Effect of Helicobacter pylori Eradication and ABO Genotype on Gastric Cancer Development

Effect of Helicobacter pylori infection and its eradication on the expression of tight junction proteins in the gastric epithelium in relation to gastric carcinogenesis

BACKGROUND

Tight junction proteins (TJPs) play a role in epithelial defense mechanisms. However, the effect of Helicobacter pylori (Hp) on TJPs remains unclear. This study aimed to evaluate the expression of TJPs in relation to Hp infection and eradication in gastric carcinogenesis.

METHODS

In total, 510 subjects (284 controls and 226 gastric cancer [GC] patients) were prospectively enrolled in the study. The expression of claudin-1 and -2 (CLDN-1, -2), occludin (OCLN), and tight junction protein 1 (TJP1) was measured based on their Hp infection status in normal corpus mucosa and evaluated following Hp eradication using quantitative real-time polymerase chain reaction (qPCR) and immunohistochemistry (IHC).

RESULTS

The expression of TJP1 in Hp⁺ controls was significantly lower than that in Hp^- controls (p = 0.006), whereas it was higher in Hp⁺ than in Hp^- GC patients (p = 0.001). Moreover, the increased expression of TJP1 in Hp⁺ GC patients was reduced to levels in Hp^- within a year after Hp eradication and was maintained for more than 5 years. Furthermore, IHC results for TJP1 were similar to qPCR results. In particular, the higher IHC staining intensity of TJP1 in the cytosol of GC patients (p = 0.019) decreased after Hp eradication (p = 0.040).

CONCLUSION

Hp infection affects TJP expression. The high expression of TJP1 in Hp⁺ GC patients was restored to control levels after Hp eradication, suggesting that TJP1 plays a role in gastric carcinogenesis.

Potential utility of nano-based treatment approaches to address the risk of Helicobacter pylori

INTRODUCTION

Helicobacter pylori (H. pylori) has occupied a significant place among infectious pathogens and it has been documented as a leading challenge due to its higher resistance to the commonly used drugs, higher adaptability, and lower targeting specificity of the available drugs.

AREAS COVERED

New treatment strategies are urgently needed in order to improve the current advancement in modern medicine. Nanocarriers have gained an advantage of drug encapsulation and high retention time in the stomach with a prolonged drug release rate at the targeted site. This article aims to highlight the recent advances in nanotechnology with special emphasis on metallic, polymeric, lipid, membrane coated, and target-specific nanoparticles (NPs), as well as, natural products for treating H. pylori infection. We discussed a comprehensive approach to understand H. pylori infection and elicits to rethink about the increasing threat posed by H. pylori and its treatment strategies.

EXPERT OPINION

To address these issues, nanotechnology has got huge potential to combat H. pylori infection and has made great progress in the field of biomedicine. Moreover, combinatory studies of natural products and probiotics in conjugation with NPs have proven efficiency against H. pylori infection, with an advantage of lower cytotoxicity, minimal side effects, and stronger antibacterial potential.[Figure: see text].

Population Attributable Fraction of Helicobacter pylori Infection-Related Gastric Cancer in Korea: A Meta-Analysis

PURPOSE

This study aimed to determine the proportion of gastric cancer attributable to Helicobactor pylori in the Korean population. Infection with H. pylori has been recognized as the most significant risk factor for gastric cancer. In Korea, gastric cancer is the most common cancer that accounted for 13.3% of all cancers in 2016. In particular, men are most commonly diagnosed with gastric cancer; the age-standardized incidence rate in men is 49.6 per 100,000, which is more than twice the incidence in women.

MATERIALS AND METHODS

The population attributable fraction (PAF) was calculated as a function of the relative risk (RR) of gastric cancer associated with H. pylori infections. To estimate PAF of gastric cancer due to H. pylori, the prevalence of H. pylori infections was extrapolated for the year of 1990 and a pooled RR was obtained by conducting a meta-analysis of studies recently published in Korea.

RESULTS

The estimated prevalence of H. pylori was 76.4% in men and 71.9% in women. The RRs (95% confidence interval) pooled from case-control studies using a random effects model was 1.69 (1.29-2.22) for overall gastric cancer and 2.17 (1.04-4.55) for non-cardia gastric cancer. Using the RR for overall gastric cancer, the estimated PAFs due to H. pylori were 34.5% in men and 33.2% in women.

CONCLUSION

The occurrence of gastric cancer in Koreans may be affected by other risk factors in addition to H. pylori infection, which may contribute to increasing baseline risk for gastric cancer.

Long-term follow up of serum pepsinogens in patients with gastric cancer or dysplasia after Helicobacter pylori eradication

BACKGROUND AND AIM

Few studies have evaluated the change in serum pepsinogen (sPG) levels after the eradication of Helicobacter pylori. The aim of this study was to evaluate the effect of H. pylori eradication on sPG levels in patients with gastric cancer/dysplasia in comparison to a control group.

METHODS

We prospectively enrolled 368 patients with gastric cancer/dysplasia and 610 control subjects. H. pylori status and sPG levels were measured before and after eradication. The follow-up time points were classified as < 12, 12-23, 24-35, and ≥ 36 months.

RESULTS

In 179 H. pylori-eradicated patients with gastric cancer/dysplasia and 168 control group subjects, sPG I significantly decreased, and the sPG I/II ratio significantly increased after eradication compared to baseline, and this improvement in sPG values was maintained during all follow-up time points. Significant differences in sPG I and the sPG I/II ratio were observed between the gastric cancer/dysplasia group and the control group < 24 months after eradication. However, these differences in sPG values disappeared after ≥ 24 months of follow up. Moreover, significant differences in the intestinal metaplasia grade were observed between these two groups before eradication until < 24 months after eradication. However, these differences in the intestinal metaplasia grade disappeared after ≥ 24 months of follow up in the corpus.

CONCLUSION

The sPG values and intestinal metaplasia grade (corpus) in the gastric cancer/dysplasia group became similar to those in the control group at long-term follow up after H. pylori eradication. It might be related with the reduction of metachronous gastric neoplasm.

Chemoprevention of gastric cancer by Helicobacter pylori eradication and its underlying mechanism

The cascade of gastric cancer, a leading cause of cancer incidence and mortality, is multifactorial. Helicobacter pylori (HP) infection plays a major role in gastric cancer (GC), and there has been an accumulation of data regarding the chemopreventive effect of HP eradication. However, it remains unclear how HP infection causes GC and how HP eradication prevents GC. To clarify this issue, the following approaches were performed in this review article. First, how HP-induced atrophic gastritis (AG) and intestinal metaplasia (IM) provoke the development of GC is shown, followed by how long HP eradication takes to induce a reversible change in AG and IM. Second, epigenetic studies of PTPN6, MOS, DCC, CRK, and VAV1 were performed in noncancerous gastric specimens in terms of HP status. Among these genes, MOS was found to be a possible surrogate marker for GC development. HP eradication decreased aberrant DNA methylation in a gene-specific manner, and MOS played a role in metachronous gastric neoplasms. Third, transforming growth factor-β1 (TGF-β1) and TGF-β1-induced epithelial-mesenchymal transition (EMT) markers were investigated in gastric mucosa. HP infection triggered the TGF-β1-induced EMT pathway and caused the emergence of GC stem cells, such as CD44v8-10. When HP was eradicated, these two pathways were inhibited. Finally, a 2222 cohort study showed that HP eradication significantly decreased the risk of noncardiac GC. Taken together, HP eradication is effective as a primary GC prevention method, and its underlying mechanism includes reversibility of AG and IM, methylation, EMT, and stem cells.

Association of ABO Blood Groups and Risk of Gastric Cancer

OBJECTIVE

This study sought to investigate the relationship between ABO blood groups and the risk of gastric cancer as well as clinical pathological parameters and prognosis.

METHODS

Gastric cancer patient data were collected from January 1995 to January 2012 at Jilin Cancer Hospital, and the blood group information of the blood donors at Jilin City Blood Center was recorded. The relationships between ABO blood group and both clinicopathological parameters and the risk of gastric cancer were analyzed retrospectively. The impact of ABO blood type on the 5-year survival rate of patients with gastric cancer was evaluated through outpatient and telephone interviews.

RESULTS

(1) Compared with the healthy population, the frequency distribution of gastric cancer patients with the A blood group was significantly increased (χ² = 4.708, P = 0.000), whereas the frequency distribution of gastric cancer patients with the AB blood group was significantly decreased (χ² = 9.630, P = 0.002). However, there was no significant difference in the distributions of the B blood group and O blood group (P > 0.05). (2) The risk of gastric cancer in people with the A blood group was higher, whereas the risk of gastric cancer in people with the AB blood group was lower. There was no significant difference in the risk of gastric cancer between type B and type O patients (P > 0.05). (3) The ABO blood group was not related to pathological factors, including the size of the gastric tumor or the T stage or N stage of the disease (P > 0.05). (4) Univariate analysis results showed that the degree of differentiation, tumor size, T stage, lymph node metastasis, and type O blood were factors affecting the 5-year survival rate of gastric cancer patients (P < 0.05). Multivariate analysis results showed that tumor size, T stage, lymph node metastasis, and O blood group were independent prognostic factors. The 5-year survival rate for gastric cancer was significantly better in patients with type O blood (hazard ratio = 0.97, 95% confidence interval = 1.67-3.92).

CONCLUSION

(1) The risk of gastric cancer was higher in patients with the A blood group and lower in those with the AB blood group. (2) The ABO blood group showed no significant effect on the clinicopathological parameters of gastric cancer. (3) The O blood group may be a prognostic factor for gastric cancer patients.

In Vitro and In Vivo Activities of Zinc Linolenate, a Selective Antibacterial Agent against Helicobacter pylori

Helicobacter pylori is a major global pathogen, and its infection represents a key factor in the etiology of various gastric diseases, including gastritis, peptic ulcers, and gastric carcinoma. The efficacy of current standard treatment for H. pylori infection including two broad-spectrum antibiotics is compromised by toxicity toward the gut microbiota and the development of drug resistance, which will likely only be resolved through novel and selective antibacterial strategies. Here, we synthesized a small molecule, zinc linolenate (ZnLla), and investigated its therapeutic potential for the treatment of H. pylori infection. ZnLla showed effective antibacterial activity against standard strains and drug-resistant clinical isolates of H. pyloriin vitro with no development of resistance during continuous serial passaging. The mechanisms of ZnLla action against H. pylori involved the disruption of bacterial cell membranes and generation of reactive oxygen species. In mouse models of multidrug-resistant H. pylori infection, ZnLla showed in vivo killing efficacy comparable and superior to the triple therapy approach when use as a monotherapy and a combined therapy with omeprazole, respectively. Moreover, ZnLla treatment induces negligible toxicity against normal tissues and causes minimal effects on both the diversity and composition of the murine gut microbiota. Thus, the high degree of selectivity of ZnLla for H. pylori provides an attractive candidate for novel targeted anti-H. pylori treatment.

The prevalence of histologic atrophy and intestinal metaplasia in the corpus has decreased over 15 years in females in the Korean population

BACKGROUND

The aim of this study was to investigate the trends of atrophy and intestinal metaplasia (IM) in 2002 subjects without significant gastroduodenal diseases.

MATERIALS AND METHODS

A total of 2002 subjects were prospectively enrolled and divided into three periods (2003-2007, 2008-2012, and 2013-2018). Trends of H pylori and atrophy/IM scored by Updated Sydney System were analyzed according to sex, and multivariate logistic analysis was performed for the risk factors for atrophy/IM.

RESULTS

H pylori-negative and H pylori-positive subjects were 1220 (61.0%) and 782 (38.0%), respectively. H pylori positivity decreased from 149/303 (49.2%), 207/515 (40.2%) and 426/1184 (36.0%), in the three periods, respectively (P < 0.001). The prevalence of atrophy (P < 0.001) and IM in the corpus (P < 0.001) significantly decreased over 15 years in females, but not in males. The mean grade of atrophy and IM was higher in males (0.36 and 0.51) than in females (0.28 and 0.41) in the corpus (P = 0.027) and in the antrum (P = 0.006), respectively. Similarly, the mean grade of IM in males (0.34) was higher in females (0.19; P < 0.001) in the corpus. Multivariate analysis showed that old age, study period, and H pylori were statistically significant in atrophy of antrum and corpus, and IM in the corpus. In cases of IM of antrum, old age, H pylori, and smoking were statistically significant.

CONCLUSION

A significant decrease in atrophy and IM in the corpus in females over 15 years suggests sex- or gender-specific characteristics.

Biologic roles of the ABH and Lewis histo-blood group antigens Part I: infection and immunity

The ABH and Lewis antigens were among the first of the human red blood cell polymorphisms to be identified and, in the case of the former, play a dominant role in transfusion and transplantation. But these two therapies are largely twentieth century innovations, and the ABH and related carbohydrate antigens are not only expressed on a very wide range of human tissues, but were present in primates long before modern humans evolved. Although we have learned a great deal about the biochemistry and genetics of these structures, the biological roles that they play in human health and disease are incompletely understood. This review and its companion, to appear in a later issue of Vox Sanguinis, will focus on a few of the biologic and pathologic processes which appear to be affected by histo-blood group phenotype. The first of the two reviews will explore the interactions of two bacteria with the ABH and Lewis glycoconjugates of their human host cells, and describe the possible connections between the immune response of the human host to infection and the development of the AB-isoagglutinins. The second review will describe the relationship between ABO phenotype and thromboembolic disease, cardio-vascular disease states, and general metabolism.

Blood groups A and AB are associated with increased gastric cancer risk: evidence from a large genetic study and systematic review

Background

The association of ABO blood groups with gastric cancer risk was proposed decades ago, but the results have been inconsistent.

Methods

We used two single nucleotide polymorphisms to determine ABO genotype in 4932 gastric cancer cases and 6158 controls of Chinese descent, and evaluated the associations of ABO blood groups and genotypes with risk of gastric cancer using multivariable logistic regression models. We also systematically reviewed published literature and performed a meta-analysis of all relevant studies.

Results

In the case-control study, compared with blood group O, both blood group A and AB were associated with increased gastric cancer risk (for group A, odds ratio (OR) = 1.13, 95% confidence interval (CI): 1.02–1.24; for group AB, OR = 1.18, 95% CI: 1.02–1.36, respectively). Analyses of ABO genotypes revealed associations of AO and AB with risk of gastric cancer compared with OO genotype. Consistent with the case-control study, meta-analysis of 40 studies including 33,613 cases and 2,431,327 controls demonstrated that blood group A (OR = 1.19, 95% CI: 1.13–1.25) and AB (OR = 1.09, 95% CI: 1.03–1.16) were associated with increased risk of gastric cancer.

Conclusions

Our analyses validated the association of blood group A with risk of gastric cancer, and suggested that blood group AB was also associated with gastric cancer risk. Functional investigations are warranted to elucidate the exact mechanism of ABO blood groups in gastric carcinogenesis.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5355-4) contains supplementary material, which is available to authorized users.

Association Between ABO Blood Groups and Helicobacter pylori Infection: A Meta-Analysis

There is no consensus among the existing literature on the relationship between ABO blood groups and risk of Helicobacter pylori infection. However, histo-blood group carbohydrates are proposed to influence the risk of acquiring this pathogen via effects on adhesion to the gastric mucosa. The objective of this meta-analysis was to evaluate the association between ABO blood groups and H. pylori infection. All relevant epidemiological studies published in English (up to October 2017) was retrieved through an extensive systematic literature search of MEDLINE/PubMed databases. Pooled estimates of effects were obtained through the use of fixed and random effects meta-analyses. Individuals with O blood group were more likely to be infected with H. pylori (pooled odds ratio (OR) 1.163; 95% confidence interval (CI) 1.074-1.259; P < 0.001). While individuals with B and AB blood group were less likely to be infected with H. pylori (OR 0.831; 95% CI 0.738-0.935; P = 0.002 and OR 0.709; 95% CI 0.605-0.832; P < 0.001, respectively). The results from this meta-analysis of observational studies suggest an estimated 16.3% increased odds of H. pylori infection amongst individuals with the O blood group. If this observed association is causal, a better understanding of the underlying mechanisms could provide indications to potential prevention strategies for H. pylori infection.

Usefulness of OLGA and OLGIM system not only for intestinal type but also for diffuse type of gastric cancer, and no interaction among the gastric cancer risk factors

BACKGROUND

The operative link on gastric atrophy (OLGA) and operative link on gastric intestinal metaplasia (OLGIM) stages have been suggested for risk estimation of gastric cancer (GC). However, usefulness of OLGA/OLGIM systems in diffuse type of GC was not investigated so far. The aims of this study were to evaluate the OLGA/OLGIM systems in estimating the GC risk according to Lauren's classification and to investigate the interaction among the risk factors.

MATERIALS AND METHODS

The OLGA/OLGIM stages were evaluated in 1398 (765 control and 633 GC patients) who were prospectively enrolled in the Seoul National University Bundang Hospital. Synergistic interaction among the risk factors for GC was calculated using an additive model.

RESULTS

Among 387 intestinal-type GC patients, 71 (18.3%) were high-risk OLGA stages (III, IV) and 113 (29.2%) were high-risk OLGIM stages (III, IV). Of the 246 patients with diffuse-type GC, 36 (14.6%) were high-risk OLGA stages and 39 (15.9%) were high-risk OLGIM stages. Multivariable analysis revealed family history of GC, Helicobacter pylori infection, high-risk OLGA stages, and high-risk OLGIM stages as independent risk factors for GC regardless of histologic type (odds ratios [ORs] 1.78, 1.94, 2.63, and 3.18, respectively). There was no significant risk modification among the H. pylori infection, family history of GC, and high-risk OLGA/OLGIM stages.

CONCLUSION

High-risk OLGA/OLGIM stages are important prediction markers for GC regardless of H. pylori infection or family history of GC not only for the intestinal type but also for diffuse-type GC.

ABO blood type and risk of hepatocellular carcinoma: a meta-analysis

BACKGROUND

ABO blood type is an invariant factor. There is a link between ABO blood type and some malignancies, such as gastric, pancreatic, and skin cancer. The role of ABO blood type in the pathogenesis of hepatocellular carcinoma (HCC) remains controversial. We performed a meta-analysis to explore the relationship between ABO blood type and risk of HCC.

METHODS

Literature search was conducted among the PubMed, EMBASE, and Cochrane Library databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Seven papers were included. They included 92,847 healthy subjects, 5,463 patients with hepatitis, 294 cirrhotic patients, and 3,322 HCC patients. The proportion of blood type O was significantly lower in HCC patients than healthy subjects (OR = 0.76, 95%CI = 0.66-0.87, P < 0.0001) without any significant heterogeneity (P = 0.55, I² = 0%). The proportions of blood types A, B, and AB were not significantly different between HCC patients and healthy subjects. The proportion of ABO blood type was not significantly different between patients with HCC and those with hepatitis or cirrhosis.

CONCLUSION

HCC patients might have a lower proportion of blood type O than healthy subjects. Among the patients with chronic liver diseases, ABO blood type might not be associated with the risk of HCC.

Reversibility of atrophic gastritis and intestinal metaplasia after Helicobacter pylori eradication - a prospective study for up to 10 years

BACKGROUND

Atrophic gastritis and intestinal metaplasia are premalignant conditions for gastric cancer. Their reversibility by Helicobacter pylori eradication remains controversial.

AIM

To evaluate the reversibility of atrophic gastritis and intestinal metaplasia by H. pylori eradication with long-term follow-up.

METHODS

598 subjects were prospectively enrolled and followed for up to 10 years. They were categorised as H. pylori-negative (n = 65), H. pylori non-eradicated (n = 91), and H. pylori-eradicated (n = 442). Histological assessment was performed for antrum and corpus by Sydney classification.

RESULTS

Histological follow-up was performed regularly at 1, 2, 3-4 and ≥5 years, with mean follow-up of 1.07 ± 0.21, 2.29 ± 0.83, 3.93 ± 1.02, and 6.45 ± 1.28 years, respectively. Atrophic gastritis in antrum and corpus gradually and significantly (both P < .05 for all timepoints) improved only in the H. pylori-eradicated group compared to that at baseline. Significant difference in atrophic gastritis between H. pylori-eradicated and H. pylori-negative groups disappeared from 1-year follow-up. Similarly, intestinal metaplasia in antrum and corpus improved significantly (both P < .05 for all timepoints) only in the H. pylori-eradicated group in comparison with that at baseline. Significant difference in intestinal metaplasia between H. pylori-eradicated and H. pylori-negative groups disappeared from ≥5 years of follow-up in the antrum and from 3 years of follow-up in the corpus.

CONCLUSION

H. pylori eradication may be a preventative strategy for intestinal-type gastric cancer by regression of atrophic gastritis and intestinal metaplasia.

Novel characteristics of alpha-fetoprotein (AFP)-producing gastric cancer

Background

Although serum AFP level is increased in the AFP-producing gastric cancer (GC) patient, AFP-producing GC may become recurrent without re-elevation of serum AFP level. Therefore, novel characteristics of AFP-producing GC such as other biomarkers are to be explored.

Results

35 AFP-GC and 48 non-AFP-GC patients were included. Our present study revealed that blood type O (15 cases, 42.8%) and A (18 cases, 37.5%) were predominantly observed among AFP-GC and non-AFP-GC patients, respectively. Intriguingly, the least consistently was blood type AB (8.5%, 14.6%). Among AFP-GC patients, pre-operative serum AFP levels were weakly and reversely associated with pre-operative percentage of lymphocytes in the peripheral blood (R2 = 0.1556). The level of alkaline phosphatase (ALP) was highly correlated with the level of lactate dehydrogenase (LDH) (R² = 0.6682) and CEA (R² = 0.6813). The level of CEA was moderately correlated with the level of LDH (R² = 0.3903). By contrast, no any associations between ALP, LDH, CEA, AFP, and peripheral lymphocytes were observed among those 48 non-AFP-GC patients.

Materials and Methods

Retrospective analysis was carried out for 2773 inpatients of gastric cancer from January 2012 to November 2016 in the Second Affiliated Hospital of Zhejiang University School of Medicine.

Conclusions

The aggressive biological features of AFP-producing GC are closely associated with abnormality of other tumor biomarkers and decrease of the proportion of peripheral lymphocytes, implying that post-operative increase of peripheral lymphocytes might benefit GC patients. Combined use of multiple biomarkers is of significance in comprehensive evaluation of AFP-producing GC patients and assessment for those with high risk of cancer recurrence.