Development Of Early Gastric Cancer Research Articles

The value of LCI-based modified Kyoto classification risk scoring system in predicting the risk of early gastric cancer

Objective To study and compare the value of the Kyoto classification risk scoring system and the modified Kyoto classification risk scoring system based on linked color imaging (LCI) in predicting the risk of early gastric cancer. Methods One hundred and fifty patients with pathologically confirmed non-cardia early gastric cancer by endoscopic LCI and 150 non-gastric cancer patients matched for age and gender were included. Basic patient data and whole gastric endoscopic images under LCI were collected, and the images were scored according to the LCI-based Kyoto classification risk scoring system and the LCI-based modified Kyoto classification risk scoring system. Results Compared with the LCI-based Kyoto classification risk scoring system, the LCI-based modified Kyoto classification risk scoring system had a higher AUC for predicting the risk of early gastric cancer (0.723 vs. 0.784, p = 0.023), with a score of ≥3 being the best cutoff value for predicting the risk of early gastric cancer (sensitivity 61.33%, specificity 86.00%), and scores of 3 to 5 were significantly associated with early gastric carcinogenesis significantly (OR = 9.032, 95% CI: 4.995–16.330, p < 0.001). Conclusions Compared with the LCI-based Kyoto classification risk scoring system, the LCI-based Kyoto modified classification risk scoring system has a better value for predicting the risk of early gastric cancer, and the score of 3 to 5 is a high-risk factor for the risk of early gastric cancer development, which is more strongly correlated with the risk of early gastric cancer.

Proteomic profiling identifies signatures associated with progression of precancerous gastric lesions and risk of early gastric cancer.

BackgroundMolecular features underlining the multistage progression of gastric lesions and development of early gastric cancer (GC) are poorly understood, restricting the ability to GC prevention and management.MethodsWe portrayed proteomic landscape and explored proteomic signatures associated with progression of gastric lesions and risk of early GC. Tissue proteomic profiling was conducted for a total of 324 subjects. A case-control study was performed in the discovery stage (n=169) based on populations from Linqu, a known high-risk area for GC in China. We then conducted two-stage validation, including a cohort study from Linqu (n = 56), with prospective follow-up for progression of gastric lesions (280–473 days), and an independent case-control study from Beijing (n = 99).FindingsThere was a clear distinction in proteomic features for precancerous gastric lesions and GC. We derived four molecular subtypes of gastric lesions and identified subtype-S4 with the highest progression risk. We found 104 positively-associated and 113 inversely-associated proteins for early GC, with APOA1BP, PGC, HPX and DDT associated with the risk of gastric lesion progression. Integrating these proteomic signatures, the ability to predict progression of gastric lesions was significantly strengthened (areas-under-the-curve=0.88 (95%CI: 0.78–0.99) vs. 0.56 (0.36–0.76), Delong's P = 0.002). Immunohistochemistry assays and examination at mRNA level validated the findings for four proteins.InterpretationWe defined proteomic signatures for progression of gastric lesions and risk of early GC, which may have translational significance for identifying particularly high-risk population and detecting GC at an early stage, improving potential for targeted GC prevention.FundingThe funders are listed in the Acknowledgement.

Diagnostic value of MRI-DWI signal intensity value combined with serum PGI, PGII and CA199 in early gastric cancer.

To explore the diagnostic value of MRI-DWI signal intensity value combined with serum PGI. PGII and CA199 in early gastric cancer. Sixty cases of gastric cancer patients admitted to our hospital from December 2019 to December 2020 were selected as the gastric cancer group and 80 cases of healthy volunteers who underwent physical examination in our hospital during the same period were selected as the healthy group. All the 60 patients underwent MRI-DWI examination, and the pathological diagnosis results were regarded as the gold standard. MRI-DWI images, MRI-DWI signal intensity values of patients with different degrees of gastric cancer differentiation. Serum PGI, PGII and CA199 levels of subjects in the two groups were compared. AUC was used to evaluate the diagnostic value of MRI-DWI signal intensity value combined with serum PGI, PG II and CA199 for early gastric cancer. In the healthy group, T1W1 showed relatively uniform low signal intensity. While T2WI showed no significant increase in signal intensity. In the gastric cancer group. There was diffuse gastric wall thickening, local thickening or mass formation; T1WI and WATS showed slightly lower signal intensity in the lesion area. T2WI, FLAIR and B-TFE showed slightly uneven or moderately increased signal intensity. DWI showed limited diffusion, and the signal intensity increased uniformly or more uniformly, and the range of increase was clear. The signal intensity of MRI-DWI was 89.12 ± 8.14 in patients with low differentiation, 82.17 ± 6.35 in patients with moderate differentiation, and 74.52 ± 4.53 in patients with high differentiation. There were significant differences in the signal intensity of MRI-DWI among the three groups, and the difference was statistically significant (F=12.214, P <0.05). Serum PGI levels of subjects in the gastric cancer group were significantly lower than those in the healthy group, and the levels of PGII and CA199 were significantly higher than that in the healthy group, with statistical significance (P <0.05). The AUC, sensitivity and specificity of MRI-DWI signal intensity value and serum PGI, PGII and CA199 combined indexes in the diagnosis of gastric cancer were significantly higher than those of the independent indexes, with statistical significance (P <0.05). Conclusion: MRI-DWI signal strength value, serum PGI, PGII and CA199 levels are closely related to the occurrence and development of early gastric cancer. The combined detection and diagnosis efficiency is higher, which is helpful to improve the detection rate of early gastric cancer and is worthy of extensive clinical application.

Somatic alterations and mutational burden are potential predictive factors for metachronous development of early gastric cancer

The risk of developing metachronous gastric cancer (MGC) following curative endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) remains even after eradicating Helicobacter pylori (HP) successfully. We screened initial EGC and adjacent non-cancerous mucosa ESD-resected specimens for somatic variants of 409 cancer-related genes, assessing their mutational burden (MB) to predict molecular markers for metachronous post-ESD development. We compared variants between ten patients diagnosed with MGC more than 3 years after ESD and ten age-matched patients who did not have MGC developments after successful HP eradication. We found no significant background differences between the two groups. In adjacent non-cancerous mucosa, the MB tended to be higher in the patients with metachronous developments than in the others. Somatic genomic alterations of RECQL4, JAK3, ARID1A, and MAGI1 genes were significantly associated with MGC development. The criteria including both the MB and their variants, which had potential significant values for predicting MGC. In conclusion, combined of assessing specific somatic variants and MB may be useful for predicting MGC development. This study included a limited number of subjects; however, our novel findings may encourage further exploration of the significance of the molecular features of EGC that predict MGC development, thereby promoting focused follow-up strategies and helping elucidate the mechanisms.

The dynamic change of cancer genome and T-cell receptor repertoire of an early gastric cancer cohort.

e16553 Background: The dynamics of the cancer genome and T-cell receptor (TCR) repertoire are largely unclear during the development of gastric cancer, especially in the early stage. In this study, we studied the characteristics of genome and tumor microenvironment changes chronologically in 15 early gastric cancer (EGC) patients and illustrated their influence on carcinogenesis. Methods: 75 gastric tissues including precancerous lesions, cancer lesions and paired reference gastric samples, and 29 peripheral blood samples were obtained chronologically from 15 patients. All the lesions were categorized into 3 groups according to its pathology type (group1: inflammation or intestinal metaplasia, group 2: low-grade dysplasia (LGD), group 3: EGC). Deep sequencing of whole-exome and CDR3 chain of TCR of each sample was performed. Tumor mutation burden (TMB), TCR repertoire diversity and clonality were evaluated based on the sequencing data. Results: Heterogeneity existed in cancer genome and TCR repertoire among different patients. During carcinogenesis, TMB increased at first and then decreased, reaching its peak at LGD, which was different from what we have known from other advanced cancer. A detailed analysis showed that only part of the driver gene mutations maintained in this process. Compared with T cells infiltrated in reference samples, tumor-infiltrating T cells shared more clones with peripheral blood T cells. Diversity and clonality of TCR repertoire didn’t show significant change with the development of cancer (Shannon index: group 1 = 6.32, group 2 = 6.06, group 3 = 6.09, p = 0.836; Clonality: group 1 = 0.19, group 2 = 0.19, group 3 = 0.17, p = 0.374). Some CDR3 clones appeared in early-stage and maintained during the carcinogenesis process. Conclusions: Our research is the first to analyze the cancer genome and TCR repertoire changes from both the spatial and temporal perspectives during the development of early gastric cancer. Somatic mutations appeared in the very early stage of gastric cancer and may induce the immune microenvironment changes in gastric mucosa.

Multimodal multiphoton imaging for label-free monitoring of early gastric cancer

BackgroundEarly gastric cancer is associated with a much better prognosis than advanced disease, and strategies to improve prognosis is strictly dependent on earlier detection and accurate diagnosis. Therefore, a label-free, non-invasive imaging technique that allows the precise identification of morphologic changes in early gastric cancer would be of considerable clinical interest.MethodsIn this study, multiphoton microscopy (MPM) using two-photon excited fluorescence combined with second-harmonic generation was used for the identification of early gastric cancer.ResultsThis microscope was able to directly reveal improved cellular detail and stromal changes during the development of early gastric cancer. Furthermore, two features were quantified from MPM images to assess the cell change in size and stromal collagen change as gastric lesion developed from normal to early cancer.ConclusionsThese results clearly show that multiphoton microscopy can be used to examine early gastric cancer at the cellular level without the need for exogenous contrast agents. This study would be helpful for early diagnosis and treatment of gastric cancer, and may provide the groundwork for further exploration into the application of multiphoton microscopy in clinical practice.

The Expression of VEGFR2 and VEGFR3 in Early Gastric Cancer and Its Clinical Significance

Background: To explore the expression and its clinical significance of vascular endothelial growth factor receptor II and III (VEGFR2 and VEGFR3) in early gastric cancer.Methods: Immunohistochemical method is applied to detect 120 cases of early gastric cancer and normal gastric tissue of its cut edge in the expression of VEGFR2 and VEGFR3.Results: The positive expression rates of VEGFR2 and VEGFR3 in early gastric cancer are 75% and 60%, which are higher than in normal gastric tissues of cut edge (22.5%, 12.5%), respectively. The expression of VEGFR2 and VEGFR3 is associated with depth of invasion, lymph node metastasis (P 0.05).Conclusion: VEGFR2 and VEGFR3 play important roles in occurrence and development of early gastric cancer, which potentially provides a basis for targeted molecular therapy of early gastric cancer.

Gastric atrophy and xanthelasma are markers for predicting the development of early gastric cancer.

The significance of gastric xanthelasma in relation to gastric cancer still remains unclear. We investigated whether gastric xanthelasma would be a useful marker for predicting the development of early gastric cancer. A total of 1823 patients who underwent a medical health checkup were enrolled. We examined the relationship between gastric xanthelasma and various clinical features, and in an endoscopic follow-up study investigated whether the presence of gastric xanthelasma was predictive of the development of early gastric cancer. In the initial endoscopic examination, gastric xanthelasma was detected in 107 (5.9 %) of the 1823 patients. The presence of gastric xanthelasma was significantly associated with age ≥65 years, male gender, open-type atrophy, and the presence of diabetes mellitus (DM) (p < 0.0001, p < 0.0001, p < 0.0001, and p < 0.0001, respectively). During the endoscopic follow-up period, early gastric cancer was found in 29 (1.6 %) of the 1823 patients. Gastric cancer occurred in 15 (14.0 %) of 107 patients with gastric xanthelasma, whereas it occurred in 14 (0.8 %) of 1716 patients without (p < 0.0001). Multivariate analysis revealed that open-type atrophy and gastric xanthelasma were independently related to the development of gastric cancer (odds ratio 7.19 [2.50-20.83]; p = 0.0003 and 5.85 [2.67-12.82]; p < 0.0001, respectively). The presence of gastric xanthelasma was significantly predictive of gastric cancer development even in the selected high-risk groups with open-type atrophy or DM (p < 0.0001 or p < 0.0001, respectively). Gastric xanthelasma is a useful marker for predicting the development of gastric cancer.

Analysis of connection networks among miRNAs differentially expressed in early gastric cancer for disclosing some biological features of disease development.

This paper first identified differentially expressed miRNAs associated with early gastric cancer and then respectively constructed relevant connection networks among the identified differentially expressed miRNAs that corresponded to early gastric cancer and control tissues. Twenty-three differentially expressed miRNAs were identified, 18 of which were different with the related results on the same data, and they provide great discriminatory power between patients and controls. There are not only conserved unchangeable sub-networks but also different sub-networks between the two connection networks. From the consistency and differences between two connection networks, we disclosed several new biological features that promote early gastric cancer development. This study shows 23 miRNAs that are early gastric cancer-specific and are worthy to do further experimental studies. The revealed biological features for early gastric cancer will provide new insights into improved understanding of the molecular mechanisms of this disease.

Diabetes mellitus increases the risk of early gastric cancer development

BackgroundThe significance of diabetes mellitus (DM) in gastric carcinogenesis still remains unclear. We investigated whether DM would be a risk factor for the development of early gastric cancer. MethodsFactors related to the presence of gastric cancer were examined in patients undergoing medical health checkups. We then investigated whether DM was related to the development of early gastric cancer during an endoscopic follow-up study. ResultsGastric cancer was detected in 14 (1.0%) of 1463 patients at the first endoscopic examination and was significantly associated with the severity of gastric atrophy and the presence of DM. During the follow-up period (range 36–108months; mean 70.0months), early gastric cancer was newly detected in 26 (1.8%) of the 1449 patients in whom gastric cancer had not been detected at the first examination. Gastric cancer was detected in 17 (1.3%) of 1301 patients without DM, and in 9 (6.1%) of 148 patients with DM (P<0.0001). Multivariate analyses demonstrated that open-type gastric atrophy and DM were independently related to the development of early gastric cancer (P<0.0001 and P=0.020, respectively). Gastric cancer was identified in 14 (5.1%) of 274 patients who had open-type atrophic gastritis without DM, whereas it was identified in 8 (16.0%) of 50 patients who had both open-type atrophic gastritis and DM (P=0.0042). ConclusionDM increases the risk of early gastric cancer development.

High Levels of Aromatic Amino Acids in Gastric Juice during the Early Stages of Gastric Cancer Progression

BackgroundEarly-stage gastric cancer is mostly asymptomatic and can easily be missed easily by conventional gastroscopy. Currently, there are no useful biomarkers for the early detection of gastric cancer, and their identification of biomarkers is urgently needed.MethodsGastric juice was obtained from 185 subjects that were divided into three groups: non-neoplastic gastric disease (NGD), advanced gastric cancer and early gastric cancer (EGC). The levels of aromatic amino acids in the gastric juice were quantitated using high-performance liquid chromatography.ResultsThe median values (25th to 75th percentile) of tyrosine, phenylalanine and tryptophan in the gastric juice were 3.8 (1.7–7.5) µg/ml, 5.3 (2.3–9.9) µg/ml and 1.0 (0.4–2.8) µg/ml in NGD; 19.4 (5.8–72.4) µg/ml, 24.6 (11.5–73.7) µg/ml and 8.3 (2.1–28.0) µg/ml in EGC. Higher levels of tyrosine, phenylalanine and tryptophan in the gastric juice were observed in individuals of EGC groups compared those of the NGD group (NGD vs. EGC, P<0.0001). For the detection of EGC, the areas under the receiver operating characteristic curves (AUCs) of each biomarker were as follows: tyrosine, 0.790 [95% confidence interval (CI), 0.703–0.877]; phenylalanine, 0.831 (95% CI, 0.750–0.911); and tryptophan, 0.819 (95% CI, 0.739–0.900). The sensitivity and specificity of phenylalanine were 75.5% and 81.4%, respectively, for detection of EGC. A multiple logistic regression analysis showed that high levels of aromatic amino acids in the gastric juice were associated with gastric cancer (adjusted β coefficients ranged from 1.801 to 4.414, P<0.001).ConclusionIncreased levels of tyrosine, phenylalanine and tryptophan in the gastric juice samples were detected in the early phase of gastric carcinogenesis. Thus, tyrosine, phenylalanine and tryptophan in gastric juice could be used as biomarkers for the early detection of gastric cancer. A gastric juice analysis is an efficient, economical and convenient method for screening early gastric cancer development in the general population.

Mutations and polymorphisms of genes moderate increase in gastric cancer risk

Results of studies performed in our center point at DNA changes of many cancer (mostly moderate) susceptibility genes. Association of weak mutations and polymorphism of many genes and additional influence of environmental factors can significantly increase the risk of cancer development. The preliminary studies performed in our department indicate, that increased risk of gastric cancer may be related to mutation in NOD2 and CHK2 genes predisposing to cancers of many organs. The CHEK2 gene encodes checkpoint kinase 2 (Chk2), it acts as a tumor suppressor whose functions are central to the induction of cell cycle arrest and apoptosis by DNA damage. Results of studies performed in our center indicate that the frequency of the IVS2+1G→A alteration was significantly increased in a group of 658 consecutive patients, especially in those under 50 years of age (OR=5.332, p=0.0174). I157T was over-represented in the group of familial gastric cancer patients, particularly in patients diagnosed at less than 50 years of age (OR=3.687, p=0.0011) and females. The specific group of intestinal and mixed histopathological subtype occurs more frequently (OR=1.671) in consecutive carriers of I157T mutation. Recently, the NOD2/CARD15, gene located on chromosome 16q12, has been associated with Crohn’s disease. It is believed to play a role both in intracellular recognition of lipopolysaccharides (LPS) typical of Gram negative bacteria and subsequent activation of NFkB. 3020insC NOD2 mutation causes an increased risk of developing chronic inflammatory diseases of the gastrointestinal tract and colorectal cancer in their course. In light of recent studies, in fact 3020insC mutation predisposes to cancers of many organs, including breast, ovarian, lung. Studies conducted in our center in the group of 103 patients with a family history of gastric cancer, have shown that NOD2 3020insC carriers in persons over 50 y of age more than doubled (OR=2.479, p=0.022) and among women almost 3-fold increased risk. In addition, NOD2 R702W alteration occurred almost three times more frequently (OR=2.816, p=0.0121) in the group of 241 consecutive patients with gastric cancer diagnosed before 50 years of age and over 2-times frequently (OR=2.268, p=0.0371) in gastric cancer selected histopathologically as intestinal type according to Lauren. There are a large number of reports describing the relationship between changes in the gene TP53, particularly polimomorfizm Arg72Pro, and risk of gastric cancer. Many researchers have found links between gene polymorphism of Interleukin-1, and the risk of stomach cancer. Gene polymorphism of angiotensin converting enzyme ACE, was recently linked with the pathogenesis and development of human cancers. Research Ebert MP, et al. conducted in a group of 88 patients shows that the insertion / deletion ACE gene may be associated with the development of early gastric cancer in the German population. In the Japanese population genetically distant, however, found no relationship between gastric cancer and ACE gene polymorphism). Sentences on the ACE polymorphism and risk of stomach cancer researchers are divided among different centers. XRCC1 gene is part of composite protein complex containing the s-polymerase DNA ligase I and PARP (polymerase poly (ADP-ribose). This multi-unit complex is involved in DNA repair pathway. T. Poplawski et al. indicate that the variant Gln / Gln XRCC1 gene polymorphism Arg399Gly occurred more frequently in patients with gastric cancer and family burden (OR=2.04, 95% CI=1,27-3,29) and the results obtained from studies in the group of 152 patients with a family history of gastric cancer suggest that gene XRCC1 399Gln allele may be considered a marker of gastric cancer. In terms of predisposition to gastric cancer has also been studied recently LAPTM4B gene associated with a genetic predisposition to liver cancer, having LAPTM4B alleles * 1 and LAPTM4B * 2. The risk of stomach cancer was increased 1.819 times in patients with genotype * 1 / 2 (CI=1.273-2.601) and 2.387 times in patients with genotype * 2 / 2 LAPTM4B (CI=1.195-4.767) compared with genotype * 1 / first. These studies indicate that allele * 2 LAPTM4B may be one of the genetic factors of gastric cancer. Further studies of newly described mutation moderately increased risk of stomach cancer may allow to estimate the real risk of gastric cancer associated with these mutations in the Polish population.

Review article: common misconceptions in the management of Helicobacter pylori-associated gastric MALT-lymphoma

Helicobacter pylori infection is the main cause of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. To review several common misconceptions in the management of H. pylori-associated gastric MALT-lymphoma. Bibliographical searches were performed in MEDLINE up to June 2011. If adequate diagnostic methods are used, and if only low-grade lymphomas are considered, the prevalence of H. pylori infection is very high (almost 90%). H. pylori eradication is effective in treating approximately 80% of patients with early stage lymphoma. In H. pylori-positive gastric high-grade lymphomas, antibiotic therapy should always be prescribed, as approximately 50% of them regress after H. pylori eradication. Patients with early stage MALT lymphoma negative for H. pylori might still benefit from antibiotic treatment as the sole treatment. Complete remission of gastric MALT lymphoma after H. pylori eradication can take even >12 months. PCR assay for the detection of monoclonal B cells remains positive in many cases after complete remission has been reached. Patients with a persistent clonal band should not be treated unless the lymphoma can be histologically demonstrated. Synchronous occurrence of gastric adenocarcinoma and MALT lymphoma has been repeatedly reported. In some patients in complete remission, eradication of H. pylori does not prevent later development of early gastric cancer. Gastric lymphoma recurrence occurs in some patients after both bacterial and lymphoma regression. H. pylori reinfection does not constitute a prerequisite for lymphoma recurrence. The present article states several misconceptions in the management of H. pylori-associated gastric MALT-lymphoma in clinical practice, reviews the related scientific evidence and proposes the adequate attitude in each case.

Promoter Hypermethylation Mediates Downregulation of Thiamine Receptor SLC19A3 in Gastric Cancer

As an important way to inactivate tumor suppressor genes (TSGs) during cancer development, promoter hypermethylation can be used to define novel TSGs and identify biomarkers for cancer diagnosis. SLC19A3 (solute carrier family 19, member 3) was found to be such a biomarker. SLC19A3 expression was downregulated in gastric cancer cell lines (71%, 5/7) and restored after pharmacological demethylation. Notably, hypermethylation of SLC19A3 promoter was detected in gastric cancer cell lines (57%, 4/7), primary gastric carcinoma tissues (51%, 52/101) and precancerous lesion (intestinal metaplasia) tissues (32%, 8/25). Exogenous SLC19A3 expression caused growth inhibition of gastric cancer cells. In summary, SLC19A3 was epigenetically downregulated in gastric cancer. Methylation of SLC19A3 promoter could be a novel biomarker for early gastric cancer development.

The Angiotensin I–Converting Enzyme Gene Insertion/Deletion Polymorphism Is Linked to Early Gastric Cancer

The insertion/deletion polymorphism of the angiotensin I-converting enzyme (ACE) gene has recently been linked to the pathogenesis and progression of human cancers. Using genomic DNA from 88 patients with early gastric cancer confined either to mucosa (pT(1a)) or submucosa (pT(1b)), we assessed the insertion (I) and deletion (D) polymorphism by PCR analysis and compared it with a large noncancer control population (n = 145). In the noncancer control group, the II genotype was observed in 33 (23%) individuals, whereas the ID and DD genotypes were found in 72 (50%) and 40 (27%) individuals, respectively. Interestingly, in the cancer group, we found the II genotype in six (7%) patients and the ID genotype in 46 (52%) individuals, whereas the DD genotype was observed in 36 (41%) individuals (P = 0.0034). Accordingly, the odds ratio for the II genotype was 0.20 [95% confidence interval (95% CI), 0.08-0.54; P = 0.009] and 0.55 for the ID/II genotype (95% CI, 0.31-0.96; P = 0.044) using the high-activity genotype DD as the reference category. No correlation was found among tumor type, tumor stage, the presence of Helicobacter pylori, and the ACE genotype. Our study provides further evidence that the ACE insertion/deletion gene polymorphism may be linked to the development of early gastric cancer.

REG Iα protein may function as a trophic and/or anti-apoptotic factor in the development of gastric cancer

Although a significant amount of regenerating gene (REG) Ialpha protein is present not only in normal gastric mucosa but also in gastric cancer tissues, its pathophysiologic role in gastric cancer development remains unclear. We investigated REG Ialpha protein expression in early gastric cancers, and examined whether cytokines are responsible for REG Ialpha gene expression and whether REG Ialpha protein has a trophic and/or an antiapoptotic effect on gastric cancer cells. Early gastric cancer specimens were analyzed histologically using immunohistochemistry for REG Ialpha protein and proliferating cell nuclear antigen (PCNA). The effects of cytokines on REG Ialpha promoter activity and its messenger RNA (mRNA) expression in AGS (a kind of gastric cancer cell line) cells were examined by luciferase reporter assay and Northern blot analysis, respectively. Effects of REG Ialpha protein on cell growth and H2O2-induced apoptosis in AGS cells were examined by 3,-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphatase nick-end labeling (TUNEL) assays, respectively. REG Ialpha-positive early gastric cancers showed a significantly higher PCNA labeling index and more severe inflammatory cell infiltration in adjacent gastric mucosa than the negative cancers. REG Ialpha gene expression and its promoter activity were enhanced by interferon (IFN)-gamma and interleukin (IL)-6. REG Ialpha protein promoted cell growth and cell resistance to H2O2-induced apoptosis in AGS cells. These effects were abolished by concomitant treatment with anti-REG Ialpha antibody. REG Ialpha protein enhanced Akt phosphorylation and Bcl-xL expression in AGS cells. REG Ialpha gene is inducible by cytokine stimulation and its gene product may function as a mitogenic and/or an antiapoptotic factor in the development of early gastric cancer.

Gene expression profile differences in gastric cancer, pericancerous epithelium and normal gastric mucosa by gene chip

To study the difference of gene expression in gastric cancer (T), pericancerous epithelium (P) and normal tissue of gastric mucosa (C), and to screen an associated novel gene in early gastric carcinogenesis by oligonucleotide microarray. U133A (Affymetrix, Santa Clara, CA) gene chip was used to detect the gene expression profile difference in T, P and C, respectively. Bioinformatics was used to analyze the detected results. When gastric cancer was compared with normal gastric mucosa, 766 genes were found, with a difference of more than four times in expression levels. Of the 766 genes, 530 were up-regulated (Signal Log Ratio (SLR) >2), and 236 were down-regulated (SLR<-2). When pericancerous epithelium was compared with normal gastric mucosa, 64 genes were found, with a difference of more than four times in expression levels. Of the 64 genes, 50 were up-regulated (SLR>2), and 14 were down-regulated (SLR<-2). Compared with normal gastric mucosa, a total of 143 genes with a difference in expression levels (more than four times, either in cancer or in pericancerous epithelium) were found in gastric cancer (T) and pericancerous epithelium (P). Of the 143 genes, 108 were up-regulated (SLR>2), and 35 were down-regulated (SLR<-2). To apply a gene chip could find 143 genes associated with the genes of gastric cancer in pericancerous epithelium, although there were no pathological changes in the tissue slices. More interesting, six genes of pericancerous epithelium were up-regulated in comparison with genes of gastric cancer and three genes were down-regulated in comparison with genes of gastric cancer. It is suggested that these genes may be related to the carcinogenesis and development of early gastric cancer.

193 Development of early gastric cancer 4 years after complete remission of Helicobacter pylori-associated gastric low-grade B-cell MALT lymphoma

Photodynamic therapy in combination with different treatment modalities has been evaluated to study the mechanism of cellular cytotoxicity and apoptosis in various forms of cancer. In the present study, human head and neck cancer cells were treated with radachlorin mediated photodynamic therapy and the chemotherapy drug, carboplatin singly or in combination. Several parameters were studied to check the enhanced cytotoxicity of combination therapy at different time interval. From the cell viability study by MTT assay, a 22% decrease in cell viability was observed in combination treatment. This enhanced activity of combination treatment was confirmed by cell migration assay and Hoechst PI staining. Generation of reactive oxygen species was observed and found to be higher than that of individual treatments. Cytochrome c was found to be released from mitochondria that also induced the enhance efficacy in combination treatment. The expression of other proteins like EGFR and PARP was also modulated with the time of incubation after treatment. In the tumor xenograft study in nude mouse model, the carboplatin treated group did not show any noticeable changes in tumor volume whereas tumor volume was reduced in PDT and the combination group. Though the difference in the reduction of the tumor size was not significant between PDT and combination group, there was a difference in the expression of EGFR between these two groups. Histologic study of the inhibition in tumor growth was also performed. Therefore, this study may provide an avenue of combating head and neck cancer by a combination of conventional chemotherapy and PDT.

Dietary Habit and Helicobacter pylori Infection in Early Gastric Cancer Patient.

Helicobacter pylori (H. pylori) is now generally accepted to be strongly associated with the development of gastric cancer, as well as intakes of some salted foods, charred foods, etc. To evaluate the association among dietary habits, H. pylori infection, and early gastric cancer in Koreans, a hospital based case-control study was conducted. A total of 268 persons participated in this case-control study. Sixty nine patients were newly diagnosed as an early gastric cancer (EGC) at the Division of Gastroenterology, Department of Internal Medicine, Asan Medical Center, Seoul, Korea. One hundred ninety-nine subjects with no symptoms who visited the Health Promotion Center for their general checkups were selected as the controls. All subjects were examined for H. pylori infection, biochemical blood test the life style, and dietary habit were interviewed by a trained dietition with semi-quantitative food frequency question naire (FFQ) and adaptive salt concentration were taste evaluated. H. pylori seropositivity was observed in 88.4% in cases, as compared with 74.9% in controls (OR=2.5, 95% CI: 1.1-5.7). The adaptive salt concentration was associated with early gastric cancer risk (chi-squir=50.8, p<0.001). The analysis of food intake frequency demonstrated that early gastric cancer risk was reduced by the intake of clear soups, raw vegetables, fruits and juices, beef with vegetables and soybean curds. On the other hand, high intake of salt-fermented fish and kimchi elevated the risk of early gastric cancer. These results suggest that some dietary factors and H. pylori infection have a significant association with the development of early gastric cancer.

Atrophic gastritis and intestinal metaplasia in Japan: results of a large multicenter study.

This study evaluated the relationship between Helicobacter pylori infection, atrophic gastritis and intestinal metaplasia in Japan. This was a multicenter study performed in 21 centers in Japan. A total of 2455 individuals were enrolled. H. pylori status was determined by validated ELISAs. Atrophic gastritis was diagnosed by histology, endoscopy with Congo Red dye scattering or the Kimura-Takemoto endoscopic classification. Atrophic gastritis increased from 9.4% in those less than 20 years of age to > 70% in those aged 60 or older and was strongly associated with H. pylori infection. The overall prevalence of atrophic gastritis in H. pylori infection was 82.9% (1272/1534) compared with 9.8% (90/921) among uninfected (OR = 44.8; 95% CI = 34.7-57.8). Intestinal metaplasia was present in 43.1% (542/1258) of H. pylori positive persons compared with 6.2% (51/823) among the uninfected (OR = 11.5; 95% CI = 8.5-15.5). Atrophic gastritis in H. pylori positive Japanese was very high in the younger generation (38.5% in those aged 20 or less and 58.5% in those 21-30). Atrophic gastritis and intestinal metaplasia were strongly associated with H. pylori and not with aging. The fall in prevalence of H. pylori in Japan has not been associated with a corresponding fall in the prevalence of atrophic gastritis among those with H. pylori infection. The high prevalence of the precursor lesion, atrophic gastritis with intestinal metaplasia, among those with H. pylori infection suggests that the risk of development of early gastric cancer will continue to remain high in Japan.