H pylori status and angiogenesis factors in human gastric carcinoma

OCTA-based research on changes of retinal microcirculation in digestive tract malignancy

PURPOSE

This cross-sectional study measured retinal vessel density (VD) in patients with digestive tract malignancy by optical coherence tomography angiography (OCTA), and compared them with healthy controls to explore the retinal microcirculation changes in patients with digestive tract malignancy.

METHODS

106 eligible participants were divided into three groups: gastric cancer (GC) group (36 individuals), colorectal cancer (CRC) group (34 individuals), and healthy control group (36 individuals). Angio 6 × 6 512 × 512 R4 and ONH Angio 6 × 6 512 × 512 R4 modes were performed to collect retinal vessel density data centered on fovea and papillary, respectively. The retina was automatically segmented into different layers (superficial vascular plexus (SVP), the inner retinal layer, radial peripapillary capillary plexus (RPCP), deep vascular plexus (DVP)) and areas to analyze.

RESULTS

At the optic nerve head (ONH) region, the VD of the inner retinal layer increased in both GC and CRC groups in all quadrants and areas. In the papillary area, VD in the inner retinal layer, SVP, and RPCP increased in the GC and CRC groups. In the parapapillary area, VD in the inner retinal layer increased in the GC and the CRC groups. Significant increase in the global VD were found in the GC group of the RPCP and SVP. Regarding the macular region, no statistical differences were observed in each layer.

CONCLUSIONS

The study suggested that retinal vessel density changed in patients with digestive tract malignancy, especially in the inner retinal layer of the ONH region, revealing the potential relevance of the relation between gastrointestinal cancer and retinal microcirculation.

Co-expression of VEGF-B and FLT-1 correlates with malignancy and prognosis of gastric cancer

Background: This study aims to investigate the correlation of VEGF-B and FLT-1 co-expression with the prognosis of gastric cancer (GC). Materials & methods: Primary GC samples and adjacent tissues were obtained from 96 patients. Results: Both VEGF-B and FLT-1 were testified to be upregulated in the human GC compared with adjacent tissues. Spearman's rank correlation analysis indicated that VEGF-B and FLT-1 expression were correlated (r = 0.321, p = 0.0015). High VEGF-B and FLT-1 co-expression patients showed poor prognosis when compared with low VEGF-B and FLT-1 co-expression patients (p = 0.0169). Conclusion: The high co-expression of VEGF-B and FLT-1 in GC shows a poor prognosis of overall survival, and targeted therapy against the interaction between VEGF-B and FLT-1 is worth further detailed analysis.

VEGF-A and VEGF-B mRNA expression in gastro-oesophageal cancers

INTRODUCTION

Angiogenesis is essential for the local growth, invasion and metastasis of the tumours. Vascular endothelial growth factors (VEGFs) play a crucial role in tumour angiogenesis. The aim of our study was to quantify the expression of several VEGF family molecules in human gastro-oesophageal cancers and to analyse possible correlations between genes expression and clinico-pathological features.

MATERIALS AND METHODS

Gene expression was quantified in 43 gastro-oesophageal paired samples using qRT-PCR with TaqMan probes specific to VEGF-A, including soluble transcript variants and VEGF-B genes.

RESULTS

VEGF-A, including the studied splice variants and VEGF-B mRNAs were expressed in both tumour and peritumour mucosa. The expression of VEGF-A and its isoforms was higher in tumour compared with paired peritumour mucosa, while no significant difference was observed in VEGF-B expression. VEGF-A expression tended to correlate with tumour invasion.

CONCLUSION

VEGF-A has a tendency to over-express in gastro-oesophageal cancers, while VEGF-B does not seem involved in these tumours. Further studies are required to establish the utility of anti-VEGF-A therapy and to find biomarkers for pathogenesis or response to therapy in gastro-oesophageal tumours.

Reduced serum vascular endothelial growth factor receptor-2 (sVEGFR-2) and sVEGFR-1 levels in gastric cancer patients

The relationship between gastric cancer and serum vascular endothelial growth factor receptor-1 (sVEGFR-1) and sVEGFR-2, which are soluble form receptor proteins of vascular endothelial growth factor (VEGF), has not been extensively studied. VEGF, sVEGFR-1 and sVEGFR-2 were measured in the sera obtained before surgical operation from 164 gastric cancer patients and from 164 healthy controls matched for age and gender. Compared with controls, the cases showed elevated VEGF (P < 0.01) and reduced sVEGFR-1 (P = 0.07) and sVEGFR-2 (P = 0.02). The difference in VEGF levels was small among men and when the outcome was early cancer. The difference in sVEGFR-1 levels was significant or borderline significant only in men and when the outcome was diffuse type cancer. The difference in sVEGFR-2 levels was significant only in men and when the outcome was advanced or diffuse type cancer. The sensitivities and specificities of VEGF, sVEGFR-1 and sVEGFR-2 were all approximately 60%. For diffuse type cancer, sVEGFR-2 showed a sensitivity of 62.4% and a specificity of 63.4%, which was similar to serum pepsinogen. In conclusion, elevated VEGF and reduced sVEGFR-1 and sVEGFR-2 in serum are characteristic of gastric cancer patients, and the value of serum sVEGFR-2 in the diagnosis of diffuse type gastric cancer should be further evaluated.

The relationship between Helicobacter pylori genes cagE and virB11 and gastric cancer

BACKGROUND

The association between Helicobacter pylori gene diversity and gastric cancer has been poorly reported, although it is one of the important ways to explain the gastric pathogenesis. The aim of this study was to investigate the frequency of cagE and virB11 genes in H. pylori isolated from patients with gastric cancer and to analyze the histology profiles.

MATERIALS AND METHODS

The presence of H. pylori and subtypes (cagE and virB11) was detected by PCR from the genomic DNA of 101 patients who had been diagnosed with gastric cancer. The cases were grouped according to the presence/absence of the genes studied and were analyzed in relation to histopathological parameters.

RESULTS

H. pylori infection was detected in 94 out of 101 (93.1%) gastric carcinomas. The cases were categorized into the following groups: cagE+/virB11+, cagE+/virB11-, cagE-/virB11+, and cagE-/virB11-. Frequencies were: 50% (47/94) cagE+/virB11+, 3.2% (3/94) cagE+/virB11-, 10.6% (10/94) cagE-/virB11+, and 36.2% (34/94) cagE-/virB11-. Tumors in the gastric antrum were predominant. An exception was the cagE-/virB11- group, in which tumors had a tendency to be located in the gastric cardia; the majority of the cardia tumors (56% (14/25)) were in this group. Intestinal histology type was the most frequent, but the cagE+/virB11- group only had diffuse tumors. H. pyloricagE+/virB11+ occurred most frequently (except at stage III), and was present at all gastric cancer stages.

CONCLUSIONS

This study is the first to include a relevant number of gastric cancer cases with H. pylori infection, reporting the frequency and relationship of cagE and virB11 genes and the genesis of this tumor. The presence of these cag pathogenicity island genes shows that they are important factors for the pathogenesis and malignancy of gastric cancer related to H. pylori.

Serum vascular endothelial growth factor and angiogenesis are related to the prognosis of patients with gastrointestinal stromal tumors

AIM

To investigate if serum vascular endothelial growth factor (SVEGF), tissue VEGF and microvessel density (MVD) have any relation to progress and prognosis in gastrointestinal stromal tumors (GIST).

METHODS

SVEGF was examined using ELISA. VEGF and MVD were examined using immunohistochemical staining.

RESULTS

The median level of SVEGF was higher in GIST than in controls. A higher level of SVEGF and a positive expression rate of VEGF were obtained in diameter >or=5 cm, mitotic count >or=2/10 high power fields (HPF), recurrence and high risk groups. The MVD of experimental was higher than that of controls. A higher MVD was observed in mitotic count >or=2/10HPF and recurrence groups. The median level of SVEGF was higher in the VEGF positive group than in the controls. The SVEGF presented a relationship with MVD. Factors predicating poor prognosis were SVEGF and VEGF.

CONCLUSIONS

SVEGF and VEGF show a correlation with poor prognosis of GIST.

Up-regulation of intestinal vascular endothelial growth factor by Afa/Dr diffusely adhering Escherichia coli

BACKGROUND

Angiogenesis has been recently described as a novel component of inflammatory bowel disease pathogenesis. The level of vascular endothelial growth factor (VEGF) has been found increased in Crohn's disease and ulcerative colitis mucosa. To question whether a pro-inflammatory Escherichia coli could regulate the expression of VEGF in human intestinal epithelial cells, we examine the response of cultured human colonic T84 cells to infection by E. coli strain C1845 that belongs to the typical Afa/Dr diffusely adhering E. coli family (Afa/Dr DAEC).

METHODOLOGY

VEGF mRNA expression was examined by Northern blotting and q-PCR. VEGF protein levels were assayed by ELISA and its bioactivity was analysed in endothelial cells. The bacterial factor involved in VEGF induction was identified using recombinant E. coli expressing Dr adhesin, purified Dr adhesin and lipopolysaccharide. The signaling pathway activated for the up-regulation of VEGF was identified using a blocking monoclonal anti-DAF antibody, Western blot analysis and specific pharmacological inhibitors.

PRINCIPAL FINDINGS

C1845 bacteria induce the production of VEGF protein which is bioactive. VEGF is induced by adhering C1845 in both a time- and bacteria concentration-dependent manner. This phenomenon is not cell line dependent since we reproduced this observation in intestinal LS174, Caco2/TC7 and INT407 cells. Up-regulation of VEGF production requires: (1) the interaction of the bacterial F1845 adhesin with the brush border-associated decay accelerating factor (DAF, CD55) acting as a bacterial receptor, and (2) the activation of a Src protein kinase upstream of the activation of the Erk and Akt signaling pathways.

CONCLUSIONS

Results demonstrate that a Afa/Dr DAEC strain induces an adhesin-dependent activation of DAF signaling that leads to the up-regulation of bioactive VEGF in cultured human intestinal cells. Thus, these results suggest a link between an entero-adherent, pro-inflammatory E. coli strain and angiogenesis which appeared recently as a novel component of IBD pathogenesis.