Development and validation of an EUS-based nomogram for prediction of the malignant potential in gastrointestinal stromal tumors.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal (GI) tract that require different therapeutic interventions according to the malignancy. We aim to develop and validate a EUS (endoscopic ultrasonography)-based nomogram to predict malignant potential in patients with GIST. METHODS: 258 patients with pathological diagnosis of gastric GISTs were enrolled retrospectively in our hospital from June 2015 to October 2020. Patients were randomly divided into the development cohort (DC, n = 179) and the validation cohort (VC, n = 79). We established a nomogram using lasso regression based on DC data. The predictive effectiveness of the nomogram was evaluated by the area under the receiver operating characteristic curve (AUC). Through bootstrapping, a consistency index (C-index) and calibration chart are developed to evaluate the reliability and accuracy of the nomogram. RESULTS: A total of 192 patients with low-malignant potential (very low and low-risk) GISTs and 66 patients with high-malignant potential (intermediate and high-risk) GISTs were included in this study. The nomogram was constructed with the following 6 EUS indicators: ulceration, hemorrhage, tumor shape, irregular border, transverse diameter, and necrosis. Internal and external validation showed that the nomogram had a good ability to predict the malignant potential of GISTs (AUC = 0.881 and 0.908, respectively). The calibration curve shows that the nomogram has a good agreement between predicted and actual probabilities for differentiating GISTs malignancy (C-index = 0.868 and 0.907, respectively). CONCLUSIONS: This study developed and verified a EUS-based nomogram, which can effectively predict the malignant potential of patients with gastric GISTs.

Twenty cases of gastric adenocarcinoma of the fundic gland type.

BACKGROUND: Gastric adenocarcinoma of the fundic gland type is a new subtype of gastric adenocarcinoma. In 2019, the World Health Organization (WHO) listed gastric adenocarcinoma of the fundic gland type (GA-FG) as a new and rare gastric tumour with a low incidence due to the small number of cumulative cases worldwide. Twenty cases of GA-FG found in our centre were retrospectively analysed to improve the diagnostic ability of endoscopy and pathology in this disease. OBJECTIVE: To investigate the clinicopathological features of fundus-derived gastric tumours and to improve the understanding of and diagnostic accuracy of endoscopy for this disease. METHODS: The clinicopathological characteristics of 20 GA-FG cases between 2018 and 2022 were analysed using clinical and follow-up data and endoscopic, immunohistochemical, and pathological morphology characteristics. RESULTS: In all cases, GA-FG was found in the fundus and the body of the stomach. In total, there were 19 patients with 20 lesions, with most of the patients having a single lesion. One patient had multiple lesions, and another patient had complications from signet ring cell carcinoma (SRCC). All lesions occurred in non-atrophic areas, and 10 patients had gastric fundic gland polyps simultaneously. There were 14 cases of gastric fundus adenocarcinoma and 6 cases of acid-secreting adenoma. Fourteen lesions were treated with endoscopic submucosal dissection (ESD), without recurrence or metastasis during the follow up; 6 patients were followed up for observation, 2 of whom showed no lesions after the first biopsy by gastric endoscopy, and 4 of whom showed no significant changes. CONCLUSIONS: The incidence rate for GA-FG lesions may be underestimated due to their benign course. ESD seems to be an adequate treatment for GA-FG. MAIN POINTS: Gastric adenocarcinoma of the fundic gland type (GA-FG) is located in the fundus and body of the stomach. All lesions occur in non-atrophic areas, and almost one-half involve gastric fundus polyps simultaneously. GA-FG lesions typically follow a benign disease course. ESD seems to be an adequate treatment for GA-FG.

Design and validation of performance-oriented injectable chitosan thermosensitive hydrogels for endoscopic submucosal dissection.

Endoscopic submucosal dissection (ESD) is a challenging procedure. The use of biomaterials to improve the operator's convenience (operating affinity) has received little attention. We prepared two thermosensitive hydrogels, lactobionic acid-modified chitosan/chitosan/ß-glycerophosphate thermosensitive hydrogel (hydrogel 1) and its lyophilized powders (hydrogel 2), characterized their physicochemical properties and evaluated their performance in ESD experiments on large animals, by comparing with the commonly used normal saline (NS) and glycerin fructose (GF). These hydrogels showed good low-temperature fluidity; their viscosities at 4 °C were 92.2 mPa.s and 26.9 mPa.s, respectively. The hydrogels provided significantly better viscoelastic properties than NS and GF. The relaxation moduli of hydrogels were higher than those of NS and GF when the strains were 1 %, 5 %, and 10 %. The hydrogels can be maintained for seven days, even at pH 1, after which they degrade entirely. In pig model experiments, we performed submucosal injection and ESD procedures in the stomach and esophagus. The cushion height produced by the hydrogels was higher than those of NS and GF 30 min after injection. The ESD operation time for hydrogels was significantly shorter. Postoperative wound observation and histological analysis showed that the hydrogels promoted wound healing. The two hydrogels differed in fluidity, viscoelasticity, and other properties, which makes it possible to select the hydrogels according to the size and location of the lesion during ESD operation, and hydrogel 2 may be more suitable for use in lengthier procedures. In general, the hydrogels showed good performance, facilitated the intraoperative operation of ESD, shorten the operation time and promoted wound healing, which is of great significance for reducing the complications and reducing the threshold of ESD operation and further promoting the popularity of ESD.

A novel ultra-low-volume regimen combining 1 L polyethylene glycol and linaclotide versus 2 L polyethylene glycol for colonoscopy cleansing in low-risk individuals: a randomized controlled trial.

BACKGROUND AND AIMS: The single dose of 2 L polyethylene glycol (PEG) has shown high cleaning efficacy and tolerability in low-risk patients. However, the dosage of this regimen is still challenging for many patients. We investigated the efficacy and tolerability of a novel ultra-low-volume regimen using 1 L PEG and linaclotide (1 L PEG+L) versus a single dose of 2 L PEG in low-risk patients. METHODS: In this prospective, randomized, observer-blinded, multicenter study, low-risk adult patients scheduled for colonoscopy were enrolled and randomized (1:1) to receive the 1 L PEG+L regimen or the 2 L PEG regimen. The primary outcome was the effectiveness of bowel cleansing according to the Boston Bowel Preparation Scale. Secondary outcomes included cecal intubation rate, cecal insertion time, withdrawal time, polyp detection rate and adenoma detection rate, tolerability, adverse events, and willingness to repeat bowel preparation. The full analysis set (FAS) and per-protocol set (PPS) were used for statistical analyses. RESULTS: A total of 548 patients comprised the FAS, and 522 patients comprised the PPS. Noninferiority on adequate bowel cleansing of 1 L PEG+L vs 2 L PEG was established both in FAS (90.5% vs 91.6%, P = .644) and PPS (90.3% vs 92.4%, P = .390). There were no significant differences regarding the total score and each segment scores of the Boston Bowel Preparation Scale, cecal intubation rate, cecal insertion time, withdrawal time, polyp detection rate, and adenoma detection rate (all, P > .05). However, patients in the 1 L PEG+L group reported less nausea (7.7% vs 17.1%, P < .01) and vomiting (4.0% vs 10.9%, P < .01) and had a higher willingness to repeat bowel preparation (95.2% vs 82.2%, P < .01). CONCLUSIONS: The regimen of 1 L PEG+L was not inferior to 2 L PEG on colon cleansing, with better tolerability and higher willingness to repeat the bowel preparation in a low-risk population. (Clinical trial registration number: ChiCTR2100053273.).

Mast cells disrupt the duodenal mucosal integrity: Implications for the mechanisms of barrier dysfunction in functional dyspepsia.

BACKGROUND: Functional dyspepsia (FD) is a common functional gastrointestinal (GI) disorder, but its pathophysiology is poorly understood. Mast cells (MCs) may play a critical role in the development of FD. Therefore, the aim of this study was to investigate the effect of MCs on barrier function, tight junction (TJ) proteins and related signaling pathways. METHODS: The expression of the TJ proteins claudin-8, ZO-1 and occludin in biopsy tissues from seven FD patients and five controls was assessed. Based on the in vivo results, we further investigated the effect of (1) MC degranulation in a coculture model of Caco-2/RBL-2H3 cells and tryptase in Caco-2 monolayers, (2) MC degranulation in the presence or absence of a PAR-2 antagonist and (3) MC degranulation in the presence or absence of an ERK1/2 signaling pathway inhibitor. The epithelial integrity of Caco-2 cell monolayers was assessed by measuring the transepithelial electrical resistance (TEER). The expression of TJ proteins was evaluated by western blotting, QT-PCR and immunostaining. RESULTS: Epithelial claudin-8, ZO-1 and occludin protein expression were significantly reduced in tissues from FD patients compared with controls. MC degranulation and tryptase decreased the TEER and reduced the expression of TJ proteins in Caco-2 cell monolayers. A PAR-2 antagonist and an ERK1/2 signaling pathway inhibitor significantly reduced the effect of MC degranulation on the TEER and TJ protein expression in Caco-2 cell monolayers. CONCLUSIONS: MCs disrupt duodenal barrier function by modulating the levels of TJ proteins, and the PAR-2 and ERK1/2 signaling pathways may mediate the pathogenesis of FD.

Effects of Chitosan/Collagen Peptides/Cinnamon Bark Essential Oil Composite Coating on the Quality of Dry-Aged Beef.

The aim of this study was to evaluate the effects of the chitosan/collagen peptides/cinnamon bark essential oil composite coating on dry-aged beef. Chitosan (2%, w/v), collagen peptides (1%, w/v), and cinnamon bark essential oil (1%, v/v) were homogenized to obtain the coating. Beef samples were divided into three groups (traditional dry-ageing, in-bag dry-ageing, and coating and then dry-ageing) and dry-aged for 42 days. Physiochemical, microbial, and sensorial parameters of samples were determined during the dry-ageing process. There were no significant differences (p > 0.05) in pH values, shear force values, cooking loss, color, juiciness, tenderness, and flavor across groups. The total volatile base nitrogen value of the coating group was lower than those of the other two groups. Compared to traditional dry-ageing, in-bag and coating dry-ageing reduced (p < 0.05) many volatile compounds such as alcohols, aldehydes, ketones, and acetate. In-bag and coating dry-ageing had no impact on the fungal community, but changed the bacterial community by inhibiting Pseudomonas. This study demonstrates that the chitosan/collagen peptides/cinnamon bark essential oil coating reduces microbial spoilage during dry-ageing, and has a small influence on product quality.

The relationship between processed meat, red meat, and risk of types of cancer: A Mendelian randomization study.

Background: Observational studies have suggested processed and red meat may increase the risk of cancer. However, the causal effects and direction between them were still unclear. We conducted two-sample Mendelian randomization (MR) analysis to evaluate the causal effect of processed meat and red meat on the risk of nine common types of cancer, namely, lung, ovarian, endometrial, breast, kidney, gastric, prostate, skin, and oropharyngeal cancer. Methods: Genome-wide association studies (GWAS) for processed meat and red meat (pork, beef, and mutton) were obtained from the UK Biobank. GWAS of types of cancer in this study were extracted from the genetic consortia and the FinnGen consortium. The inverse variance weighted (IVW) was carried out as the main method for two-sample MR analysis. Sensitivity analyses were used to assess the robustness of the results. Results: Genetically predicted processed meat intake was causally associated with increased risk of lung cancer (OR [odds ratio] = 1.923, 95% CI = 1.084-3.409, P = 0.025). There is no convincing evidence for the associations between genetically determined processed meat, red meat, and the risk of other cancers we studied. Conclusion: Our results suggested that intake of processed meat may increase the risk of lung cancer. These findings provided no evidence to support that consumption of processed and red meat has a large effect on the risk of other cancers we studied. Further research is needed to clarify the results.

FJX1 as a candidate diagnostic and prognostic serum biomarker for colorectal cancer

Purpose: Colorectal cancer (CRC) is one of the most common cancer worldwide. It is essential to identify non-invasive diagnostic and prognostic biomarkers of CRC. The aim of the present study was to screen candidate biomarkers in diagnosis and prognosis of CRC based on a novel strategy.Materials and methodsThe expression level of gene higher in cancer than in adjacent non-cancer tissue was defined as “positive”, and the top 10% genes with “positive rate” were filtered out as candidate diagnostic biomarkers in four Gene Expression Omnibus (GEO) datasets. Then, the prognostic value of candidate biomarkers was estimated Cox regression analysis. Moreover, the concentration of biomarker in serum was detected in CRC patients.ResultsEighteen candidate biomarkers were identified with efficient diagnostic value in CRC. As a prognostic biomarker, FJX1 (four-jointed box kinase 1) showed a good performance in predicting overall survivals in CRC patients. In serum levels, FJX1 showed high sensitivity and specificity in distinguishing CRC patients from controls, and the concentration of serum FJX1 was associated with distant metastasis in CRC. In addition, serum FJX1 was significantly decreased after surgery in CRC patients. Compared with traditional CRC biomarkers CEA and CA 19-9, FJX1 still showed good efficiency in diagnosis and prognosis. Moreover, inhibition of FJX1 expression by siRNA or neutralization of secreted FJX1 by antibody could suppress cell proliferation and migration in vitro.ConclusionOur findings provided a novel strategy to identify diagnostic biomarkers based on public datasets, and suggested that FJX1 was a candidate diagnostic and prognostic biomarker in CRC patients. (AU)

Inflammatory bowel disease and cardiovascular disease: A two-sample Mendelian randomization analysis.

Background: Although epidemiological studies have shown a positive relationship between inflammatory bowel disease (IBD) and risk of cardiovascular disease (CVD) outcomes, a solid causal relationship has not been established. Thus, a two-sample Mendelian randomization (MR) study was conducted to explore the potential causal effect between IBD and CVD outcomes. Methods: We performed a two-sample MR analysis to analyze the causal effect of the IBD on CVD outcome by using summary-level genome-wide association studies of European descent. The inverse-variance weighted (IVW) method was used as the main MR analysis, with complementary analyses of MR Egger, maximum likelihood, weighted median, penalized weighted media, simple mode, weighted mode, and MR-PRESSO methods. Multiple sensitivity analyses were used to evaluate the robustness of our results. Results: All P-values were greater than 0.05 in the IVW method, showing no evidence of a causal association between circulating IBD and CVD. Similar results were observed by using other MR methods. No evidence of heterogeneity, pleiotropy, or outlier single-nucleotide polymorphisms was detected. Sensitivity analyses demonstrated the robustness of the results. Conclusion: The findings of this study provided no evidence to support that IBD has a large effect on risk of CVD outcomes, which is in contrast to many previous observational reports. Further studies are needed to determine the potential mechanism of association identified in observational studies.

IL-33 Participates in the Development of Esophageal Adenocarcinoma.

Background: The progression from chronic gastroesophageal reflux disease (GERD) to Barrett esophagus (BE) and esophageal adenocarcinoma (EAC) is an inflammatory-driven neoplastic change. Interleukin-33 (IL-33) has identified as a crucial factor in several inflammatory disorders and malignancies. Methods: The high-density tissue microarray of the human EAC was analyzed with IL-33 immunohistochemistry staining (IHC). By anastomosing the jejunum with the esophagus, the rat model of EAC with mixed gastroduodenal reflux was established. The expression of IL-33 was determined using quantitative real-time polymerase chain reaction (RT-qPCR), western blot (WB), IHC and enzyme-linked immunosorbent assay (ELISA). Esophageal adenocarcinoma cells (OE19 and OE33) and human esophageal epithelial cells (HEECs) were used. Results: In the cytoplasm of human EAC tissue, IL-33 expression was substantially greater than in adjacent normal tissue. In rat model, the expression of IL-33 in the EAC group was considerably greater than in the control group, and this expression increased with the upgrade of pathological stage. In in vitro experiment, the mRNA and protein levels of IL-33 were considerably greater in OE19 and OE33 than in HEECs. The stimulation of IL-33 enhanced the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of OE19 and OE33, but soluble ST2 (sST2) inhibited these effects. IL-33 stimulated the release of IL-6 by OE19 and OE33 cells. Conclusion: This study demonstrated the overexpression of IL-33 in the transition from GERD to EAC and that IL-33 promoted carcinogenesis in EAC cells through ST2. IL-33 might be a possible preventive target for EAC.

Metabolic Disorders and Risk of Portal Vein Thrombosis in Liver Cirrhosis: A Systematic Review and Meta-Analysis.

Portal vein thrombosis is considered to be an indicator of worse outcomes in patients with hepatic cirrhosis. More and more evidence shows that metabolic disorders are noticeable pro-thrombotic factors. However, whether or not metabolic disorders increase the risk of cirrhotic portal vein thrombosis is controversial. We aim to quantify the magnitude of the association between metabolic disorders and the risk of cirrhotic portal vein thrombosis. Databases were searched for papers to identify studies in which metabolic disorders were compared in liver cirrhosis with or without portal vein thrombosis. Based on data from the eligible studies, metabolic disorders related to portal vein thrombosis included diabetes mellitus, nonalcoholic fatty liver disease, hypercholesterolemia, and body mass index. Pooled adjusted odds ratios with 95% CIs were calculated. Data for 22 studies with a total of 57 371 portal vein thrombosis cases and 3 979 015 participants were included. Statistically significant pooled odds ratios for portal vein thrombosis were obtained for diabetes mel- litus (odds ratio 1.80, 95% CI 1.42-2.28), nonalcoholic fatty liver disease (odds ratio 1.61, 95% CI 1.34-1.95), and hypercholesterolemia (odds ratio 3.59, 95% CI 1.83-7.03). Body mass index was likely irrelevant with cirrhotic portal vein thrombosis (odds ratio 1.01, 95% CI 0.87-1.17), both in overall and subgroup meta-analyses. Significant heterogeneities among studies were observed, except for the hypercholesterolemia group. Metabolic disorders, such as diabetes mellitus, nonalcoholic fatty liver disease, and hypercholesterolemia, increased the risk of portal vein thrombosis in cirrhotic patients by 1.80-fold, 1.61-fold, and 3.59-fold, respectively. Body mass index did not appear to be a risk predictor of cirrhotic portal vein thrombosis. Further, well-designed clinical and mechanistic studies are required to strengthen the arguments, especially in obese patients.

FJX1 as a candidate diagnostic and prognostic serum biomarker for colorectal cancer.

PURPOSE: Colorectal cancer (CRC) is one of the most common cancer worldwide. It is essential to identify non-invasive diagnostic and prognostic biomarkers of CRC. The aim of the present study was to screen candidate biomarkers in diagnosis and prognosis of CRC based on a novel strategy. MATERIALS AND METHODS: The expression level of gene higher in cancer than in adjacent non-cancer tissue was defined as "positive", and the top 10% genes with "positive rate" were filtered out as candidate diagnostic biomarkers in four Gene Expression Omnibus (GEO) datasets. Then, the prognostic value of candidate biomarkers was estimated Cox regression analysis. Moreover, the concentration of biomarker in serum was detected in CRC patients. RESULTS: Eighteen candidate biomarkers were identified with efficient diagnostic value in CRC. As a prognostic biomarker, FJX1 (four-jointed box kinase 1) showed a good performance in predicting overall survivals in CRC patients. In serum levels, FJX1 showed high sensitivity and specificity in distinguishing CRC patients from controls, and the concentration of serum FJX1 was associated with distant metastasis in CRC. In addition, serum FJX1 was significantly decreased after surgery in CRC patients. Compared with traditional CRC biomarkers CEA and CA 19-9, FJX1 still showed good efficiency in diagnosis and prognosis. Moreover, inhibition of FJX1 expression by siRNA or neutralization of secreted FJX1 by antibody could suppress cell proliferation and migration in vitro. CONCLUSION: Our findings provided a novel strategy to identify diagnostic biomarkers based on public datasets, and suggested that FJX1 was a candidate diagnostic and prognostic biomarker in CRC patients.

Emerging Trends and Research Foci in Tumor Microenvironment of Pancreatic Cancer: A Bibliometric and Visualized Study.

Background: Pancreatic cancer (PC) is a serious disease with high mortality. The tumor microenvironment plays a key role in the occurrence and development of PC. The purpose of this study is to analyze trends by year, country, institution, journal, reference and keyword in publications on the PC microenvironment and to predict future research hotspots. Methods: The Web of Science Core Collection was used to search for publications. We analyzed the contributions of various countries/regions, institutes, and authors and identified research hotspots and promising future trends using the CiteSpace and VOSviewer programs. We also summarized relevant completed clinical trials. Results: A total of 2,155 papers on the PC microenvironment published between 2011 and 2021 were included in the study. The number of publications has increased every year. The average number of citations per article was 32.69. The USA had the most publications, followed by China, and a total of 50 influential articles were identified through co-citation analysis. Clustering analysis revealed two clusters of keywords: basic research and clinical application. The co-occurrence cluster analysis showed glutamine metabolism, carcinoma-associated fibroblasts, oxidative phosphorylation as the highly concerned research topics of basic research in recently. The three latest hot topics in clinical application are liposomes, endoscopic ultrasound and photodynamic therapy. Conclusion: The number of publications and research interest have generally increased, and the USA has made prominent contributions to the study of the tumor microenvironment of PC. The current research hotspots mainly focus on energy metabolism in the hypoxic tumor microenvironment, cancer associated fibroblasts in regulating the tumor microenvironment, accurate diagnosis, drug delivery and new treatments.

Evaluation of fecal SYPL1 as a diagnostic biomarker in colorectal cancer.

BACKGROUND: At present, there is still no ideal non-invasive biomarker for colorectal cancer (CRC) screening. Previously, we foundserum synaptophysin like 1 (SYPL1) served as a potential biomarker for CRC diagnosis. However, whether fecal SYPL1 (fSYPL1) are more sensitive and specific for CRC remains unclear. METHODS: We analyzed fSYPL1 in controls (n = 70), adenoma patients (n = 80), CRC patients (n = 150) and postoperative CRC patients (n = 25) by ELISA. RESULTS: SYPL1 was stable in feces. The fSYPL1 levels were significantly higher in CRC patients than in either controls or adenoma patients (P < 0.0001). ROC curves showed that fSYPL1 performed superbly in distinguishing CRC patients from controls (AUC = 0.947; 95% CI: 0.920-0.974, P < 0.0001, sensitivity: 80.67%, specificity: 100.00%), which showed much stronger performance than the traditional biomarkers (FOBT, CEA and CA19-9). Meanwhile, the fSYPL1 level positively correlated with tumor size, tumor invasion, lymph node invasion and clinical stage (P < 0.05). In addition, the detection rate of fSYPL1 was high in early CRC (75.00% in stage I and II). The fSYPL1 levels in CRC patients declined substantially after surgery (P = 0.0002). By means of a lower cut off level, 73.58% of high-risk adenomas were detected. The combination of fSYPL1 and FOBT performed better than the combination of plasma SYPL1, CEA and CA199 in distinguishing CRC patients from controls. CONCLUSION: The fSYPL1 might be a potential biomarker for CRC screening, early diagnosis, prognosis prediction and therapeutic effect monitoring.

A Novel Mast Cell Stabilizer JM25-1 Rehabilitates Impaired Gut Barrier by Targeting the Corticotropin-Releasing Hormone Receptors.

Mast cell (MC) plays a central role in intestinal permeability; however, few MC-targeting drugs are currently available for protection of the intestinal barrier in clinical practice. A nonfluorinated Lidocaine analog 2-diethylamino-N-2,5-dimethylphenyl acetamide (JM25-1) displays anti-allergic effect, but its impact on MC remains elusive. In this study, we explored whether JM25-1 has therapeutic potential on intestinal barrier defect through stabilizing MC. JM25-1 alleviated release of ß-hexosaminidase and cytokine production of MC. The paracellular permeability was redressed by JM25-1 in intestinal epithelial cell monolayers co-cultured with activated MC. In vivo, JM25-1 diminished intestinal mucosal MC amount and cytokine production, especially downregulating the expression of CRHR1, accompanied by an increase of CRHR2. Protective effects appeared in JM25-1-treated stress rats with a recovery of weight and intestinal barrier integrity. Through network pharmacology analysis, JM25-1 showed a therapeutic possibility for irritable bowel syndrome (IBS) with predictive targeting on PI3K/AKT/mTOR signaling. As expected, JM25-1 reinforced p-PI3K, p-AKT, p-mTOR signaling in MC, while the mTOR inhibitor Rapamycin reversed the action of JM25-1 on the expression of CRHR1 and CRHR2. Moreover, JM25-1 successfully remedied intestinal defect and declined MC and CRHR1 expression in rat colon caused by colonic mucus of IBS patients. Our data implied that JM25-1 possessed therapeutic capacity against intestinal barrier defects by targeting the CRH receptors of MC through PI3K/AKT/mTOR signaling.

A novel strategy to identify candidate diagnostic and prognostic biomarkers for gastric cancer.

BACKGROUND: Gastric cancer (GC) is one of the most common cancer worldwide. It is essential to identify non-invasive diagnostic and prognostic biomarkers of GC. The aim of the present study was to screen candidate biomarkers associated with the pathogenesis and prognosis of GC by a novel strategy. METHODS: The expression level of gene higher in cancer than in adjacent non-cancer tissue was defined as "positive", and the top 5% genes with "positive rate" were filtered out as candidate diagnostic biomarkers in three Gene Expression Omnibus (GEO) datasets. Further, a prognostic risk model was constructed by multivariate Cox regression analysis in GEO dataset and validated in The Cancer Genome Atlas (TCGA). The expression level of candidate biomarkers was determined in serum and serum-derived exosomes of GC patients. Moreover, the effect of biomarkers in exosomes on migration of GC cells was analyzed by transwell assay. RESULTS: Ten candidate biomarkers (AGT, SERPINH1, WNT2, LIPG, PLAU, COL1A1, MMP7, MXRA5, CXCL1 and COL11A1) were identified with efficient diagnostic value in GC. A prognostic gene signature consisted of AGT, SERPINH1 and MMP7 was constructed and showed a good performance in predicting overall survivals in TCGA. Consistently, serum levels of the three biomarkers also showed high sensitivity and specificity in distinguishing GC patients from controls. In addition, the expression level of the three biomarkers were associated with malignant degree and decreased after surgery in GC patients. Moreover, the expression level of AGT and MMP7 in exosomes correlated positively with serum level. The exosomes derived from serum of GC patients can promote migration of SGC-7901 cells. After neutralized the expression level of three proteins in exosomes with antibodies, the migration of GC cells was obviously suppressed. CONCLUSIONS: Our findings provided a novel strategy to identify diagnostic biomarkers based on public datasets, and suggested that the three-gene signature was a candidate diagnostic and prognostic biomarker for patients with GC.

Exosomes derived from colon cancer cells and plasma of colon cancer patients promote migration of SW480 cells through Akt/mTOR pathway.

OBJECTIVE: To investigate the effect of exosomes derived from colon cancer (CC) cells and plasma of CC patients on migration of SW480 cells. METHODS: The exosomes derived from culture medium of human colon epithelial cell line NCM460 and CC cell line SW620 were isolated by ultracentrifugation. The exosomes derived from plasma of CC patients and healthy controls were isolated by size exclusion chromatography (SEC). The particle size and morphology of exosomes were identified by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM) respectively, and exosomal markers were detected by Western blotting. The uptake of fluorescent DiI labeled exosomes by SW480 cells was observed by confocal microscopy. Transwell assay was used to detect the effect of exosomes on the migration of SW480 cells. The expression level of associated proteins in signaling pathway were analyzed by Western blotting. Rapamycin, an inhibitor of mTOR, was used to study the role of mTOR signaling pathway on exosomes mediated migration of SW480 cells. RESULTS: The results of NTA and TEM showed that the particle size of the isolated exosomes was about 120 nm, which were small vesicles with membrane structure. The expressions of exosomal markers Alix, TSG101 and CD63 could be detected. The exosomes were evidenced by a red fluorescent signal inside the cytoplasm of SW480 recipient cells, and could promote the migration of SW480 cells, which is associated with Akt/mTOR signaling pathway. Compared with the control group, plasma exosomes derived from CC patients could significantly promote the migration of SW480 cells. Inhibition the activity of mTOR signaling could attenuate the migration of SW480 cells. CONCLUSIONS: Exosomes derived from CC cells and plasma of CC patients could promote the migration of SW480 cells, which is associated with Akt/mTOR signaling pathway.

Author Correction: Genetically encoded tags for direct synthesis of EM-visible gold nanoparticles in cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Effects of Lactobacillus plantarum Inoculum on the Fermentation Rate and Rice Noodle Quality.

To accelerate the fermentation rate and reduce the adverse effects of undesirable microorganism contamination on rice noodle quality, the pure inoculum fermentation method was used to produce fermented rice noodles. The results indicated that the pure inoculum fermented rice slurry required 10 h to reach a stable pH value. While, the pH value of the natural, pure and natural inoculum fermented rice slurries required 54, 18 and 20 h to stabilize, respectively. Free amino acids and lactic acid concentrations of the pure inoculum fermented rice slurry were higher than those of the natural and natural inoculum fermented rice slurries. The pure inoculum fermentation modified the proximate composition and lowered the pasting viscosities of the rice flour. The texture, cooking and eating qualities of the pure inoculum fermented rice noodles were similar to those of the natural fermented ones. In addition, the pure inoculum fermented rice noodles had higher relative contents of aldehydes than other fermented rice noodles and thus had a better flavor. Therefore, pure inoculum fermentation accelerated the fermentation rate and improved the rice noodle flavor while maintaining the texture, cooking and eating qualities of the rice noodles.

Genetically encoded tags for direct synthesis of EM-visible gold nanoparticles in cells.

Genetically encoded tags for single-molecule imaging in electron microscopy (EM) are long-awaited. Here, we report an approach for directly synthesizing EM-visible gold nanoparticles (AuNPs) on cysteine-rich tags for single-molecule visualization in cells. We first uncovered an auto-nucleation suppression mechanism that allows specific synthesis of AuNPs on isolated tags. Next, we exploited this mechanism to develop approaches for single-molecule detection of proteins in prokaryotic cells and achieved an unprecedented labeling efficiency. We then expanded it to more complicated eukaryotic cells and successfully detected the proteins targeted to various organelles, including the membranes of endoplasmic reticulum (ER) and nuclear envelope, ER lumen, nuclear pores, spindle pole bodies and mitochondrial matrices. We further implemented cysteine-rich tag-antibody fusion proteins as new immuno-EM probes. Thus, our approaches should allow biologists to address a wide range of biological questions at the single-molecule level in cellular ultrastructural contexts.