Downregulation of Potential Tumor Suppressor miR-203a by Promoter Methylation Contributes to the Invasiveness of Gastric Cardia Adenocarcinoma

Helicobacter pylori infection induces abnormal expression of pro-angiogenic gene ANGPT2 and miR-203a in AGS gastric cell line

Helicobacter pylori colonizes the stomach and induces an inflammatory response that can develop into gastric pathologies including cancer. The infection can alter the gastric vasculature by the deregulation of angiogenic factors and microRNAs. In this study, we investigate the expression level of pro-angiogenic genes (ANGPT2, ANGPT1, receptor TEK), and microRNAs (miR-135a, miR-200a, miR-203a) predicted to regulate those genes, using H. pylori co-cultures with gastric cancer cell lines. In vitro infections of different gastric cancer cell lines with H. pylori strains were performed, and the expression of ANGPT1, ANGPT2, and TEK genes, and miR-135a, miR-200a, and miR-203a, was quantified after 24 h of infection (h.p.i.). We performed a time course experiment of H. pylori 26695 infections in AGS cells at 6 different time points (3, 6, 12, 28, 24, and 36 h.p.i.). The angiogenic response induced by supernatants of non-infected and infected cells at 24 h.p.i. was evaluated in vivo, using the chicken chorioallantoic membrane (CAM) assay. In response to infection, ANGPT2 mRNA was upregulated at 24 h.p.i, and miR-203a was downregulated in AGS cells co-cultured with different H. pylori strains. The time course of H. pylori 26695 infection in AGS cells showed a gradual decrease of miR-203a expression concomitant with an increase of ANGPT2 mRNA and protein expression. Expression of ANGPT1 and TEK mRNA or protein could not be detected in any of the infected or non-infected cells. CAM assays showed that the supernatants of AGS-infected cells with 26695 strain induced a significantly higher angiogenic and inflammatory response. Our results suggest that H. pylori could contribute to the process of carcinogenesis by downregulating miR-203a, which further promotes angiogenesis in gastric mucosa by increasing ANGPT2 expression. Further investigation is needed to elucidate the underlying molecular mechanisms.

Timing Expression of miR203a-3p during OA Disease: Preliminary In Vitro Evidence

Osteoarthritis (OA) is a degenerative bone disease that involves the microenvironment and macroenvironment of joints. Progressive joint tissue degradation and loss of extracellular matrix elements, together with different grades of inflammation, are important hallmarks of OA disease. Therefore, the identification of specific biomarkers to distinguish the stages of disease becomes a primary necessity in clinical practice. To this aim, we investigated the role of miR203a-3p in OA progression starting from the evidence obtained by osteoblasts isolated from joint tissues of OA patients classified according to different Kellgren and Lawrence (KL) grading (KL ≤ 3 and KL > 3) and hMSCs treated with IL-1β. Through qRT-PCR analysis, it was found that osteoblasts (OBs) derived from the KL ≤ 3 group expressed high levels of miR203a-3p and low levels of ILs compared with those of OBs derived from the KL > 3 group. The stimulation with IL-1β improved the expression of miR203a-3p and the methylation of the IL-6 promoter gene, favoring an increase in relative protein expression. The gain and loss of function studies showed that the transfection with miR203a-3p inhibitor alone or in co-treatments with IL-1β was able to induce the expression of CX-43 and SP-1 and to modulate the expression of TAZ, in OBs derived from OA patients with KL ≤ 3 compared with KL > 3. These events, confirmed also by qRT-PCR analysis, Western blot, and ELISA assay performed on hMSCs stimulated with IL-1β, supported our hypothesis about the role of miR203a-3p in OA progression. The results suggested that during the early stage, miR203a-3p displayed a protective role reducing the inflammatory effects on CX-43, SP-1, and TAZ. During the OA progression the downregulation of miR203a-3p and consequently the upregulation of CX-43/SP-1 and TAZ expression improved the inflammatory response and the reorganization of the cytoskeleton. This role led to the subsequent stage of the disease, where the aberrant inflammatory and fibrotic responses determined the destruction of the joint.

One stomach, two subtypes of carcinoma-the differences between distal and proximal gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors of the digestive tract, posing a significant risk to human health. Over the past 10 years, the pathological characteristics and the prognosis of GC have been determined based on the locations of the tumors that were then classified into two types-proximal and distal GC. This review focuses on the differences in epidemiology, etiology, cell source, pathological characteristics, gene expression, molecular markers, manifestations, treatment, prognosis, and prevention between proximal and distal GC to provide guidance and a basis for clinical diagnosis and treatment.

MicroRNA-320d regulates tumor growth and invasion by promoting FoxM1 and predicts poor outcome in gastric cardiac adenocarcinoma

Recent evidences demonstrate that dysregulated expression of microRNA-320d (miR-320d) has been associated with several cancer development and progression. However the effect of miR-320d on gastric cardiac adenocarcinoma (GCA) and the association of miR-320d with its potential gene target FoxM1 remain unclear. Here, we evaluated expression profile of miR-320d and FoxM1 in 60 human GCA tissues and GCA cell lines (OE-19 and SK-GT2). Immunohistochemistry, qualitative PCR and western-blotting were performed in GCA tissues to detect the expression level of miR-320d and FoxM1. CCK-8, transwell, wound-healing assays, and in vivo experiments were conducted using GCA cells that treated with miR-320d mimics or inhibitors to evaluate the biological functions of miR-320d. Luciferase reporter assay was conducted to confirm possible binding sites of FoxM1 for miR-320d. Compared with paired non-cancerous tissues, it showed that miR-320d expression was significantly decreased in GCA specimens (P < 0.0001), while FoxM1 was significantly upregulated in GCA tissues (P < 0.0001). Modulating miR-320d function by transfection of miR-320 mimics or inhibitor led to inhibition or promotion of GCA cell proliferation and invasion, thus regulating tumor progression in GCA-tumor bearing mice. The mechanism analysis of miR-320d/FoxM1 showed that FoxM1 has two miR-320d binding sites in its 3′-untranslated region (3′-UTR), that contributes to regulation of the cell biological behaviors. Taken together, our data suggested that miR-320d acts as a tumor suppressor in GCA by directly targeting FoxM1 and thus potentially serves as a biomarker for anti-GCA therapy in GCA patients.

LINC02595 promotes tumor progression in colorectal cancer by inhibiting miR-203b-3p activity and facilitating BCL2L1 expression

Colorectal cancer (CRC) is one of the most prevalent tumors worldwide. Recently, long noncoding RNAs (lncRNAs) have been recognized as key regulators in postgenomic biology. Numerous lncRNAs have been identified as diagnostic biomarkers and therapeutic targets. However, the molecular mechanisms underlying the role of lncRNAs in CRC progression are not fully understood. Differentially expressed lncRNAs and messenger RNAs were investigated using a microarray approach in five paired primary CRC tumor tissues and the corresponding nontumor tissues and confirmed in an additional 116 paired tissues and 21 inflammatory bowel disease tissues and 15 adjacent normal tissues by a quantitative real‐time polymerase chain reaction. We also performed comprehensive transcriptome profiling analysis on Gene Expression Omnibus and The Cancer Genome Atlas datasets. We identified LINC02595 and evaluated its clinical significance as a plasma biomarker. The function of LINC02595 was evaluated using a panel of in vivo and vitro assays, including cell counting kit‐8, colony formation, cell cycle, apoptosis, RNA fluorescence in situ hybridization, luciferase reporter, immunohistochemistry, and CRC xenografts. We found that LINC02595 is upregulated in tumor tissues and blood samples of patients with CRC and CRC cell lines. Functional research found that LINC02595 promotes CRC cell growth, influences the cell cycle, and reduces apoptosis in vitro and vivo. Mechanistically, LINC02595 promoted BCL2‐like 1 (BCL2L1) expression through miR‐203b‐3p sponging. Our research demonstrated that LINC02595 is an oncogene in CRC and established the presence of a LINC02595‐miR‐203b‐BCL2L1 axis in CRC, which might provide a new diagnostic biomarker and therapeutic targets for the treatment of this disease.

Risk factors predisposing to cardia gastric adenocarcinoma: Insights and new perspectives

Recent decades have seen an alarming increase in the incidence of cardia gastric adenocarcinoma (CGA) while noncardia gastric adenocarcinoma (NCGA) has decreased. In 2012, 260 000 CGA cases (age‐standardised rate (ASR); 3.3/100 000) and 691 000 NCGA cases (ASR; 8.8/100 000) were reported worldwide. Compared with women, men had greater rates for both the subsites, especially for CGA. Recently, four molecular subtypes of GC have been proposed by the Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG); however, these classifications do not take into account predisposing germline variants and their possible interaction with somatic alterations in carcinogenesis. The etiology of adenocarcinoma of the cardia and the gastroesophageal junction (GEJ) is not known. It is thought that CGA is distinct from adenocarcinomas located in the esophagus or distal stomach, both epidemiologically and biologically. Moreover, CGA is often identified in the advanced stage having a poor prognosis. Therefore, understanding the risk and the role of predisposing factors in etiology of CGA can inform clinical practice and counseling for risk reduction. In this paper, we showed that GC family history, lifestyle, demographics, gastroesophageal reflux disease, Helicobacter pylori infection, and multiple genetic and epigenetic risk factors as well as several predisposing conditions may underlie susceptibility to CGA. However, several genome‐wide association studies (GWASs) should be conducted to identify novel high‐penetrance genes and pathways as well as causal germline variants predisposing to CGA. They must include different ethnic groups, especially from high‐incidence countries for CGA, because some risk loci are ancestry‐specific. In parallel, statistical methods can be developed to identify cancer predisposition genes (CPGs) from tumor sequencing data. It is also necessary to find novel long noncoding RNAs related to the risk of CGA. Taken altogether, new cancer risk prediction models, including all genetic and nongenetic factors influencing risk, should be developed to facilitate risk assessment, disease prevention, and early diagnosis and intervention of CGA in the future.

MicroRNAs as Potential Biomarkers for Chemoresistance in Adenocarcinomas of the Esophagogastric Junction

Concerning adenocarcinomas of the esophagogastric junction, neoadjuvant chemotherapy is regularly implemented, but patients' response varies greatly, with some cases showing no therapeutic effect, being deemed as chemoresistant. Small, noncoding RNAs (miRNAs) have evolved as key players in biological processes, including malignant diseases, often promoting tumor growth and expansion. In addition, specific miRNAs have been implicated in the development of chemoresistance through evasion of apoptosis, cell cycle alterations, and drug target modification. We performed a retrospective study of 33 patients receiving neoadjuvant chemotherapy by measuring their miRNA expression profiles. Histologic tumor regression was evaluated using resection specimens, while miRNA profiles were prepared using preoperative biopsies without prior therapy. A preselected panel of 96 miRNAs, known to be of importance in various malignancies, was used to test for significant differences between responsive (chemosensitive) and nonresponsive (chemoresistant) cases. The cohort consisted of 12 nonresponsive and 21 responsive cases with the following 4 miRNAs differentially expressed between both the groups: hsa-let-7f-5p, hsa-miRNA-221-3p, hsa-miRNA-31-5p, and hsa-miRNA-191-5p. The former 3 showed upregulation in chemoresistant cases, while the latter showed upregulation in chemosensitive cases. In addition, significant correlation between high expression of hsa-miRNA-194-5p and prolonged survival could be demonstrated (p value <0.0001). In conclusion, we identified a panel of 3 miRNAs predicting chemoresistance and a single miRNA contributing to chemosensitivity. These miRNAs might function as prognostic biomarkers and enable clinicians to better predict the effect of one or more reliably select patients benefitting from (neoadjuvant) chemotherapy.

MiR-203a-3p regulates the biological behaviors of ovarian cancer cells through mediating the Akt/GSK-3β/Snail signaling pathway by targeting ATM

OBJECTIVE

To investigate whether miR-203a-3p can regulate the biological behaviors of ovarian cancer cells by targeting ATM to affect the Akt/GSK-3β/Snail signaling pathway.

METHODS

The expression levels of miR-203a-3p and ATM were detected by qRT-PCR, immunohistochemical staining and Western blotting in ovarian cancer tissues and adjacent normal tissues obtained from 152 subjects. A dual-luciferase reporter gene assay was performed to verify the relationship between miR-203a-3p and ATM. Human ovarian cancer cell lines (A2780 and SKOV3) were used to generate the Blank, miR-NC, miR-203a-3p mimic, Control siRNA, ATM siRNA, and miR-203a-3p inhibitor + ATM siRNA groups. The biological behaviors of ovarian cancer cells were evaluated by CCK-8, wound healing, and Transwell invasion assays, annexin V-FITC/PI staining and flow cytometry. The levels of Akt/GSK-3β/Snail pathway-related proteins were assessed by Western blotting.

RESULTS

Ovarian cancer tissues showed lower miR-203a-3p levels and higher ATM levels than adjacent normal tissues, both of which were associated with the FIGO stage, grade and prognosis of ovarian cancer. As confirmed by a dual-luciferase reporter gene assay, miR-203a-3p could target ATM. Furthermore, the miR-203a-3p mimic had multiple effects, including the inhibition of the proliferation, invasion and migration of A2780 and SKOV3 cells, the promotion of cell apoptosis, the arrest of the cell cycle at the G1 phase, and the blockage of the Akt/GSK-3β/Snail signaling pathway. ATM siRNA had similar effects on the biological behaviors of ovarian cancer cells, and these effects could be reversed by a miR-203a-3p inhibitor.

CONCLUSION

miR-203a-3p was capable of hindering proliferation, migration, and invasion and facilitating the apoptosis of ovarian cancer cells through its modulation of the Akt/GSK-3β/Snail signaling pathway by targeting ATM, and therefore it could serve as a potential therapeutic option for ovarian cancer.

Five serum-based miRNAs were identified as potential diagnostic biomarkers in gastric cardia adenocarcinoma

BACKGROUND

Circulating microRNAs (miRNAs) have been implicated as novel biomarkers for various types of cancers. The aim of the study is to identify serum miRNAs with potential in detecting gastric cardia adenocarcinoma (GCA).

METHODS

A three-phase study was designed with 102 GCA patients and 84 cancer-free controls. In the screening phase (3 GCA pools vs. 1 normal control (NC) pool), a total of 35 miRNAs were identified using quantitative reverse transcription polymerase chain reaction (qRT-PCR) based Exiqon panel. Subsequently, these miRNAs were further assessed by qRT-PCR in the training phase (30 GCAs vs. 30 NCs) and testing phase (72 GCAs vs. 54 NCs). Finally, the expression levels of the identified miRNAs were assessed in GCA tissues and exosomes.

RESULTS

Five up-regulated miRNAs (miR-200a-3p, miR-296-5p, miR-132-3p, miR-485-3p and miR-22-5p) were identified in serum of the GCA patients compared with NCs. The areas under the receiver operating characteristic curve (AUCs) of the five-miRNA panel were 0.766 and 0.724 for the training and testing phases, respectively. In addition, miR-200a-3p, miR-296-5p, miR-485-3p and miR-22-5p were significantly up-regulated in GCA tissues. However, none of the miRNAs in the exosomes showed different expression between GCA patients and NCs.

CONCLUSIONS

We identified a five-miRNA panel in peripheral serum samples as a non-invasive biomarker in detection of GCA.

Upregulated miR‑203a‑3p and its potential molecular mechanism in breast cancer: A study based on bioinformatics analyses and a comprehensive meta‑analysis

Breast cancer (BC) has been identified as the leading malignancy in women worldwide. However, the potential molecular mechanism of microRNA (miR)‑203a‑3p in BC remains to be elucidated. The present study evaluated the expression of miR‑203a‑3p in BC and adjacent normal tissue in several publically available datasets. The distinguishability of precursor miR‑203a and miR‑203a‑3p in BC tissue and adjacent breast tissue was assessed using receiver operating characteristic (ROC) and summarized ROC (sROC) approaches. In addition, gene ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes pathway analysis and protein‑protein interaction analysis were performed to determine the potential molecular mechanism of miR‑203a‑3p in BC. It was identified that the expression of precursor miR‑203a was markedly upregulated in 1,077 BC tissue samples compared to 104 adjacent breast tissue samples from The Cancer Genome Atlas. Additionally, an increasing trend in miR‑203a‑3p expression was observed in 756 BC tissue samples compared with 76 adjacent breast tissue samples from the University of California Santa Cruz Xena project. In addition, a comprehensive meta‑analysis suggested that the expression of miR‑203a‑3p was markedly increased in 2,444 BC tissue samples compared with 559 adjacent breast tissue samples. The area under the curve of the ROC and sROC revealed that miR‑203a‑3p expression was able to distinguish between BC tissue and adjacent breast tissue. However, miR‑203a‑3p exhibited no prognostic value in BC. The results of GO enrichment demonstrated that the miR‑203a target genes were associated with 'plasma membrane integrity', 'cell surface receptor linked signal and transduction' and '3',5'‑cyclic nucleotide phosphodiesterase activity'. 'Purine metabolism' was identified as the pathway with the most enrichment of miR‑203a‑3p target genes in BC. The present study also identified insulin‑like growth factor receptor (IGF1) as a hub gene associated with miR‑203a in BC. In summary, miR‑203a‑3p may enhance the development and oncogenesis of BC, and IGF1 was defined as a hub gene of miR‑203a‑3p in BC.

ANK1 Methylation regulates expression of MicroRNA-486-5p and discriminates lung tumors by histology and smoking status

The intragenic tumor-suppressor microRNA miR-486-5p is often down-regulated in non-small cell lung cancer (NSCLC) but the mechanism is unclear. This study investigated epigenetic co-regulation of miR-486-5p and its host gene ANK1. MiR-486-5p expression in lung tumors and cell lines was significantly reduced compared to normal lung (p < 0.001) and is strongly correlated with ANK1 expression. In vitro, siRNA-mediated ANK1 knockdown in NSCLC cells also reduced miR-486-5p while the DNA methylation inhibitor 5-aza-2'-deoxycytidine induced expression of both. ANK1 promoter CpG island was unmethylated in normal lung but methylated in 45% (118/262) lung tumors and 55% (17/31) NSCLC cell lines. After adjustment for tumor histology and smoking, methylation was significantly more prevalent in adenocarcinoma (101/200, 51%) compared to squamous cell carcinoma (17/62, 27%), p < 0.001; HR = 3.513 (CI: 1.818-6.788); and in smokers (73/128, 57%) than never-smokers (28/72, 39%), p = 0.014; HR = 2.086 (CI: 1.157-3.759). These results were independently validated using quantitative methylation data for 809 NSCLC cases from The Cancer Genome Atlas project. Together, our data indicate that aberrant ANK1 methylation is highly prevalent in lung cancer, discriminate tumors by histology and patients' smoking history, and contributes to miR-486-5p repression.

Development and validation of nomogram based on miR-203 and clinicopathological characteristics predicting survival after neoadjuvant chemotherapy and surgery for patients with non-metastatic osteosarcoma

Background

Recently, nomograms have been used as models for risk prediction in malignant tumor because they can predict the outcome of interest for a certain individual based on many variables. This study aimed to establish an effective prognostic nomogram for osteosarcoma based on the clinicopathological factors and microRNA-203.

Results

The results showed that miR-203 expression was significantly lower in osteosarcoma tissues compared with the corresponding adjacent tissues (P < 0.001). Patients with low miR-203 expression had poor overall survival (OS) in osteosarcoma. The histological type, tumor size, AJCC stage and miR-203 expression were integrated in the nomogram. The nomogram showed significantly better prediction of OS than for patients with non-metastatic osteosarcoma. The ROC curve also showed higher specificity and sensitivity for predicting 3- and 5-year osteosarcoma patients’ survival compared with AJCC stage. The decision curve analysis also indicated more potential of clinical application of the nomogram compared with AJCC staging system. Moreover, our findings were supported by the validation cohort.

Materials and Methods

We retrospectively investigated 301 patients with non-metastatic osteosarcoma. Data from primary cohort (n = 198) were used to develop multivariate nomograms. This nomogram was internally validated for discrimination and calibration with bootstrap samples and was externally validated with an independent patient cohort (n = 103).

Conclusions

Our proposed nomogram showed more accurate prognostic prediction for patients with non-metastatic osteosarcoma.

Host microRNA-203a Is antagonistic to the progression of foot-and-mouth disease virus infection

Sam68 was previously shown to be a critical host factor for foot-and-mouth disease virus (FMDV) replication. MicroRNA (miR) miR-203a is reportedly a negative regulator of Sam68 expression both in vitro and in vivo. Here, transfection of miR-203a-3p and miR-203a-5p mimics separately and in combination in a porcine cell line followed by FMDV infection resulted in diminished viral protein synthesis and a 4 and 6log reduction in virus titers relative to negative controls, respectively. Unexpectedly, Sam68 expression was increased by miR-203a-5p transfection, but not miR-203a-3p. miR-203a-5p also down-regulated Survivin expression, which was predicted to play a role in FMDV infection. Moreover, miR-203a-5p but not miR-203a-3p affected a reduction in FMDV viral RNA. These effects were not replicated with a related Picornavirus, suggesting FMDV specificity. Importantly, miR-203a-3p and miR-203a-5p impaired FMDV infection across multiple FMDV serotypes. We concluded that miR-203a-3p and miR-203a-5p represent attractive potential naturally occurring bio-therapeutics against FMDV.