Identification of a five-long non-coding RNA signature to improve the prognosis prediction for patients with hepatocellular carcinoma.

AIM: To construct a long non-coding RNA (lncRNA) signature for predicting hepatocellular carcinoma (HCC) prognosis with high efficiency. METHODS: Differentially expressed lncRNAs (DELs) between HCC specimens and peritumor liver specimens were identified using the edgeR package to analyze The Cancer Genome Atlas (TCGA) LIHC dataset. Univariate Cox proportional hazards regression was performed to obtain the DELs significantly associated with overall survival (OS) in a training set. These OS-related DELs were further analyzed using a stepwise multivariate Cox regression model. Those lncRNAs fitted in the multivariate Cox regression model and independently associated with overall survival were chosen to build a prognostic risk formula. The prognostic value of this formula was then validated in the test group and the entire cohort and further compared with two previously identified prognostic signatures for HCC. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed to explore the potential biological functions of the lncRNAs in the signature. RESULTS: Based on lncRNA expression profiling of 370 HCC patients from the TCGA database, we constructed a 5-lncRNA signature (AC015908.3, AC091057.3, TMCC1-AS1, DCST1-AS1 and FOXD2-AS1) that was significantly associated with prognosis. HCC patients with high-risk scores based on the expression of the 5 lncRNAs had significantly shorter survival times compared to patients with low-risk scores in both the training and test groups. Multivariate Cox regression analysis demonstrated that the prognostic value of the 5 lncRNAs was independent of clinicopathological parameters. A comparison study involving two previously identified prognostic signatures for HCC demonstrated that this 5-lncRNA signature showed improved prognostic power compared with the other two signatures. Functional enrichment analysis indicated that the 5 lncRNAs were potentially involved in metabolic processes, fibrinolysis and complement activation. CONCLUSION: Our present study constructed a 5-lncRNA signature that improves survival prediction and can be used as a prognostic biomarker for HCC patients.

Milk fat globule-epidermal growth factor 8 is decreased in intestinal epithelium of ulcerative colitis patients and thereby causes increased apoptosis and impaired wound healing.

Milk fat globule-epidermal growth factor 8 (MFG-E8) plays an important role in maintaining intestinal barrier homeostasis and accelerating intestinal restitution. However, studies of MFG-E8 expression in humans with ulcerative colitis are lacking. We examined MFG-E8 expression in colonic mucosal biopsies from ulcerative colitis patients and healthy controls (n = 26 each) by real-time quantitative polymerase chain reaction (PCR), Western blot analysis and immunohistochemistry. MFG-E8 mRNA and protein expression was lower in ulcerative colitis patients than in controls. MFG-E8 expression was inversely correlated with mucosal inflammatory activity and clinical disease activity in patients. MFG-E8 was present in human intestinal epithelial cells both in vivo and in vitro. Apoptosis induction was also detected in the intestinal epithelium of ulcerative colitis patients by terminal-deoxynucleoitidyl transferase mediated nick-end labeling assay. We used lentiviral vectors encoding human MFG-E8 targeting short hairpin RNA to obtain MFG-E8 knockdown intestinal epithelia cell clones. MFG-E8 knockdown could promote apoptosis in intestinal epithelial cell lines, accompanied by a decrease in level of the antiapoptotic protein B-cell lymphoma 2 (BCL-2) and induction of the proapoptotic protein BCL2-associated protein X (BAX). The addition of recombinant human MFG-E8 led to decreased BAX and cleaved caspase-3 levels and induction of BCL-2 level in intestinal epithelia cells. MFG-E8 knockdown also attenuated wound healing on scratch assay of intestinal epithelial cells. The mRNA level of intestinal trefoid factor 3, a pivotal factor in intestinal epithelial cell migration and restitution, was downregulated with MFG-E8 knockdown. In conclusion, we demonstrated that decreased colonic MFG-E8 expression in patients with ulcerative colitis may be associated with mucosal inflammatory activity and clinical disease activity through basal cell apoptosis and preventing tissue healing in the pathogenesis of ulcerative colitis.

Brain-derived neurotrophic factor contributes to abdominal pain in irritable bowel syndrome.

OBJECTIVE: Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, may play a critical role in many chronic pain conditions. The possible involvement of BDNF in the altered gut sensation in patients with irritable bowel syndrome (IBS) was investigated in the present study. METHODS: Rectosigmoid biopsies were collected from 40 patients with IBS fulfilling the Rome II criteria and 21 healthy controls. Abdominal pain was quantified by a validated questionnaire. The presence of BDNF and nerve fibres in the mucosa was assessed by immunohistochemistry. The structure of mucosal nerve fibres was assessed by transmission electron microscopy. Mucosal BDNF release was measured by ELISA and correlated with abdominal pain scores. Animal studies using BDNF(+/-) mice were carried out to evaluate visceral sensitivity, mucosal nerve fibre density and ultrastructural changes. Alterations of visceral sensitivity and TrkB expression in dorsal root ganglia were examined in BDNF(+/+) mice following different doses of BDNF administration. RESULTS: Biopsies from patients with IBS revealed a significant upregulation of BDNF (p=0.003), as compared with controls. Total nerve fibres were also substantially increased in patients with IBS. Electron microscopy showed ultrastructural damage on the mucosal nerve fibres (eg, swollen mitochondria and nerve axons). Elevated BDNF release was significantly correlated with the abdominal pain scores. Meanwhile, abdominal withdrawal reflex scores to colorectal distension and mucosal protein gene product 9.5 immunoreactivity were significantly lowered in BDNF(+/-) than in BDNF(+/+) mice. Electron microscopy showed degenerative changes on the mucosal nerve fibres in BDNF(+/-) mice. Exogenous BDNF induced an obvious dose-dependent increase in TrkB expression in dorsal root ganglia and dose-dependent decrease in threshold pressure in BDNF(+/+) mice. CONCLUSIONS: The increased expression of BDNF in colonic mucosa, together with the structural alterations of mucosal innervation, may contribute to the visceral hyperalgesia in IBS.

Prevalence of irritable bowel syndrome in Chinese college and university students assessed using Rome III criteria.

AIM: To estimate the prevalence of irritable bowel syndrome (IBS) in college and university students of North China and certain related factors for IBS. METHODS: A total of 2500 students from Shandong University in North China were asked in February-March 2009 to complete questionnaires, including the Rome III questionnaire, hospital anxiety and depression scale, and IBS-quality of life questionnaire (IBS-QOL). RESULTS: Among the 2126 students with complete data, the prevalence of IBS was 7.85% according to the Rome III criteria, with a female/male ratio of 1.78:1. Most students had the IBS-constipation subtype (36.5%), followed by IBS-diarrhea subtype (31.1%) and IBS-mixed subtype (23.9%). The students with IBS had a higher anxiety and depression score than those without IBS. Low exercise level and anxiety indicated a high risk for IBS. The mean score of IBS patients was 74.2 +/- 4.242 on the IBS-QOL. CONCLUSION: The prevalence of IBS is 7.85% in Chinese college and university students according to the Rome III criteria. Low exercise level and anxiety may be the risk factors for IBS.