mainly introduces the relationship between H. pylori-infected gastric cancer and non-coding RNA, providing a new perspective for gastric cancer treatment.

High Expression of miR-204 in Chicken Atrophic Ovaries Promotes Granulosa Cell Apoptosis and Inhibits Autophagy

Chicken atrophic ovaries have decreased volume and are indicative of ovarian failure, presence of a tumor, or interrupted ovarian blood supply. Ovarian tumor is accompanied by an increase in follicular atresia, granulosa cell (GC) apoptosis, and autophagy. In a previous study, we found using high throughput sequencing that miR-204 is highly expressed in chicken atrophic ovaries. Thus, in the present study, we further investigated its function in GC apoptosis and autophagy. We found that overexpression of miR-204 reduced mRNA and protein levels of proliferation-related genes and increased apoptosis-related genes. Cell counting kit-8 (CCK-8), 5-ethynyl-2-deoxyuridine (EdU), and flow cytometry assays revealed that miR-204 inhibited GC proliferation and promoted apoptosis. Furthermore, we confirmed with reporter gene assays that Forkhead box K2 (FOXK2) was directly targeted by miR-204. FOXK2, as a downstream regulator of phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signal pathways, promoted GC proliferation and inhibited apoptosis. Subsequently, we observed that miR-204 was involved in GC autophagy by targeting Transient Receptor Potential Melastatin 3 (TRPM3). The luciferase activities of the two binding sites of TRPM3 were decreased in response to treatment with a miR-204 mimic, and the autophagic flux was increased after miR-204 inhibition. However, overexpression of miR-204 had opposite results in autophagosomes and autolysosomes. miR-204 inhibits GC autophagy by suppressing the protein expression of TRPM3/AMP-activated protein kinase (AMPK)/ULK signaling pathway components. Inhibition of miR-204 enhanced autophagy by accumulating and degrading the protein levels of LC3-II (Microtubule Associated Protein Light Chain 3B) and p62 (Protein of 62 kDa), respectively, whereas miR-204 overexpression was associated with contrary results. Immunofluorescence staining showed that there was a significant reduction in the fluorescent intensity of LC3B, whereas p62 protein was increased after TRPM3 silencing. Collectively, our results indicate that miR-204 is highly expressed in chicken atrophic ovaries, which promotes GC apoptosis via repressing FOXK2 through the PI3K/AKT/mTOR pathway and inhibits autophagy by impeding the TRPM3/AMPK/ULK pathway.

BCYRN1 is correlated with progression and prognosis in gastric cancer

Long non-coding RNA brain cytoplasmic RNA 1 (BCYRN1) has been found to play an important role in tumorigenesis of a variety of tumors including gastric cancer (GC). However, the prognostic significance and molecular mechanism of BCYRN1 was still unknown in GC. In the present study, we found BCYRN1 expression was dramatically elevated in GC tissues and cell lines, and positively associated with tumor depth, lymph node metastasis and clinical stage in patients with GC. Moreover, univariate and multivariate Cox regression analyses demonstrated that high BCYRN1 expression was independent prognostic factor for overall survival in GC patients. In lncRNA-microRNA interactome database, we found that there were putative binding sites between BCYRN1 and miR-204-5p. Furthermore, we confirmed that down-regulation of BCYRN1 inhibited GC cell proliferation, migration and invasion through directly up-regulated miR-204-5p expression. In conclusion, BCYRN1 acts as a promising prognostic predictor in GC patients and regulated GC cell proliferation, cell cycle, migration and invasion through targeting miR-204-5p.

Comprehensive analysis of Helicobacter pylori infection-associated diseases based on miRNA-mRNA interaction network

Helicobacter pylori (H. pylori) infection remains a cause of significant morbidity and mortality worldwide. Comprehensive understanding of the pathogenic mechanism of H. pylori and its interaction with host will contribute to developing novel prophylactical and therapeutical strategies. Here, we first determined microRNA (miRNA) levels in H. pylori-infected patients with gastritis, duodenal ulcer, gastric cancer or mucosa-associated lymphoid tissue lymphoma using miRNA data sets. Thirty-four differentially expressed miRNAs were identified and functional enrichment analysis of those miRNA target genes revealed that H. pylori infection were strongly associated with pathway in cancer and regulation of mRNA synthesis. Using disease connectivity analysis of 28 hub genes, we found that H. pylori may increase the risk of many extragastric diseases (e.g. cardiovascular disease, hemic and lymphatic diseases and nervous system disease). Altogether, our integrated analysis provided a new method to predict pathogen–human disease connectivity based on miRNA-mRNA interaction network and indicated anti-H. pylori therapy as an effective means of human diseases prevention.

Salivary MicroRNA for Diagnosis of Cancer and Systemic Diseases: A Systematic Review

: Background: The aberrant expression of microRNAs (miRNAs) has been associated with several diseases, including cancer, inflammatory, and autoimmune conditions. Interest in salivary miRNAs as non-invasive tools for the diagnosis of malignancies and systemic diseases is rapidly increasing. The present systematic review was developed for answering the question: "Are salivary microRNAs reliable biomarkers for diagnosis of cancer and systemic diseases?"

METHODS

The application of inclusion and exclusion criteria led to the selection of 11 papers. Critical appraisals and quality assessments of the selected studies were performed through the National Institute of Health "Study Quality Assessment Tool" and the classification of the Oxford Center for Evidence-Based Medicine.

RESULTS

Seven studies reported statistically significant correlations between one or more salivary miRNAs and the investigated disease. The critical analysis allowed us to classify only two studies (18.2%) as having "good" quality, the rest being scored as "intermediate" (8; 73%) and "poor" (1; 9%). Evidence exists that salivary miR-940 and miR-3679-5p are reliable markers for pancreatic cancer and that miR140-5p and miR301a are promising molecules for the salivary diagnosis of gastric cancer.

CONCLUSIONS

Further studies, possibly avoiding the risk of bias highlighted here, are necessary to consolidate these findings and to identify new reliable salivary biomarkers.

MicroRNA-204 as an Indicator of Severity of Pulmonary Hypertension in Children with Congenital Heart Disease Complicated with Pulmonary Hypertension

BACKGROUND The objective of this study was to investigate the changes and significance of microRNA-204 (miR-204) in children with congenital heart disease (CHD) complicated with pulmonary hypertension (PH). MATERIAL AND METHODS Fifty-two CHD patients with left-to-right shunt were divided into 3 groups according to preoperative pulmonary artery systolic pressure (PASP) detected by color Doppler echocardiography: a control group (PASP <30 mmHg), a mild PH group (PASP 30-49 mmHg), and a severe PH group (PASP >50 mmHg). Peripheral venous blood and supernatant were collected on an empty stomach at 1 h before surgery and 7 days after surgery. The expression of miR-204 in plasma was detected by RT-qPCR. RESULTS One hour before surgery and 7 days after surgery, plasma miR-204 expression was at a higher level than that in the mild PH group and higher than in the severe PH group. miR-204 expression in children in each group showed a decreasing trend after surgery. The mild PH and severe PH groups had lower plasma miR-204 expression and PASP after surgery than before surgery. In the mild PH and severe PH groups, plasma miR-204 expression was negatively correlated with PASP. In all 52 cases, plasma miR-204 expression was negatively correlated with PASP. CONCLUSIONS The plasma miR-204 expression in CHD children with PH was negatively correlated with the degree of PH, suggesting miR-204 may be involved in PH development, and miR-204 expression may be an indicator of PH severity.

The Prognostic and Predictive Value of microRNAs in Patients with H. pylori-positive Gastric Cancer

Gastric cancer (GC) has a high mortality rate with a poor 5-year survival. Helicobacter pylori (H. pylori) is present as part of the normal flora of stomach. It is found in the gastric mucosa of more than half of the world population. This bacterium is involved in developing H. pylori-induced GC due to the regulation of different micro ribonucleic acid (miRNA or miR). miRNAs are small noncoding RNAs and are recognized as prognostic biomarkers for GC that may control gene expression. miRNAs may function as tumor suppressors, or oncogenes. In this review, we evaluated studies that investigated the ectopic expression of miRNAs in the prognosis of H. pylori positive and negative GC.

Protease activated receptor 2 mediates tryptase-induced cell migration through MYO10 in colorectal cancer

MYO10 is an actin-based motor protein and correlates with cancer metastasis. However, the regulation of MYO10 by tumor microenvironment is unknown. In the current study, we found that the expression of protease activated receptor 2 (PAR2) was highly correlated with that of MYO10 in colorectal carcinoma (CRC) specimens. Both MYO10 and PAR2 were up-regulated in lymph node metastasis group compared with non-metastasis group. Activation of PAR2 significantly induced cell migration through the up-regulation of MYO10, which was mediated by repression of miR-204 in multiple cell lines. Interestingly, it was observed that tryptase was highly expressed in adjacent tissue around primary tumor of CRC. Furthermore, tryptase stimulated cell migration and up-regulated MYO10 expression through a PAR2-dependent manner. Taken together, our findings showed that PAR2 enhanced the expression of MYO10 through the repression of miR-204. PAR2 mediated tryptase-induced cell migration and might contribute to the invasion of cancer cells at the edge of tumor.

Sinomenine exerts antitumour effect in gastric cancer cells via enhancement of miR-204 expression

Gastric carcinoma (GC) is a pernicious neoplasm with high morbidity and mortality. Sinomenine (SIN) has long been exploited to heal rheumatoid arthritis. Recently, SIN has been discovered to exert the antitumour functions in diverse cancers. However, the impacts of SIN on GC remain indistinct. We attempted to expose the antitumour effect of SIN on GC. MKN45 and SGC-7901 cells were administered with SIN for 24 hours, cell viability, proliferation, apoptosis, migration, invasion and the associated proteins in the above processes were examined via exploiting CCK-8, BrdU, flow cytometry, Transwell and Western blot. MiR-204 expression in GC tumour tissues, different GC cell lines and SIN-stimulated GC cells was investigated by executing RT-qPCR. The above cell biological processes were reassessed after transfection with miR-204 inhibitor. The latent mechanisms were probed by examining AMPK and Wnt/β-catenin pathways. We found that SIN memorably repressed cell proliferation, evoked apoptosis and affected CyclinD1, Bcl-2, Bax and cleaved-caspase-3 expression in MKN45 and SGC-7901 cells. Cell migration, invasion and expression of MMP-9 and Vimentin were all restrained by SIN stimulation. The increase of miR-204 was discovered in GC tissues and SIN-treated MKN45 and SGC-7901 cells. But suppression of miR-204 was observed in AGS, MKN28, MKN45 and SGC-7901 cells. Suppression of miR-204 overturned the inhibitory functions of SIN in MKN45 and SGC-7901 cells. Besides, SIN prohibited AMPK and Wnt/β-catenin pathways via enhancement of miR-204. In conclusion, these findings suggested that SIN exerted the antitumour activity in GC cells by hindering AMPK and Wnt/β-catenin pathways via enhancement of miR-204.

SOX4: Epigenetic regulation and role in tumorigenesis

Sex-determining region Y-related (SRY) high-mobility group box 4 (SOX4) is a member of the group C subfamily of SOX transcription factors and promotes tumorigenesis by endowing cancer cells with survival, migratory, and invasive capacities. Emerging evidence has highlighted an unequivocal role for this transcription factor in mediating various signaling pathways involved in tumorigenesis, epithelial-to-mesenchymal transition (EMT), and tumor progression. During the last decade, numerous studies have highlighted the epigenetic interplay between SOX4-targeting microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and SOX4 and the subsequent modulation of tumorigenesis, invasion and metastasis. In this review, we summarize the current state of knowledge about the role of SOX4 in cancer development and progression, the epigenetic regulation of SOX4, and the potential utilization of SOX4 as a diagnostic and prognostic biomarker and its depletion as a therapeutic target.

ceRNA network construction and comparison of gastric cancer with or without Helicobacter pylori infection

Gastric cancer (GC) is a lethal disease, and among its variety of etiological factors, Helicobacter pylori (H. pylori) infection is the strongest risk factor. However, the genetic and molecular mechanisms underlying H. pylori-related GC need further elucidation. We investigated the competing endogenous RNA (ceRNA) network differences between H. pylori (+) and H. pylori (-) GC. The long noncoding RNA (lncRNA), microRNA (miRNA), and messenger RNA (mRNA) expression data from 32 adjacent noncancerous samples and 18 H. pylori (+) and 141 H. pylori (-) stomach adenocarcinoma samples were downloaded from the TCGA database. After construction of lncRNA-miRNA-mRNA ceRNA networks of H. pylori (+) and H. pylori (-) GC, Panther and Kobas databases were used to analyze the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Finally, survival analysis was used to discover the key genes. In H. pylori (+) GC, we identified a total of 1,419 lncRNAs, 82 miRNAs, and 2,501 mRNAs with differentially expressed profiles. In H. pylori (-) GC, 2,225 lncRNAs, 130 miRNAs, and 3,146 mRNAs were differentially expressed. Furthermore, three unique pathways (cytokine-cytokine receptor interaction, HIF-1 signaling pathway, and Wnt signaling pathway) were enriched in H. pylori (+) GC. According to the overall survival analysis, three lncRNAs (AP002478.1, LINC00111, and LINC00313) and two mRNAs (MYB and COL1A1) functioned as prognostic biomarkers for patients with H. pylori (+) GC. In conclusion, our study has identified the differences in ceRNA regulatory networks between H. pylori (+) and H. pylori (-) GC and provides a rich candidate reservoir for future studies.

Downregulation of microRNA-204 increases the expression of matrix metallopeptidase 9 in pediatric patients with pulpitis and Helicobacter pylori infection in the stomach

The present study examined the expression of microRNA (miRNA or miR)-204 in pulp tissues, blood and saliva from pediatric patients with pulpitis and an underlying Helicobacter pylori (Hp) infection in the stomach, and the mechanism of the associated regulation by miR-204 was assessed. A total of 26 children with pulpitis who received tooth extraction at the Children's Hospital of Nanjing Medical University (Nanjing, China) between December 2014 and August 2016 were diagnosed with Hp infection in the stomach and included in the present study (HP⁺ group); furthermore, 19 children with pulpitis but without Hp infection in the stomach were enrolled as a control (HP^- group). Pulp tissues, blood (serum) and saliva samples were collected from all subjects. Reverse-transcription quantitative polymerase chain reaction was used to determine the expression of miR-204 and matrix metalloproteinase 9 (MMP9) mRNA. Western blot analysis was performed to determine MMP9 protein expression in pulp tissues, while ELISA was performed to measure the contents of MMP9 in serum and saliva. A dual luciferase reporter assay was used to identify the direct interaction between miR-204 and its target protein. The results indicated that Hp infection in the stomach was associated with an upregulation of MMP9 mRNA and protein in pulp tissues, serum and saliva from children with pulpitis. Furthermore, the levels of miR-204 in pulp tissues, serum and saliva from children with pulpitis and Hp infection in the stomach were significantly reduced. miR-204 was confirmed to regulate the expression of MMP9 by directly binding with the 3'-untranslated region of MMP9 mRNA. The present study demonstrated that MMP9 expression in pulp tissues, blood and saliva from children with pulpitis and Hp infection in the stomach was upregulated, while miR-204 expression was downregulated. miR-204 may affect inflammatory processes and other oral diseases in children with pulpitis and Hp infection via MMP9, and may be a potential marker for the detection of Hp infection in children with pulpitis.

MicroRNA‑199a‑5p suppresses migration and invasion in oral squamous cell carcinoma through inhibiting the EMT‑related transcription factor SOX4

MicroRNAs (miRs) are small, non-coding RNAs that can act as oncogenes or tumor suppressor genes in human cancer. Recent studies have revealed that miR-199a-5p is abnormally expressed in various types of human cancer; however, the potential role of miR-199a-5p in oral squamous cell carcinoma (OSCC) remains elusive. The present study investigated the role of miR-199a-5p in OSCC cells and explored the potential molecular mechanism. Reverse transcription-quantitative polymerase chain reaction was used to measure miR-199a-5p expression in OSCC tissues and adjacent normal oral epithelial tissues. Cell invasion and migration were evaluated using Transwell invasion and wound-healing assays in OSCC cells post-transfection with miR-199a-5p mimics or negative control mimics. In addition, a luciferase reporter assay was conducted to identify the target gene of miR-199a-5p in OSCC cells. The results demonstrated that miR-199a-5p expression was significantly downregulated in OSCC tissues and cell lines, and was associated with tumor progression in OSCC. Furthermore, overexpression of miR-199a-5p inhibited cell invasion and migration, and blocked the epithelial-mesenchymal transition (EMT) cascade. Notably, the results revealed that the EMT-related transcription factor SRY-box 4 (SOX4) was a direct target gene of miR-199a-5p, as determined by the direct binding of miR-199a-5p with the 3′-untranslated region of SOX4. In addition, knockdown of SOX4 by small interfering RNA-SOX4 suppressed proliferation, migration and invasion of OSCC cells. Conversely, overexpression of SOX4 rescued the suppressive effects of miR-199a-5p on cell migration and invasion. Collectively, these data indicated that miR-199a-5p may inhibit the migration and invasion of OSCC cells via targeting the EMT-related transcription factor SOX4, thus suggesting that miR-199a-5p may serve as a prognostic biomarker and therapeutic target in the treatment of OSCC.

An overview of the multifaceted roles of miRNAs in gastric cancer: Spotlight on novel biomarkers and therapeutic targets

MicroRNAs (miRNAs) are a group of small non-coding RNAs that have displayed strong association with gastric cancer (GC). Through the repression of target mRNAs, miRNAs regulate many biological pathways that are involved in cell proliferation, apoptosis, migration, invasion, metastasis as well as drug resistance. The detection of miRNAs in tissues and in body fluids emerges as a promising method in the diagnosis and prognosis of GC, due to their unique expression pattern in correlation with GC. Notably, miRNAs are also identified as potential therapeutic targets for GC therapy. The present review is thus to highlight the multifaceted roles of miRNAs in GC and in GC therapies, which would give indications for future research.

Epigenetic Field Cancerization in Gastric Cancer: microRNAs as Promising Biomarkers

Background: The biological role of microRNAs (miRNAs) in field cancerization is unknown. To investigate the involvement of miRNAs in gastric field cancerization, we evaluated the expression profile of ten miRNAs and their diagnostic value.

Methods: We used three groups of FFPE gastric samples: non-cancer (NC), cancer adjacent (ADJ) and gastric cancer (GC). The expression profiles of hsa-miR-10a, -miR-21, -miR-29c, -miR-135b, -miR-148a, -miR-150, -miR-204, -miR-215, -miR-483 and -miR-664a were investigated using qRT-PCR. The results obtained by qRT-PCR were validated in Small RNA-Seq data from the TCGA database. The search for target genes of the studied miRNAs was performed in the miRTarBase public database and miRTargetLink tool, using experimentally validated interactions. In addition, we also performed the functional analysis of these genes using enrichment in KEGG pathways. The potential as biomarker was evaluated using a receiver operating characteristic (ROC) curve and the derived area under the curve (AUC>0.85) analysis.

Results: The miRNAs hsa-miR-10a, -miR-21, -miR-135b, hsa-miR-148a, -miR-150, -miR-215, -miR-204, -miR-483 and -miR-664a were up-regulated in ADJ and GC compared to NC (P<0.03); and hsa-miR-21 and -miR-135b were up-regulated in GC compared to ADJ (P<0.01). Hsa-miR-148a, -miR-150, -miR-215, -miR-483 and -miR-664a were not differentially expressed between GC and ADJ, suggesting that both share similar changes (P>0.1). The TS-miR hsa-miR-29c was up-regulated in ADJ compared to NC and GC (P<0.01); we did not observe a significant difference in the expression of this miRNA between NC and GC. This feature may be an antitumor mechanism used by cancer-adjacent tissue because this miRNA regulates the BCL-2, CDC42 and DMNT3A oncogenes. The expression level of hsa-miR-204 was associated with Helicobacter pylori infection status (P<0.05). Functional analysis using the genes regulated by the studied miRNAs showed that they are involved in biological pathways and cellular processes that are critical for the establishment of H. pylori infection and for the onset, development and progression of GC. hsa-miR-10a, -miR-21, -miR-135b, -miR-148a, -miR-150, -miR-215, -miR-483 and -miR-664a were able to discriminate NC from other tissues with great accuracy (AUC>0.85).

Conclusion: The studied miRNAs are closely related to field cancerization, regulate genes important for gastric carcinogenesis and can be potentially useful as biomarkers in GC.

Role of abnormal microRNA expression in Helicobacter pylori associated gastric cancer

Epidemiological studies have shown that Helicobacter pylori (HP) infection is a risk factor for gastric cancer (GC). HP infection may induce the release of pro-inflammatory mediators, and abnormally increase the level of reactive oxygen species (ROS), nitric oxide (NO), and cytokines in mucosal epithelial cells of the stomach. However, the specific mechanism underlying the pathogenesis of HP-associated GC is still poorly understood. Recent studies have revealed that abnormal microRNA expression may affect the proliferation, differentiation, and apoptosis of mucosal epithelial cells of the stomach to further influence GC occurrence, development, and metastasis. Herein, we summarize the role of abnormal microRNAs in the regulation of HP-associated GC progression. Abnormal microRNA expression in HP-positive GC may be a biomarker for GC diagnosis, occurrence, and development as well as its targeted treatment and prognosis.

Mechanisms of Inflammasome Signaling, microRNA Induction and Resolution of Inflammation by Helicobacter pylori

Inflammasome-controlled transcription and subsequent cleavage-mediated activation of mature IL-1β and IL-18 cytokines exemplify a crucial innate immune mechanism to combat intruding pathogens. Helicobacter pylori represents a predominant persistent infection in humans, affecting approximately half of the population worldwide, and is associated with the development of chronic gastritis, peptic ulcer disease, and gastric cancer. Studies in knockout mice have demonstrated that the pro-inflammatory cytokine IL-1β plays a central role in gastric tumorigenesis. Infection by H. pylori was recently reported to stimulate the inflammasome both in cells of the mouse and human immune systems. Using mouse models and in vitro cultured cell systems, the bacterial pathogenicity factors and molecular mechanisms of inflammasome activation have been analyzed. On the one hand, it appears that H. pylori-stimulated IL-1β production is triggered by engagement of the immune receptors TLR2 and NLRP3, and caspase-1. On the other hand, microRNA hsa-miR-223-3p is induced by the bacteria, which controls the expression of NLRP3. This regulating effect by H. pylori on microRNA expression was also described for more than 60 additionally identified microRNAs, indicating a prominent role for inflammatory and other responses. Besides TLR2, TLR9 becomes activated by H. pylori DNA and further TLR10 stimulated by the bacteria induce the secretion of IL-8 and TNF, respectively. Interestingly, TLR-dependent pathways can accelerate both pro- and anti-inflammatory responses during H. pylori infection. Balancing from a pro-inflammation to anti-inflammation phenotype results in a reduction in immune attack, allowing H. pylori to persistently colonize and to survive in the gastric niche. In this chapter, we will pinpoint the role of H. pylori in TLR- and NLRP3 inflammasome-dependent signaling together with the differential functions of pro- and anti-inflammatory cytokines. Moreover, the impact of microRNAs on H. pylori-host interaction will be discussed, and its role in resolution of infection versus chronic infection, as well as in gastric disease development.

Systematic analysis of lncRNA-miRNA-mRNA competing endogenous RNA network identifies four-lncRNA signature as a prognostic biomarker for breast cancer

Background

Increasing evidence has underscored the role of long non-coding RNAs (lncRNAs) acting as competing endogenous RNAs (ceRNAs) in the development and progression of tumors. Nevertheless, lncRNA biomarkers in lncRNA-related ceRNA network that can predict the prognosis of breast cancer (BC) are still lacking. The aim of our study was to identify potential lncRNA signatures capable of predicting overall survival (OS) of BC patients.

Methods

The RNA sequencing data and clinical characteristics of BC patients were obtained from the Cancer Genome Atlas database, and differentially expressed lncRNA (DElncRNAs), DEmRNAs, and DEmiRNAs were then identified between BC and normal breast tissue samples. Subsequently, the lncRNA–miRNA–mRNA ceRNA network of BC was established, and the gene oncology enrichment analyses for the DEmRNAs interacting with lncRNAs in the ceRNA network was implemented. Using univariate and multivariate Cox regression analyses, a four-lncRNA signature was developed and used for predicting the survival in BC patients. We applied receiver operating characteristic analysis to assess the performance of our model.

Results

A total of 1061 DElncRNAs, 2150 DEmRNAs, and 82 DEmiRNAs were identified between BC and normal breast tissue samples. A lncRNA–miRNA–mRNA ceRNA network of BC was established, which comprised of 8 DEmiRNAs, 48 DElncRNAs, and 10 DEmRNAs. Further gene oncology enrichment analyses revealed that the DEmRNAs interacting with lncRNAs in the ceRNA network participated in cell leading edge, protease binding, alpha-catenin binding, gamma-catenin binding, and adenylate cyclase binding. A univariate regression analysis of the DElncRNAs revealed 7 lncRNAs (ADAMTS9-AS1, AC061992.1, LINC00536, HOTAIR, AL391421.1, TLR8-AS1 and LINC00491) that were associated with OS of BC patients. A multivariate Cox regression analysis demonstrated that 4 of those lncRNAs (ADAMTS9-AS1, LINC00536, AL391421.1 and LINC00491) had significant prognostic value, and their cumulative risk score indicated that this 4-lncRNA signature independently predicted OS in BC patients. Furthermore, the area under the curve of the 4-lncRNA signature associated with 3-year survival was 0.696.

Conclusions

The current study provides novel insights into the lncRNA-related ceRNA network in BC and the 4 lncRNA biomarkers may be independent prognostic signatures in predicting the survival of BC patients.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1640-2) contains supplementary material, which is available to authorized users.

An androgen receptor negatively induced long non-coding RNA ARNILA binding to miR-204 promotes the invasion and metastasis of triple-negative breast cancer

Androgen receptor (AR) is emerging as a novel prognostic biomarker in triple-negative breast cancer (TNBC), but the underlying mechanisms remain unknown. As accumulating evidence has shown that long non-coding RNAs (lncRNAs) regulate important cancer hallmarks, we hypothesised that AR-regulated lncRNAs might play roles in TNBC progression. Here, we performed experiments with or without DHT treatment in three TNBC cell lines, and we identified an AR negatively induced lncRNA (ARNILA), which correlated with poor progression-free survival (PFS) in TNBC patients and promoted epithelial-mesenchymal transition (EMT), invasion and metastasis in vitro and in vivo. Subsequently, we demonstrated that ARNILA functioned as a competing endogenous RNA (ceRNA) for miR-204 to facilitate expression of its target gene Sox4, which is known to induce EMT and contribute to breast cancer progression, thereby promoting EMT, invasion and metastasis of TNBC. Our findings not only provide new insights into the mechanisms of lncRNA in regulating AR but also suggest ARNILA as an alternative therapeutic target to suppress metastasis of TNBC patients.

miRNAs reshape immunity and inflammatory responses in bacterial infection

Pathogenic bacteria cause various infections worldwide, especially in immunocompromised and other susceptible individuals, and are also associated with high infant mortality rates in developing countries. MicroRNAs (miRNAs), small non-coding RNAs with evolutionarily conserved sequences, are expressed in various tissues and cells that play key part in various physiological and pathologic processes. Increasing evidence implies roles for miRNAs in bacterial infectious diseases by modulating inflammatory responses, cell penetration, tissue remodeling, and innate and adaptive immunity. This review highlights some recent intriguing findings, ranging from the correlation between aberrant expression of miRNAs with bacterial infection progression to their profound impact on host immune responses. Harnessing of dysregulated miRNAs in bacterial infection may be an approach to improving the diagnosis, prevention and therapy of infectious diseases.

Changes in production of tiny cellular RNAs in response to bacterial infection could guide the development of better diagnostics and therapies. MicroRNAs regulate other genes by binding to messenger RNA strands and controlling their translation into proteins. Xikun Zhou, Min Wu and colleagues of the University of North Dakota have now reviewed current knowledge about how microRNA levels shift during infection with various bacterial pathogens. These microRNAs can modulate the immune response as well as pathways that influence metabolic activity and cell survival. Increasing studies have indicated that shifts in microRNA levels in response to different infections could provide a potential bacterial ‘fingerprint’ for achieving accurate diagnosis. With deeper insight into how different microRNAs influence infection, it might one day day become possible to target these molecules with ‘antisense’ or ‘agonist’ drugs that modulate their activity.

MicroRNA-204 inhibits cell migration and invasion in human cervical cancer by regulating transcription factor 12

Deregulated microRNAs (miRs) and their roles in carcinogenesis have attracted great attention in recent years. Although miR-204 was reportedly dysregulated in various types of cancer, its function and mechanism in cervical cancer remain unknown. The present study focused on the expression and mechanisms of miR-204 in cervical cancer development. Expression of miR-204 in cervical cancer tissues and non-tumor tissues was measured using PCR analysis. The effect of ectopic expression of miR-204 on cell motility was evaluated using wound-healing and Transwell invasion assays. Luciferase activity and western blot assays were used to verify the regulatory effect of miR-204 on its target gene. It was demonstrated that miR-204 was significantly decreased in primary cervical cancer tissues, and that downregulated miR-204 was associated with lymph node metastasis and poor survival. In addition, it was revealed that ectopic expression of miR-204 significantly inhibited the migratory and invasive ability of cervical cancer cells in vitro. In addition, bioinformatic prediction and experimental validation demonstrated that transcription factor 12 (TCF12) was a direct target of miR-204. Overexpression of TCF12 attenuated the inhibitory effect of miR-204 on cell motility. Taken together, the present data indicated that miR-204 is a metastasis-associated gene and may contribute to the progression of cervical cancer by regulating TCF12, providing novel insights, including that miR-204/TCF12 may be an important mechanism for cervical cancer metastasis.

SNP rs3202538 in 3'UTR region of ErbB3 regulated by miR-204 and miR-211 promote gastric cancer development in Chinese population

Background/aims

ErbB3 is an oncogene which has proliferation and metastasis promotion effects by several signaling pathways. However, the individual expression difference regulated by miRNA was almost still unknown. We focused on the miRNAs associated SNPs in the 3′-UTR of ErbB3 to investigate the further relationship of the SNPs with miRNAs among Chinese gastric cancer (GC) patients.

Methods

We performed case–control study including 851 GC patients and 799 cancer-free controls. Genotyping, real-time PCR assay, cell transfection, the dual luciferase reporter assay, western-blot, cell proliferation and trans-well based cell invasion assay were used to investigate the effects of the SNP on ErbB3 expression. Moreover, a 5-years-overall survival and relapse free survival were investigated between different genotypes.

Results

We found that patients suffering from Helicobacter pylori (Hp.) infection indicated to be the susceptible population by comparing with controls. Besides, SNP rs3202538 (G/T) in ErbB3 3′-UTR was involved in the occurrence of GC by acting as tumor risk factors. SNP rs3202538 (G/T) could be regulated by both miR-204 and miR-211 which caused an upregulation of ErbB3 in patients. Furthermore, the carriers of T genotype was related to the significantly high expression of ErbB3, and to big tumor size, poor differentiation as well as the high probability of metastasis. Both miR-211 and miR-204 can significantly decrease cell proliferation, metastasis as well as downstream AKT activation through G but not T allele of ErbB3 3′UTR. Moreover, the SNP of G/T was associated with shorter survival of post-surgery GC patients with 5 years of follow up study.

Conclusion

In conclusion, our findings have shown that the SNP rs3202538 (G/T) in ErbB3 3′-UTR acted as promotion factors in the GC development through disrupting the regulatory role of miR-204 and miR-211 in ErbB3 expression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-017-0449-z) contains supplementary material, which is available to authorized users.

MicroRNA mediated regulation of immunity against gram-negative bacteria

Evidence over the last couple decades has comprehensively established that short, highly conserved, non-coding RNA species called microRNA (miRNA) exhibit the ability to regulate expression and function of host genes at the messenger RNA (mRNA) level. MicroRNAs play key regulatory roles in immune cell development, differentiation, and protective function. Intrinsic host immune response to invading pathogens rely on intricate orchestrated events in the development of innate and adaptive arms of immunity. We discuss the involvement of miRNAs in regulating these processes against gram negative pathogens in this review.

Down-regulated miRs specifically correlate with non-cardial gastric cancers and Lauren's classification system

BACKGROUND AND OBJECTIVES

Gastric cancers are usually characterized using Lauren's classification into intestinal and diffuse types. We previously documented the down-modulation of miR31, miR148a, miR204, and miR375 in gastric cancers. We aimed this manuscript to investigate these miRs with the end-points of diagnosis, Lauren's classification and prognosis.

METHODS

A total of 117 resected non-cardial adenocarcinomas were evaluated for miRs' expressions. The performance of miRs' expressions for cancer diagnosis was tested using ROC curves. Logistic regression was conducted with the end-point of Lauren's classification. Kaplan-Meier and Cox analyses were performed for OS, DFS, and DSS. miRs' targets were reviewed using PRISMA method and BCL-2 was further investigated in cell lines.

RESULTS

ROC curves documented that miRs' down-modulation was significant in differentiating cancer versus normal tissues. Diffuse type cancers were associated with female sex, young age, and miR375 higher expression. We confirmed BCL-2 as a miR204 target. However, survival analyses confirmed the pathologic criteria (advanced stages, LNR, and low LNH) as the significant variables correlated to worse prognosis.

CONCLUSIONS

The down-modulation of miR31, miR148a, miR204, and miR375 is significantly associated with non-cardial gastric cancers and miR375 is specifically linked to Lauren's classification. Nevertheless, standard pathological features display as the independent variables associated with worse prognosis.

Histological and Pathological Assessment of miR-204 and SOX4 Levels in Gastric Cancer Patients

Gastric cancer is one of the most common cancers and the efficient therapeutic methods are limited. Further study of the exact molecular mechanism of gastric cancer to develop novel targeted therapies is necessary and urgent. We herein systematically examined that miR-204 suppressed both proliferation and metastasis of gastric cancer AGS cells. miR-204 directly targeted SOX4. In clinical tissue research, we determined that miR-204 was expressed much lower and SOX4 expressed much higher in gastric cancer tissues compared with normal gastric tissues. Associated analysis with clinicopathological parameters in gastric cancer patients showed miR-204 was associated with no lymph node metastasis and early tumor stages whereas SOX4 was associated with lymph node metastasis and advanced tumor stages. In addition, miR-204 and SOX4 were negatively correlated in tissues from gastric cancer patients. Our findings examined the important role of miR-204 and SOX4 played in gastric cancer, and they could be used as candidate therapeutic targets for gastric cancer therapy.

miR-20b Inhibits T Cell Proliferation and Activation via NFAT Signaling Pathway in Thymoma-Associated Myasthenia Gravis

Purpose. We examined the role of miR-20b in development of thymoma-associated myasthenia gravis, especially in T cell proliferation and activation. Materials and Methods. Using qRT-PCR, we assessed expression levels of miR-20b and its target genes in cultured cells and patient samples and examined the proliferation of cultured cells, using MTT cell proliferation assays and flow cytometry based cell cycle analysis. Activation of T cells was determined by both flow cytometry and qRT-PCR of activation-specific marker genes. Results. Expression of miR-20b was downregulated in samples of thymoma tissues and serum from patients with thymoma-associated myasthenia gravis. In addition, T cell proliferation and activation were inhibited by ectopic overexpression of miR-20b, which led to increased T cell proliferation and activation. NFAT5 and CAMTA1 were identified as targets of miR-20b. Expression levels of NFAT5 and CAMTA1 were inhibited by miR-20b expression in cultured cells, and the expression levels of miR-20b and NFAT5/CAMTA1 were inversely correlated in patients with thymoma-associated myasthenia gravis. Conclusion. miR-20b acts as a tumor suppressor in the development of thymoma and thymoma-associated myasthenia gravis. The tumor suppressive function of miR-20b in thymoma could be due to its inhibition of NFAT signaling by repression of NFAT5 and CAMTA1 expression.

Dual targeting of ANGPT1 and TGFBR2 genes by miR-204 controls angiogenesis in breast cancer

Deregulated expression of microRNAs has been associated with angiogenesis. Studying the miRNome of locally advanced breast tumors we unsuspectedly found a dramatically repression of miR-204, a small non-coding RNA with no previous involvement in tumor angiogenesis. Downregulation of miR-204 was confirmed in an independent cohort of patients and breast cancer cell lines. Gain-of-function analysis indicates that ectopic expression of miR-204 impairs cell proliferation, anchorage-independent growth, migration, invasion, and the formation of 3D capillary networks in vitro. Likewise, in vivo vascularization and angiogenesis were suppressed by miR-204 in a nu/nu mice model. Genome-wide profiling of MDA-MB-231 cells expressing miR-204 revealed changes in the expression of hundred cancer-related genes. Of these, we focused on the study of pro-angiogenic ANGPT1 and TGFβR2. Functional analysis using luciferase reporter and rescue assays confirmed that ANGPT1 and TGFβR2 are novel effectors downstream of miR-204. Accordingly, an inverse correlation between miR-204 and ANGPT1/TGFβR2 expression was found in breast tumors. Knockdown of TGFβR2, but not ANGPT1, impairs cell proliferation and migration whereas inhibition of both genes inhibits angiogenesis. Taken altogether, our findings reveal a novel role for miR-204/ANGPT1/TGFβR2 axis in tumor angiogenesis. We propose that therapeutic manipulation of miR-204 levels may represent a promising approach in breast cancer.

miR-582-5P induces colorectal cancer cell proliferation by targeting adenomatous polyposis coli

Background

microRNA (miRNAs) dysregulation is widely involved in cancer progression and contributed to sustained cell proliferation by directly targeting multiple targets. Therefore, better understand the underlying mechanism of miRNA in carcinogenesis may improve diagnostic and therapeutic strategies for malignancy.

Methods

We assessed microRNA-582 (miR-582-5P) expression in colorectal cancer (CRC) specimens and cell lines by real-time PCR. Luciferase reporter assay was used to confirm the target associations. Colony formation assay and anchorage-independent growth assay were used to analyze the effect of miR-582-5P on cell proliferation. Adenomatous polyposis coli (APC) gene and protein expression were examined using real-time PCR and western blotting, respectively.

Results

miR-582-5P was upregulated in the CRC specimens and cell lines and targeted the 3′ untranslated region of APC directly. miR-582-5P overexpression increased cyclin D1 and c-MYC expression, which subsequently induced CRC cell proliferation in an APC-dependent manner.

Conclusions

Our findings suggest that miR-582-5P plays an important role in the progression of CRC by inducing proliferation and may identify new targets for anti-cancer treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12957-016-0984-4) contains supplementary material, which is available to authorized users.

[Investigation of Gene Expression Profile of A549 Cells after Overexpression of GPC5 by High Throughput Transcriptome Sequencing]

背景与目的

磷脂酰肌醇蛋白聚糖-5(glypican-5, GPC5)是一个重要的抑癌基因, 然而GPC5对肺腺癌细胞增殖能力和基因表达的影响目前研究甚少。本研究拟在肺腺癌A549细胞中过表达GPC5以研究细胞增殖能力和基因表达变化情况。

方法

通过慢病毒载体构建稳定过表达GPC5的A549细胞株, 通过Cell Counter Kit 8 (CCK8)、平板克隆和EdU实验检测细胞增殖能力; 通过高通量转录组测序研究基因表达变化。

结果

相对于空白载体组, CCK8实验发现过表达GPC5可以明显抑制A549细胞的增殖速率; 平板克隆实验结果显示, 过表达GPC5之后A549细胞克隆形成能力下降(181±17 vs 278±23);EdU染色结果显示过表达GPC5后阳性染色细胞比例下降。转录组测序结果提示过表达GPC5之后, 2, 108个基因表达发生明显变化, 其中具有正性调节细胞增殖作用的基因明显下调。

结论

过表达GPC5可以明显抑制肺腺癌细A549的增殖能力, 而且过表达GPC5后具有正性调节细胞增殖作用的基因表达下调。

MiR-155-5p inhibits proliferation and invasion of gastric cancer cells by downregulation of SOX4

AIM: To investigate the mechanism of miR-155-5p to inhibit the proliferation and invasion of gastric cancer (GC) cells.

METHODS: The expression of miR-155-5p in GC cells was detected by quantitative real-time PCR. The miR-155-5p mimics and inhibitor were designed and transfected into BGC-823 cells. Then, the role of miR-155-5p in GC cell proliferation and invasion in vitro was explored. Luciferase reporter assay and Western blot were performed to confirm the target gene of miR-155-5p.

RESULTS: MiR-155-5p expression was significantly down-regulated in GC cells (P < 0.05). Overexpression of miR-155-5p inhibited GC cell proliferation and invasion in vitro, while down-regulated expression of miR-155-5p promoted GC cell proliferation and invasion. SOX4 was identified as a target of miR-155-5p in GC cells, and SOX4 expression levels were inversely correlated with miR-155-5p. Knockdown of Sox4 inhibited the proliferation and invasion of GC cells (P < 0.05).

CONCLUSION: MiR-155-5p could inhibit GC cell proliferation and invasion partially by down-regulating SOX4. MiR-155-5p might be a potential therapeutic target for GC treatment in the future.

The dual regulatory role of miR-204 in cancer

MicroRNAs (miRNAs) are a group of endogenous, small (about 22 nucleotides) non-coding RNAs which negatively regulate gene expressions. As one of them, miR-204 originates from the sixth intron of the transient receptor potential melastatin 3 (TRPM3) gene. Therefore, expression of miR-204 is under the control of the TRPM3 promoter and regulated by genetic and epigenetic mechanisms. miR-204 has been found to play the important roles in development of eyes and adipogenesis. Its pathological functions have been observed in a few diseases including pulmonary arterial hypertension, diabetes, and various types of cancers. It is believed that miR-204 acts as a tumor-suppressor via promoting apoptosis, conferring the resistance of cancer cells to chemotherapy, and suppressing the self-renewal of cancer stem cells (CSCs) and the epithelial to mesenchymal transition (EMT). Expression of miR-204 is repressed by its targets XRN1 and TRKB in prostate cancer and endometrial carcinoma, respectively; therefore, they establish an oncogenic feedback loops that play an important role promoting development of cancer. In this review, we summarize our current knowledge regarding miR-204, including its expression, regulation and biological functions, especially focusing our discussion on its role in tumor development and tumor progression.

Potential Diagnostic, Prognostic and Therapeutic Targets of MicroRNAs in Human Gastric Cancer

Human gastric cancer (GC) is characterized by a high incidence and mortality rate, largely because it is normally not identified until a relatively advanced stage owing to a lack of early diagnostic biomarkers. Gastroscopy with biopsy is the routine method for screening, and gastrectomy is the major therapeutic strategy for GC. However, in more than 30% of GC surgical patients, cancer has progressed too far for effective medical resection. Thus, useful biomarkers for early screening or detection of GC are essential for improving patients’ survival rate. MicroRNAs (miRNAs) play an important role in tumorigenesis. They contribute to gastric carcinogenesis by altering the expression of oncogenes and tumor suppressors. Because of their stability in tissues, serum/plasma and other body fluids, miRNAs have been suggested as novel tumor biomarkers with suitable clinical potential. Recently, aberrantly expressed miRNAs have been identified and tested for clinical application in the management of GC. Aberrant miRNA expression profiles determined with miRNA microarrays, quantitative reverse transcription-polymerase chain reaction and next-generation sequencing approaches could be used to establish sample specificity and to identify tumor type. Here, we provide an up-to-date summary of tissue-based GC-associated miRNAs, describing their involvement and that of their downstream targets in tumorigenic and biological processes. We examine correlations among significant clinical parameters and prognostic indicators, and discuss recurrence monitoring and therapeutic options in GC. We also review plasma/serum-based, GC-associated, circulating miRNAs and their clinical applications, focusing especially on early diagnosis. By providing insights into the mechanisms of miRNA-related tumor progression, this review will hopefully aid in the identification of novel potential therapeutic targets.

MiR-204 inhibits the proliferation and invasion of renal cell carcinoma by inhibiting RAB22A expression

While miR-204 expression may be linked to renal cell carcinoma (RCC) progression, the detailed mechanisms remain unclear. In the present study, we demonstrated that miR-204 was differentially expressed in RCC tissues when compared with surrounding normal kidney tissues. Ectopic overexpression of miR-204 in human RCC cells suppressed cell proliferation and invasion in vitro and in vivo. Mechanism dissection revealed that miR-204 may function through RAB22A signals to inhibit RCC proliferation and invasion. Overexpression of RAB22A by oe-RAB22A was able to partially reverse the miR-204-mediated suppression of RCC tumor progression. Together, these results revealed that miR-204 suppressed RCC proliferation and invasion by directly targeting the RAB22A gene. Targeting newly identified RAB22A with miR-204 may aid in the suppression of RCC proliferation and invasion.

Helicobacter pylori-induced inflammation and epigenetic changes during gastric carcinogenesis

The sequence of events associated with the development of gastric cancer has been described as “the gastric precancerous cascade”. This cascade is a dynamic process that includes lesions, such as atrophic gastritis, intestinal metaplasia and dysplasia. According to this model, Helicobacter pylori (H. pylori) infection targets the normal gastric mucosa causing non-atrophic gastritis, an initiating lesion that can be cured by clearing H. pylori with antibiotics or that may then linger in the case of chronic infection and progress to atrophic gastritis. The presence of virulence factors in the infecting H. pylori drives the carcinogenesis process. Independent epidemiological and animal studies have confirmed the sequential progression of these precancerous lesions. Particularly long-term follow-up studies estimated a risk of 0.1% for atrophic gastritis/intestinal metaplasia and 6% in case of dysplasia for the long-term development of gastric cancer. With this in mind, a better understanding of the genetic and epigenetic changes associated with progression of the cascade is critical in determining the risk of gastric cancer associated with H. pylori infection. In this review, we will summarize some of the most relevant mechanisms and focus predominantly but not exclusively on the discussion of gene promoter methylation and miRNAs in this context.

miR-211 and MITF modulation by Bcl-2 protein in melanoma cells

Melanoma, the most lethal form of skin cancer, is frequently associated with alterations in several genes, among which the Bcl-2 oncogene plays an important role in progression, chemosensitivity and angiogenesis. Also microRNA (miRNA) are emerging as modulators of melanoma development and progression, and among them, miR-211, located within the melastatin-1/TRPM1 (transient receptor potential cation channel, subfamily M, member 1 protein) gene, is prevalently expressed in the melanocyte lineage and acts as oncosuppressor. Using several human melanoma cell lines and their Bcl-2 stably overexpressing derivatives, we evaluated whether there was a correlation between expression of Bcl-2 and miR-211. Western blot analysis and quantitative real-time polymerase chain reaction demonstrated reduced expression of pri-miR-211, miR-211, TRPM1, and MLANA levels, after Bcl-2 overexpression, associated with increased expression of well-known miR-211 target genes. Overexpression of mature miR-211 in Bcl-2 overexpressing cells rescued Bcl-2 ability to increase cell migration. A decreased nuclear localization of microphthalmia-associated transcription factor (MITF), a co-regulator of both miR-211 and TRPM1, and a reduced MITF recruitment at the TRPM1 and MLANA promoters were also evidenced in Bcl-2 overexpressing cells by immunofluorescence and chromatin immunoprecipitation experiments, respectively. Reduction of Bcl-2 expression by small interference RNA confirmed the ability of Bcl-2 to modulate miR-211 and TRPM1 expression. © 2015 Wiley Periodicals, Inc.

SOX4 contributes to the progression of cervical cancer and the resistance to the chemotherapeutic drug through ABCG2

SOX4, a member of the SOX (sex-determining region Y-related HMG box) transcription factor family, has been reported to be abnormally expressed in a wide variety of cancers, and to exert a pleiotropic function. However, its function in progression of cervical cancer (CC) remains unknown. In this study, we found that SOX4 was highly expressed in CC cells and tissues, and overexpression of SOX4 in CC CaSki cells enhanced tumor clone formation and cell proliferation, and accelerated cell cycle progress. Meanwhile, downregulation of SOX4 by shRNA in CaSki cells inhibited cell proliferation, and slowed cell cycle progress, indicating that SOX4 contributes to the development of CC. In addition, SOX4 overexpression by gene transfer reduced the sensitivity of CaSki cells in response to the chemotherapeutic drug cisplatin, and SOX4 downregulation by RNA interference increased the sensitivity of CaSki cells in response to cisplatin. Moreover, SOX4 overexpression upregulated multiple drug resistant gene ABCG2, and SOX4 downregulation inhibited ABCG2 expression. Taken together, these results suggested that SOX4 functions to modulate cancer proliferation by regulation of cell cycle, and inhibit cancer cell sensitivity to therapeutic drug via upregulation of ABCG2. Thus, SOX4 may be a target for CC chemotherapy.

Decreased expression of miR-204 in plasma is associated with a poor prognosis in patients with non-small cell lung cancer

In order to identify novel non-invasive biomarkers with high accuracy for the screening of non-small cell lung cancer (NSCLC), we investigated the predictive power of 4 microRNAs (miR-146, miR-204, miR-106a and miR-124) in plasma samples obtained from patients with NSCLC and healthy controls (n=50; training phase) by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We found that the levels of miR-204 in the patients with NSCLC were significantly dysregulated compared with the healthy controls, and thus this miRNA was selected for further validation. For the validation phase, RT-qPCR was performed on plasma samples from patients with NSCLC and healthy controls (n=176) in order to examine the expression levels of the candidate miRNA, miR-204. The results revealed that the plasma levels of miR-204 were significantly downregulated in the patients with NSCLC compared with the healthy controls (p<0.001). The value of the area under the receiver operating characteristic (ROC) curve obtained for miR-204 was 0.809 (sensitivity, 76%; specificity, 82%), which was higher than the values obtained for carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9). The expression of miR-204 in plasma significantly correlated with the tumor stage (p=0.009) and distant metastasis (p=0.048). A log-rank test revealed that lower plasma levels of miR-204 were associated with a shorter overall survival and disease-free survival (p=0.006 and 0.0065, respectively). Both univariate and multivariate Cox regression analyses indicated that a lower miR-204 expression level in plasma was a prognostic factor with a relative risk of death of 1.936 and 1.712, respectively. On the whole, our results suggest that the decreased expression of miR-204 in plasma is a promising biomarker for the detection of NSCLC and the prediction of poor survival in patients with the disease.

miR-221 and miR-222 Simultaneously Target RECK and Regulate Growth and Invasion of Gastric Cancer Cells

BACKGROUND

Although Helicobacter pylori infection is necessary for development of gastric adenocarcinoma (GAC), the underlying mechanism remains poorly defined. This study aimed to explore how miR-221 and miR-222 are dysregulated after H. pylori infection and how these 2 miRNAs are involved in pathological development of gastric cancer.

MATERIAL AND METHODS

qRT-PCR analysis was performed to quantify miR-221 and miR-222 expression in patients with H. pylori - induced chronic gastritis, H. pylori-negative healthy controls, and in gastric cancer tissues and the corresponding adjacent normal tissues. Cell models were used to verify the expression profile. Dual luciferase assay was performed to verify putative binding between miR-221 or miR-222 and RECK. A loss-and-gain function study was performed to assess the miR-221/miR-222-RECK axis in gastric cancer cells.

RESULTS

H. pylori infection leads to significantly higher miR-221 and miR-222 expression. MiR-221 and miR-222 can bind the same sequence of RECK 3'UTR, thereby modulating its expression. Through simultaneous regulation over RECK, miR-221 and miR-222 can promote gastric cancer cell growth and invasion.

CONCLUSIONS

The miR-221/miR-222-RECK axis might be an important path modulating H. pylori infection-related gastric cancer development.

miR-221 and miR-222 Simultaneously Target RECK and Regulate Growth and Invasion of Gastric Cancer Cells

BACKGROUND

Although Helicobacter pylori infection is necessary for development of gastric adenocarcinoma (GAC), the underlying mechanism remains poorly defined. This study aimed to explore how miR-221 and miR-222 are dysregulated after H. pylori infection and how these 2 miRNAs are involved in pathological development of gastric cancer.

MATERIAL AND METHODS

qRT-PCR analysis was performed to quantify miR-221 and miR-222 expression in patients with H. pylori - induced chronic gastritis, H. pylori-negative healthy controls, and in gastric cancer tissues and the corresponding adjacent normal tissues. Cell models were used to verify the expression profile. Dual luciferase assay was performed to verify putative binding between miR-221 or miR-222 and RECK. A loss-and-gain function study was performed to assess the miR-221/miR-222-RECK axis in gastric cancer cells.

RESULTS

H. pylori infection leads to significantly higher miR-221 and miR-222 expression. MiR-221 and miR-222 can bind the same sequence of RECK 3'UTR, thereby modulating its expression. Through simultaneous regulation over RECK, miR-221 and miR-222 can promote gastric cancer cell growth and invasion.

CONCLUSIONS

The miR-221/miR-222-RECK axis might be an important path modulating H. pylori infection-related gastric cancer development.

MicroRNA-132 inhibits cell growth and metastasis in osteosarcoma cell lines possibly by targeting Sox4

Increasing evidence has confirmed that dysregulation of microRNAs (miRNAs) can contribute to the progression and metastasis of human tumors. Previous studies have shown that dysregulation of microRNAs (miRNAs) can contribute to the progression and metastasis of human tumors. However, the precise mechanisms of miR-132 in osteosarcoma have not been well clarified. Real-time PCR was performed to detect the expression of miR-132 in osteosarcoma cell lines. miR-132 mimic, miR-132 inhibitor and negative control were transfected into osteosarcoma cells and the effects of miR-132 on the cell growth and metastasis were investigated. Furthermore, protein level of Sox4 was measured by western blotting. Luciferase assays were performed to validate Sox4 as miR-132 target in osteosarcoma cells. We found that miR-132 was downregulated in osteosarcoma cell lines. Introduction of miR-132 significantly inhibited proliferation, arrested cell cycle and induced apoptosis in osteosarcoma cells. Besides, invasion and epithelial-mesenchymal transition (EMT) of osteosarcoma cells was suppressed by overexpressing miR-132. However, downregulation of miR-132 promoted cell growth and metastasis in osteosarcoma cells. Bioinformatics analysis predicted that Sox4 was a potential target gene of miR-132. Luciferase reporter assay demonstrated that miR-132 could directly target Sox4. Moreover, the low level of miR-132 was associated with increased expression of Sox4 in osteosarcoma cells. Sox4 inhibition suppressed cell malignant behaviors. Overexpression of Sox4 in osteosarcoma cells transfected with miR-132 mimic partially reversed the inhibitory effect of miR-132. In conclusion, miR-132 inhibited cell growth and metastasis in osteosarcoma cells by downregulation of Sox4, and knockdown of Sox4 was essential for the miR-132-inhibited cell growth and metastasis in osteosarcoma cells.

Estrogen induces androgen-repressed SOX4 expression to promote progression of prostate cancer cells

BACKGROUND

The sex determing region Y-box 4 (SOX4) gene is a critical developmental transcriptional factor that is overexpressed in prostate cancer (PCa). While we and others have investigated the role of SOX4 overexpression in PCa, the molecular mechanism underlying its aberrant expression remains unclear.

METHODS

Immunohistochemistry were utilized to detect SOX4 expression and the correlation between estrogen receptor β (ERβ), androgen receptor (AR) and SOX4 in a cohort of 94 clinical specimens. Real-time quantitative PCR and Western blotting were used to study the transcript and protein expression levels. Immunofluorescence staining and co-immunoprecipitation were performed to assess the interaction and subcellular location of ERβ and AR. Chromatin immunoprecipitation (ChIP) assays and Luciferase reporter assays were performed to explore the binding and transcriptional activities of ERβ and AR to the SOX4 promoter. Cellular function was evaluated by MTS, invasion and wound healing assays.

RESULTS

SOX4 expression is up-regulated in Castration-Resistant Prostate Cancer (CRPC) tumors compared to hormone-dependent PCa (HDPC) cases. Increased expression was also observed in PCa cells after long-term androgen-deprivation treatment (ADT). In vitro data indicated that SOX4 is an AR transcriptional target and down-regulated by dihydrotestosterone (DHT) via AR. 17β-estradiol (E2) up-regulates SOX4 expression in the absence of androgen through the formation of a protein complex between ERβ and AR. Knockdown of AR or ERβ blocks the E2-induced SOX4 expression. ChIP assays confirmed that both ERβ and AR bind to the SOX4 promoter in response to E2. Functionally, silencing SOX4 significantly attenuates the proliferative effect, as well as the capacity of migration and invasion of E2 on PCa cells. Clinically, overexpression of SOX4 is significantly associated with ERβ expression in PCa. In addition, this association is still retained in CRPC patients with poor prognosis.

CONCLUSION

These findings suggest that SOX4 is a novel DHT-repressed AR-target gene. E2 could promote proliferation of PCa cells through the up-regulation of SOX4 under androgen-depleted environment. Our data provides a possible molecular basis for the overexpression of SOX4 in CRPC and may facilitate the detection and prevention of the emergence of CRPC.

Upregulation of microRNA-204 inhibits cell proliferation, migration and invasion in human renal cell carcinoma cells by downregulating SOX4

MicroRNA-204 (miR-204) has been reported to be frequently downregulated in various types of cancer, including renal, brain, ovary, hematological and colon cancer. The present study, investigated the effects of miR‑204 on renal cell carcinoma. Following transfection of miR‑204, an MTT assay, cell migration assay, cell invasion assay, western blot analysis and luciferase assay were performed in renal cell carcinoma cell lines. It was demonstrated that miR‑204 inhibits cell proliferation, migration and invasion in 786‑O and A498 cells. To the best of our knowledge, this study is the first to demonstrate that miR‑204 directly targets SOX4 in renal cell carcinoma. These results suggested that miR-204 may have value as a marker for the early detection of tumor metastasis and a therapeutic target preventing the invasion of renal cell carcinoma.

Noncoding Genomics in Gastric Cancer and the Gastric Precancerous Cascade: Pathogenesis and Biomarkers

Gastric cancer is the fifth most common cancer and the third leading cause of cancer-related death, whose patterns vary among geographical regions and ethnicities. It is a multifactorial disease, and its development depends on infection by Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV), host genetic factors, and environmental factors. The heterogeneity of the disease has begun to be unraveled by a comprehensive mutational evaluation of primary tumors. The low-abundance of mutations suggests that other mechanisms participate in the evolution of the disease, such as those found through analyses of noncoding genomics. Noncoding genomics includes single nucleotide polymorphisms (SNPs), regulation of gene expression through DNA methylation of promoter sites, miRNAs, other noncoding RNAs in regulatory regions, and other topics. These processes and molecules ultimately control gene expression. Potential biomarkers are appearing from analyses of noncoding genomics. This review focuses on noncoding genomics and potential biomarkers in the context of gastric cancer and the gastric precancerous cascade.

Analysis of Deregulated microRNAs and Their Target Genes in Gastric Cancer

BACKGROUND

MicroRNAs (miRNAs) are widely studied non-coding RNAs that modulate gene expression. MiRNAs are deregulated in different tumors including gastric cancer (GC) and have potential diagnostic and prognostic implications. The aim of our study was to determine miRNA profile in GC tissues, followed by evaluation of deregulated miRNAs in plasma of GC patients. Using available databases and bioinformatics methods we also aimed to evaluate potential target genes of confirmed differentially expressed miRNA and validate these findings in GC tissues.

METHODS

The study included 51 GC patients and 51 controls. Initially, we screened miRNA expression profile in 13 tissue samples of GC and 12 normal gastric tissues with TaqMan low density array (TLDA). In the second stage, differentially expressed miRNAs were validated in a replication cohort using qRT-PCR in tissue and plasma samples. Subsequently, we analyzed potential target genes of deregulated miRNAs using bioinformatics approach, determined their expression in GC tissues and performed correlation analysis with targeting miRNAs.

RESULTS

Profiling with TLDA revealed 15 deregulated miRNAs in GC tissues compared to normal gastric mucosa. Replication analysis confirmed that miR-148a-3p, miR-204-5p, miR-223-3p and miR-375 were consistently deregulated in GC tissues. Analysis of GC patients' plasma samples showed significant down-regulation of miR-148a-3p, miR-375 and up-regulation of miR-223-3p compared to healthy subjects. Further, using bioinformatic tools we identified targets of replicated miRNAs and performed disease-associated gene enrichment analysis. Ultimately, we evaluated potential target gene BCL2 and DNMT3B expression by qRT-PCR in GC tissue, which correlated with targeting miRNA expression.

CONCLUSIONS

Our study revealed miRNA profile in GC tissues and showed that miR-148a-3p, miR-223-3p and miR-375 are deregulated in GC plasma samples, but these circulating miRNAs showed relatively weak diagnostic performance as sole biomarkers. Target gene analysis demonstrated that BCL2 and DNMT3B expression in GC tissue correlated with their targeting miRNA expression.

miR-204 mediates post-transcriptional down-regulation of PHOX2B gene expression in neuroblastoma cells

Neuroblastoma (NB) is a rare childhood cancer of the peripheral sympathetic nervous system and accounts for approximately 10% of all pediatric tumors. Heterozygous PHOX2B mutations have been found in association with NB development in familial, sporadic and syndromic cases. In addition, the PHOX2B gene is widely over-expressed both in tumor samples and NB cell lines. Post-transcriptional gene regulation is known to be involved in mRNA stability and, in NB, microRNAs (miRNAs) seem to be responsible for altered expression of genes driving differentiation, apoptosis, and migration. To assess the possible impact of post-transcriptional regulation in NB cell lines, we have focused on the PHOX2B mRNA stability by both in silico analysis and functional studies on its 3'untranslated region (3'UTR). PHOX2B gene expression has resulted under post-transcriptional control, as suggested by: i) instability of PHOX2B mRNA, demonstrated by short mRNA half-life levels in both IMR32 and LAN-1 cell lines, ii) role of the PHOX2B-3'UTR, confirmed by the activity of proper reporter constructs, and iii) miRNA-204, shown to enhance the PHOX2B 3'UTR mediated down-regulation of the reporter construct activity. Finally, miRNA-204 has resulted to decrease the stability of the PHOX2B mRNA at different extents in the presence of different SNP rs1063611 alleles. Therefore, post-transcriptional down-regulation of the PHOX2B gene takes place in NB cell lines and miRNA-204 participates in such a 3'UTR mediated control.

MicroRNA-204 inhibits proliferation, migration, invasion and epithelial-mesenchymal transition in osteosarcoma cells via targeting Sirtuin 1

MicroRNAs (miRs) play crucial roles in tumorigenesis by directly suppressing the protein expression levels of their target genes. miR-204 has been suggested to act as a tumor suppressor in several types of human cancer. However, the exact role of miR-204 in osteosarcoma (OS) remains undetermined. In the present study, we aimed to investigate the effects of miR-204 on OS cell proliferation, migration and invasion, as well as the underlying molecular mechanisms. We found that the expression of miR-204 was frequently downregulated in four OS cell lines compared to the level in normal human osteoblast cells. Moreover, overexpression of miR-204 significantly inhibited the proliferation, migration and invasion of OS cells. Based on bioinformatics prediction and a luciferase reporter assay, we identified Sirtuin 1 (Sirt1) as a direct target gene of miR-204 in OS Saso-2 cells. Moreover, the protein expression of Sirt1 was negatively mediated by miR-204 in the OS cells. siRNA-mediated knockdown of Sirt1 also inhibited the proliferation, migration and invasion of the OS cells. Moreover, overexpression of Sirt1 reversed the inhibitory effect of miR-204 overexpression on the proliferation, migration and invasion of the OS cells. In addition, after miR-204 overexpression or Sirt1 knockdown in OS cells, the expression of E-cadherin was increased, while the N-cadherin protein level was reduced. Based on these findings, we suggest that miR-204 inhibits the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of OS cells by directly targeting Sirt1.

MicroRNAs in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating disease without effective treatment. Despite decades of research and the development of novel treatments, PAH remains a fatal disease, suggesting an urgent need for better understanding of the pathogenesis of PAH. Recent studies suggest that microRNAs (miRNAs) are dysregulated in patients with PAH and in experimental pulmonary hypertension. Furthermore, normalization of a few miRNAs is reported to inhibit experimental pulmonary hypertension. We have reviewed the current knowledge about miRNA biogenesis, miRNA expression pattern, and their roles in regulation of pulmonary artery smooth muscle cells, endothelial cells, and fibroblasts. We have also identified emerging trends in our understanding of the role of miRNAs in the pathogenesis of PAH and propose future studies that might lead to novel therapeutic strategies for the treatment of PAH.