[Show abstract][Hide abstract] ABSTRACT: Helicobacter pylori has been suggested to be the major cause of gastric malignancy. However, the pathogenesis and molecular mechanisms of gastric tumorigenesis induced by H. pylori infection are yet to be elucidated. In the present study, the expression levels of vascular endothelial growth factor (VEGF), which has been suggested to promote angiogenesis in gastric cancer, were found to be elevated in H. pylori‑infected MKN45 cells. Furthermore, it was demonstrated that the expression of VEGF was modulated by the p38 mitogen‑activated protein kinases (MAPK) pathway via regulation of the cyclooxygenase (COX)‑2 pathway. It was also found that prostaglandin E2 (PGE2) and its receptor EP2/EP4 may mediate the upregulation of VEGF in gastric cells exposed to H. pylori. In combination, these results suggest that VEGF expression is regulated by the p38 MAPK COX‑2-PGE2‑EP2/EP4 pathway in gastric cancer cells induced by H. pylori. This provides a theoretical basis for the investigation of the pathogenesis of H. pylori‑induced gastric cancer.
Preview · Article · Aug 2014 · Molecular Medicine Reports
[Show abstract][Hide abstract] ABSTRACT: Gastric cancer remains one of the major health problems worldwide, and it is one of the most common cancers and the leading cause of cancer-related deaths in China. This study was to analyze the expression profiles of genes in gastric carcinoma, and predict potential regulating factors. The gene expression profile data GSE13911 was downloaded from Gene Expression Omnibus and the differentially expressed genes (DEGs) were identified by t-test. Gene modules were constructed using hierarchical clustering in R based on average linkage and Pearson's correlation coefficient and functional analysis for these genes were performed with DAVID. Genes in each module with Pearson's correlation coefficient > 0.3 were obtained to construct co-expression network. Protein-protein interactions (PPI) were identified by comparing protein-protein interaction (PPI) network with co-expression networks. In addition, the potential regulatory microRNAs and the transcription factors for each module were screened out. In this study, six modules associated with protein degradation, cell cycle, protein trafficking and immunoreaction etc. were identified. COPS5 (COP9 Subunit 5) was the core protein in the largest PPI network of module 1. The transcription factors MYC and MAZ (Myc-associated zinc-finger protein) were enriched in module 1. A total of 9 MicroRNA-target bi-clusters were identified and module 1 enriched 20 genes targeting to miR-17-92 gene cluster(miR-17/20ab)and miR-106b-25 gene cluster (miR-106b/93). In conclusion, we constructed 6 gene modules and screened out some genes, transcriptional factors and microRNAs that may be used as potential molecular biomarkers for gastric carcinoma.
No preview · Article · Jun 2014 · Experimental and Molecular Pathology
[Show abstract][Hide abstract] ABSTRACT: It is costly and time-consuming to conduct the standard manual titration to identify an effective pressure before continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea (OSA) patients. Automatic titration is cheaper and more easily available than manual titration. The purpose of this systematic review was to evaluate the effect of automatic titration in identifying a pressure and on the improvement of apnea/hyponea index (AHI) and somnolence, the change of sleep quality, and the acceptance and compliance of CPAP treatment, compared with the manual titration.
A systematic search was made of the PubMed, EMBASE, Cochrane Library, SCI, China Academic Journals Full-text Databases, Chinese Biomedical Literature Database, Chinese Scientific Journals Databases and Chinese Medical Association Journals. Randomized controlled trials comparing automatic titration and manual titration were reviewed. Studies were pooled to yield odds ratios (OR) or mean differences (MD) with 95% confidence intervals (CI).
Ten trials involving 849 patients met the inclusion criteria. It is hard to identify a trend in the pressures determined by either automatic or manual titration. Automatic titration can improve the AHI (MD = 0.03/h, 95% CI = -4.48 to 4.53) and Epworth sleepiness scale (SMD = -0.02, 95% CI = -0.34 to 0.31,) as effectively as the manual titration. There is no difference between sleep architecture under automatic titration or manual titration. The acceptance of CPAP treatment (OR = 0.96, 95% CI = 0.60 to 1.55) and the compliance with treatment (MD = -0.04, 95% CI = -0.17 to 0.10) after automatic titration is not different from manual titration.
Automatic titration is as effective as standard manual titration in improving AHI, somnolence while maintaining sleep quality similar to the standard method. In addition, automatic titration has the same effect on the acceptance and compliance of CPAP treatment as manual titration. With the potential advantage of time and cost savings, automatic titration was recommended to be applied in identifying a proper pressure for CPAP treatment instead of manual titration in clinical practice.
No preview · Article · Feb 2011 · Sleep And Breathing
[Show abstract][Hide abstract] ABSTRACT: To investigate the effects of Jianpi Jiedu Formula (JPJDF), a compound Chinese herbal medicine, on vascular endothelial growth factor (VEGF) expression induced by Helicobacter pylori (Hp) in human gastric cancer cells, and to explore the possible mechanism.
Human gastric MKN45 cancer cells were infected with standard Hp NCTC11637 by coculture, and the cells were divided into 7 groups: normal control group, Hp group, NS398 inhibitor group, blank serum group, and 5%, 10% and 20% JPJDF groups. The expressions of VEGF and cyclooxygenase-2 (COX-2) mRNAs in human gastric cancer cells infected by Hp were evaluated by real-time fluorogenic quantitative polymerase chain reaction (PCR). After inhibiting the expression of COX-2 with COX-2 specific inhibitor NS398 (50 μmol/L), VEGF mRNA expression induced by Hp in human gastric cancer MKN45 cells was evaluated by real-time fluorogenic quantitative PCR.
Real-time fluorogenic quantitative PCR results showed that COX-2 mRNA expression increased significantly after MKN45 cells were infected with Hp for 6 h (P<0.01), and VEGF mRNA expression also increased significantly after MKN45 cells were infected with Hp for 12 h as compared with the normal control group (P<0.01). After inhibiting COX-2 expression with COX-2 specific inhibitor NS398, Hp-induced VEGF mRNA expression significantly reduced (P<0.01). 5%, 10% and 20% JPJDF-containing sera all down-regulated VEGF and COX-2 mRNA expressions induced by Hp in a dose-dependent manner as compared with the Hp infection group.
Hp could induce the expressions of COX-2 and VEGF in human gastric cancer cells, and JPJDF down-regulates Hp-induced expression of VEGF by inhibiting COX-2, which might be one of the important mechanisms of its prevention and treatment of gastric cancer.
No preview · Article · Oct 2010 · Journal of Chinese Integrative Medicine