Robust analysis of novel mRNA-lncRNA cross talk based on ceRNA hypothesis uncovers carcinogenic mechanism and promotes diagnostic accuracy in esophageal cancer.

BACKGROUND: ceRNAs have emerged as pivotal players in the regulation of gene expression and play a crucial role in the physiology and development of various cancers. Nevertheless, the function and underlying mechanisms of ceRNAs in esophageal cancer (EC) are still largely unknown. METHODS: In this study, profiles of DEmRNAs, DElncRNAs, and DEmiRNAs between normal and EC tumor tissue samples were obtained from the Cancer Genome Atlas database using the DESeq package in R by setting the adjusted P<0.05 and |log2(fold change)|>2 as the cutoff. The ceRNA network (ceRNet) was initially constructed to reveal the interaction of these ceRNAs during carcinogenesis based on the bioinformatics of miRcode, miRDB, miRTarBase, and TargetScan. Then, independent microarray data of GSE6188, GSE89102, and GSE92396 and correlation analysis were used to validate molecular biomarkers in the initial ceRNet. Finally, a least absolute shrinkage and selection operator logistic regression model was built using an oncogenic ceRNet to diagnose EC more accurately. RESULTS: We successfully constructed an oncogenic ceRNet of EC, crosstalk of hsa-miR372-centered CADM2-ADAMTS9-AS2 and hsa-miR145-centered SERPINE1-PVT1. In addition, the risk-score model -0.0053*log2(CADM2)+0.0168*log2(SERPINE1)-0.0073*log2(ADAMTS9-AS2)+0.0905*log2(PVT1)+0.0047*log2(hsa-miR372)-0.0193*log2(hsa-miR145), (log2[gene count]) could improve diagnosis of EC with an AUC of 0.988. CONCLUSION: We identified two novel pairs of ceRNAs in EC and its role of diagnosis. The pairs of hsa-miR372-centered CADM2-ADAMTS9-AS2 and hsa-miR145-centered SERPINE1-PVT1 were likely potential carcinogenic mechanisms of EC, and their joint detection could improve diagnostic accuracy.

The 50 Most-cited Articles in Gastroenterology and Hepatology from Mainland China.

OBJECTIVE: To identify and analyze the 50 most-cited gastroenterology and hepatology articles originating from mainland China. METHODS: We utilized the 2015 edition of Journal Citation Reports and PubMed to determine the 50 most-cited gastroenterology and hepatology articles from 75 professional journals and four leading journals in clinical medicine, which are The New England Journal of Medicine, The Lancet, The Journal of the American Medical Association, and The British Medical Journal. Then we excluded the articles written outside mainland China and collected the basic information, including the title, authors, year of publication, source journal, city, institution, number of citations, and topic of the research. RESULTS: The number of citations for the top 50 papers ranged from 279 to 89 (mean, 129). These articles were published between 2005 and 2012, in which 2009 was the year with the largest number of highly cited papers(13). All articles were published in 15 journals. The journal Hepatology published the largest number of articles(21), followed by Journal of Gastroenterology and Hepatology(4), Journal of Hepatology(4) and World Journal of Gastroenterology(4). The top 50 articles originated mainly from Shanghai(20), Guangzhou(13) and Beijing(6). Sun Yat-sen University produced most highly cited papers(10). The number of basic research was far more than clinical research, of which the ratio was about 1.78(32:18). In all these articles, hepatocellular carcinoma was the most-discussed topic(19), followed by hepatitis B virus(8) and endoscopic(5). CONCLUSIONS: Although a large gap remains between mainland China and the global community, the gastroenterology and hepatology research from China is gradually recognized by the world.

Differential expression of Notch1 intracellular domain and p21 proteins, and their clinical significance in gastric cancer.

Changes in the expression of the Notch1 intracellular domain (NICD) and p21 proteins have been shown to be closely associated with the development and progression of a number of cancers. The present study aimed to investigate the expression levels of the two proteins in gastric carcinoma and precancerous lesions, and to determine the clinical significance of this. A total of 109 gastric cancer, 57 precancerous gastric lesion, 50 chronic superficial gastritis and 17 normal gastric mucosa patients were recruited for immunohistochemical staining of NICD and p21 protein expression. The protein expression levels in the gastric cancer patient samples were associated with the clinicopathological and survival data. NICD protein levels were upregulated gradually from normal gastric mucosae through chronic superficial gastritis and precancerous gastric lesions to gastric cancer tissues (P<0.01), whereas p21 protein levels were downregulated accordingly (P<0.01). Increased NICD and a loss of p21 expression were closely associated with tumor dedifferentiation, depth of tumor invasion, lymph node metastasis, surface morphology and Lauren classification in gastric cancer. Thus, NICD expression was inversely associated with p21 expression. In addition, the overall survival rate was greater in NICD- and P21+ patients than in NICD+ and P21- patients, respectively (P<0.05). The COX regression multivariate analysis revealed that NICD+, p21-, depth of tumor invasion and lymph node metastasis were all independent prognostic factors for patients with gastric cancer. NICD and p21 proteins are differentially expressed in gastric cancer and the aberrant expression of these proteins is associated with an advanced tumor stage, tumor metastasis and overall patient survival. Future studies are required to further evaluate the two proteins as novel prognostic markers for patients with gastric cancer.