Association of Dietary Antioxidant Vitamin Intake and Gastric Cancer Risk According to Smoking Status and Histological Subtypes of Gastric Cancer: A Case-Control Study in Korea

Smoking is a risk factor for gastric cancer (GC) and causes oxidative stress. Antioxidant vitamins may protect against oxidative stress. This study aimed to determine the association between dietary antioxidant vitamin intake and GC risk according to smoking status and the histological subtype. This case-control study included 286 pairs of patients with GC and controls aged 20-79 years enrolled at two hospitals from 2002 to 2006, matched by age (± 2 years), sex, hospital, and participation period (± 1 years). Dietary information was collected using a quantitative food frequency questionnaire (FFQ). When stratified by smoking status, increased intake of vitamin C (OR = 0.38; 95% CI = 0.17-0.84 for highest vs. lowest; P for trend = 0.033) and folate (OR = 0.28; 95% CI = 0.12-0.64 for highest vs. lowest; P for trend = 0.003) decreased GC risk in nonsmokers. Vitamin C (P for interaction = 0.043) and folate (P for interaction =0.015) levels were significantly associated with smoking status. Similar results were observed in nonsmokers with diffuse and mixed types of GC, but not in those with intestinal type of GC. Therefore, we found an inverse association between higher intake of dietary vitamin C and folate with the risk of GC among nonsmokers. These protective associations were strong in nonsmokers with diffuse and mixed types of GC.

Association between soy products, fruits, vegetables, and dairy products and gastric cancer risk in Helicobacter pylori-infected subjects: a case-control study in Korea

BACKGROUND/OBJECTIVES

Consumption of certain protective foods may help inhibit Helicobacter pylori (H. pylori) associated gastric pathologies. However, studies conducted to assess the efficacy of protective foods in H. pylori-infected subjects are either limited or inconsistent. This study evaluated the association of individual or a combination of protective foods on the incidence of gastric cancer (GC) in H. pylori-positive subjects through a case-control study.

MATERIALS/METHODS

Subjects aged 20-79 years were selected from 2 hospitals between December 2002 and September 2006. In total, 134 patients and 212 controls tested positive for H. pylori infection. Among these, we included 82 pairs of cases and controls matched by sex, age (± 5 years), enrollment period (± 1 years), and hospital.

RESULTS

A higher intake of soy products was associated with a significantly lower risk of GC than a lower intake of soy products (odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.14-0.96). Additionally, a higher fruit intake resulted in a significantly lower risk of GC than a lower fruit intake (OR = 0.35, 95% CI = 0.13-0.94). A combination of food groups was evaluated, and a lower risk of GC was observed with a high intake of both soy products and fruits (OR = 0.20, 95% CI = 0.06-0.67), high intake of soy and dairy products (OR = 0.28, 95% CI = 0.10-0.78) and high intake of fruits and dairy products (OR = 0.28, 95% CI = 0.09-0.83).

CONCLUSIONS

A high intake of soy products or fruits was associated with a lower risk of GC. A combination of soy products or fruits with dairy products was associated with a lower risk of GC. A balanced intake of soy products, fruits, and dairy products may help reduce GC risk.

Dietary zinc intake and mortality in patients with intestinal-type gastric cancer: A prospective cohort study in Korea

Purpose

Current evidence regarding the association between zinc intake and gastric cancer (GC)-specific survival in patients with intestinal-type GC is lacking. Therefore, this cohort study investigated the association between zinc intake and GC mortality through follow-up on GC death among patients with intestinal-type GC and whether these effects differ according to the source of zinc intake.

Methods

A total of 185 patients with intestinal-type GC were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephone surveys.

Results

A total of 178 patients were included and analyzed. The median follow-up period was 7.3 years. In the fully adjusted models, the highest tertile of total zinc intake showed a significantly lower GC mortality than the lowest tertile (hazard ratio, 0.22; 95% confidence interval: 0.08–0.64). In addition, the tertile of total zinc intake showed a dose-response association with GC mortality (p=0.015). Analysis of the source of zinc intake revealed that when zinc intake from staples (rice and noodles), animal, and plant food sources were combined, the results were similar to those of total zinc intake and GC mortality.

Conclusion

Zinc intake through various foods may be effective in reducing GC mortality by achieving balance with other nutrients. Our results suggest that zinc improves the survival of patients with intestinal-type GC in Korea.

Gastric Cancer Risk Was Associated with Dietary Factors Irritating the Stomach Wall: A Case-Control Study in Korea

The incidence of gastric cancer is high in Korea, and dietary factors are important risk factors for gastric cancer. This study examined whether gastric cancer risk was related to dietary factors that directly irritate the stomach wall. This case−control study consisted of 308 matched pairs of gastric cancer cases and controls recruited from 2002 to 2006 at two hospitals in Korea. Dietary assessments were completed using a food frequency questionnaire and a dietary habit questionnaire. Gastric cancer risk was increased for high meal frequency of >3 vs. low meal frequency of ≤3 times per day, overeating vs. not overeating, and preferred vs. not preferred spicy or salty foods. Furthermore, participants with dietary factors of high meal frequency, overeating, and preference for spicy or salty foods elevated the risk of gastric cancer compared to those with low meal frequency, not overeating, and not preferring spicy or salty foods, simultaneously. In conclusion, gastric cancer risk was significantly increased in people with dietary factors that irritate the stomach wall, such as high meal frequency, overeating, and preference for spicy or salty foods.

Dietary Intake of Soy Products, Vegetables, and Dairy Products and Gastric Cancer Survival according to Histological Subtype: a Long-term Prospective Cohort Study

PURPOSE

Owing to differences in the general characteristics of gastric cancer (GC) according to histological type, the association of GC risk factors, such as diet, may also differ depending on the histological type. We investigated the associations between individual and combined intake of soy products, vegetables, and dairy products and GC mortality by following up cases of death among Korean GC cases and whether these associations differ according to the histological type.

MATERIALS AND METHODS

A total of 508 GC cases were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephonic surveys. Finally, 300 GC cases classified as intestinal- or diffuse-type GC cases were included. The median follow-up period was 7.1 years.

RESULTS

In the fully adjusted model, a high intake of soy products (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19-0.96) and the combination of soy products and vegetables (HR, 0.34; 95% CI, 0.12-0.96) or soy products and dairy products (HR, 0.37; 95% CI, 0.14-0.98) decreased the mortality from intestinal-type GC. In particular, patients consuming various potentially protective foods (HR, 0.23; 95% CI, 0.06-0.83) showed a highly significant association with a lower mortality from intestinal-type GC. However, no significant association was found with diffuse-type GC.

CONCLUSIONS

High intake of potentially protective foods, including soy products, vegetables, and dairy products, may help increase survival in intestinal-type GC.

Clinical Significance of Tumor and Immune Cell PD-L1 Expression in Gastric Adenocarcinoma

BACKGROUND/AIM

The prognostic relevance of programmed cell death ligand-1 (PD-L1) protein expression in gastric cancer (GC) remains controversial. The aims of the present study were to determine the correlations between tumor cell (TC) and immune cell (IC) PD-L1 protein levels with prognosis, and to determine the correlation between PD-L1 expression and different molecular GC subtypes.

MATERIALS AND METHODS

TC and IC PD-L1 protein levels were measured in 286 GC patients. The patients were classified according to the Cancer Genome Atlas and Asian Cancer Research Group guidelines using immunohistochemistry and in situ hybridization.

RESULTS

TC and IC PD-L1 protein levels were positively correlated with patient survival. TC PD-L1 expression was negatively correlated with tumor grade. TC and IC PD-L1 expression was associated with improved prognosis in Epstein-Barr virus negative (EBV^-), microsatellite instability (MSI) rather than microsatellite stability (MSS) subgroup GC patients.

CONCLUSION

PD-L1 protein expression in TCs and ICs can be used as a prognostic indicator for GC patients, particularly in the EBV^-, MSI, and MSS subgroups.

LAD1 expression is associated with the metastatic potential of colorectal cancer cells

BACKGROUND

Anchoring filament protein ladinin-1 (LAD1) was related to the aggressive progression of breast, lung, laryngeal and thyroid cancers. However, the association of LAD1 with colorectal cancer remained unknown. Here, to determine the relationship of LAD1 with colorectal cancer progression, we explored the effect of LAD1 loss on the malignant features of colorectal cancer cells.

METHODS

We constructed LAD1-depleted cell lines and examined the effect of LAD1 deficiency on the phenotypic and molecular features of colorectal cancer cells in vitro. The function of LAD1 in metastasis in vivo was examined by establishing a spleen-to-liver metastasis mouse model. LAD1 protein expression in colorectal cancer patient specimens was assessed by immunohistochemistry of tumor microarrays.

RESULTS

We found that LAD1 was abundant in most colorectal cancer cells. In addition, high expression of LAD1 significantly correlated with poor patient outcome. LAD1 depletion inhibited the migration and invasion of two different colorectal cancer cell lines, SW620 and Caco-2, without affecting their proliferation. In addition, LAD1 loss led to defects in liver metastasis of SW620 cells in the mouse model. Immunohistochemistry of colorectal cancer tissues revealed LAD1 enrichment in metastatic tissues compared to that in primary tumor and normal tissues.

CONCLUSION

These results suggest that LAD1 expression is associated with the metastatic progression of colorectal cancer by promoting the migration and invasion of cancer cells.

Subepithelial Spread of Early Gastric Signet Ring Cell Carcinoma: How Far They Can Reach?

INTRODUCTION

Although signet ring cell carcinoma (SRC) is a poorly differentiated cancer subtype, recent studies suggest that endoscopic resection can be applied in small, mucosal early gastric SRC. However, other studies report frequent positive lines at the lateral resection margin after endoscopic treatment. Subepithelial spread beneath normal mucosa can exist in SRC, and such lesions may be the cause of positive margins after endoscopic resection. Thus, we conducted a retrospective study in order to evaluate the significance of subepithelial spread in early gastric SRC.

METHOD

Medical records of early gastric SRC patients who underwent surgery or endoscopic resection from January 2011 to December 2016 at a single tertiary hospital (Daejeon, South Korea) were reviewed to examine subepithelial spread and clinical datum. Two expert pathologists reviewed all pathologic specimens, and only patients showing a pure SRC component were included.

RESULTS

Eighty-six patients were initially enrolled, and subepithelial spread existed in 62 patients (72.1%). The mean distance of subepithelial spread was 1,132.1 µm, and the maximal distance was 6,000 μm. Only discoloration was significantly associated with the presence of a subepithelial spread (p < 0.05, χ2 test, and logistic regression test). Distance of subepithelial spread did not correlate with total lesion size.

CONCLUSION

Subepithelial spread of early gastric SRC occurs frequently and can reach up to 6 mm. Lesion discoloration may be associated with the presence of subepithelial spread. Our results suggest that careful decision of the margin is needed when performing endoscopic resection of early gastric SRC.

Prediagnostic Smoking and Alcohol Drinking and Gastric Cancer Survival: A Korean Prospective Cohort Study

Background/Aims

Behavioral factors, such as smoking and heavy alcohol consumption, increase the risk of gastric cancer (GC), but their effects on survival are not clear. We examined associations between prediagnostic smoking and alcohol drinking behavior and GC death by long-term follow-up.

Methods

The participants were 508 GC patients enrolled at Chungnam University Hospital and Hanyang University Guri Hospital from 2001 to 2006. Information on clinicopathologic and behavioral risk factors was collected, and patient survival was prospectively followed until 2016 by medical chart review and telephone survey.

Results

During above 10 years follow-up period, overall death was 46.2% (n=226) and GC deaths was 38.2% (n=187) among the 489 GC patients included in the analysis. No significant association was found between smoking habits and overall or GC survival. However, after stratification by histological type, the hazard ratio (HR) of GC death for current smokers tended to be higher for the diffuse type (HR 1.61, 95% CI 0.57-4.59 for current vs. never) rather than for the intestinal type (HR 0.78, 95% CI 0.28-2.19 for current vs. never). Light alcohol consumption was found to be associated with a significantly lower risk of GC death (HR 0.52, 95% CI 0.36-0.75 for <20 g/day for women or <40 g/day for men vs. never and past), and the effects of alcohol drinking habits had similar effects on GC death for the intestinal and diffuse types.

Conclusions

These results suggest smoking and alcohol drinking behaviors before a diagnosis of GC are weakly associated with GC survival. Nevertheless, the effect of smoking behavior on prognosis appears to depend on the histological type of GC.

Alcohol consumption and gastric cancer risk in Korea: a case-control study

BACKGROUND/OBJECTIVES

The International Agency for Research on Cancer defined alcohol beverages and acetaldehyde derived from alcoholic beverages as a Group 1 carcinogen to humans. However, the association between alcohol consumption and gastric cancer risk has been controversial in Korean. We assessed the relationship between alcohol consumption and gastric cancer risk in Korea through a case-control study.

SUBJECTS/METHODS

From 2 hospitals, a total of 316 cases with gastric cancer (208 men, 108 women) were selected and matched to 316 controls by sex and age (± 5 years) during the same duration. The current status, frequency, and amount of alcohol consumption for a year three years ago were assessed by trained interviewers.

RESULTS

Alcohol consumption status and frequency did not show any significant association with gastric cancer risk. However, high alcohol consumption (≥ 20 g/day for women or ≥ 40 g/day for men) significantly increased the risk of gastric cancer (odds ratio (OR) 1.73; 95% confidence interval (CI) 1.05–2.85). Gastric cancer risk was strongly positively associated with alcohol consumption of ≥ 20 g/day, especially in women (OR 5.62; 95% CI 1.32–23.81).

CONCLUSION

The results from this study suggest that excessive alcohol consumption rather than the current status or frequency of alcohol consumption contributes to the increased risk of gastric cancer, especially in women.

Impact of age on stage-specific mortality in patients with gastric cancer: A long-term prospective cohort study

Controversies exist regarding the impact of age on gastric cancer-related mortality according to cancer stage. In our prospective cohort study, we evaluated the impact of age on stage-specific mortality in patients with gastric cancer. Between 2002 and 2006, patients with newly diagnosed gastric cancer were recruited from two university-affiliated hospitals in Korea. Follow-up data were updated regularly based on medical records and telephone surveys. Patients were classified into four subgroups according to age: <50, 50-59, 60-69, and 70-79 years. A total of 448 patients were followed up for 81.6 months (interquartile range, 25.0-139.3 months). The number of patients with stage I, II, III, and IV disease was 247, 74, 88, and 39, respectively. Overall, age was an independent risk factor for gastric cancer-specific mortality (hazard ratio [HR], [95% confidence interval (CI)]: 1.53 [0.91-2.57], 1.88 [1.21-2.91], and 2.64 [1.69-4.14] in the 50-59, 60-69, and 70-79 years groups, respectively, with the <50 years group as reference). In patients with stage I and II gastric cancer, the 70-79 years group was associated with a significantly higher rate of cancer-specific mortality than the <50 years group (stage I: HR [95% CI], 9.55 [2.11-43.12]; stage II: HR [95% CI], 7.17 [2.32-22.18]). However, age was not an independently associated factor for cancer-specific mortality in patients with stage III and IV gastric cancer. Although age was an independent risk factor for gastric cancer-related mortality in patients with gastric cancer, its impact may differ depending on the stage of cancer.

Proteogenomic Characterization of Human Early-Onset Gastric Cancer

We report proteogenomic analysis of diffuse gastric cancers (GCs) in young populations. Phosphoproteome data elucidated signaling pathways associated with somatic mutations based on mutation-phosphorylation correlations. Moreover, correlations between mRNA and protein abundances provided potential oncogenes and tumor suppressors associated with patient survival. Furthermore, integrated clustering of mRNA, protein, phosphorylation, and N-glycosylation data identified four subtypes of diffuse GCs. Distinguishing these subtypes was possible by proteomic data. Four subtypes were associated with proliferation, immune response, metabolism, and invasion, respectively; and associations of the subtypes with immune- and invasion-related pathways were identified mainly by phosphorylation and N-glycosylation data. Therefore, our proteogenomic analysis provides additional information beyond genomic analyses, which can improve understanding of cancer biology and patient stratification in diffuse GCs.

High red blood cell composition in clots is associated with successful recanalization during intra-arterial thrombectomy

We evaluated the composition of individual clots retrieved during intra-arterial thrombectomy in relation to recanalization success, stroke subtype, and the presence of clot signs on initial brain images. We analyzed clot and interventional data from 145 retrieval trials performed for 37 patients (69.5±14.0 years, 20 men, large artery atherosclerosis, n = 7; cardioembolism, n = 22; undetermined etiology, n = 8) who had undergone intra-arterial thrombectomy. Rates of clot retrieval and successful recanalization (Arterial Occlusive Lesion score of 2–3) for separate retrieval trials were evaluated. The area occupied by red blood cell (RBC), fibrin/platelets, and white blood cell (WBC) was measured from digitized images of hematoxylin-eosin stained clots. Compositional differences were compared according to recanalization success, stroke subtype, and the presence of hyperdense clot sign on initial computed tomography and/or blooming artifact on magnetic resonance image. Of the 145 total retrieval trials (3.4±2.4 times per patient), clot was retrieved in 93 trials (64%), while recanalization was successful in 73 (50%). Fibrin/platelets (63%) occupied the greatest area in retrieved clots, followed by RBCs (33%) and WBCs (4%). Clots retrieved from successful recanalization exhibited higher RBC composition (37%) than those retrieved from non-recanalization trials (20%, p = 0.001). RBC composition was higher in cardioembolic stroke (38%) rather than large artery atherosclerosis (23%) and undetermined etiology (26%, p = 0.01). Clots exhibiting clot signs (40%) had higher RBC composition than those without clot signs (19%, p = 0.001). RBC-rich clots were associated with successful recanalization of intra-arterial thrombectomy, cardioembolic stroke, and the presence of clot-signs on initial brain images.

Comparison of Somatic and Sudomotor Nerve Fibers in Type 2 Diabetes Mellitus

Background and Purpose

The objective of this study was to find a sensitive method for the early detection of diabetic polyneuropathy (DPN) and determine the relationship between the functions of somatic and autonomic small nerve fibers in DPN.

Methods

Patients with type 2 diabetes mellitus and DPN based on clinical symptoms, signs, intraepidermal nerve fiber density (IENFD), and findings in the quantitative sudomotor axon reflex test (QSART) were enrolled retrospectively. Neurological examinations and nerve conduction studies were performed on all patients. Heart-rate variability during deep breathing (DB ratio) and the Valsalva maneuver (Valsalva ratio) were used to quantify the cardiovagal function. Patients were divided into two groups: 1) normal nerve conduction, defined as small-fiber neuropathy (SFN) and 2) abnormal nerve conduction, defined as mixed-fiber neuropathy.

Results

In total, 82 patients were enrolled (age: 60.7±10.7 years, mean±SD). A decreased IENFD was the most frequent abnormality across all of the patients, followed by abnormalities of the QSART and cardiovagal function. A decreased IENFD was more sensitive than the QSART, DB ratio, and Valsalva ratio for detecting diabetic SFN. The DB ratio was significantly correlated with the duration of diabetes mellitus and clinical symptoms and signs. There was no correlation between the IENFD and the findings of the QSART for the distal leg.

Conclusions

Measuring the IENFD was a more sensitive method than the QSART for the early detection of DPN. The degree of involvement of the somatic small nerve fibers and sudomotor nerve fibers was independent in DPN.

Sporadic Early-Onset Diffuse Gastric Cancers Have High Frequency of Somatic CDH1 Alterations, but Low Frequency of Somatic RHOA Mutations Compared With Late-Onset Cancers

BACKGROUND & AIMS

Early-onset gastric cancer, which develops in patients younger than most gastric cancers, is usually detected at advanced stages, has diffuse histologic features, and occurs more frequently in women. We investigated somatic genomic alterations associated with the unique characteristics of sporadic diffuse gastric cancers (DGCs) from younger patients.

METHODS

We conducted whole exome and RNA sequence analyses of 80 resected DGC samples from patients 45 years old or younger in Korea. Patients with pathogenic germline mutations in CDH1, TP53, and ATM were excluded from the onset of this analysis, given our focus on somatic alterations. We used MutSig2CV to evaluate the significance of mutated genes. We recruited 29 additional early-onset Korean DGC samples and performed SNP6.0 array and targeted sequencing analyses of these 109 early-onset DGC samples (54.1% female, median age, 38 years). We compared the SNP6.0 array and targeted sequencing data of the 109 early-onset DGC samples with those from diffuse-type stomach tumor samples collected from 115 patients in Korea who were 46 years or older (late onset) at the time of diagnosis (controls; 29.6% female, median age, 67 years). We compared patient survival times among tumors from different subgroups and with different somatic mutations. We performed gene silencing of RHOA or CDH1 in DGC cells with small interfering RNAs for cell-based assays.

RESULTS

We identified somatic mutations in the following genes in a significant number of early-onset DGCs: the cadherin 1 gene (CDH1), TP53, ARID1A, KRAS, PIK3CA, ERBB3, TGFBR1, FBXW7, RHOA, and MAP2K1. None of 109 early-onset DGC cases had pathogenic germline CDH1 mutations. A higher proportion of early-onset DGCs had mutations in CDH1 (42.2%) or TGFBR1 (7.3%) compared with control DGCs (17.4% and 0.9%, respectively) (P < .001 and P = .014 for CDH1 and TGFBR1, respectively). In contrast, a smaller proportion of early-onset DGCs contained mutations in RHOA (9.2%) than control DGCs (19.1%) (P = .033). Late-onset DGCs in The Cancer Genome Atlas also contained less frequent mutations in CDH1 and TGFBR1 and more frequent RHOA mutations, compared with early-onset DGCs. Early-onset DGCs from women contained significantly more mutations in CDH1 or TGFBR1 than early-onset DGCs from men. CDH1 alterations, but not RHOA mutations, were associated with shorter survival times in patients with early-onset DGCs (hazard ratio, 3.4; 95% confidence interval, 1.5-7.7). RHOA activity was reduced by an R5W substitution-the RHOA mutation most frequently detected in early-onset DGCs. Silencing of CDH1, but not RHOA, increased migratory activity of DGC cells.

CONCLUSIONS

In an integrative genomic analysis, we found higher proportions of early-onset DGCs to contain somatic mutations in CDH1 or TGFBR1 compared with late-onset DGCs. However, a smaller proportion of early-onset DGCs contained somatic mutations in RHOA than late-onset DGCs. CDH1 alterations, but not RHOA mutations, were associated with shorter survival times of patients, which might account for the aggressive clinical course of early-onset gastric cancer. Female predominance in early-onset gastric cancer may be related to relatively high rates of somatic CDH1 and TGFBR1 mutations in this population.

Synergy of circulating miR-212 with markers for cardiovascular risks to enhance estimation of atherosclerosis presence

Synergy of specific microRNAs (miRNAs) with cardiovascular risk factors to estimate atherosclerosis presence in ischemic stroke patients has not been investigated. The present study aimed to identify atherosclerosis-related circulating miRNAs and to evaluate interaction with other cardiovascular markers to improve the estimation of atherosclerosis presence. We performed a miRNA profiling study using serum of 15 patients with acute ischemic stroke who were classified by the presence of no (n = 8) or severe (n = 7) stenosis on intracranial and extracranial vessels, which identified miR-212, -372, -454, and -744 as miRNAs related with atherosclerosis presence. Of the 4 miRNAs, only miR-212 showed a significant increase in expression in atherosclerosis patients in a validation study (atherosclerotic patients, n = 32, non-atherosclerotic patients, n = 33). Hemoglobin A1c, a high-density lipoprotein cholesterol, and lipoprotein(a), both established risk markers, were independently related with atherosclerosis presence in the validation population. miR-212 enhanced the accuracy of atherosclerosis presence by the three existing markers (three markers, 78.5%; three markers+miR-212, 84.6%, P<0.05) and significantly added to the area under the receiver operating characteristic curve (three markers, 0.8258; three markers+miR-212, 0.8646, P<0.05). The inclusion of miR-212 increased the reclassification index calculated using net reclassification improvement (0.4527, P<0.05) and integrated discrimination improvement (0.0737, P<0.05). We identified circulating miR-212 as a novel marker of atherosclerosis. miR-212 enhanced the estimation of atherosclerosis presence in combination with hemoglobin A1c, high-density lipoprotein cholesterol, and lipoprotein(a). Thus, miR-212 is expected to improve the estimation of atherosclerosis using peripheral blood of patients.

Abstract 106: High Red Blood Cell Components of Retrieved Clot Related With Recanalization During Intraarterial Thrombectomy

Background: Retrieved clots obtained during intraarterial thrombectomy (IAT) had variable histologic composition containing red (RBC) and white blood cells (WBC), congregated fibrin/platelets. We analyzed histologic composition differences of the retrieved clots by stroke subtypes and recanalization status of the occluded vessels after IAT.

Method: We analyzed histologic and angiographic findings of 69 retrieved clots obtained from 26 acute ischemic stroke patients (large-artery atherosclerosis, 6; cardioembolism, 15; undetermined etiology, 5 patients), who received IAT. The individual clot was measured positive pixels of RBC, WBC, and congregated-fibrin/platelet components on Hematoxylin-eosin stained clot using semiautomated quantitative analysis (Aperioscanscope, ver. 12.2, Leica Biosystems). Differences of the three components were compared by the stroke subtypes and by achievement of recanalization status defined as 2 or 3 of the Arterial Occlusive Lesion Scale. Finally, relationship of the recanalization status with clot composition and other risk factors was evaluated using multivariate analysis.

Result: RBC component was higher in subtype of cardioembolism (36.04%) than large-artery atherosclerosis (18.18%) and undetermined etiology (24.26%, p=0.019, Kruskal-Wallis test). Instead, congregated-fibrin/platelet component was higher in large-artery atherosclerosis (78.87%) than cardioembolism (59.95%) and undetermined etiology (72.28%, p=0.012). On comparison by the recanalization status, RBC component was higher in retrieved clots achieved recanalization (34.65%) than no-recanalization (13.98%, p=0.003, Mann-Whitney test) of the occluded vessel. Congregated-fibrin/platelet component was lower in the recanalized (61.81%) than the no-recanalized clot (81.63%, p=0.003). On multivariate analysis, RBC component only showed statistical significance as a factor related with recanalization status of the occluded vessels.

Conclusion: The present study showed that the high RBC and low fibrin/platelet composition of retrieved clot related with cardioembolic stroke. The RBC-rich clot was related with achievement of recanalization after IAT rather than the platelet/fibrin-rich clot.

Up-regulation of Cytoplasmic CD24 Expression Is Associated with Malignant Transformation but Favorable Prognosis of Colorectal Adenocarcinoma

AIM

Cluster of differentiation 24 (CD24) is known to be a putative marker of stem cell and tumor metastasis. This study aimed to verify the clinicopathological value of CD24 expression in colorectal adenocarcinoma (CRAC).

MATERIALS AND METHODS

A total of seven whole-tissue sections of malignant polyps including the sequence non-neoplastic colorectal tissue-adenoma-CRAC, 48 adenomas and 161 CRACs arranged as tissue microarray were examined by immunohistochemistry for CD24 protein expression. Association of CD24 expression with clinicopathological parameters were also studied.

RESULTS

CD24 was not detected in normal mucosal epithelia. Cytoplasmic CD24 expression was higher in CRAC than in adenoma (p<0.001). In CRACs, cytoplasmic CD24 expression was inversely correlated with poor differentiation (grades 1 to 3), tumor size, and pathological TNM stage (I to III versus IV) (p=0.005, p=0.034, and p=0.006, respectively). Statistical correlations between high CD24 expression and longer overall and disease-free survival were found (p=0.023 and p=0.033, respectively).

CONCLUSION

Our findings suggest that up-regulation of CD24 expression in CRAC occurs at malignant transformation but is a marker of good prognosis, being down-regulated in pathological TNM stage IV. CD24 expression may be a challenging diagnostic marker in differentiating early invasive CRAC from adenoma and may serve as a prognostic marker in patients with CRAC.

[A case of gastric leiomyosarcoma with multiple metastases]

Leiomyosarcoma is an uncommon tumor that originates from various organs, including uterus, kidney, retroperitoneum, and soft tissues. In particular, leiomyosarcoma of the stomach is extremely rare. Only 9 cases have been reported worldwide since the discovery of KIT-activating mutation. A 48-year-old woman was admitted to our hospital with abdominal discomfort and generalized weakness. Upon detection of multiple nodules in both lung on chest posterior-anterior radiograph taken at the time of admission, chest CT was performed and it revealed multiple mass lesions in the lung, liver, and pancreas along with multiple lymph node metastases. On endoscopic examination, a 2.0 cm sized ulcerofungating mass lesion was found on the stomach body. Biopsy was performed and the mass lesion proved to be leiomyosarcoma confirmed by immunohistochemical staining. Chemotherapy was thus initiated, but the patient died after one year due to tumor progression. Our experience suggests that leiomyosarcoma can manifest aggressive behavior in its early stage. Herein, we report a case of gastric leiomyosarcoma with multiple metastases along with review of relevant literature.

Acute gastritis associated with Epstein-Barr virus infection in a child

Infectious mononucleosis is Epstein-Barr virus (EBV) inducing a self-limiting clinical syndrome characterized by fever, sore throat, hepatosplenomegaly, and generalized lymphadenopathy. Gastrointestinal symptoms of EBV infection are nonspecific and occur rarely. EBV inducing acute gastrointestinal pathology is poorly recognized without suspicion. Careful consideration is needed to diagnose gastric involvement of EBV infection including gastric lymphoma, gastric cancer, and gastritis. A few recent cases of gastritis associated with EBV infection have been reported in adolescents and adults. However, there is no report of EBV-associated gastritis in early childhood. We experienced a rare case of 4-year-old girl with EBV gastritis confirmed by in situ hybridization.

Scaffold-Free Coculture Spheroids of Human Colonic Adenocarcinoma Cells and Normal Colonic Fibroblasts Promote Tumorigenicity in Nude Mice

The aim of this study was to form a scaffold-free coculture spheroid model of colonic adenocarcinoma cells (CACs) and normal colonic fibroblasts (NCFs) and to use the spheroids to investigate the role of NCFs in the tumorigenicity of CACs in nude mice. We analysed three-dimensional (3D) scaffold-free coculture spheroids of CACs and NCFs. CAC Matrigel invasion assays and tumorigenicity assays in nude mice were performed to examine the effect of NCFs on CAC invasive behaviour and tumorigenicity in 3D spheroids. We investigated the expression pattern of fibroblast activation protein-α (FAP-α) by immunohistochemical staining. CAC monocultures did not form densely-packed 3D spheroids, whereas cocultured CACs and NCFs formed 3D spheroids. The 3D coculture spheroids seeded on a Matrigel extracellular matrix showed higher CAC invasiveness compared to CACs alone or CACs and NCFs in suspension. 3D spheroids injected into nude mice generated more and faster-growing tumors compared to CACs alone or mixed suspensions consisting of CACs and NCFs. FAP-α was expressed in NCFs-CACs cocultures and xenograft tumors, whereas monocultures of NCFs or CACs were negative for FAP-α expression. Our findings provide evidence that the interaction between CACs and NCFs is essential for the tumorigenicity of cancer cells as well as for tumor propagation.

Decreased efficacy of drugs targeting the vascular endothelial growth factor pathway by the epigenetic silencing of FLT1 in renal cancer cells

BACKGROUND

The vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR) signaling pathway is involved in cancer-related biological functions and is a therapeutic target in cancer. However, the influence of epigenetic regulation of VEGF-VEGFR signaling-related genes remains unclear. Here, we evaluated the effects of FLT1 and KDR promoter hypermethylation combined with drugs targeting VEGF-VEGFR signaling on cancer-related phenotypes in renal cancer cells (RCCs) and examined changes in FLT1 and KDR promoter hypermethylation in tissues from patients with renal cancer.

RESULTS

In vitro experiments were performed to evaluate the effects of beavacizumab (an anti-VEGF antibody), an anti-FLT1 peptide, an anti-KDR antibody, and the VEGFR tyrosine kinase inhibitors (TKIs) sunitinib and axitinib in 13 RCC lines with different levels of FLT1 and/or KDR promoter methylation and in 2 FLT1 or KDR in vitro knockdown models. The synergistic effects of sunitinib and axitinib treatment were also evaluated in four RCC lines having different levels of FLT1 and/or KDR methylation. In our in vitro experiments, bevacizumab and an anti-KDR antibody did not affect the proliferation of RCCs having FLT1 and/or KDR hypermethylation. In contrast, in RCCs with FLT1 hypermethylation, proliferation inhibition was counteracted by treatment with an anti-FLT1 peptide and both VEGF-TKIs (sunitinib and axitinib). Demethylation with sunitinib or axitinib synergistically increased proliferation inhibition in the RCCs exhibiting FLT1 hypermethylation. Using in vitro FLT1 or KDR knockdown models, decreased proliferation inhibition following anti-FLT1 peptide, sunitinib, and axitinib treatment was observed only in FLT1-knockdown cells. In patients with renal cancer who received sunitinib, FLT1 promoter methylation was higher in renal cancer tissues from eight nonresponders (stable or progressive disease assessed by the Response Evaluation Criteria in Solid Tumors) than in cancer tissues from five responders (complete response or partial response).

CONCLUSIONS

The present data showed that hypermethylated FLT1 was important for the efficacy of anti-VEGF/VEGFR drugs targeting FLT1 or intracellular VEGFR signaling. FLT1 hypermethylation causing alterations of FLT1 function could serve as a useful biomarker for predicting changes in FLT1 status in RCCs.

Altered Expression of Yes-associated Protein and β-Catenin in Non-neoplastic and Neoplastic Gastric Surface Epithelia

AIM

To investigate whether differential expression of Yes-associated protein (YAP) and β-catenin is important in gastric carcinogenesis.

MATERIALS AND METHODS

A total of 284 paraffin-embedded samples collected from 232 patients with gastric adenocarcinoma were used to evaluate YAP and β-catenin expression by immunohistochemistry, and the experimental findings were compared against those for gastric adenocarcinoma cell lines.

RESULTS

Nuclear YAP expression gradually increased from non-neoplastic epithelia to tubular or papillary adenocarcinomas (TPADs) and decreased in signet-ring cell carcinoma (SRCC). Cytoplasmic β-catenin expression increased from non-neoplastic epithelia to high-grade dysplasia and was decreased in TPAD and SRCC. YAP-overexpressing cell lines exhibited marked tumor cell invasion, whereas YAP-depleted cells showed reduced invasion.

CONCLUSION

Nuclear YAP and cytoplasmic β-catenin play important roles in carcinogenesis, and the differential patterns YAP and β-catenin expression between TPAD and SRCC imply the existence of different carcinogenic pathways in these conditions.

Gene polymorphisms in the ornithine decarboxylase-polyamine pathway modify gastric cancer risk by interaction with isoflavone concentrations

BACKGROUND

The study aimed to examine the association between genes encoding molecules in the ornithine decarboxylase (ODC)-polyamine pathway (ODC1, AMD1, NQO1, NOS2A, and OAZ2) and gastric cancer risk and whether the gene-phytoestrogen interaction modifies gastric cancer risk.

METHODS

Among 76 gastric cancer cases and their 1:4 matched controls within the Korean Multi-center Cancer Cohort, a total of 30 SNPs in five genes involved in the ODC pathway were primarily analyzed. The second-stage genotyping in 388 matched case-control sets was conducted to reevaluate the significant SNPs interacting with phytoestrogens during the primary analysis. The summary odds ratios (ORs) [95 % confidence intervals (CIs)] for gastric cancer were estimated. Interaction effects between the SNPs and plasma concentrations of phytoestrogens (genistein, daidzein, equol, and enterolactone) were evaluated.

RESULTS

In the pooled analysis, NQO1 rs1800566 showed significant genetic effects on gastric cancer without heterogeneity [OR 0.83 (95 % CI 0.70-0.995)] and a greater decreased risk at high genistein/daidzein levels [OR 0.36 (95 % CI 0.15-0.90) and OR 0.26 (95 % CI 0.10-0.64), respectively; p interaction < 0.05]. Risk alleles of AMD1 rs1279599, AMD1 rs7768897, and OAZ2 rs7403751 had a significant gene-phytoestrogen (genistein and daidzein) interaction effect to modify the development of gastric cancer. They had an increased gastric cancer risk at low isoflavone levels, but a decreased risk at high isoflavone levels (p interaction < 0.01).

CONCLUSIONS

Our findings suggest that common variants in the genes involved in the ODC pathway may contribute to the risk of gastric cancer possibly by modulating ODC polyamine biosynthesis or by interaction between isoflavones and NQO1, OAZ2, and AMD1.

nc886, a non-coding RNA of anti-proliferative role, is suppressed by CpG DNA methylation in human gastric cancer

nc886 is a 101 nucleotide long non-coding RNA that has been designated as a precursor microRNA or a vault RNA based upon it sequence. nc886 has also been suggested to be a tumor suppressor, mainly inferred by its expression pattern as well as its genomic location at human chromosome 5q31, a locus for a tumor suppressor gene(s). However, legitimate data based on nc886's correct identity for its functional cellular roles as a tumor suppressor have not been provided yet. Here we have investigated nc886 in gastric cancer where its expression is suppressed due to CpG DNA hypermethylation at its promoter region in a cohort of paired tumor/normal tissues from 88 gastric cancer patients. CpG hypermethylation of nc886 and thus its diminished expression is significantly associated with poor survival in these cancer patients. nc886 inhibits cell proliferation when ectopically expressed in gastric cancer cells. nc886's tumor suppressive role is corroborated by the induction of well-known oncogenes such as FOS, NF-κB, and MYC upon its knockdown. All these activities of nc886 are undoubtedly independent of mature microRNA or vault RNA. Our data indicate that nc886 is a putative tumor suppressor and could potentially be used as a diagnostic marker in gastric cancer.

Differences in gastric mucosal microbiota profiling in patients with chronic gastritis, intestinal metaplasia, and gastric cancer using pyrosequencing methods

BACKGROUND

Helicobacter pylori (H. pylori) infection plays an important role in the early stage of cancer development. However, various bacteria that promote the synthesis of reactive oxygen and nitrogen species may be involved in the later stages. We aimed to determine the microbial composition of gastric mucosa from the patients with chronic gastritis, intestinal metaplasia, and gastric cancer using 454 GS FLX Titanium.

METHODS

Gastric mucosal biopsy samples were collected from 31 patients during endoscopy. After the extraction of genomic DNA, variable region V5 of the 16S rRNA gene was amplified. PCR products were sequenced using 454 high-throughput sequencer. The composition, diversity, and richness of microbial communities were compared between three groups.

RESULTS

The composition of H. pylori-containing Epsilonproteobacteria class appeared to be the most prevalent, but the relative increase in the Bacilli class in the gastric cancer group was noticed, resulting in a significant difference compared with the chronic gastritis group. By analyzing the Helicobacter-dominant group at a family level, the relative abundance of Helicobacteraceae family was significantly lower in the gastric cancer group compared with chronic gastritis and intestinal metaplasia groups, while the relative abundance of Streptococcaceae family significantly increased. In a UPGMA clustering of Helicobacter-dominant group based on UniFrac distance, the chronic gastritis group and gastric cancer group were clearly separated, while the intestinal metaplasia group was distributed in between the two groups. The evenness and diversity of gastric microbiota in the gastric cancer group was increased compared with other groups.

CONCLUSIONS

In Helicobacter predominant patients, the microbial compositions of gastric mucosa from gastric cancer patients are significantly different to chronic gastritis and intestinal metaplasia patients. These alterations of gastric microbial composition may play an important, as-yet-undetermined role in gastric carcinogenesis of Helicobacter predominant patients.

Successful treatment of a gastric plasmacytoma using a combination of endoscopic submucosal dissection and oral thalidomide

We report a rare case of a gastric plasmacytoma treated with endoscopic resection and oral thalidomide therapy. A 70-year-old man was admitted to our hospital with indigestion. He had no specific medical history and unremarkable laboratory results. Gastroendoscopic findings revealed a focal, erythematous, flat elevated lesion in the anterior wall of the stomach antrum. A biopsy revealed atypical lymphocytes. Endoscopic submucosal dissection (ESD) with an insulation-tipped knife was performed 45 days after diagnosis. Radiological and hematological evaluations, including a bone marrow biopsy, were performed and showed no involvement of other organs. The patient was diagnosed with extramedullary gastric plasmacytoma. Follow-up gastroendoscopy was performed three times during a 2-year period and showed nonspecific ESD scarring. The patient's condition was found to be stable.

Abstract 394: TET1, which act as an tumor suppressor gene, is suppressed by DNA hypermethylation in gastric cancer

5-hydromethylcytosine (5hmC) is a hydroxmethylated form of DNA cytosine catalyzed by TET proteins. Recently, it was reported that aberrant regulation of 5hmC is associated with many cancers such as breast cancer, glioma, leukemia and melanoma. In this study, we examined the status of 5hmC and the role of TET1, which converts 5mC to 5hmC, in gastric cancer. Dot blot and ELISA assay results revealed global loss of 5hmC level in gastric cancer, and that decreased TET1 expression was associated with decreased 5hmC levels. Importantly, in gastric cancer patients, TET1-low group had advanced metastasis and poor survival compared with TET1-high group. To understand the mechanisms of TET1 suppression in gastric cancer, we performed pyrosequencing in 80 paired normal and tumors samples from gastric cancer patients, and found that the promoter region of TET1 was hypermethylated in tumors than adjacent normal tissues. Treating AGS cells with 5-Aza-2′deoxycytidine (Aza-dC) restored the expression of TET1. Transient transfection of in vitro transcribed TET1 mRNA into AGS cells significantly reduced the growth of AGS cells. In summary, our results showed that DNA methylation is responsible for the suppression of TET1 which has a tumor suppressor role in gastric cancer

Citation Format: Jong-Lyul Park, Oh-Hyung Kwon, Kyu Sang Song, Seon-Young Kim, Yong Sung Kim. TET1, which act as an tumor suppressor gene, is suppressed by DNA hypermethylation in gastric cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 394. doi:10.1158/1538-7445.AM2014-394

Acceleration of peripheral nerve regeneration through asymmetrically porous nerve guide conduit applied with biological/physical stimulation

Sufficient functional restoration of damaged peripheral nerves is a big clinical challenge. In this study, a nerve guide conduit (NGC) with selective permeability was prepared by rolling an asymmetrically porous polycaprolactone/Pluronic F127 membrane fabricated using a novel immersion precipitation method. Dual stimulation (nerve growth factor [NGF] as a biological stimulus and low-intensity pulse ultrasound [US] as a physical stimulus) was adapted to enhance nerve regeneration through an NGC. The animal study revealed that each stimulation (NGF or US) has a positive effect to promote the peripheral nerve regeneration through the NGC, however, the US-stimulated NGC group allowed more accelerated nerve regeneration compared with the NGF-stimulated group. The NGC group that received dual stimulation (NGF and US) showed more effective nerve regeneration behavior than the groups that received a single stimulation (NGF or US). The asymmetrically porous NGC with dual NGF and US stimulation may be a promising strategy for the clinical treatment of delayed and insufficient functional recovery of a peripheral nerve.

Adenocarcinoma occurring in a gastric hyperplastic polyp treated with endoscopic submucosal dissection

Gastric hyperplastic polyps are generally considered benign lesions, although rare cases of adenocarcinoma have been reported. Although, the underlying mechanism of carcinogenesis in gastric hyperplastic polyps is still uncertain, most malignant polyps are seen to originate from dysplastic epithelium rather than from hyperplastic epithelium. Herein, we report the case of a woman diagnosed with adenocarcinoma that originated from a hyperplastic gastric polyp that was successfully removed by endoscopic submucosal dissection. In this case, we observed adenomatous changes around the cancerous component.

Differential expression of Yes-associated protein and phosphorylated Yes-associated protein is correlated with expression of Ki-67 and phospho-ERK in colorectal adenocarcinoma

Yes-associated protein (YAP) is a transcriptional co-activator and functions as a nuclear downstream effector of the Hippo pathway. Differential expression of YAP and phosphorylated Yes-associated protein (pYAP), which are involved in the expression of Ki-67 and phosphorylated extracellular signal-regulated kinase (pERK) in colorectal adenocarcinoma (CRAC), is not clear. Herein, we hypothesized that nuclear expression of YAP could predict cell proliferation and poor prognosis, while cytoplasmic expression of pYAP would show a reverse correlation with cell proliferation. Paraffin-embedded samples from 144 CRAC patients were studied using immunohistochemistry for YAP, pYAP, Ki-67 and pERK. Frozen samples from 20 CRAC patients were examined for YAP mRNA in tumor and non-tumor tissues, using quantitative real-time PCR. High nuclear YAP expression coincided with high Ki-67 expression (P=0.002). The high nuclear YAP expression group tended to display a poor overall and disease-free survival (P=0.089 and P=0.089, respectively), but YAP mRNA levels in the 20 CRAC tissues were not significantly different in comparison with the 20 non-tumor tissues (P=0.929). We observed an inverse correlation between high cytoplasmic pYAP expression and high Ki-67 expression (P=0.001). Nuclear pERK expression was positively correlated with nuclear YAP expression, but negatively correlated with cytoplasmic pYAP expression (P=0.017 and P=0.020, respectively). Activated nuclear YAP and inactivated cytoplasmic pYAP in CRAC showed a positive correlation with Ki-67 and nuclear pERK expression, suggesting that the expression of YAP and pYAP is a possible predictor of tumor cell proliferation and prognosis in CRAC.

Effect of surface pore structure of nerve guide conduit on peripheral nerve regeneration

Polycaprolactone (PCL)/Pluronic F127 nerve guide conduits (NGCs) with different surface pore structures (nano-porous inner surface vs. micro-porous inner surface) but similar physical and chemical properties were fabricated by rolling the opposite side of asymmetrically porous PCL/F127 membranes. The effect of the pore structure on peripheral nerve regeneration through the NGCs was investigated using a sciatic nerve defect model of rats. The nerve fibers and tissues were shown to have regenerated along the longitudinal direction through the NGC with a nano-porous inner surface (Nanopore NGC), while they grew toward the porous wall of the NGC with a micro-porous inner surface (Micropore NGC) and, thus, their growth was restricted when compared with the Nanopore NGC, as investigated by immunohistochemical evaluations (by fluorescence microscopy with anti-neurofilament staining and Hoechst staining for growth pattern of nerve fibers), histological evaluations (by light microscopy with Meyer's modified trichrome staining and Toluidine blue staining and transmission electron microscopy for the regeneration of axon and myelin sheath), and FluoroGold retrograde tracing (for reconnection between proximal and distal stumps). The effect of nerve growth factor (NGF) immobilized on the pore surfaces of the NGCs on nerve regeneration was not so significant when compared with NGCs not containing immobilized NGF. The NGC system with different surface pore structures but the same chemical/physical properties seems to be a good tool that is used for elucidating the surface pore effect of NGCs on nerve regeneration.

Soluble c-Met protein as a susceptible biomarker for gastric cancer risk: A nested case-control study within the Korean Multicenter Cancer Cohort

This study was conducted to evaluate the relevance of the soluble form of c-Met protein, a truncated form of the c-Met membrane receptor involved in the CagA pathway, as a potential biomarker for gastric cancer. Among 290 gastric cancer case-control sets selected from the Korean Multicenter Cancer Cohort, the plasma concentrations of soluble c-Met protein were measured with enzyme-linked immunosorbent assays. Using analysis of variance and covariance models with age, sex, smoking, Helicobacter pylori infection, and CagA seropositivity, the mean concentrations of soluble c-Met protein between cases and controls were compared. To evaluate the association between gastric cancer and a c-Met protein level, odds ratios and 95% confidence intervals were estimated using conditional logistic regression models. Interactions between CagA-related genes and the soluble c-Met protein concentration were also investigated. The overall median plasma concentration of soluble c-Met among cases was significantly lower than those of controls (1.390 vs. 1.610 ng/mL, p < 0.0001). Closer to the onset of gastric cancer, the soluble c-Met protein level decreased linearly in a time-dependent manner (p for trend = 0.0002). The combined effects between the CagA-related genes and the soluble c-Met protein concentration significantly intensified risks for gastric cancer. Restricted analyses including cases that had been diagnosed within 1 year after entering the cohort had a fair degree of ability (area under the receiver operating characteristic curve of 0.73-0.77) to discriminate gastric cancer cases from normal controls. Our findings demonstrate the potential of the soluble form of c-Met protein as a novel biomarker for gastric cancer. The beneficial effects of a high soluble c-Met concentration in human plasma are strongly supported.

Genetic susceptibility factors on genes involved in the steroid hormone biosynthesis pathway and progesterone receptor for gastric cancer risk

Background

The objective of the study was to investigate the role of genes (HSD3B1, CYP17A1, CYP19A1, HSD17B2, HSD17B1) involved in the steroid hormone biosynthesis pathway and progesterone receptor (PGR) in the etiology of gastric cancer in a population-based two-phase genetic association study.

Methods

In the discovery phase, 108 candidate SNPs in the steroid hormone biosynthesis pathway related genes and PGR were analyzed in 76 gastric cancer cases and 322 controls in the Korean Multi-Center Cancer Cohort. Statistically significant SNPs identified in the discovery phase were re-evaluated in an extended set of 386 cases and 348 controls. Pooled- and meta-analyses were conducted to summarize the results.

Results

Of the 108 SNPs in steroid hormone biosynthesis pathway related genes and PGR analyzed in the discovery phase, 23 SNPs in PGR in the recessive model and 10 SNPs in CYP19A1 in the recessive or additive models were significantly associated with increased gastric cancer risk (p<0.05). The minor allele frequencies of the SNPs in both the discovery and extension phases were not statistically different. Pooled- and meta-analyses showed CYP19A1 rs1004982, rs16964228, and rs1902580 had an increased risk for gastric cancer (pooled OR [95% CI] = 1.22 [1.01–1.48], 1.31 [1.03–1.66], 3.03 [1.12–8.18], respectively). In contrast, all PGR SNPs were not statistically significantly associated with gastric cancer risk.

Conclusions

Our findings suggest CYP19A1 that codes aromatase may play an important role in the association of gastric cancer risk and be a genetic marker for gastric cancer susceptibility.

Interaction effects between genes involved in the AKT signaling pathway and phytoestrogens in gastric carcinogenesis: a nested case-control study from the Korean Multi-Center Cancer Cohort

SCOPE

To investigate whether genes involved in AKT/nuclear factor kappa B signaling and/or gene-environment interactions between the genes and phytoestrogens may be susceptible factors for gastric cancer.

METHODS AND RESULTS

The representative single nucleotide polymorphisms (SNPs) identified during the primary analysis (screening a total of 622 SNPs within ± 5 kbp of the 51 target gene locations) were further investigated in 317 matched case-control sets. The summary odds ratios (ORs) and 95% confidence intervals (CIs) for gastric cancer were calculated. Interaction effects between the SNPs and phytoestrogen biomarkers (genistein, daidzein, equol, and enterolactone) were computed. CDK1 rs4145643, FAS rs6586161, and FAS rs1468063 in the AKT signaling pathway presented significant genetic effects on gastric cancer (OR = 0.81 (95% CI: 0.66-0.99) for CDK1 rs4145643; OR = 1.27 (95% CI: 1.03-1.58) for FAS rs6586161; OR = 1.29 (95% CI: 1.03-1.56) for FAS rs1468063; Cochran Q statistics > 0.10). Risk alleles of FAS rs6586161, FAS rs1468063, MAP3K1 rs16886448, and MAP3K1 rs252902 showed significant interaction effects with enterolactone (p(interaction) < 0.05).

CONCLUSION

CDK1 and FAS genes involved in AKT signaling and influenced by anti-carcinogenic property of phytoestrogens can play a role as susceptible genetic factors in gastric carcinogenesis. FAS and MAP3K1 genes significantly interact with enterolactone, thereby modifying the individual's risk for gastric cancer.

Correlation of expression of phosphorylated and non-phosphorylated Yes-associated protein with clinicopathological parameters in esophageal squamous cell carcinoma in a Korean population

Yes-associated protein (YAP) is a nuclear downstream effector of the Hippo pathway, a regulator of cell growth. The phosphorylated form of YAP (pYAP), located in the cytoplasm, prevents cellular proliferation by spatially segregating YAP from the nucleus. This study aimed at investigating the relationships of pYAP and YAP with clinicopathological variables in esophageal squamous cell carcinoma (ESCC). Samples of ESCC from 142 patients were studied using immunohistochemistry for YAP, pYAP and Ki-67. In all cases of ESCC, higher nuclear expression of YAP was correlated with Ki-67 expression, tumor diameter, histological grade (1-2 versus 3), and pathological TNM stage (I versus II-IV) in univariate analyses (p=0.036, p=0.025, p=0.021, and p=0.033, respectively). Higher nuclear expression of YAP was associated with worse overall and disease-free survival (p=0.006 and p=0.008, respectively). Multivariate analysis showed higher nuclear expression of YAP to be an independent prognostic marker for overall survival (p=0.034). We observed a trend towards inverse correlation of cytoplasmic pYAP expression and histological grade (1-2 versus 3) (p=0.087). Our results suggest that YAP shifts from the nucleus to the cytoplasm as a consequence of phosphorylation, which occurs in the presence of high tumor cell density in the case of ESCC, and may be a potential indication of histological differentiation. Nuclear expression of YAP is correlated with tumor cell proliferation and is an independent predictor of worse prognosis of ESCC.

Hyaluronic acid/mildly crosslinked alginate hydrogel as an injectable tissue adhesion barrier

Although hyaluronic acid (HA) has been conventionally utilized as a tissue adhesion barrier material, its rapid clearance in the body still remains as a big challenge in the clinical practice. In this study, we prepared a hydrogel of HA embedded in mildly crosslinked alginate (HA/mcALG hydrogel), which is injectable, easily covers injured tissues, and remains stably at the applied site during wound healing (by muco-adhesive HA embedded in the network structure of the mcALG hydrogel). The HA/mcALG hydrogel was highly effective for the prevention of peritoneal tissue adhesion compared to HA and mcALG hydrogels, and did not lead to any abnormal tissue responses during wound healing. The HA/mcALG hydrogel can be a good candidate as an injectable tissue adhesion barrier for clinical applications.

Conservative treatment of pediatric trigger thumb: follow-up for over 4 years

We analyzed the outcomes of our conservative treatment for pediatric trigger thumb. Since March 2004, we have used conservative treatment for all patients with pediatric trigger thumb. We prospectively analyzed 30 patients in whom 35 thumbs were affected (10 right, 15 left, 5 bilateral). The mean age at diagnosis was 28 (11-50) months. The treatment consisted of passive exercises performed by the children's mothers, 10-20 times daily. How reliably this was performed is unproven. Trigger thumb severity was graded as 0A (extension beyond 0°), 0B (extension to 0°), 1 (active extension with triggering), 2 (passive extension with triggering), and 3 (cannot extend either actively or passively i.e. locked). At diagnosis, six of the 35 thumbs (17%) were grade 1, 25 (71%) were grade 2, and four (11%) were grade 3. After a mean follow-up period of 63 (range, 49-73) months, 28 thumbs (80%) were grade 0A or 0B, 5 (14%) were grade 1 and 2 (6%) were grade 2. The bilateral cases and the patients who initially had grade 3 severity had significantly more unfavorable results than the other patients. This study suggests that conservative treatment for pediatric trigger thumb is a successful method, although cases that present with bilateral involvement or locking (grade 3) should be considered for early surgical release.

c-Ets1 inhibits the interaction of NF-κB and CREB, and downregulates IL-1β-induced MUC5AC overproduction during airway inflammation

Mucin hypersecretion is frequently observed in many inflammatory diseases of the human respiratory tract. As mucin hypersecretion refers to uncontrolled mucin expression and secretion during inflammation, studies examining the negative control mechanisms of mucin hypersecretion are vital in developing novel therapeutic medications. We hypothesized that the c-Ets1 induced by interleukin (IL)-1β would decrease MUC5AC overproduction by inhibiting the interaction of NF-κB with cAMP response element-binding protein (CREB) in vivo. Stimulation with IL-1β caused the direct binding of NF-κB and CREB to the MUC5AC promoter, thus increasing MUC5AC gene expression. However, IL-1β-induced MUC5AC messenger RNA levels were surprizingly downregulated by c-Ets1 (located -938 to -930). Interestingly, c-Ets1 also suppressed IL-1β-induced MUC5AC gene expression in vitro and in vivo by disrupting the interaction of NF-κB with CREB on the MUC5AC promoter. In addition, c-Ets1 also inhibited significant morphologic changes and inflammatory cell infiltration after IL-1β exposure in mouse lungs infected with either wild-type or shRNA-c-Ets1. Moreover, reactive oxygen species produced by NOX4 increased c-Ets1 gene expression and MUC5AC gene expression in alveolar macrophages from bronchoalveolar lavage fluid. These results suggest a molecular paradigm for the establishment of a novel mechanism underlying the negative regulation of mucin overproduction, thus enhancing our understanding of airway inflammation.

Genetic susceptibility on CagA-interacting molecules and gene-environment interaction with phytoestrogens: a putative risk factor for gastric cancer

OBJECTIVES

To evaluate whether genes that encode CagA-interacting molecules (SRC, PTPN11, CRK, CRKL, CSK, c-MET and GRB2) are associated with gastric cancer risk and whether an interaction between these genes and phytoestrogens modify gastric cancer risk.

METHODS

In the discovery phase, 137 candidate SNPs in seven genes were analyzed in 76 incident gastric cancer cases and 322 matched controls from the Korean Multi-Center Cancer Cohort. Five significant SNPs in three genes (SRC, c-MET and CRK) were re-evaluated in 386 cases and 348 controls in the extension phase. Odds ratios (ORs) for gastric cancer risk were estimated adjusted for age, smoking, H. pylori seropositivity and CagA strain positivity. Summarized ORs in the total study population (462 cases and 670 controls) were presented using pooled- and meta-analysis. Plasma concentrations of phytoestrogens (genistein, daidzein, equol and enterolactone) were measured using the time-resolved fluoroimmunoassay.

RESULTS

SRC rs6122566, rs6124914, c-MET rs41739, and CRK rs7208768 showed significant genetic effects for gastric cancer in both the pooled and meta-analysis without heterogeneity (pooled OR = 3.96 [95% CI 2.05-7.65], 1.24 [95% CI = 1.01-1.53], 1.19 [95% CI = 1.01-1.41], and 1.37 [95% CI = 1.15-1.62], respectively; meta OR = 4.59 [95% CI 2.74-7.70], 1.36 [95% CI = 1.09-1.70], 1.20 [95% CI = 1.00-1.44], and 1.32 [95% CI = 1.10-1.57], respectively). Risk allele of CRK rs7208768 had a significantly increased risk for gastric cancer at low phytoestrogen levels (p interaction<0.05).

CONCLUSIONS

Our findings suggest that SRC, c-MET and CRK play a key role in gastric carcinogenesis by modulating CagA signal transductions and interaction between CRK gene and phytoestrogens modify gastric cancer risk.

Quantitative analysis of cell-free DNA in the plasma of gastric cancer patients

In the present study, an accurate and reproducible method for quantifying cell-free DNA (cfDNA) in human blood was established and tested for its ability to predict gastric cancer in patients. Using 'Alu81-qPCR' to amplify 81-bp Alu DNA sequences, we first estimated the amount of cfDNA in the serum or plasma of 130 patients with gastric cancer to identify which source of cfDNA is more suitable for the biomarker screening of these patients. The results of Alu81-qPCR revealed that the amount of cfDNA in the plasma was low compared with that in the serum, but was found at similar levels among the samples, indicating that the plasma may be a more suitable source of cfDNA for biomarker screening. For the 54 patients with gastric cancer and the 59 age-matched healthy controls, the mean levels of plasma cfDNA were 2.4-fold higher in the patient group compared with the control group, indicating that plasma cfDNA levels may be useful for predicting patients with gastric cancer. The results of our study suggest that Alu81-qPCR is a more reliable method than other techniques, such as the PicoGreen assay, for quantifying cfDNA in human blood, demonstrating the potential to complement current diagnostic procedures for the management of gastric cancer patients.

Spectrum of final pathological diagnosis of gastric adenoma after endoscopic resection

AIM: To investigate how many discrepancies occur in patients before and after endoscopic treatment of referred adenoma and the reason for these results.

METHODS: We retrospectively reviewed data from 554 cases of 534 patients who were referred from primary care centres for adenoma treatment and treated for endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) at Chungnam National University Hospital, from July 2006 to June 2009. Re-endoscopy was examined in 142 cases and biopsy was performed in 108 cases prior to treatment. Three endoscopists (1, 2 and 3) performed all EMRs or ESDs and three pathologists (1, 2 and 3) diagnosed most of the cases. Transfer notes, medical records and endoscopic pictures of these cases were retrospectively reviewed and analyzed.

RESULTS: Adenocarcinoma was 72 (13.0%) cases in total 554 cases after endoscopic treatment of referred adenoma. When the grade of dysplasia was high (55.0%), biopsy number was more than three (22.7%), size was no smaller than 2.0 cm (23.2%), morphologic type was depressed (35.8%) or yamada type IV (100%), and color was red (30.9%) or mixed-or-undetermined (25.0%), it had much more malignancy rate than the others (P < 0.05). All 18 cases diagnosed as adenocarcinoma in the re-endoscopic forceps biopsy were performed by endoscopist 1. There were different malignancy rates according to the pathologist (P = 0.027).

CONCLUSION: High grade dysplasia is the most im-portant factor for predicting malignancy as a final pathologic diagnosis before treating the referred gastric adenoma. This discrepancy can occur mainly through inappropriately selecting a biopsy site where cancer cells do not exist, but it also depends on the pathologist to some extent.