Role of therapy or monitoring in preventing progression to gastric cancer

Effects of Granule Dendrobii on chronic atrophic gastritis induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats

BACKGROUND

Dendrobium officinale is an herb of Traditional Chinese Medicine (TCM) commonly used for treating stomach diseases. One formula of Granule Dendrobii (GD) consists of Dendrobium officinale and American Ginseng (Radix Panacis quinquefolii), and is a potent TCM product in China. Whether treatment with GD can promote gastric acid secretion and alleviate gastric gland atrophy in chronic atrophic gastritis (CAG) requires verification.

AIM

To determine the effect of GD treatment on CAG and its potential cellular mechanism.

METHODS

A CAG model was induced by feeding rats N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) for 12 wk. After oral administration of low, moderate, and high doses of GD in CAG rats for 8 wk, its effects on body weight, gastric mucosa histology, mucosal atrophy, intestinal metaplasia, immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and B-cell lymphoma-2, and hemoglobin and red blood cells were examined.

RESULTS

The body weights of MNNG-induced CAG model rats before treatment (143.5 ± 14.26 g) were significantly lower than that of healthy rats (220.2 ± 31.20 g, P < 0.01). At the 8^th week of treatment, the body weights of rats in the low-, moderate-, and high-dose groups of GD (220.1 ± 36.62 g) were significantly higher than those in the untreated group (173.3 ± 28.09 g, all P < 0.01). The level of inflammation in gastric tissue of the high-dose group (1.68 ± 0.54) was significantly reduced (P < 0.01) compared with that of the untreated group (3.00 ± 0.00, P < 0.05). The number and thickness of gastric glands in the high-dose group (31.50 ± 6.07/mm, 306.4 ± 49.32 µm) were significantly higher than those in the untreated group (26.86 ± 6.41/mm, 244.3 ± 51.82 µm, respectively, P < 0.01 and P < 0.05), indicating improved atrophy of gastric mucosa. The areas of intestinal metaplasia were significantly lower in the high-dose group (1.74% ± 1.13%), medium-dose group (1.81% ± 0.66%) and low-dose group (2.36% ± 1.08%) than in the untreated group (3.91% ± 0.96%, all P < 0.01). The expression of PCNA in high-dose group was significantly reduced compared with that in untreated group (P < 0.01). Hemoglobin level in the high-dose group (145.3 ± 5.90 g/L), medium-dose group (139.3 ± 5.71 g/L) and low-dose group (137.5 ± 7.56 g/L) was markedly increased compared with the untreated group (132.1 ± 7.76 g/L; P < 0.01 or P < 0.05).

CONCLUSION

Treatment with GD for 8 wk demonstrate that GD is effective in the treatment of CAG in the MNNG model by improving the histopathology of gastric mucosa, reversing gastric atrophy and intestinal metaplasia, and alleviating gastric inflammation.

Expression of GCRG213p, LINE-1 endonuclease variant, significantly different in gastric complete and incomplete intestinal metaplasia

Background

Intestinal metaplasia (IM) of the gastric mucosa is classified as complete (Type I) and incomplete IM (Type II and III) subtypes, which showed significantly different risk for developing to gastric adenocarcinoma (GAC). GCRG213, a variant of L1-endonuclease (L1-EN), first identified in our lab, was upregulated in GAC tissue. However, the relationship between GCRG213 and IM subtypes is not clear. Our study explored the association of GCRG213 protein (GCRG213p) with IM subtypes.

Methods

Gastric cancer and/or para-tumor tissue samples were collected from 123 patients who underwent gastrectomy for intestinal type gastric adenocarcinoma. The subtypes of IM were characterized with Alcian blue-periodic acid-Schiff and High Iron Diamine-Alcian blue staining methods. Immunohistochemistry of GCRG213p was performed, and its expression in gastric adenocarcinoma and para-tumor tissue including dysplasia, IM, and normal mucosa were analyzed.

Results

GCRG213p was expressed in 48.94% IM, 57.14% dysplasia and 55.32% GAC, respectively. GCRG213p expression was higher in well and moderately differentiated adenocarcinoma (P = 0.037). In IM glands, GCRG213p expressed mainly in the cytoplasm of absorptive enterocytes with defined brush borders, but not in goblet cells. The expression of GCRG213p in type I IM (90.00%) was significantly higher than that in type II (36.36%) and type III (25.00%) (P < 0.001). In normal gastric mucosa, GCRG213p was exclusively positive in the cytoplasm of gastric chief cells.

Conclusions

The expression of GCRG213p in complete IM was significantly higher than in incomplete IM, which implies that GCRG213p may play a role on the developing of IM to adenocarcinoma. GCRG213p was exclusively expressed in chief cells, suggesting that it might be involved in cell differentiation from the chief cells to IM.

Characterization of progressive metaplasia in the gastric corpus mucosa of Mongolian gerbils infected with Helicobacter pylori

Spasmolytic polypeptide-expressing metaplasia (SPEM) and intestinal metaplasia are considered neoplastic precursors of gastric adenocarcinoma in humans. Loss of parietal cells causes the development of SPEM in the gastric corpus and then chronic inflammation drives SPEM toward a more proliferative lineage. Mongolian gerbils infected with Helicobacter pylori develop chronic gastritis and metaplasia, mimicking aspects of human gastritis with H. pylori infection. We therefore examined metaplastic lineages in the gastric corpus mucosa of gerbils infected by H. pylori strain 7.13, which produces rapid onset of severe inflammation. Six weeks following H. pylori infection, Griffonia simplicifolia lectin II (GSII)-positive SPEM developed in the base of oxyntic glands in association with parietal cell loss and inflammation. In association with severe inflammation, SPEM glands evolved into aberrant phenotypes, including branched lesions, dilated lesions, and penetrating invasive glands. Mucin 4 (MUC4) was up-regulated in SPEM and progressive SPEM. Clusterin was expressed in the tips of branched and dilated lesions and throughout regions of invasive glands. Intriguingly, clusterin-positive regions in these lesions expressed Ki67 and matrix metalloproteinase 7 (MMP-7). These same regions were also positive for expression of phospho-IkBα, suggestive of activated NFkB signalling. These findings suggest that clusterin-positive regions in progressive phenotypes of SPEM have invasive characteristics. Thus, H. pylori infection in gerbils induces SPEM, which then can progress to further aberrant and invasive metaplastic phenotypes. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Correlation between Endoscopic and Histological Diagnoses of Gastric Intestinal Metaplasia

BACKGROUND/AIMS

Intestinal metaplasia (IM) is a premalignant condition. This study aimed to evaluate the correlation between endoscopic and histological findings of IM.

METHODS

The cases of IM were graded by conventional endoscopy, and biopsies were taken from the antrum and body of 1,333 subjects for histological IM diagnosis. Multivariate analyses were performed to identify the factors that affect the sensitivity of endoscopic IM diagnosis.

RESULTS

The sensitivity/specificity of endoscopic IM diagnosis based on histology was 24.0%/91.9% for the antrum and 24.2%/88.0% for the body. As indicated by multivariate analysis, the presence of endoscopic atrophic gastritis (AG) (odds ratio [OR], 4.73; 95% confidence interval [CI], 2.07 to 10.79) and the activity of mucosal inflammation (OR, 2.21; 95% CI, 1.08 to 4.54) were associated with the sensitivity of endoscopic IM diagnosis in the antrum, while the presence of endoscopic AG (OR, 8.02; 95% CI, 4.55 to 14.15), dysplasia (OR, 2.40; 95% CI, 1.07 to 5.39), and benign gastric ulcers (OR, 0.35; 95% CI, 0.15 to 0.081) were associated with the sensitivity of endoscopic IM diagnosis in the body.

CONCLUSIONS

As the sensitivity of endoscopic IM diagnosis was low, a high index of suspicion for IM is necessary in the presence of atrophy, and confirmation by histology is also necessary.

[Predictive significance of serum IL-6, VEGF, and CRP in gastric adenoma and mucosal carcinoma before endoscopic submucosal dissection]

BACKGROUND/AIMS

Endoscopic submucosal dissection (ESD) is commonly used for radical resection of gastric adenoma and mucosal cancer, but there is about 30% of discrepancy rate between the histology of the endoscopic biopsy and that of the resected specimen obtained from the same lesion by ESD. The aim of this study was to clarify the clinical significance of IL-6, VEGF, CRP before ESD.

METHODS

We investigated the correlation between serum IL-6, VEGF, CRP level and discrepancy rate of gastric neoplastic lesions (10 low-grade dysplasias, 18 high-grade dysplasias, and 25 early gastic cancers).

RESULTS

Serum levels of IL-6 in gastric adenoma and mucosal cancer patients were significantly higher than in healthy controls (p<0.05). Especially, serum IL-6 level of high-grade dysplasia patient was significantly higher than low-grade dysplasia and mucosal cancer patients, and the positive rate, sensitivity, and negative predictive value of serum IL-6 levels were higher in high-grade dysplasia patient compared to low-grade dysplasia patient and mucosal cancer patient. Serum levels of VEGF in patients with gastric adenoma and mucosal cancer were significantly higher than healthy controls (p<0.01). Serum levels of CRP in patients with mucosal cancer were significantly higher than in the controls (p<0.05), and the positive rate, sensitivity, and positive predictive value of serum CRP levels were higher in high-grade dysplasia and mucosal cancer patients compared to low-grade dysplasia patient.

CONCLUSIONS

Serum levels of IL-6, VEGF, and CRP in patients with gastric neoplastic lesions were significantly higher than healthy controls, especially, serum IL-6 level of high grade dysplasia patient was significantly higher than low-grade dysplasia and mucosal cancer patients.

Helicobacter pylori infection and related gastrointestinal diseases

Helicobacter pylori has been implicated in the pathogenesis of a number of digestive tract disorders, such as chronic active gastritis, peptic ulceration, gastric cancer, and mucosa-associated lymphoid tissue lymphoma. Disease outcome is dependent on many factors, including bacterial genotype, host physiology and genetics, and environmental factors such as diet. Researchers continue to explore the complexities of H. pylori infection, seeking to explain why some individuals have asymptomatic infection, whereas others experience clinical disease. The importance of treating H. pylori infection in patients with gastrointestinal problems has been confirmed in recent years, with clinical trials showing that cure of infection can prevent duodenal ulcer and, to a lesser extent, gastric ulcer recurrence; cure early stage mucosa-associated lymphoid tissue lymphoma; and reduce the chances of developing gastric cancer in high-risk individuals.

Inflammation, atrophy, and gastric cancer

The association between chronic inflammation and cancer is now well established. This association has recently received renewed interest with the recognition that microbial pathogens can be responsible for the chronic inflammation observed in many cancers, particularly those originating in the gastrointestinal system. A prime example is Helicobacter pylori, which infects 50% of the world's population and is now known to be responsible for inducing chronic gastric inflammation that progresses to atrophy, metaplasia, dysplasia, and gastric cancer. This Review provides an overview of recent progress in elucidating the bacterial properties responsible for colonization of the stomach, persistence in the stomach, and triggering of inflammation, as well as the host factors that have a role in determining whether gastritis progresses to gastric cancer. We also discuss how the increased understanding of the relationship between inflammation and gastric cancer still leaves many questions unanswered regarding recommendations for prevention and treatment.

Gastric bypass surgery does not increase susceptibility to Helicobacter pylori infection in the stomach of rat or mouse

Gastric bypass is a clinical option for obesity surgery. An increased susceptibility to Helicobacter pylori infection in the bypassed stomach has been speculated. The aim of the present study was to examine the susceptibility of the bypassed stomach to H. pylori infection in rats and mice. Adult Sprague-Dawley and Wistar rats and NMRI mice were subjected to either gastric bypass or laparotomy only as control. The animals were inoculated with the CagA- and VacA- positive H. pylori strain 67/21 (not mouse-adapted) in the first experiment and with 9 additional isolates in the second, by injection into the bypassed stomach or the control stomach during surgery. The stomach of each animal was collected for H. pylori culture 2-3 weeks later. While all the rats were H. pylori negative, 54% of gastric bypassed mice and 75% of controls were positive (P = 0.4). We conclude that susceptibility to H. pylori infection in the stomach is not increased by gastric bypass surgery.

Gastric cancer: Worldwide burden and prevention opportunities

Gastric cancer is a major worldwide problem in developing and developed countries. It contributes substantially to the economic medical resource burden and population mortality in many countries. The absolute numbers of new cases of death are expected to increase significantly over the next decades because of the enlarging and aging of the world population. The putative factors are better understood today, and control of these factors, together with screening can help prevent this cancer from becoming an increasing burden to society.

New tumor necrosis factor-alpha-inducing protein released from Helicobacter pylori for gastric cancer progression

PURPOSE

To investigate the association between Helicobacter pylori infection and its inflammatory reaction in gastritis, gastric ulcer, and gastric cancer, a new tumor necrosis factor-alpha (TNF-alpha)-inducing protein of H. pylori was studied.

METHODS

The HP0596 gene of H. pylori was identified as the TNF-alpha-inducing protein (Tipalpha) gene from genome sequence of H. pylori strain 26695. Using recombinant Tipalpha (rTipalpha) and deleted Tipalpha (rdel-Tipalpha) proteins, the latter of which lacks six amino acids containing two cysteines in the N-terminal domain, we examined their activities in TNF-alpha gene expression and NF-kappaB activation in both Bhas 42 (v-H-ras transfected BALB/3T3) cells and mouse gastric epithelial cell line MGT-40, and in vitro transformation of Bhas 42 cells.

RESULTS

Tipalpha protein as a homodimer form (38 kDa) was found in both extracts and culture medium of various H. pylori strains. rTipalpha significantly induced TNF-alpha gene expression and NF-kappaB activation in both Bhas 42 cells and MGT-40, and induced in vitro transformation of Bhas 42 cells. However, rdel-Tipalpha did not. Treatment with MG-132, a proteasome inhibitor, inhibited translocation of NF-kappaB p65, and abrogated TNF-alpha induction induced by Tipalpha protein.

CONCLUSION

Tipalpha is a new carcinogenic factor released from H. pylori mediated through NF-kappaB activation.

New tumor necrosis factor-alpha-inducing protein released from Helicobacter pylori for gastric cancer progression

PURPOSE

To investigate the association between Helicobacter pylori infection and its inflammatory reaction in gastritis, gastric ulcer, and gastric cancer, a new tumor necrosis factor-alpha (TNF-alpha)-inducing protein of H. pylori was studied.

METHODS

The HP0596 gene of H. pylori was identified as the TNF-alpha-inducing protein (Tipalpha) gene from genome sequence of H. pylori strain 26695. Using recombinant Tipalpha (rTipalpha) and deleted Tipalpha (rdel-Tipalpha) proteins, the latter of which lacks six amino acids containing two cysteines in the N-terminal domain, we examined their activities in TNF-alpha gene expression and NF-kappaB activation in both Bhas 42 (v-H-ras transfected BALB/3T3) cells and mouse gastric epithelial cell line MGT-40, and in vitro transformation of Bhas 42 cells.

RESULTS

Tipalpha protein as a homodimer form (38 kDa) was found in both extracts and culture medium of various H. pylori strains. rTipalpha significantly induced TNF-alpha gene expression and NF-kappaB activation in both Bhas 42 cells and MGT-40, and induced in vitro transformation of Bhas 42 cells. However, rdel-Tipalpha did not. Treatment with MG-132, a proteasome inhibitor, inhibited translocation of NF-kappaB p65, and abrogated TNF-alpha induction induced by Tipalpha protein.

CONCLUSION

Tipalpha is a new carcinogenic factor released from H. pylori mediated through NF-kappaB activation.

Upregulated Akt signaling adjacent to gastric cancers: implications for screening and chemoprevention

Most gastric adenocarcinomas arise as a longterm complication of Helicobacter pylori infection of the stomach, but the high prevalence of this infection limits the cost-effectiveness of antibiotic eradication as a cancer prevention strategy. Here we have used phosphorylation-specific antibodies against the Akt kinase consensus sequence to detect downstream substrates of this oncogenic signaling pathway in normal and malignant gastric tissues. In vitro studies confirm that phosphorylation of Akt and its substrates is inducible by epithelial mitogens such as epidermal growth factor (EGF), which is implicated in the pathogenesis of H. pylori gastritis. Control clinical studies confirm far stronger Akt substrate phosphorylation in primary human breast cancers than in matched adjacent normal breast tissues; unexpectedly, however, increased Akt signaling is apparent in both primary stomach cancers and adjacent normal gastric tissues. These findings raise the possibility of a preneoplastic field defect induced in morphologically normal tissues, and suggest that immunoassays of mucosal Akt activity could guide preventive surveillance and/or intervention in patients at risk of gastric cancer. Moreover, since recent reports confirm Akt inhibition by COX-2 inhibitors, these data support the chemopreventive efficacy of such drugs for at-risk individuals.

C-reactive protein, procalcitonin, interleukin-6, vascular endothelial growth factor and oxidative metabolites in diagnosis of infection and staging in patients with gastric cancer

AIM: The current study was to determine the serum/plasma levels of VEGF, IL-6, malondialdehyde (MDA), nitric oxide (NO), PCT and CRP in gastric carcinoma and correlation with the stages of the disease and accompanying infection.

METHODS: We examined the levels of serum VEGF, IL-6, PCT, CRP and plasma MDA, NO in 42 preoperative gastric cancer patients and 23 healthy subjects. There were infection anamneses that had no definite origin in 19 cancer patients.

RESULTS: The VEGF levels (mean ± SD; pg/mL) were 478.05 ± 178.29 and 473.85 ± 131.24 in gastric cancer patients with and without infection, respectively, and these values were not significantly different (P>0.05). The levels of VEGF, CRP, PCT, IL-6, MDA and NO in cancer patients were significantly higher than those in healthy controls and the levels of CRP, PCT, IL-6, MDA and NO were statistically increased in infection group when compared with non-infection group (P<0.001).

CONCLUSION: Although serum VEGF concentrations were increased in gastric cancer, this increase might not be related to infection. CRP, PCT, IL-6, MDA and NO have obvious drawbacks in the diagnosis of infections in cancer patients. These markers may not help to identify infections in the primary evaluation of cancer patients and hence to avoid unnecessary antibiotic treatments as well as hospitalization. According to the results of this study, IL-6, MDA, NO and especially VEGF can be used as useful parameters to diagnose and grade gastric cancer.

Helicobacter pylori and gastric cancer prevention is possible

Epidemiological data gathered during the past few years have shown an association between Helicobacter pylori infection and gastric carcinoma. This association is considered to be causal because of its biological plausibility and the existence of an animal model, even though the positive consequences of eradication on cancer prevention have not yet been definitely proven. The limited proportion of H. pylori infected subjects who develop a gastric cancer can be explained by host factors (certain alleles of IL-1beta) and bacterial factors (cag positive strains), and to a lesser extent by environmental factors (diet). Arguments in favor of the prevention of gastric carcinoma by eradicating H. pylori are now stronger than before, given the availability of simple and accurate diagnostic tests (serology) and treatment follow-up (urea breath test), as well as a 7-day treatment which is usually sufficient for eradication.

Helicobacter and gastric cancer disease mechanisms: host response and disease susceptibility

Helicobacter infection is the single most common cause of gastric cancer worldwide. Although infection prevention and eradication of established infection offer the potential for cure, these strategies are neither feasible nor practical for widespread implementation. Patients most at risk need to be identified and targeted for treatment. For disease to occur, bacterial, environmental, and nutritional factors require a genetically susceptible host. Consequently, it is important to understand how the organism interacts with the host to cause disease. Only through an understanding of what places a patient at risk can we hope to identify susceptible patients early enough in disease to have an impact on their outcome. The immune response is the single most important determinant of disease. Single nucleotide polymorphisms within the promoter region of several critical proinflammatory genes dramatically increase the risk of Helicobacter-associated gastric cancer. Additionally, environmental and dietary factors may modulate the immune response or directly influence key apoptotic and proliferative signaling cascades to alter disease presentation. Lastly, concurrent disease states may have a dramatic impact on the host response to Helicobacter infection and influence disease. An understanding of the immune signaling pathways responsible for disease and the ways in which environmental risk factors influence these pathways will allow identification of populations that are most at risk and targeted prevention and treatment strategies.