scholarly journals Helicobacter pylorias an oncogenic pathogen, revisited

Author(s):  
Muhammad Miftahussurur ◽  
Yoshio Yamaoka ◽  
David Y. Graham

Gastric cancer is an inflammation-associated malignancy aetiologically related to infection with the bacterium,Helicobacter pylori, which is considered a necessary but insufficient cause. Unless treated,H. pyloricauses life-long acute and chronic gastric inflammation resulting in progressive gastric mucosal damage that may result in gastric cancer. The rate of progression from superficial gastritis, to an atrophic metaplastic mucosa, and ultimately to cancer relates to the virulence of the infectingH. pylorias well as host and environmental factors.H. pylorivirulence is a reflection of its propensity to cause severe gastric inflammation. Both mucosal inflammation andH. pylorican cause host genomic instability, including dysregulation of DNA mismatch repair, stimulation of expression of activation-induced cytidine deaminase, abnormal DNA methylation and dysregulation of  micro RNAs, which may result in an accumulation of mutations and loss of normal regulation of cell growth. The difference in cancer risk between the most and least virulentH. pyloristrain is only approximately 2-fold. Overall, none of the putative virulence factors identified to date have proved to be disease-specific. The presence, severity, extent and duration of inflammation appear to be the most important factors and current evidence suggests that any host, environmental or bacterial factor that reliably enhances the inflammatory response to theH. pyloriinfection increases the risk of gastric cancer.

1990 ◽  
Vol 68 (2) ◽  
pp. 207-210 ◽  
Author(s):  
B. L. Tepperman ◽  
B. D. Soper

We have observed that removal of the salivary glands is associated with an increase in the susceptibility to gastric mucosal damage in the rat. In the present study, we have examined the effect of sialoadenectomy on ethanol-induced mucosal hemorrhagic damage and myeloperoxidase (MPO) activity. Hemorrhagic damage and MPO activity in response to intragastric 50% w/v ethanol were greater in sialoadenectomized rats when compared with sham-operated animals. Pretreatment with 16,16-dimethylprostaglandin E2 (0.3 μg/kg s.c.) reduced damage and MPO activity in both sialoadenectomized and sham control rats receiving 50% ethanol. The reduction in these parameters was greater in control than in sialoadenectomized rats. Pretreatment with epidermal growth factor (5 μg/kg s.c.) significantly reduced MPO activity but did not significantly affect the extent of damage. These data suggest that sialoadenectomy is associated with an increase in mucosal inflammation in animals given ethanol. However, in some situations tissue inflammation (as indicated by MPO activity) was reduced, while the proportion of gastric mucosa exhibiting hemorrhagic damage was not changed.Key words: salivary glands, gastric mucosa, neutrophils, prostaglandin E2, epidermal growth factor.


2000 ◽  
Vol 68 (5) ◽  
pp. 2863-2869 ◽  
Author(s):  
Satoko Oka ◽  
Esteban Cesar Gabazza ◽  
Yukiko Taguchi ◽  
Michihiko Yamaguchi ◽  
Shigehito Nakashima ◽  
...  

ABSTRACT The protein C (PC) pathway has recently been suggested to play a role in the regulation of the inflammatory response. To further extend the anti-inflammatory effect of activated PC (APC) in vivo, particularly its biological relevance to human disease, the activity of APC in the mucosa of patients with Helicobacter pylori-associated gastritis and the effect of vacuolating cytotoxin (VacA), cytotoxin-associated antigen (CagA), andH. pylori lipopolysaccharide (LPS) on PC activation were evaluated. This study comprised 35 patients with chronic gastritis. There were 20 patients with and 15 without H. pylori infection. The levels of PC and APC-PC inhibitor (PCI) complex were measured by immunoassays. The level of PC was significantly decreased and the level of APC-PCI complex was significantly increased in biopsy specimens from gastric corpus and antrum in patients with H. pylori-associated gastritis as compared to H. pylori-negative subjects. The concentrations of VacA, CagA, and LPS were significantly correlated with those of the APC-PCI complex in biopsy mucosal specimens from the gastric corpus and antrum. H. pylori LPS, VacA, and CagA induced a dose-dependent activation of PC on the surface of monocytic cells. APC inhibited the secretion of tumor necrosis factor alpha (TNF-α) induced by H. pylori LPS. Overall, these results suggest that H. pylori infection is associated with increased APC generation in the gastric mucosa. The inhibitory activity of APC on TNF-α secretion may serve to protect H. pylori-induced gastric mucosal damage.


2003 ◽  
Vol 17 (suppl b) ◽  
pp. 13B-17B ◽  
Author(s):  
Gregory Naylor ◽  
Anthony Axon

Gastric bacteria can either be ingested or ascend from the distal bowel; however, their survival is usually limited by gastric acidity and motility. A reduction in gastric acid can result in bacterial overgrowth in the stomach and proximal small bowel, and the number of organisms rises as the intragastric pH rises.The increased risk of noncardia gastric cancer seen in patients with hypochlorhydria may be explained by an excess of nitrites and N-nitroso compounds (NOCs). These compounds are found in the diet of populations with a high gastric cancer risk, but can also be produced by the organisms that exist in the hypochlorhydria stomach. It has long been hypothsized that nitrites and NOCs act as one of the triggers in the atrophy-metaplasia-dysplasia-carcinoma path. However, although indirect data have linked the premalignant changes of metaplasia and dysplasia to NOCs, direct measurement of gastric nitrites and NOCs has not confirmed such a link.The role ofHelicobacter pyloriin bacterial overgrowth is mainly as a cause of hypochlorhydria resulting from atrophic gastritis, leading to a reduction in the parietal cell mass.Acid-suppressing drugs can result in bacterial overgrowth and increased nitrites and NOCs, although there is no current evidence for an increased risk of gastric cancer in patients taking them. One explanation is that the stomach appears to be colonized by different organisms than those in patients with hypochlorhydria for other reasons. There is some evidence that bacterial overgrowth per se can cause gastric inflammation in mice; however, although in humans the degree of gastric inflammation is greater when overgrowth is more prominant this may simply reflect the greater degree of hypochlorhydria in patients with a more severe H pylori-induced inflammation.


2019 ◽  
Vol 12 ◽  
pp. 175628481983451 ◽  
Author(s):  
Ka Shing Cheung ◽  
Wai K. Leung

Gastric cancer remains one of the leading cancers in the world with a high mortality, particularly in East Asia. Helicobacter pylori infection accounts for the majority of the noncardia gastric cancers by triggering gastric inflammation and subsequent neoplastic progression. Eradication of H. pylori can reduce, but not totally eliminate, subsequent risk of developing gastric cancer. Proton-pump inhibitors (PPIs) are one of the most widely prescribed medications worldwide. With their profound gastric-acid suppression, there are concerns about a possible carcinogenic role in gastric cancer, due to induced hypergastrinemia, gastric atrophy and bacterial overgrowth in the stomach. While randomized clinical trials to establish causality between long-term PPI use and gastric cancer are lacking, current evidence based on observational studies suggests PPIs are associated with an increased gastric cancer risk. However, opinions on causality remain divergent due to unmeasured and possible residual confounding in various studies. Our recent study has showed that even after H. pylori eradication, long-term PPI use is still associated with an increased risk of gastric cancer by more than twofold. Hence, long-term PPIs should be used judiciously after considering individual’s risk–benefit profile, particularly among those with history of H. pylori infection. Further well-designed prospective studies are warranted to confirm the potential role of PPIs in gastric cancer according to baseline gastric histology and its interaction with other chemopreventive agents like aspirin, statins and metformin.


Gut ◽  
1998 ◽  
Vol 42 (6) ◽  
pp. 772-778 ◽  
Author(s):  
N Figura ◽  
C Vindigni ◽  
A Covacci ◽  
L Presenti ◽  
D Burroni ◽  
...  

Background/Aims—Infection with Helicobacter pylori strains harbouring the cagA gene (cagA+) is associated with an increased risk of developing peptic ulcer and gastric cancer. The aim of this study was to assess whether H pylori isolates with different cagA status were present in patients with non-ulcer dyspepsia, and whether a variable cagA status is relevant to histological gastric mucosal damage and glandular cell proliferation.Methods—Well separated H pyloricolonies (between 2 and 25) from primary plates, per gastric area, for each of 19 patients with non-ulcer dyspepsia were examined forcagA by hybridisation. Western blotting was used to examine both representative colonies for CagA expression and the patients’ sera for antibody response to CagA. Glandular gastric cell proliferation was assessed immunohistochemically.Results—Of the 747 colonies examined, 45.3% werecagA+. All colonies from four patients werecagA+, and all colonies from two patients werecagA−. In 13 patients (68%) both cagA+ andcagA− colonies were found. CagA expression of isolates corresponded to their cagA status. H pyloristrains with different CagA molecular masses were present in three patients. Results based on all 19 patients studied showed that the prevalence of cagA+ colonies in areas with mucosal atrophy associated or not with intestinal metaplasia (67.9%) was significantly higher than in normal mucosa (44.7%) and mucosa from patients with chronic gastritis (44.0%) (p< 0.001). High levels of cell proliferation were associated with histological atrophy with or without intestinal metaplasia, but not with the possession of cagA by organisms colonising the same mucosal sites.Conclusions—Most patients with non-ulcer dyspepsia are infected by both cagA+ and cagA−H pylori colonies. The cagA status of infecting organisms may play a role in the development of atrophy and intestinal metaplasia.


2021 ◽  
Vol 49 (12) ◽  
pp. 030006052110553
Author(s):  
Guang Zhao ◽  
Zhishang Zhang ◽  
Baohui Li ◽  
Silin Huang ◽  
Wensi Li ◽  
...  

Objective To investigate the histomorphological characteristics of the gastric mucosa and the prognosis in patients with Helicobacter pylori infection. Methods Progressive damage to the gastric mucosa was examined by immunohistochemistry in 2294 patients with H. pylori infection and follow-up information was analyzed. Results H. pylori initially colonized the mucus layer covered by the gastric mucosa epithelium, then selectively adhered to and destroyed the surface mucus cells causing intra-gastric and extra-gastric lesions. Gastric mucosal damage induced by H. pylori was divided into five stages according to the depth of H. pylori invasion and degree of lesion deterioration: mucilaginous, surface mucocellular, lamina propria lesion, mucosal atrophy, and intraepithelial neoplasia stages. Morphological follow-up analysis revealed no significant difference in 6-month curative effects between stage I and stage II, but significant differences were found between stages II and III, stages III and IV, and between stages IV and stage V, respectively. Conclusions This novel staging strategy may be a valuable tool for diagnosing and predicting the results of gastric mucosal damage induced by H. pylori infection.


2013 ◽  
Vol 304 (2) ◽  
pp. G193-G202 ◽  
Author(s):  
Jung Mogg Kim ◽  
Su Hyun Kim ◽  
Su Hyuk Ko ◽  
Jireh Jung ◽  
Jaeyoung Chun ◽  
...  

Gastric mucosal inflammation can develop after challenge with noxious stimuli such as alcohol. Specially, alcohol stimulates the release of inflammatory cytokines but does not increase gastric acid secretion, leading to gastric mucosal damage. The plant sterol guggulsterone and its novel derivative GG-52 have been reported to inhibit nuclear factor-κB (NF-κB) signaling in intestinal epithelial cells and experimental colitis. In the present study, we investigated the anti-inflammatory effects of GG-52 on gastric epithelial cells and on ethanol-induced gastric mucosal inflammation in mice. GG-52 inhibited the expression of interleukin-8 (IL-8) in gastric epithelial AGS and MKN-45 cell lines stimulated with tumor necrosis factor (TNF)-α in a dose-dependent manner. Pretreatment with GG-52 suppressed TNF-α-induced activation of IκB kinase (IKK) and NF-κB signaling in MKN-45 cells. In contrast, the inactive analog GG-46 did not produce significant changes in IL-8 expression or NF-κB activation. In a model of ethanol-induced murine gastritis, administration of GG-52 significantly reduced the severity of gastritis, as assessed by macroscopic and histological evaluation of gastric mucosal damage. In addition, the ethanol-induced upregulation of chemokine KC, a mouse homolog of IL-8, and phosphorylated p65 NF-κB signals were significantly inhibited in murine gastric mucosa pretreated with GG-52. These results indicate that GG-52 suppresses NF-κB activation in gastric epithelial cells and ameliorates ethanol-induced gastric mucosal lesions in mice, suggesting that GG-52 may be a potential gastroprotective agent.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Tran Thi Huyen Trang ◽  
Seiji Shiota ◽  
Miyuki Matsuda ◽  
Tran Thanh Binh ◽  
Rumiko Suzuki ◽  
...  

Gastric cancer is a significant health problem in Asia. Although the prevalence ofHelicobacter pyloriinfection is similar in Bhutan, Vietnam, and Myanmar, the incidence of gastric cancer is highest in Bhutan, followed by Vietnam and Myanmar. We hypothesized thatH. pylorivirulence factors contribute to the differences. The status ofcagA,vacA,jhp0562, andβ-(1,3)galT(jhp0563)was examined in 371H. pylori-infected patients from Bhutan, Vietnam, and Myanmar. Each virulence factor could not explain the difference of the incidence of gastric cancer. However, the prevalence of quadruple-positive forcagA,vacAs1,vacAm1, andjhp0562-positive/β-(1,3)galT-negative was significantly higher in Bhutan than in Vietnam and Myanmar and correlated with gastric cancer incidence. Moreover, gastritis-staging scores measured by histology of gastric mucosa were significantly higher in quadruple-positive strains. We suggest that thecagA,vacAs1,vacAm1, andjhp0562-positive/β-(1,3)galT-negative genotype may play a role in the development of gastric cancer.


2019 ◽  
Vol 7 (8) ◽  
pp. 1266-1269
Author(s):  
Dumawan Harris Parhusip ◽  
Gontar Alamsyah Siregar ◽  
Leonardo Basa Dairi

BACKGROUND: Gastritis was defined as the histological presence of gastric mucosal inflammation. One of the most common aetiology was H. pylori. Gastrin-17 was a hormone that was secreted by G cells. H. pylori infection induced increased in gastrin-17 in gastritis. Therefore, this study was to investigate the relationship of gastrin-17 with gastritis severity and H. pylori infection. AIM: To determine the difference in serum Gastrin-17 level based on gastritis severity and H. pylori infection. METHODS: A cross-sectional study enrolling 45 patients with gastritis was conducted in Haji Adam Malik General Hospital between April and July 2018. Endoscopy and biopsy examinations were performed to confirm the diagnosis of gastritis. Gastritis severity was assessed using the Updated Sydney System. The presence of H. pylori infection was detected by a Campylobacter-like organism (CLO) examination. Gastrin-17 level and demographic data were also gathered. The analysis was done using Mann Whitney and Kruskal-Wallis test. P-value of < 0.05 was considered statistically significant. RESULTS: Serum Gastrin-17 level was significantly different based on gastritis severity (P = 0.001 according to neutrophils infiltration and P = 0.023 according to degree of atrophy), H. pylori infection (P = 0.038), and combined gastritis severity and H. pylori infection (P < 0.001). Serum Gastrin-17 level was higher in subjects with severe neutrophils infiltration, without atrophy, and with H. pylori infection. CONCLUSION: There was a significant difference in serum Gastrin-17 level based on gastritis severity and H. pylori infection.


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