miR-20b and miR-451a Are Involved in Gastric Carcinogenesis through the PI3K/AKT/mTOR Signaling Pathway: Data from Gastric Cancer Patients, Cell Lines and Ins-Gas Mouse Model

Gastric cancer (GC) is one of the most common and lethal gastrointestinal malignancies worldwide. Many studies have shown that development of GC and other malignancies is mainly driven by alterations of cellular signaling pathways. MicroRNAs (miRNAs) are small noncoding molecules that function as tumor-suppressors or oncogenes, playing an essential role in a variety of fundamental biological processes. In order to understand the functional relevance of miRNA dysregulation, studies analyzing their target genes are of major importance. Here, we chose to analyze two miRNAs, miR-20b and miR-451a, shown to be deregulated in many different malignancies, including GC. Deregulated expression of miR-20b and miR-451a was determined in GC cell lines and the INS-GAS mouse model. Using Western Blot and luciferase reporter assay we determined that miR-20b directly regulates expression of PTEN and TXNIP, and miR-451a: CAV1 and TSC1. Loss-of-function experiments revealed that down-regulation of miR-20b and up-regulation of miR-451a expression exhibits an anti-tumor effect in vitro (miR-20b: reduced viability, colony formation, increased apoptosis rate, and miR-451a: reduced colony forming ability). To summarize, the present study identified that expression of miR-20b and miR-451a are deregulated in vitro and in vivo and have a tumor suppressive role in GC through regulation of the PI3K/AKT/mTOR signaling pathway

Replication study of ulcerative colitis risk loci in a Lithuanian-Latvian case control sample

Background: Differences between populations might be reflected in their different genetic risk maps to complex diseases, for example, inflammatory bowel disease. We here investigated the role of known inflammatory bowel disease associated single nucleotide polymorphisms (SNPs) in a subset of patients with ulcerative colitis (UC) from the Northeastern European countries Lithuania and Latvia and evaluated possible epistatic interactions between these genetic variants. Methods: We investigated 77 SNPs derived from 5 previously published genome-wide association studies for Crohn's disease and UC. Our study panel comprised 444 Lithuanian and Latvian patients with UC and 1154 healthy controls. Single marker case control association and SNP-SNP epistasis analyses were performed. Results: We found 14 SNPs tagging 9 loci, including 21q21.1, NKX2-3, MST1, the HLA region, 1p36.13, IL10, JAK2, ORMDL3, and IL23R, to be associated with UC. Interestingly, the association of UC with previously identified variants in the HLA region was not the strongest association in our study (P = 4.34 × 1023, odds ratio [OR] = 1.25), which is in contrast to all previously published studies. No association with any disease subphenotype was found. SNP-SNP interaction analysis showed significant epistasis between SNPs in the PTPN22 (rs2476601) and C13orf31 (rs3764147) genes and increased risk for UC (P = 1.64 × 1026, OR = 2.44). The association has been confirmed in the Danish study group (P = 0.04, OR = 3.25). Conclusions: We confirmed the association of the 9 loci (21q21.1, 1p36.13, NKX2-3, MST1, the HLA region, IL10, JAK2, ORMDL3, and IL23R) with UC in the Lithuanian Latvian population. SNP-SNP interaction analyses showed that the combination of SNPs in the PTPN22 (rs2476601) and C13orf31 (rs3764147) genes increase the risk for UC.publishersversionPeer reviewe

Molecular characterization and seroprevalence of hepatitis E virus in inflammatory bowel disease patients and solid organ transplant recipients

16 p.-3 fig.-5 tab.Seroprevalence rates and molecular characterization of hepatitis E virus (HEV) prevalent in the Lithuanian human population has not yet been evaluated. Immunosuppressed individuals have been recognized as a risk group for chronic hepatitis due to HEV genotype 3 (HEV-3) infections. The objectives of the present study were to determine prevalence rates of anti-HEV antibodies among inflammatory bowel disease (IBD) patients and solid organ transplant (SOT) recipients, to isolate and characterize HEV strain present in the Lithuanian human population, and to investigate its capacity to infect non-human primate (MARC-145 and Vero), swine (PK-15) and murine (Neuro-2a) cells in vitro. In the present study, the significant difference of anti-HEV IgG prevalence between healthy (3.0% (95% CI 0–6.3)) and immunosuppressed individuals (12.0% [95% CI 8.1–15.9]) was described. Moreover, our findings showed that anti-HEV IgG seropositivity can be significantly predicted by increasing age (OR = 1.032, p < 0.01), diagnosis of IBD (OR = 4.541, p < 0.01) and reception of SOT (OR = 4.042, <0.05). Locally isolated HEV strain clustered within genotype 3i subtype of genotype 3 and was capable of infecting MARC-145 cells. This study demonstrates higher HEV seroprevalence in the risk group compared to healthy control individuals without confidence interval overlap. The high level of genetic homology between human and animal strains in Lithuania and the capacity of locally isolated strains to infect cells of non-human origin suggests its potential for zoonotic transmission.This research was partly funded by the Lithuanian University of Health Sciences Science Foundation (LSMUSF), grant number 119-05 and COST Action CA15116 ASF-STOP, supported by COST (European Cooperation in Science and Technology).Peer reviewe

Lack of association between gene polymorphisms of Angiotensin converting enzyme, Nod-like receptor 1, Toll-like receptor 4, FAS/FASL and the presence of Helicobacter pylori-induced premalignant gastric lesions and gastric cancer in Caucasians

<p>Abstract</p> <p>Background</p> <p>Several polymorphisms of genes involved in the immunological recognition of <it>Helicobacter pylori </it>and regulating apoptosis and proliferation have been linked to gastric carcinogenesis, however reported data are partially conflicting. The aim of our study was to evaluate potential associations between the presence of gastric cancer (GC) and high risk atrophic gastritis (HRAG) and polymorphisms of genes encoding <it>Angiotensin converting enzyme </it>(<it>ACE</it>), <it>Nod-like receptor 1 </it>(<it>NOD1</it>), <it>Toll-like receptor 4 </it>(<it>TLR4</it>) and <it>FAS/FASL</it>.</p> <p>Methods</p> <p>Gene polymorphisms were analyzed in 574 subjects (GC: n = 114; HRAG: n = 222, controls: n = 238) of Caucasian origin. <it>ACE I/D </it>(rs4646994), <it>NOD1 796G>A </it>(rs5743336), <it>TLR4 3725G>C </it>(rs11536889), <it>FAS 1377G>A </it>(rs2234767), <it>FAS 670A>G </it>(rs1800682) and <it>FASL 844T>C </it>(rs763110) were genotyped by different PCR approaches and restriction fragment length polymorphism analysis.</p> <p>Results</p> <p>Frequencies of genotypes in our study are similar to the data reported on subjects of Caucasian ethnicity. There was a tendency for <it>NOD1 796G/G </it>genotype to be associated with increased risk of HRAG (62.4% <it>vs</it>. 54.5% in controls, <it>p </it>= 0.082). <it>FAS 670G/G </it>genotype was more frequent in HRAG when compared to controls, 23.9% and 17.2% respectively, however it failed to reach significance level (<it>p </it>= 0.077). We did not find any significant associations for all polymorphisms in relation to GC or HRAG. <it>NOD1 796G>A </it>and <it>TLR4 3725G>C </it>gene polymorphisms were also not associated with <it>Helicobacter pylori </it>infection.</p> <p>Conclusions</p> <p><it>ACE, NOD1, TRL4 </it>and <it>FAS/FASL </it>gene polymorphisms are not linked with gastric carcinogenesis in Caucasians, and therefore they should not be considered as potential biomarkers for identifying individuals with higher risk for GC.</p

Assessment of heterogeneity between European Populations: a Baltic and Danish replication case-control study of SNPs from a recent European ulcerative colitis genome wide association study

<p>Abstract</p> <p>Background</p> <p>Differences in the genetic architecture of inflammatory bowel disease between different European countries and ethnicities have previously been reported. In the present study, we wanted to assess the role of 11 newly identified UC risk variants, derived from a recent European UC genome wide association study (GWAS) (Franke <it>et al</it>., 2010), for 1) association with UC in the Nordic countries, 2) for population heterogeneity between the Nordic countries and the rest of Europe, and, 3) eventually, to drive some of the previous findings towards overall genome-wide significance.</p> <p>Methods</p> <p>Eleven SNPs were replicated in a Danish sample consisting of 560 UC patients and 796 controls and nine missing SNPs of the German GWAS study were successfully genotyped in the Baltic sample comprising 441 UC cases and 1156 controls. The independent replication data was then jointly analysed with the original data and systematic comparisons of the findings between ethnicities were made. Pearson's χ², Breslow-Day (BD) and Cochran-Mantel-Haenszel (CMH) tests were used for association analyses and heterogeneity testing.</p> <p>Results</p> <p>The rs5771069 (<it>IL17REL</it>) SNP was not associated with UC in the Danish panel. The rs5771069 (<it>IL17REL</it>) SNP was significantly associated with UC in the combined Baltic, Danish and Norwegian UC study sample driven by the Norwegian panel (OR = 0.89, 95% CI: 0.79-0.98, P = 0.02). No association was found between rs7809799 <it>(SMURF1/KPNA7) </it>and UC (OR = 1.20, 95% CI: 0.95-1.52, P = 0.10) or between UC and all other remaining SNPs. We had 94% chance of detecting an association for rs7809799 <it>(SMURF1/KPNA7) </it>in the combined replication sample, whereas the power were 55% or lower for the remaining SNPs.</p> <p>Statistically significant P_BDwas found for OR heterogeneity between the combined Baltic, Danish, and Norwegian panel versus the combined German, British, Belgian, and Greek panel (rs7520292 (P = 0.001), rs12518307 (P = 0.007), and rs2395609 (TCP11) (P = 0.01), respectively).</p> <p>No SNP reached genome-wide significance in the combined analyses of all the panels.</p> <p>Conclusions</p> <p>This replication study supports an important role for the studied rs5771069 (<it>IL17REL</it>) SNP, but not for rs7809799 (<it>SMURF1</it>/<it>KPNA7</it>), in UC etiology in the Danish, Baltic, and Norwegian populations. Significant genetic heterogeneity was suggested for rs7520292, rs12518307, and rs2395609 (<it>TCP11</it>) in UC etiology between the Nordic and the other European populations.</p

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

Evaluation of a novel 14C-urea breath test “Heliprobe” in diagnosis of Helicobacter pylori infection

Background. At present, 14C-urea breath test is considered a gold standard for diagnosis of Helicobacter pylori infection, but they are time-consuming, comparably expensive, and usually not portable tests. The aim of our study was to establish the diagnostic value of the novel, inexpensive, quick, and convenient to use 14C-urea breath test “Heliprobe”, Noster AB, Sweden.Material and methods. Helicobacter pylori testing using “Heliprobe” was performed in 108 consecutive patients. Helicobacter pylori was also investigated using rapid urease test and Giemsa stained histological specimens according to Sydney system.Results. The diagnostic values of “Heliprobe” assuming the Helicobacter pylori positivity, if the results of two tests (rapid urease test and histology) are positive, were: sensitivity – 97%, specificity – 87%, positive predictive value – 93%, negative predictive value – 95%, accuracy – 94%. The diagnostic values of “Heliprobe” assuming the Helicobacter pylori positivity, if at least the results of one test are positive: sensitivity – 92%, specificity – 100%, positive predictive value – 100%, negative predictive value – 84%, accuracy – 94%.Conclusions. The novel, quick, convenient to use 14C-urea breath test “Heliprobe” is accurate, reliable, and useful for the diagnosis of Helicobacter pylori infection in routine clinical practic

Gastroesophageal reflux disease after Helicobacter pylori eradication in gastric ulcer patients: A one-year follow-up study

The aim of this study was to evaluate the course of gastroesophageal reflux disease in gastric ulcer patients after successful Helicobacter pylori eradication (group A), in patients with persistent infection after attempt to eradicate Helicobacter pylori (group B), and in control group without Helicobacter pylori eradication treatment (group C). Materials and methods. Gastric ulcer patients (n=88) were assigned either to the group receiving Helicobacter pylori eradication treatment (54 patients) or to the control group (34 patients; omeprazole treatment for 4 weeks) and were followed up for 1-year or until gastric ulcer relapsed. Gastroesophageal reflux disease was diagnosed in patients who had erosive esophagitis and/or without esophagitis if they experienced heartburn and/or regurgitation at least 2 times a week and it was associated with impairment of daily activities (Genval consensus). Results. The study was completed by 69 patients: 25 in group A, 19 in group B, and 25 in group C. At the beginning and at the end of the follow-up, gastroesophageal reflux disease was diagnosed in 10 (40%) and 9 (36%) group A patients, respectively (P&gt;0.05); in 12 (63%) and 8 (42%) group B patients, respectively (P&gt;0.05); and in 9 (36%) and 5 (20%) group C patients, respectively (P&gt;0.05). At the beginning and at the end of the follow-up, reflux esophagitis was found in 3 (12%) and 5 (20%) group A patients, respectively (P&gt;0.05); in 5 (26%) and 5 (26%) group B patients (P&gt;0.05); in 4 (16%) and 3 (12%) group C patients (P&gt;0.05). Conclusion. There was no statistically significant difference regarding the development of gastroesophageal reflux disease in gastric ulcer patients after Helicobacter pylori eradication, in the patients with persistent infection after attempt to eradicate, and in the control group without Helicobacter pylori eradication treatment

Risk Factors for Erosive Esophagitis and Barrett’s Esophagus in a high Helicobacter pylori Prevalence Area

Objective. To establish the prevalence and risk factors of erosive esophagitis (EE) and Barrett’s esophagus (BE) among patients routinely referred for upper endoscopy. Material and Methods. A total of 4032 consecutive patients referred to a regional hospital for upper endoscopy due to upper gastrointestinal and/or “alarm” symptoms were examined. Analysis was performed on the prospectively selected patients (40 in each group) with EE of different grades and BE. Results. EE was diagnosed in 474 patients (11.75%): grade A, in 194 (41%); grade B, in 167 (35%); grade C, in 65 (14%); and grade D, in 48 patients (10%). Increasing severity of erosive esophagitis and presence of its complication – Barrett’s esophagus – were associated with the decreasing prevalence of H. pylori and increasing hiatal hernia size (P&lt;0.05). Male gender (OR, 3.57; 95% CI, 1.12 to 10.62), hiatal hernia &gt;2 cm (OR, 3.73; 95% CI, 1.60 to 8.68), and absence of H. pylori (OR, 4.24; 95% CI, 1.07 to 16.84) were the factors found to be associated with severe EE. The factors associated with BE were as follows: ulcer and/or stricture of esophagus (OR, 11.94; 95% CI, 2.51 to 41.37), age &gt;60 years (OR, 1.06; 95% CI, 1.01 to 1.20), smoking &gt;10 cigarettes per day (OR, 4.62; 95% CI, 1.01 to 12.50), hiatal hernia &gt;2 cm (OR, 5.22; 95% CI, 1.86 to 14.64), and absence of H. pylori (OR, 5.60; 95% CI, 1.38 to 22.72). Conclusions. The prevalence of EE was found to be low, and the prevalence of BE was found to be very low among routinely endoscoped patients in primary and secondary care settings in a Lithuanian rural area with high H. pylori prevalence. Increasing severity of gastroesophageal reflux disease was associated with the decreasing prevalence of Helicobacter pylori

Helicobacter pylori išnaikinimo įtaka gastroezofaginio refliukso ligos eigai sergantiesiems skrandžio opalige (vienerių metų stebėjimo studija)

The aim of this study was to evaluate the course of gastroesophageal reflux disease in gastric ulcer patients after successful Helicobacter pylori eradication (group A), in patients with persistent infection after attempt to eradicate Helicobacter pylori (group B), and in control group without Helicobacter pylori eradication treatment (group C). Materials and methods. Gastric ulcer patients (n=88) were assigned either to the group receiving Helicobacter pylori eradication treatment (54 patients) or to the control group (34 patients; omeprazole treatment for 4 weeks) and were followed up for 1-year or until gastric ulcer relapsed. Gastroesophageal reflux disease was diagnosed in patients who had erosive esophagitis and/or without esophagitis if they experienced heartburn and/or regurgitation at least 2 times a week and it was associated with impairment of daily activities (Genval consensus). Results. The study was completed by 69 patients: 25 in group A, 19 in group B, and 25 in group C. At the beginning and at the end of the follow-up, gastroesophageal reflux disease was diagnosed in 10 (40%) and 9 (36%) group A patients, respectively (P>0.05); in 12 (63%) and 8 (42%) group B patients, respectively (P>0.05); and in 9 (36%) and 5 (20%) group C patients, respectively (P>0.05). At the beginning and at the end of the follow-up, reflux esophagitis was found in 3 (12%) and 5 (20%) group A patients, respectively (P>0.05); in 5 (26%) and 5 (26%) group B patients (P>0.05); in 4 (16%) and 3 (12%) group C patients (P>0.05). Conclusion. There was no statistically significant difference regarding the development of gastroesophageal reflux disease in gastric ulcer patients after Helicobacter pylori eradication, in the patients with persistent infection after attempt to eradicate, and in the control group without Helicobacter pylori eradication treatment