Deregulation of E2F1 activity is characteristic of gastric tumorigenesis, which involves in complex molecular mechanisms. microRNA is one of the post-transcriptional regulators for gene expression. Here, we report a member of miR-331 family, miR-331-3p, which was decreased in some kinds of malignancies. However, the biological function of miR-331-3p on gastric cancer is largely unknown. In this study, we screened the expressing levels of miR-331-3p and E2F1 in gastric cancer cell lines. We transfected precursor or inhibitor of miR-331-3p into gastric cancer cells. As results, miR-331-3p is down-regulated in all gastric cancer cell lines by real-time PCR. Over-expression of miR-331-3p blocked G1/S transition on SGC-7901 and AGS cell lines. Introduction of miR-331-3p dramatically suppressed the ability of colony formation and cell growth in vitro by interfering E2F1 activity. Our data highlight an important role of miR-331-3p in cell cycle control by targeting 3'-UTR of cell cycle-related molecule E2F1. We concluded that miR-331-3p is a potential tumor suppressor in gastric cancer. Restoring miR-331-3p in gastric cancer cells revealed potential application in gastric cancer therapy.
"Similarly, overexpression of miR-766 was shown to significantly inhibit the expression of pro-apoptotic genes caspase-3 and Bax in acute promyelocytic leukemia cells . Previous studies have also shown that miR-331-3p, a member of miR-331 family, may be involved in cell cycle control by targeting the 3′-untranslated region of the cell cycle-related molecule, E2F1 . The ORA in this study also revealed a significant enrichment of miRNA targets involved in NSCLC and SCLC KEGG pathways. "
[Show abstract][Hide abstract] ABSTRACT: Background
Lung adenocarcinoma is a heterogernous disease that creates challenges for classification and management. The purpose of this study is to identify specific miRNA markers closely associated with the survival of LUAD patients from a large dataset of significantly altered miRNAs, and to assess the prognostic value of this miRNA expression profile for OS in patients with LUAD.
We obtained miRNA expression profiles and corresponding clinical information for 372 LUAD patients from The Cancer Genome Atlas (TCGA), and identified the most significantly altered miRNAs between tumor and normal samples. Using survival analysis and supervised principal components method, we identified an eight-miRNA signature for the prediction of overall survival (OS) of LUAD patients. The relationship between OS and the identified miRNA signature was self-validated in the TCGA cohort (randomly classified into two subgroups: n = 186 for the training set and n = 186 for the testing set). Survival receiver operating characteristic (ROC) analysis was used to assess the performance of survival prediction. The biological relevance of putative miRNA targets was also analyzed using bioinformatics.
Sixteen of the 111 most significantly altered miRNAs were associated with OS across different clinical subclasses of the TCGA-derived LUAD cohort. A linear prognostic model of eight miRNAs (miR-31, miR-196b, miR-766, miR-519a-1, miR-375, miR-187, miR-331 and miR-101-1) was constructed and weighted by the importance scores from the supervised principal component method to divide patients into high- and low-risk groups. Patients assigned to the high-risk group exhibited poor OS compared with patients in the low-risk group (hazard ratio [HR] = 1.99, P <0.001). The eight-miRNA signature is an independent prognostic marker of OS of LUAD patients and demonstrates good performance for predicting 5-year OS (Area Under the respective ROC Curves [AUC] = 0.626, P = 0.003), especially for non-smokers (AUC = 0.686, P = 0.023).
We identified an eight-miRNA signature that is prognostic of LUAD. The miRNA signature, if validated in other prospective studies, may have important implications in clinical practice, in particular identifying a subgroup of patients with LUAD who are at high risk of mortality.
Journal of Translational Medicine 06/2014; 12(1):159. DOI:10.1186/1479-5876-12-159 · 3.93 Impact Factor
"We and others identified several targets of miR-331-3p in prostate cancer cells, including ErbB-2 , DOHH  and KLK4 . It was also proposed that miR-331-3p may coordinately regulate cell cycle progression in gastric cancer cells . Interestingly, in the present study we observed that expression of DOHH, an enzyme involved in the activation of eIF5A and control of cell cycle progression , is regulated by miR-331-3p in GBM cell lines. "
[Show abstract][Hide abstract] ABSTRACT: Aberrant expression of microRNAs (miRNAs), a class of small non-coding regulatory RNAs, has been implicated in the development and progression of high-grade gliomas. However, the precise mechanistic role of many miRNAs in this disease remains unclear. Here, we investigate the functional role of miR-331-3p in glioblastoma multiforme (GBM). We found that miR-331-3p expression in GBM cell lines is significantly lower than in normal brain, and that transient overexpression of miR-331-3p inhibits GBM cell line proliferation and clonogenic growth, suggesting a possible tumor suppressor role for miR-331-3p in this system. Bioinformatics analysis identified neuropilin-2 (NRP-2) as a putative target of miR-331-3p. Using transfection studies, we validated NRP-2 mRNA as a target of miR-331-3p in GBM cell lines, and show that NRP-2 expression is regulated by miR-331-3p. RNA interference (RNAi) to inhibit NRP-2 expression in vitro decreased the growth and clonogenic growth of GBM cell lines, providing further support for an oncogenic role for NRP-2 in high-grade gliomas. We also show that miR-331-3p inhibits GBM cell migration, an effect due in part to reduced NRP-2 expression. Finally, we identified a significant inverse correlation between miR-331-3p and NRP-2 expression in The Cancer Genome Atlas GBM cohort of 491 patients. Together, our results suggest that a loss of miR-331-3p expression contributes to GBM development and progression, at least in part via upregulating NRP-2 expression and increasing cell proliferation and clonogenic growth.
Journal of Neuro-Oncology 10/2013; 116(1). DOI:10.1007/s11060-013-1271-7 · 3.07 Impact Factor
"MKN-45, MKN-28, SGC-7901, the immortalized human gastric mucosal cell line GES-1(provided by the institute of digestive surgery of Ruijin hospital affiliated to Shanghai Jiao Tong University) [13,14,15,16,17] and human umbilical vein endothelial cells (HUVECs) were preserved in our institute. Gastric cancer cell lines SNU-1 and NCI-N87 cells were obtained from American Type Culture Collection (Manassas, VA, USA). "
[Show abstract][Hide abstract] ABSTRACT: Vezatin (VEZT), an adherens junctions transmembrane protein, was identified as a putative tumor suppressor in our previous study. However, the role of VEZT in tumorigenesis remains elusive. We aimed to clarify its epigenetic regulation and biological functions in gastric cancer. In this study, we show that the expression level of VEZT is involved in lymphatic metastasis, depth of cancer invasion and TNM stage in 104 gastric cancer patients. Bisulfate sequencing polymerase chain reaction (BSP) methods showed that VEZT was hypermethylated in tissues and corresponding blood of gastric cancer patients compared with healthy controls. Helicobacter pylori (H. pylori) infection induces the methylation and silencing of VEZT in GES-1 cells. Restoring VEZT expression in MKN-45 and NCI-N87 gastric cancer cells inhibited growth, invasion and tumorigenesis in vitro and in vivo. Global microarray analysis was applied to analyze the molecular basis of the biological functions of VEZT after VEZT transfection combined with real-time PCR and chromatin immunoprecipitation assay. G protein-coupled receptor 56(GPR56), cell growth, cell division cycle 42(CDC42), migration/invasion and transcription factor 19(TCF19), cell cycle progression, were identified as direct VEZT target genes. TCF19, a novel target of VEZT, was functionally validated. Overexpression of TCF19 in MKN-45 cells increased cell cycle progress and growth ability. This study provides novel insight into the regulation of the VEZT gene, which could represent a potential target for therapeutic anti-cancer strategies.
PLoS ONE 09/2013; 8(9):e74409. DOI:10.1371/journal.pone.0074409 · 3.23 Impact Factor
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