Relationship between IL-1beta gene polymorphism and gastric mucosal IL-1beta levels in patients with Helicobacter pylori infection

The Effectiveness of Sechium edule Jacq. Swartz Extract Changes in the Histopathology of Aspirin-Induced Rat Gastritis Model

BACKGROUND: Gastritis is one of the most common diseases found in internal medicine clinics and daily life. AIM: The purpose of this study was to determine the histopathological changes of gastric rat model of aspirin-induced gastritis. MATERIALS AND METHODS: Group K(−) is a negative control (normal) not given any treatment, Group K(+) is a positive control induced by aspirin 200 mg/kgBW, Group 1 (P1) is a treatment group induced by aspirin 200 mg/kgBW with ethanol extract of chayote 100 mg/kgBW, po, Group 2 (P2) was the treatment group induced by aspirin 200 mg/kgBW with ethanol extract of chayote 200 mg/kgBW, po, Group 3 (P3) was the treatment group induced by aspirin 200 mg/kgBW with ethyl acetate fraction chayote 100 mg/kgBW, PO, Group 4 (P4) was the treatment group induced by aspirin 200 mg/kgBW with ethyl acetate fraction chayote 200 mg/kgBW, PO, and Group 5 (P5) was the treatment group induced by aspirin 200 mg/kgBW with omeprazole 20 mg. RESULTS: Analysis of the results of inflammatory infiltration in gastric histopathology in Groups P1, P2, P3, and P4 showed mild inflammatory infiltration compared to Groups P(5) and K(+). The description of the acinar glands on gastric histopathology showed that the P2 group gave a better picture of the acinar gland repair than the K(+), P2, P3, P4, and P5 groups. CONCLUSION: This study showed that ethanol extracts of squash 200 mg/KgBW own effectiveness as an anti-inflammatory on the improvement of infiltration of inflammatory and picture histopathological gastric mice compared with the ethanol extract of squash 100 mg/kg, the fraction of ethyl acetate chayote 100 mg/KgBW and 200 mg/KgBW and omeprazole 20 mg.

A global and physical mechanism of gastric cancer formation and progression

Gastric cancer is regarded as a major health issue for human being nowadays. The Helicobacter pylori (H. pylori) infection has been found to accelerate the development of gastritis and gastric cancer. Significant efforts have been made towards the understanding of the biology of gastric cancer on both genetic and epigenetic levels. However the physical mechanism behind the gastric cancer formation is still elusive. In this study, we constructed a model for investigating gastric cancer formation by explored the gastric cancer landscape and the flow flux. We uncovered three stable state attractors on the landscape: normal, gastritis and gastric cancer. The definition of each attractor is based on the biological function and gene expression levels. The global stabilities and the switching processes were quantified through the barrier heights and dominant kinetic paths. To investigate the underlying mechanism of the process from normal through the gastritis to the gastric cancer caused by genetic or epigenetic factors, we simulate the oncogenesis of gastric cancer through changes of several gene regulation strengths and H. pylori infection. The simulated results can illustrate the developmental and metastasis process of gastric cancer. Different H. pylori infection degrees accelerating the process from gastritis to gastric cancer can be quantified. Then we applied global sensitivity analysis, one key gene and four key regulations were found. These results are consist with the experimental results and can be used to design the polygenic anti-cancer agents through multiple key genes or regulations. The landscape approach provides a physical and simple strategy for analyzing gastric cancer in a systematic and quantitative way. It also offers new insight into treatment strategy for gastric cancer by adjusting relevant polygenic genes and regulations.

Association of single nucleotide polymorphisms in TNFA and CCR5 genes with Japanese Encephalitis: A study from an endemic region of North India

TNFA, IL1B, HMGB1, IL10, CXCL8, CCL2 and CCR5 gene polymorphisms were investigated in 183 Japanese Encephalitis (JE) cases and 361 healthy controls from North India. Higher frequency of TNFA rs1800629 G/A, CCR5 rs1799987 genotypes with A allele and lower frequency of combination lacking TNFA rs1800629 A, CCR5 rs333 Δ32, andCCR5 rs1799987 A alleles and CCL2 rs1024611 G/G genotype was observed in JE cases. TNFA rs1800629 A and CCR5 rs1799987 A alleles were associated with susceptibility while combination lacking TNFA rs1800629 A, CCR5 rs333 Δ32, and rs1799987 A alleles and CCL2 rs1024611 G/G genotype was associated with protection to JE.

Helicobacter pylori Infection Synergistic with IL-1β Gene Polymorphisms Potentially Contributes to the Carcinogenesis of Gastric Cancer

Helicobacter pylori (H. pylori) infection is the most common chronic bacterial infection in the world and the etiological agent for most gastric cancer (GC). Interleukin-1β (IL-1β) is a potent proinflammatory cytokine, and its deregulation is closely associated with the tumorigenesis of several cancers. Recent studies have revealed that the IL-1β-31 and -511T alleles are closely associated with gastric carcinogenesis due to their roles in the induction of gastric precancerous lesions and hypochlorhydria. Furthermore, H. pylori infection has a synergistic effect on the development of GC with IL-1β gene polymorphisms, and the highest prevalence of severe gastric abnormalities are found in patients with both host and bacterial high-risk genotypes (cagA(+)/vacAs1(+)/IL-1β-511T). Therefore, these recent advances demonstrate that H. pylori synergistic with IL-1β gene polymorphisms contribute to the gastric carcinogenesis by their involvement in precancerous gastric lesions and low gastric acid secretion.

Association of combinations of interleukin-10 and pro-inflammatory cytokine gene polymorphisms with dengue hemorrhagic fever

Pro-inflammatory and anti-inflammatory cytokines have been shown to play an important role in dengue disease pathogenesis. In the present study, to find out whether single nucleotide polymorphisms (SNPs) in the pro-inflammatory and anti-inflammatory cytokine genes are associated with dengue disease severity, SNPs in TNF, IFNG, IL1B, IL8, IL0, IL17A and IL17F genes were investigated using polymerase chain reaction based methods in 132 dengue (DEN) cases [87 dengue fever (DF), 45 dengue hemorrhagic fever (DHF) cases] and 108 apparently healthy controls (HC) from Pune, Maharashtra, western India. Under recessive genetic model (C/C vs. T/T+T/C), the TNF rs1799964 C/C genotype was significantly associated with DEN [P=0.014, OR with 95% CI 3.07 (1.18-7.98)]. Frequency of T/C genotype of IL17F rs763780 was significantly lower in DEN group as compared to HC [P=0.033, OR with 95% CI 0.43 (0.19-0.95)]. Under overdominant genetic model (A/T vs. A/A+T/T), IL8 rs4973 A/T genotype was negatively associated with DHF compared to HCs [p=0.029, OR with 95% CI 0.43 (0.20-0.93)]. Under overdominant genetic model, A/G genotype of IL10 rs1800871 was significantly negatively associated with DHF compared to DF cases [p=0.014, OR with 95% CI 0.35 (0.15-0.84)]. Significantly higher frequency of the combined genotype IL10 A/A-IFNG A/T and lower frequency of the combined genotypes IL10 A/G-IL1B A/A, IL10 A/G-IL8 A/T and IL10 A/G-IL17F T/T were observed in DHF cases compared to DF. The results suggest that heterozygous genotypes of IL8 rs4973 and IL10 rs1800871 are associated with reduced risk of DHF. Combinations of IL10 rs1800871 and pro-inflammatory cytokine genotypes influence the risk of DHF.

Cytokines, cytokine gene polymorphisms and Helicobacter pylori infection: Friend or foe?

Helicobacter pylori (H. pylori) is a flagellated, spiral-shaped, microaerophilic Gram-negative bacillus that colonises the gastric mucosa of more than 50% of the human population. Infection is a risk factor for gastritis, ulcer disease and stomach cancer. Immunity against H. pylori is mainly related to Th1/Th17 skewing, and the activation of regulatory T cells is the main strategy used to limit inflammatory responses, which can result in the pathogen persistence and can lead to chronic gastrointestinal diseases, including cancer. Furthermore, host genetic factors that affect cytokines may determine differences in the susceptibility to many diseases. In this review, we present the cytokine profiles and the main cytokine gene polymorphisms associated with resistance/susceptibility to H. pylori and discuss how such polymorphisms may influence infection/disease outcomes.

Interleukin 1 beta (IL1B) promoter polymorphism and cancer risk: evidence from 47 published studies

Interleukin 1β (IL-1B) is a pro-inflammatory cytokine against infection, playing an important role in the pathogenesis of cancers. The -31T/C polymorphism of the interleukin 1β gene (IL1B) has been implicated in cancer risk through its influence on the IL1B transcription. However, results from studies are conflicting. To clarify the association, a meta-analysis was performed for 11 125 cases and 14 415 controls from 47 published case-control studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. No significant associations were observed for total cancer from all the comparisons. Through the stratified analyses, there was a statistically significant decreased risk of hepatocellular cancer in carriers of the C allele than non-carriers (CC versus TT: OR = 0.87, 95% CI: 0.77-0.98, P(heterogeneity) = 0.103; TC versus TT: OR = 0.77, 95% CI: 0.62-0.95, P(heterogeneity) = 0.734; TC + CC versus TT: OR = 0.74, 95% CI: 0.61-0.91, P(heterogeneity) = 0.472). Similarly, decreased risk was observed for gastric cancer of the C/C genotype compared with the T/T genotype (OR = 0.87, 95% CI: 0.77-0.98, P(heterogeneity) = 0.103). Using the recessive model, a significantly decreased risk was observed for gastric cancer (OR = 0.88, 95% CI: 0.80-0.97, P(heterogeneity) = 0.158), European population (OR = 0.84, 95% CI: 0.73-0.97, P(heterogeneity) = 0.070) and positive infection-matched studies (OR = 0.75, 95% CI: 0.60-0.94, P(heterogeneity) = 0.220); however, an increased risk was found for breast cancer (OR = 1.34, 95% CI: 1.18-1.61, P(heterogeneity) = 0.116). Although some modest bias could not be eliminated, this meta-analysis suggests that the IL1B -31C allele is a low-penetrance protective factor for the development of cancer, in particular for that associated with infection.

IL-1 polymorphisms in children with peptic symptoms in South China

BACKGROUND

Polymorphisms of IL-1 gene cluster are reported to be associated with histological changes and IL-1β expression in the gastric mucosa in adults, especially in Helicobacter pylori-infected subjects. As H. pylori infecting adults and children own different virulence genotypes, the aim of this study was to investigate whether IL-1 polymorphisms are risk factors in young children in South China.

MATERIALS AND METHODS

A total of 128 children with peptic symptoms were enrolled in this study. Polymorphisms of IL-1B-511 and IL-1B-31 were identified by dual fluorescence PCR. Variable number of tandem repeat region in IL-1RN was detected by conventional PCR and IL-1β mRNA expression by real-time PCR ddCT assay.

RESULTS

IL-1B-31T and IL-1B-511C were completely linked in this study. Significant differences of IL-1B-511/-31 genotypes were observed among different clinical outcomes (p = .001). The IL-1B-511TT/-31CC was mostly found in the moderate gastritis and the above (severe gastritis or gastric ulcer) groups, with percentage of 60.7%. While no association was observed between IL-1RN genotypes and the gastric mucosal histological changes (p = .128). Also no relationships were found between IL-1 polymorphisms and H. pylori infection or gastric mucosal IL-1β mRNA expression level.

CONCLUSION

Children with IL-1B-511TT/-31CC may have a risk to develop relatively severe gastric mucosal histological changes in South China.

Polymorphisms in inflammatory response genes and their association with gastric cancer: A HuGE systematic review and meta-analyses

To evaluate the association between gastric cancer susceptibility and inflammation-related gene polymorphisms, the authors conducted a series of meta-analyses using a predefined protocol. Genes investigated were those coding for the interleukin (IL) proteins (IL1B, IL1RN, IL8, and IL10) and for tumor necrosis factor-alpha. Gastric cancers were stratified by histologic subtype and anatomic subsite, by Helicobacter pylori infection status, by geographic location (Asian or non-Asian study population), and by a quantitative index of study quality. All published literature and meeting abstracts from the period 1990-2006 were considered. Results consistently supported increased cancer risk for IL1RN2 carriers; the increased risk was specific to non-Asian populations and was seen for intestinal and diffuse cancers, distal cancers, and, to a lesser extent, cardia cancers. Analyses restricted to high-quality studies or H. pylori-positive cases and controls also showed significant associations with both carrier status and homozygosity status. In Asian populations, reduced risk was observed in association with IL1B-31C carrier status. This effect was also observed in analyses restricted to high-quality studies. These results indicate the importance of stratification by anatomic site, histologic type, H. pylori infection, and country of origin. Study quality considerations, both laboratory and epidemiologic, can also affect results and may explain, in part, the variability in results published to date.

Inflammatory genetic markers of prostate cancer risk

Prostate cancer is the most common cancer in Western society males, with incidence rates predicted to rise with global aging. Etiology of prostate cancer is however poorly understood, while current diagnostic tools can be invasive (digital rectal exam or biopsy) and/or lack specificity for the disease (prostate-specific antigen (PSA) testing). Substantial histological, epidemiological and molecular genetic evidence indicates that inflammation is important in prostate cancer pathogenesis. In this review, we summarize the current status of inflammatory genetic markers influencing susceptibility to prostate cancer. The focus will be on inflammatory cytokines regulating T-helper cell and chemokine homeostasis, together with the Toll-like receptors as key players in the host innate immune system. Although association studies indicating a genetic basis for prostate cancer are presently limited mainly due to lack of replication, larger and more ethnically and clinically defined study populations may help elucidate the true contribution of inflammatory gene variants to prostate cancer risk.

IL-1 gene cluster polymorphisms and sudden infant death syndrome

Several studies indicate that interleukin gene polymorphisms are of importance to sudden infant death syndrome (SIDS), and so far it has been reported that associations between SIDS and polymorphism in the genes encoding tumor necrosis factor alpha, IL (interleukin)-6, and IL-10. IL-1 are important for the synthesis of acute phase proteins, and it is a pyrogen cytokine that may cause fever. The purpose of the present study was to investigate two polymorphisms in the IL-1alpha gene; a variable number of tandem repeat (VNTR) in intron 6 and a single nucleotide polymorphism in +4845G/T, as well as the -511C/T polymorphism in the gene encoding IL-1beta, and a VNTR in intron 2 of the competitive antagonist IL-1Ra, in SIDS cases, cases of infectious death, and controls. Furthermore, the genotypes were correlated with known external risk factors for SIDS. When investigating each polymorphism separately, no differences in genotype distribution between the diagnosis groups and controls were found. However, when combining VNTR and single nucleotide polymorphism genotypes, an association between the gene combination IL-1alpha VNTR A1A1/IL-1beta+ +4845TT and SIDS was disclosed (p < 0.01). In the SIDS group it was also found that the genotypes IL-1beta -511CC/CT were significantly more frequent in the SIDS victims found dead in a prone sleeping position, compared with SIDS victims found dead in other sleeping positions (p = 0.004). The findings in the present study indicate that specific interleukin gene variants may be a predisposing factor for sudden unexpected infant death.

Interleukin-1 beta single-nucleotide polymorphism's C allele is associated with elevated risk of gastric cancer in Helicobacter pylori-infected Peruvians

Particular alleles of the interleukin-1B (IL-1B) gene have been correlated with increased risk of atrophic gastritis and gastric cancer in the populations of East Asia and Europe. No such data exist from Peru, a developing country with a population genotypically different from others studied and with a high prevalence of Helicobacter pylori infection and gastric cancer. We conducted a case-control study comparing 334 hospitalized patients with atrophic gastritis or gastric cancer with 158 nonatrophic gastritis patients (controls). Conditional logistic regression analysis revealed that an increased risk of atrophic gastritis (odds ratio, 5.60) and gastric cancer (odds ratio, 2.36) was associated with the IL-1B-511 C allele. Our study is the first to establish this allele as a risk for these conditions. Given the high prevalence of H. pylori and recurrence rate after treatment, IL-1B-511 single-nucleotide polymorphism analysis may identify those individuals who would benefit most from robust H. pylori eradication efforts in Peru.

Relevance of IL-1 and TNF gene polymorphisms on interleukin-1beta and tumor necrosis factor-alpha gastric mucosal production

We aimed to evaluate the influence of Helicobacter pylori infection and IL-1/TNF gene polymorphisms on interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha gastric mucosal production. IL-1beta and TNF-alpha levels in homogenized biopsy specimens taken from the antrum and corpus of 81 patients were measured by enzyme-linked immunosorbent assay. Genomic DNA was typed for the IL1B-511, IL1B+3954, variable number of tandem repeat (VNTR) IL1RN, TNFA-308, TNFA-238, LTA NcoI, and LTA Bsi gene polymorphisms by polymerase chain reaction, restriction fragment length polymorphism, and TaqMan assays. H. pylori infection and CagA/VacA antibody status were determined by Western blot. IL-1beta and TNF-alpha protein levels were significantly higher in the gastric antrum of patients infected with H. pylori compared with uninfected patients [9.54 (5.07-16.28) vs. 4.55 (3.69-8.28) pg IL-1beta/mg protein, p = 0.004, and 1.5 (0.7-2.71) vs. 0.63 (0.3-1.26) pg TNF-alpha/mg protein, p = 0.001]. Among H. pylori-infected individuals, carriers of the IL1RN*2 allele had significantly higher antrum mucosal IL-1beta levels than noncarriers [15.97 (9.59-26.6) vs. 10.08 (7.72-13.33), p = 0.008]. No association between gastric mucosal TNF-alpha levels and genotypes of the TNFA and LTA gene polymorphisms was reported. Our results indicate that the VNTR polymorphism of the IL1RN gene influences IL-1beta gastric mucosal production in patients infected with H. pylori.

IL-1beta and IL-8, matrix metalloproteinase 3, and pepsinogen secretion before and after H. pylori eradication in gastroduodenal phenotypes

OBJECTIVE

Relations between host genetic factors and clinical outcomes of Helicobacter pylori infection are variable among ethnicities. The aim of this study was to examine gastric mucosal cytokines, matrix metalloproteinase 3 (MMP-3), and serum pepsinogen levels before and after eradication of H. pylori according to IL-1B genotypes and benign gastroduodenal phenotypes in a Korean population.

MATERIAL AND METHODS

A total of 349 Koreans including H. pylori-infected subjects (n=230) and H. pylori-negative controls (n=119) were enrolled. The former subjects were classified into groups according to the presence of non-atrophic gastritis (n=74), atrophic gastritis (n=56), gastric ulcer (n=37), and duodenal ulcer (n=63). IL-1B polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Gastric mucosal IL-1beta, IL-8, and MMP-3, and serum pepsinogen I and II levels were measured by ELISA and radioimmunoassay, respectively.

RESULTS

There were no significant differences between the IL-1B-31/-511 haplotype (TT/CC, CT/CT, and CC/TT) frequencies among the H. pylori-positive and -negative groups. The genotypes of IL-1B-31/-511 polymorphisms did not affect clinical phenotypes, inflammatory cytokines, MMP-3, and pepsinogen secretion. Subjects with H. pylori-infected atrophic gastritis exhibited significantly higher basal levels of cytokines and a lower pepsinogen I/II ratio than those of other groups. Following H. pylori eradication, inflammatory cytokines significantly decreased and the pepsinogen I/II ratio increased in all groups.

CONCLUSIONS

Mucosal inflammatory cytokines, MMP-3, and pepsinogen secretion are related to gastroduodenal phenotypes but not to IL-1B genotypes. Eradication of H. pylori can reduce mucosal inflammation and restore pepsinogen secretion.

A method of oligochip for single nucleotide polymorphism genotyping in the promoter region of the interleukin-1 beta gene and its clinical application

Single nucleotide polymorphisms (SNPs) can contribute to genetic predispositions or serve as genetic markers that are associated with complex diseases. So far, a few SNP arrays containing a limited number of SNPs have been used in routine genetic testing. This study described an oligochip-based method that genotypes two SNPs (-511 and -31) in the promoter region of the interleukin (IL)-1 beta gene. The sensitivity of this SNP genotyping method is derived from polymerase chain reaction (PCR)-amplified allele-specific primer-probes with a biotin label incorporated from the reverse primers. The amplified primer-probes can specifically hybridize with the oligonucleotides that are spotted on the oligochip. This oligochip-based method successfully discriminated the two biallelic SNPs with 9 different genotypes and all the genotyping results are in concordance with those from PCR restriction fragment length polymorphism (RFLP) analysis. Selective samples with various genotypes were also confirmed by direct sequencing. This method was applied in the genotyping of the patients with tuberculosis or gastric cancer and healthy controls. In the case control study, our genotyping data supported the reported association between gastric cancer and the genotypes of IL-1 beta -31 TT and -511 CC (p < 0.05). We also found that there is a significant difference of IL-1 beta -31 genotypes between 98 tuberculosis patients and healthy controls (p < 0.002). All of our results demonstrated that the oligochip can effectively and accurately identify SNP genotypes in the IL-1 beta promoter region.

Interaction of polymorphisms in the interleukin 1B-31 and general transcription factor 2A1 genes on the susceptibility to gastric cancer

Proinflammatory genotypes of the IL-1 (interleukin-1) gene have been associated with an increased gastric cancer risk in Caucasians, whereas some studies in Asian populations did not find such association. Furthermore, the risk genotypes differed somewhat between Caucasian and Asian populations. These findings might reflect more complex genetic mechanisms in Asian compared with Caucasian populations. Therefore, we examined a polymorphism (rs1864169) in the general transcription factor 2A1 (GTF2A1) gene as a test of the hypothesis that this transcription factor and IL-IB gene polymorphisms interact in the effects on the gastric cancer risk due to the possible biological relationship between the two genes. Genotyping of the 515 control and 342 case samples was performed by primer extension assay and SNaPshot assays. We found an association between carriage of the IL1B-31C allele and gastric cancer among Koreans, which was observed only in subjects with GTF2A1 GG genotype. The GTF2A1GG/IL1B-31C carrier genotype combination showed stronger association with diffuse type gastric cancer cases. These findings indicate that the effect of the two genetic polymorphisms on risk of gastric cancer is synergistic. Our results also suggest that an additional host genetic factor acting epistatically may differentially contribute to the histogenesis of the diffuse and intestinal subtypes.

Novel interleukin-4 and interleukin-1 receptor antagonist gene variations associated with non-cardia gastric cancer in Japan: comprehensive analysis of 207 polymorphisms of 11 cytokine genes

BACKGROUND AND AIM

Helicobacter pylori (H. pylori)-induced chronic atrophic gastritis is a high-risk factor for gastric cancer. Immune responses to H. pylori are involved in gastric mucosal inflammation, and might affect clinical outcome, including the development of gastric cancer. The present study examines the significance of gene polymorphisms of various cytokines in the development of gastric cancer following H. pylori infection.

METHODS

One hundred Japanese non-cardia gastric cancer patients and 93 dyspeptic patients as controls were enrolled in the study (age range 50-75 years). All patients were positive for H. pylori. Genomic DNA was extracted from peripheral whole blood leukocytes, and we comprehensively analyzed 207 single nucleotide polymorphisms (SNP) in 11 cytokine genes; interleukin (IL)-1alpha, IL-1beta, IL-1 receptor antagonist (RN), IL-4, IL-4R, IL-8, IL-10, IL-12, TNF-alpha, TNF-beta, and IFN-gamma, using either invader assay (163 SNP), direct sequencing (22 SNP), or PCR-restriction fragment length polymorphism (22 SNP).

RESULTS

Among the 207 SNP examined, the IL-4 gene diplotypes (984 and 2983 AA/GA) had a significant negative association with gastric cancer development (odds ratio =0.3, 95% confidence interval =0.1-0.9). When we adopted the dyspeptic patients over 66 years of age as the controls, the IL-1RN gene diplotypes (-1102 and 6110 CG/GA) also had a significant negative association (odds ratio =0.2, 95% confidence interval =0.1-0.7).

CONCLUSION

A comprehensive analysis of 207 SNP of 11 cytokine genes revealed that variations in IL-4 and IL-1RN genes are negatively associated with the risk of developing gastric cancer following H. pylori infection. Distinct host cytokine responses in the gastric mucosa might have a role in H. pylori-induced carcinogenesis.

Polymorphisms of interleukin-1beta in Japanese patients with hepatitis B virus infection

BACKGROUND/AIMS

Hepatitis B virus (HBV) induces liver cirrhosis (LC) and hepatocellular carcinoma (HCC) mainly by causing chronic necro-inflammatory hepatic disease. Our aim was to investigate the relationships between the polymorphisms of the interleukin-1B (IL-1B) promoter region and the interleukin-1 receptor antagonist gene (IL-1RN) and disease progression in an HBV-infected Japanese population.

METHODS

Genomic DNA was extracted from the peripheral blood of 237 HBV carriers. Polymorphisms in IL-1B and IL-1RN were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR with confronting two-pair primers (PCR-CTPP) methods. These polymorphic sites include the promoter regions of IL-1B at positions -511 and -31, and IL-1RN variable tandem repeats.

RESULTS

The IL-1B -31 and -511 loci were in complete linkage disequilibrium, and the frequency of the IL-1B -31 T carrier (IL-1B -31 T/T or T/C) was significantly higher in HBV carriers with LC compared to those without LC (LC; 86.1% vs non-LC; 72.1%, P=0.009). There was no difference in the genotype distribution of the IL-1RN polymorphism.

CONCLUSIONS

This is the first report describing the association between IL-1B polymorphism and HBV-related hepatic fibrosis, and our data suggest that IL-1B polymorphisms may be related to disease progression of HBV-related hepatitis in Japan.

Genetic susceptibility to infectious diseases: big is beautiful, but will bigger be even better?

Genetic epidemiology, including twin studies, provides robust evidence that genetic variation in human populations contributes to susceptibility to infectious disease. One of the major limitations of studies that attempt to identify the genes and mechanisms that underlie this susceptibility has been lack of power caused by small sample size. With the development of novel technologies, burgeoning information on the human genome, the HapMap project, and human genetic diversity, we are at the beginning of a new era in the study of the genetics of complex diseases. This review looks afresh at the epidemiological evidence that supports a role for genetics in susceptibility to infectious disease, examines the somewhat limited achievements to date, and discusses current advances in methodology and technology that will potentially lead to translational data in the future.

A polymorphism of C-to-T substitution at -31 IL1B is associated with the risk of advanced gastric adenocarcinoma in a Japanese population

Proinflammatory cytokine gene polymorphisms have been demonstrated to associate with gastric cancer risk, of which IL1B-31T/C and -511C/T changes have been well investigated due to the possibility that they may alter the IL1B transcription. The signal transduction target upon interleukin 1 beta (IL1beta) stimulation, the nuclear factor of kappa B (NFkappaB) activation, supports cancer development, signal transduction in which is mediated by FS-7 cell-associated cell surface antigen (FAS) signaling. Based on recent papers describing the prognostic roles of the polymorphisms and the NFkappaB functions on cancer development, we sought to determine if Japanese gastric cancer patients were affected by the IL1B -31/-511 and FAS-670 polymorphisms. A case-control study was conducted on incident gastric adenocarcinoma patients (n=271) and age-gender frequency-matched control subjects (n=271). We observed strong linkage disequilibrium between the T allele at -511 and the C allele at -31 and between the C allele at -511 and the T allele at -31 in IL1B in both the cases and controls (R (2)=0.94). Neither IL1B-31, -511 nor FAS-670 polymorphisms showed significantly different risks of gastric adenocarcinoma. Though FAS-670 polymorphisms did not show any significant difference, the proportion of subjects with IL1B-31TT (or IL1B-511CC) increased according to stage (trend P=0.019). In particular, subjects with stage IV had a two times higher probability of having either IL1B-31TT (or IL1B-511CC) genotype compared with stage I subjects. These observations suggest that IL1B-31TT and IL1B-511CC are associated with disease progression.

Genetic factors involved in the development of Helicobacter pylori-related gastric cancer

Developmental process to gastric cancer by Helicobacter pylori infection consists of three steps: (1) H. pylori infection; (2) gastric atrophy development; and (3) carcinogenesis. In each step, genetic traits may influence the process, interacting with lifestyle. In the step of H. pylori infection, two lines of genetic polymorphisms were assumed: one influencing gastric acid inhibition interacting with smoking, and the other concerning innate immune response attenuation. The former includes functional polymorphisms of IL-1B (C-31T or tightly linked T-511C), and TNF-A (T-1031C and C-857T), and the latter possibly includes NQO1 C609T. In the step to gastric atrophy, polymorphisms pertaining to the signal transduction from cytotoxin-associated gene A (PTPN11 A/G at intron 3) and to T-cell responses (IL-2 T-330G and IL-13 C-1111T) were hypothesized. There are a limited number of epidemiological genotype studies on the final step of literal carcinogenesis, potentially interacting with smoking, a low vegetable and fruit intake, and salty foods, the well-documented risk factors. In past case-control studies on the associations between genotype and gastric cancer risk, the cases consisted of H. pylori-related and unrelated gastric cancer patients and the controls consisted of individuals including the uninfected (H. pylori unexposed and exposed) and the infected with and without gastric atrophy. Accordingly, it was not clear whether the observed risk was for H. pylori-related or -unrelated gastric cancer, nor which step was involved in the observed associations even when nearly all cases were H. pylori-related. In order to elucidate the genetic traits of H. pylori-related gastric cancer, stepwise evaluation will be required.