A convolutional neural network-based system for detecting early gastric cancer in white-light endoscopy.

BACKGROUND: White-light endoscopy (WLE) is a main and standard modality for detection of early gastric cancer (EGC). The detection rate of EGC is not satisfactory so far. In this single-center retrospective study we developed a convolutional neural network (CNN)-based system to automatically detect EGC in WLE images. METHODS: An EGC detecting system was constructed based on the CNN architecture EfficientDet. We trained our system with a data set including 4527 images from 130 cases (cancerous images, 1737; noncancerous images, 2790). Then we tested its performance with a data set including 1243 images from 64 cases (cancerous images, 445; noncancerous images, 798). RESULTS: For case-based analysis, our system successfully detected EGC in 63 of 64 cases and the sensitivity was 98.4%. For image-based analysis, the accuracy was 88.3%. The sensitivity, specificity, positive predictive value and negative predictive value were 84.5%, 90.5%, 83.2% and 91.3%, respectively. The most common cause for false positives was gastritis (57.9%). The most common cause for false negatives was that the lesion was too small with a diameter of 10 mm or less (44.9%). CONCLUSION: Our CNN-based EGC detecting system was able to achieve satisfactory sensitivity for detecting EGC in WLE images and shows great potential in assisting endoscopists with the detection of EGC.

Survival benefits from neoadjuvant treatment in gastric cancer: a systematic review and meta-analysis.

BACKGROUND: Surgery is the main treatment option for patients with local gastric cancer. However, surgery alone is usually not sufficient for stomach cancer patients, and combined therapies are recommended for these patients. In recent studies, some preoperative treatments have shown benefits. However, the treatment selection is still uncertain because previous studies failed to obtain a statistically significant difference between preoperative chemotherapy and preoperative chemoradiotherapy. Therefore, we plan to perform a systematic review and meta-analysis to compare the benefits among these preoperative treatments. METHODS/DESIGN: This review includes randomized controlled trials with or without blinding as well as published studies, high-quality unpublished studies, full articles and meeting abstracts with an English context if sufficient results were provided for analysis. Data sources include the Cochrane Central Register of Controlled Trials, Embase, MEDLINE, major relevant international conferences and manual screening of references. Patients with a diagnosis of resectable primary gastric or EGJ adenocarcinoma (stage II or higher) who underwent surgery alone or preoperative treatment followed by surgery and who were pathologically confirmed as proposed by the AJCC 2017 guidelines without age, sex, race, subtypes of adenocarcinoma and molecular pathology limitations will be included. The following three interventions will be included: surgery alone, neoadjuvant chemistry followed by surgery and neoadjuvant chemoradiotherapy followed by surgery. All-cause mortality, overall survival (OS, the time interval from diagnosis to death) and/or progression-free survival (PFS, the time interval from diagnosis to disease progression or death from any cause) will be defined as major results of concern. The clinical and pathological response rate (according to RECIST and tumour regression score), R0 resection rate, quality of life and grade 3 or above adverse events (according to the National Cancer Institute Common Terminology Criteria for Adverse Events, NCI-CTCAE) will be defined as the secondary outcomes. DISCUSSION: The aim of this systematic review is to compare the benefits of different preoperative treatments for patients with locoregional stomach cancer. This systematic review will improve the understanding of the relative efficacy of these treatment options by providing the latest evidence on the efficacy of various treatment options in the management of gastric cancer patients and may guide clinical practice. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD4202123718.

Cancer type classification using plasma cell-free RNAs derived from human and microbes.

The utility of cell-free nucleic acids in monitoring cancer has been recognized by both scientists and clinicians. In addition to human transcripts, a fraction of cell-free nucleic acids in human plasma were proven to be derived from microbes and reported to have relevance to cancer. To obtain a better understanding of plasma cell-free RNAs (cfRNAs) in cancer patients, we profiled cfRNAs in ~300 plasma samples of 5 cancer types (colorectal cancer, stomach cancer, liver cancer, lung cancer, and esophageal cancer) and healthy donors (HDs) with RNA-seq. Microbe-derived cfRNAs were consistently detected by different computational methods when potential contaminations were carefully filtered. Clinically relevant signals were identified from human and microbial reads, and enriched Kyoto Encyclopedia of Genes and Genomes pathways of downregulated human genes and higher prevalence torque teno viruses both suggest that a fraction of cancer patients were immunosuppressed. Our data support the diagnostic value of human and microbe-derived plasma cfRNAs for cancer detection, as an area under the ROC curve of approximately 0.9 for distinguishing cancer patients from HDs was achieved. Moreover, human and microbial cfRNAs both have cancer type specificity, and combining two types of features could distinguish tumors of five different primary locations with an average recall of 60.4%. Compared to using human features alone, adding microbial features improved the average recall by approximately 8%. In summary, this work provides evidence for the clinical relevance of human and microbe-derived plasma cfRNAs and their potential utilities in cancer detection as well as the determination of tumor sites.

Synchronized early gastric cancer occurred in a patient with serrated polyposis syndrome: A case report.

BACKGROUND: Serrated polyposis syndrome (SPS) is a relatively rare disease that is characterized by multiple serrated lesions/polyps. Very little is known regarding the extracolonic cancers associated with SPS. The genetic basis of the process remains unknown. CASE SUMMARY: A 67-year-old male patient initially presented with belching and abdominal distension for a year as well as diarrhea for over 2 mo. The patient underwent colonoscopy and was diagnosed with serrated polyposis syndrome. Half a year later, a gastroscopy was performed during the postoperative re-examination to screen for other lesions of the upper gastrointestinal tract. An elevated lesion was detected in the anterior wall of the gastric antrum. Curative en bloc resection of the lesion was achieved via endoscopic submucosal dissection. The pathological result was high-grade dysplasia with focal intramucosal carcinoma. Exome sequencing was performed for the patient and five gastric cancer-associated variants (methylenetetrahydrofolate reductase, metaxin 1, coiled-coil domain containing 6, glutamate ionotropic receptor delta type subunit 1, and aldehyde dehydrogenase 1) were identified. CONCLUSION: This paper reports a case that presented with both SPS and early gastric cancer. Genetic mutations that were potentially responsible for this condition were sought by exome sequencing.

CAF promotes chemoresistance through NRP2 in gastric cancer.

BACKGROUND: Fibroblasts are the predominant cell type in the stroma of tumor, and cancer-associated fibroblasts (CAFs) promote cancer chemoresistance by secreting various bioactive molecules. However, the differential expression between CAFs and normal fibroblasts (NFs) and how can CAFs uniquely impact cancer cells are still unexplored. METHODS: Primary CAFs and NFs were cultured from gastric cancer specimens, and their variant expression was analyzed by RNA-sequencing. Chemoresistance was evaluated by measuring cell viability, apoptosis, and 3D-coculture techniques. RESULTS: CAFs were isolated from gastric cancers and defined by specific cell-surface markers. CAFs decreased the sensitivity of gastric cancer cells to 5-FU. RNA-sequencing showed that CAFs expressed a higher level of NRP2 than NFs. And the high expression of NRP2 was correlated with worse oncological outcomes in gastric cancer patients. Further study showed that the knockdown of NRP2 eradicated the resistance to 5-FU. And the secretion of stromal cell-derived factor-1 (SDF-1) was reduced following NRP2 knockdown. Furthermore, we found that the increased sensitivity to 5-FU was induced by DNA damage. And this process was mediated by predominant effectors of the Hippo pathway, YAP/TAZ. CONCLUSIONS: The present study indicated that CAFs within gastric cancers promote chemoresistance through the expression of NRP2. The secretion of SDF-1 that mediated by VEGF/NRP2 signaling in CAFs and the activation of Hippo pathway in cancer cells in large part participated in this project.

Proliferation Cycle Transcriptomic Signatures are Strongly associated With Gastric Cancer Patient Survival.

Gastric cancer is one of the most heterogeneous tumors with multi-level molecular disturbances. Sustaining proliferative signaling and evading growth suppressors are two important hallmarks that enable the cancer cells to become tumorigenic and ultimately malignant, which enable tumor growth. Discovering and understanding the difference in tumor proliferation cycle phenotypes can be used to better classify tumors, and provide classification schemes for disease diagnosis and treatment options, which are more in line with the requirements of today's precision medicine. We collected 691 eligible samples from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database, combined with transcriptome data, to explore different heterogeneous proliferation cycle phenotypes, and further study the potential genomic changes that may lead to these different phenotypes in this study. Interestingly, two subtypes with different clinical and biological characteristics were identified through cluster analysis of gastric cancer transcriptome data. The repeatability of the classification was confirmed in an independent Gene Expression Omnibus validation cohort, and consistent phenotypes were observed. These two phenotypes showed different clinical outcomes, and tumor mutation burden. This classification helped us to better classify gastric cancer patients and provide targeted treatment based on specific transcriptome data.

M2 Macrophage-Based Prognostic Nomogram for Gastric Cancer After Surgical Resection.

A good prediction model is useful to accurately predict patient prognosis. Tumor-node-metastasis (TNM) staging often cannot accurately predict prognosis when used alone. Some researchers have shown that the infiltration of M2 macrophages in many tumors indicates poor prognosis. This approach has the potential to predict prognosis more accurately when used in combination with TNM staging, but there is less research in gastric cancer. A multivariate analysis demonstrated that CD163 expression, TNM staging, age, and gender were independent risk factors for overall survival. Thus, these parameters were assessed to develop the nomogram in the training data set, which was tested in the validation and whole data sets. The model showed a high degree of discrimination, calibration, and good clinical benefit in the training, validation, and whole data sets. In conclusion, we combined CD163 expression in macrophages, TNM staging, age, and gender to develop a nomogram to predict 3- and 5-year overall survivals after curative resection for gastric cancer. This model has the potential to provide further diagnostic and prognostic value for patients with gastric cancer.

SPARC enhances 5-FU chemosensitivity in gastric cancer by modulating epithelial-mesenchymal transition and apoptosis.

Previous studies have shown that secreted protein acidic and rich in cysteine (SPARC) proteins can inhibit the development of cancer cells in various ways, such as by inhibiting angiogenesis and inhibiting cell proliferation. In fact, SPARC proteins may have an effect on the chemoresistance of gastric cancer cells to 5-Fluorouracil (5-FU), which needs further research in the future. Therefore, the purpose of this study was to explore the relationship between SPARC proteins and the chemosensitivity of gastric cancer cells to 5-FU. In vitro, after SPARC protein levels were regulated by plasmid, siRNA and human recombinant SPARC protein transfection in MGC-803, SGC-7901 and BGC-823 cells, we detected epithelial-mesenchymal transition (EMT), apoptosis markers and cell viability after 5-FU treatment. In vivo, we implanted BGC-823 cells with stable SPARC overexpression into nude mice. Tumour size was measured to assess the effect of SPARC protein on tumour formation and 5-FU chemosensitivity. In SGC-7901 and BGC-823 cells, both endogenous and exogenous upregulation of SPARC protein levels decreased cell viability, destroyed cytoskeletal F-actin, inhibited cell migration, and downregulated a series of transcription factors to inhibit cell EMT; it also upregulated cell apoptosis-related proteins to promote cell apoptosis. However, we obtained opposite results in SPARC knockdown MGC-803 cells. In vivo, compared with the control group, the group engrafted with BGC-823 cells stably overexpressing SPARC had a significant smaller tumour size. After 5-FU treatment, the new tumour gradually decreased in size. Our results show that the SPARC protein could enhance 5-FU chemosensitivity in gastric cancer cell lines by inhibiting EMT and promoting cell apoptosis.

The Status of Occupational Protection During COVID-19 Pandemic: Knowledge, Attitudes, and Practice of Healthcare Workers in Endoscopy Units, China.

Background: SARS-CoV-2 spreads rapidly around the world, and some patients present gastrointestinal symptoms. The existence of the virus in the gastrointestinal tract makes digestive endoscopy a high-risk operation, which associated with an increased risk of infection rate in healthcare workers. This study aimed at exploring current knowledge, practice and attitudes of healthcare workers in endoscopy units in China regarding the status of occupational protection during COVID-19 pandemic. Methods: A cross-sectional study of a national online survey involving 717 healthcare workers in endoscopy units from 94 medical structures in 24 provinces and municipalities around China was conducted online via a questionnaire platform called Wenjuanxing (wjx.cn). The data were analyzed using correlation approaches, Kruskal-Wallis test for independent samples, and linear regression models. Results: Most Chinese healthcare workers in endoscopy units had a good knowledge of COVID-19 (median: 10; range: 7-12), showed a strikingly positive attitude (median: 65; range: 39-65), and carried out good practice (median: 47; range: 14-50) in strengthening the protection, disinfection and management of COVID-19. In terms of attitudes, female staff was more concerned about protection against COVID-19 than male staff (KW = 8.146, P = 0.004). Nurses performed better in both attitude (KW = 2.600, P = 0.009) and practice (KW = 6.358, P < 0.001) than endoscopic physicians when carrying out personal protection, patient care and environmental disinfection against SARS-CoV-2 infection. More positive attitudes in protection were related to better protective behavior in endoscopic daily medical work (r = 0.312; P < 0.001). Conclusion: The findings of this study suggest that Chinese endoscopy healthcare workers have an excellent mastery of knowledge about COVID-19, which is transformed into positive beliefs and attitudes, contributing to good practice during daily endoscopic procedures. Medical staff may benefit from further education. With the gradual normalization amid the ongoing COVID-19 pandemic, protection and management in endoscopy units may be changed accordingly.

Surgical resection after endoscopic resection in patients with T1 colorectal cancer: a meta-analysis.

PURPOSE: Additional surgical resection (ASR) after endoscopic resection (ER) in patients with colorectal cancer (CRC) allows a complete staging and may decrease the recurrence rate, but no meta-analysis is available. This study aimed to compare the effectiveness of ER vs. ER + ASR as a treatment for patients with T1 (stage 1) CRC. METHODS: We performed a systematic search from databases (PubMed, Embase, and Cochrane library) for cohort studies published up to November 2019. The outcomes were overall survival (OS), local recurrence, recurrence, disease-specific survival, recurrence-free survival, and metastasis. RESULTS: Seven studies were included. There were 1205 patients in the ASR group and 993 patients in the ER group. Compared with ER, ASR was associated with better OS (OR = 0.31, 95% CI: 0.18-0.53, P < 0.001) and a borderline significant difference in lower local recurrence rates (OR = 0.29, 95% CI: 0.08-1.01, P = 0.052), but no differences were observed in recurrences, disease-specific survival, recurrence-free survival, and distant metastasis. A sensitivity analysis was performed; excluding each study sequentially from the pooled analysis did not affect the overall conclusion of the study. CONCLUSION: Compared with ER, ASR after ER could improve the overall survival for patients with T1 CRC.

Multivisceral resection for locally advanced gastric cancer: A retrospective study.

BACKGROUND: Multivisceral resection may be the exclusive radical procedure for cT4b gastric cancer patients. However, most surgeons refuse to select surgery because of the theoretical higher mortality, morbidity and poorer prognosis. METHODS: We retrospectively reviewed cT4b gastric cancer patients who underwent surgery from January 1,1997 to December 31,2018. The primary endpoint was overall survival. Short-term results and prognostic values of clinical and pathologic factors were also analyzed. RESULTS: Patients underwent multivisceral resection had an acceptable mortality and morbidity. The overall 5-year survival rate of multivisceral resection was higher than that of palliative surgery (P < 0.05). And independent prognostic factors of multivisceral resection were R+ resection, extensive lymph node involved (>15), vascular cancer emboli, and postoperative chemotherapy. CONCLUSIONS: cT4b gastric cancer patients underwent multivisceral resection experience acceptable mortality and morbidity. The independent prognostic factors for multivisceral resection were completeness of resection, extensive lymph node involvement (>15), vascular cancer emboli, and postoperative chemotherapy.

Paxillin knockdown suppresses metastasis and epithelial­mesenchymal transition in colorectal cancer via the ERK signalling pathway.

Paxillin (PXN) is a cytoplasmic protein that plays an important role in regulating focal adhesion, cytoskeletal rearrangements and cell motility. The present study aimed to investigate the role of PXN in the metastasis of human colorectal cancer (CRC) and its possible mechanisms. Immunohistochemical staining of tissues from 102 surgical CRC patients revealed that high PXN expression was positively correlated with tumour­node­metastasis (TNM) stage, lymph node metastasis, distant metastasis, and recurrence at distant sites after radical surgery. In 24 cases of stage IV CRC, PXN expression in liver metastasis was higher than that in the matched primary tumour. The knockdown of PXN inhibited the proliferation, migration and invasion potential of SW480 cells in vitro and in vivo. Transmission electron microscopy revealed the effect of PXN on ultrastructural characteristics, observed mainly in microvilli and desmosomes. The downregulation of PXN decreased the activation of extracellular regulated protein kinase (ERK) and suppressed the epithelial­mesenchymal transition (EMT) process. Following the downregulation of PXN, the addition of an ERK activator or inhibitor restored or further suppressed EMT, respectively, accompanied by corresponding changes in cell migration and invasion. Collectively, the present results confirmed the important role of PXN in CRC metastasis and revealed that PXN regulated EMT progression via the ERK signalling pathway. PXN may represent a future therapeutic strategy to prevent the EMT­associated progression and invasion of CRC.

Macrophage-derived SPARC Attenuates M2-mediated Pro-tumour Phenotypes.

Since the theory of seed and soil was put forward, people have increasingly recognized that the tumour microenvironment is an important regulator of tumour progression and therapeutic response. Among them, M2-type macrophages (M2, as the major macrophage subtype in the tumour foci) have important promoting effects on various biological behaviours. Secreted protein acidic and rich in cysteine (SPARC) is an important anti-tumour component in the microenvironment of gastric cancer. This study shows that macrophages are an important source of the SPARC and that SPARC overexpression in M2 can reduce M2-mediated promoting proliferation, migration and anti-apoptotic effects in gastric cancer. Additionally, the AKT/mTOR signalling pathways may participate in the malignant process.

Aminooxyacetic acid (AOAA) sensitizes colon cancer cells to oxaliplatin via exaggerating apoptosis induced by ROS.

Background: As the third confirmed gaseous transmitter, the role of hydrogen sulfide (H2S) in the pathogenesis of multiple types of cancer has been attracting increasing attention. Increased expression of cystathionine ß-synthase (CBS) and H2S in colon cancer tissue samples has been validated and tumor-derived H2S, mainly produced by CBS, stimulates bioenergetics, cell proliferation, and angiogenesis in colon cancer. Recently, the therapeutic manipulation of H2S has been proposed as a promising anticancer approach. However, the effect of aminooxyacetic acid (AOAA), which has been widely used as an inhibitor of CBS dependent synthesis of H2S, on the chemotherapeutic effect of oxaliplatin (OXA) and the underlying mechanisms remain to be illustrated. Methods: We examined the expression of CBS in human colorectal cancer specimens and matched normal mucosa by immunohistochemistry. The effect of AOAA on the sensitivity of colon cancer cells to OXA and the level of apoptosis induced by caspase cascade was investigated in both HCT116 and HT29 cell lines utilizing CCK-8 assays, flow cytometry analysis and western blot analysis. The endogenous levels of reactive oxygen species (ROS) were detected fluorescently by DCF-DA, and glutathione (GSH) levels were measured by a Total GSH Detection Kit. Tumor bearing xenograft mouse models and in vivo imaging systems were further used to investigate the effect of AOAA in vivo and immunohistochemistry (IHC) and TUNEL analysis were performed. Results: In the current study, we confirmed CBS, the main target of AOAA, is overexpressed in human colorectal cancer by immunohistochemistry. The inhibitory effect of AOAA on the synthesis of H2S was validated utilizing fluorescent probe and specific electrode. AOAA significantly reduced the IC50 values of OXA in both colon cancer cell lines. Co-incubation with AOAA elicited increased apoptosis induced by OXA, featured by increased activation of caspase cascade. Besides, AOAA further increased the levels of ROS induced by OXA and attenuated the synthesis of glutathione (GSH), which is a vital antioxidant. Besides, the results of in vivo imaging and following IHC and TUNEL analysis were in accordance with cellular experiments, indicating that AOAA sensitizes colon cancer cells to OXA via exaggerating intrinsic apoptosis. Conclusion: The results suggested that CBS is overexpressed in colorectal cancer tissues and AOAA sensitizes colon cancer cells to OXA via exaggerating apoptosis both in vitro and in vivo. Decreasing the endogenous level of GSH and consequently impaired detoxification of ROS might be one of the mechanisms underlying the effect of AOAA.

The novel long noncoding RNA CRART16 confers cetuximab resistance in colorectal cancer cells by enhancing ERBB3 expression via miR-371a-5p.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been shown to participate in multiple biological processes and confer drug resistance. However, it remains unclear whether lncRNAs are involved in conferring cetuximab resistance in colorectal cancer (CRC) cells. METHODS: Cell Counting Kit-8 (CCK-8) assays were performed to assess the sensitivity of CRC cell lines to cetuximab treatment. We incubated Caco-2 cells, which are partially responsive to cetuximab, with increasing concentrations of cetuximab for approximately 6 months to generate Caco-2 cetuximab-resistant (Caco-2 CR) cells. Microarray analysis comparing Caco-2 CR with Caco-2 cells was used to identify lncRNAs that were potentially related to cetuximab resistance. Caco-2 cells were stably transduced with cetuximab resistance-associated RNA transcript 16 (CRART16) or an empty vector using lentiviral infection; the cells were designated Caco-2-CRART16 and Caco-2-NC, respectively, and were analyzed with RNA sequencing (RNA-seq). Quantitative real-time PCR (qRT-PCR) was performed to investigate RNA expression. Flow cytometry and TUNEL assays were used to assess apoptosis levels induced by cetuximab. The cell cycle, stemness biomarkers and membrane proteins of CRC cells were assessed via flow cytometry. RNA fluorescence in situ hybridization (FISH) was used to examine CRART16 localization and expression. Bioinformatics analysis was performed to predict the potential mechanism of CRART16, which was further validated by a dual-luciferase reporter assay. Differences in measurement data were compared using Student's t test, one-way ANOVA followed by Dunnett's test and two-way ANOVA. RESULTS: The novel lncRNA CRART16 was upregulated in Caco-2 CR cells. CRART16 overexpression reversed the effects of cetuximab on cell viability and reduced cetuximab-induced apoptosis. Meanwhile, CRART16 overexpression led to increases in the proportion of CD44+/CD133+ cells. In addition, CRART16 acts as a competing endogenous RNA (ceRNA) for miR-371a-5p to regulate V-Erb-B2 Erythroblastic Leukemia Viral Oncogene Homolog 3 (ERBB3) expression. MiR-371a-5p mimics counteracted the cetuximab resistance induced by CRART16 overexpression. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that after CRART16 was overexpressed, the resulting differentially expressed mRNAs were mainly enriched in the MAPK signaling pathway. CONCLUSIONS: CRART16 overexpression may contribute to cetuximab resistance through the miR-371a-5p/ERBB3/MAPK pathway. Additionally, CRART16 contributes to the acquisition of stemness properties.

Prognostic role of secreted protein acidic and rich in cysteine in patients with solid tumors.

OBJECTIVES: To analyze the heterogeneous functions of secreted protein acidic and rich in cysteine (SPARC) from different origins and in different tumor microenvironments with the purpose of determining its clinical significance. Methods: The PubMed, CINAHL, Cochrane, Web of Science and Embase databases were utilized. Studies that focused on the effects of SPARC expression on solid tumor progression and clinical implications were used. The different outcomes including overall survival and disease-free survival were analyzed to evaluate their relations with tumor- and stroma-derived SPARC expression. Results: A total of 26 studies including 5,939 patients were enrolled in the present meta-analysis. Tumor-derived SPARC overexpression was significantly related with poor overall survival (hazard ratio: 1.478; 95% CI: 1.143-1.910; p=0.003), and a similar tendency was also observed in disease-free survival (hazard ratio: 1.476; 95% CI: 0.993-2.195; p=0.054). However, the hazard ratios for overall survival and disease-free survival did not present a statistical trend in stromal SPARC overexpression. Tumor type subgroup analysis revealed marked heterogeneity among outcomes. In pancreatic cancer, SPARC overexpression in the stroma was significantly associated with poorer overall survival and disease-free survival. In colorectal cancer, SPARC overexpression in the stroma was associated with better disease-free survival. Conclusion: For the majority of solid tumors, SPARC in cancer cells may be an unfavorable indicator for long-term survival for patients. As for stromal expression, SPARC indicates a poorer prognosis in pancreatic cancer, but a better disease-free survival in colorectal cancer. Secreted protein acidic and rich in cysteine might be a potential biomarker for solid tumor prognosis.

Escherichia coli Nissle 1917 Protects Intestinal Barrier Function by Inhibiting NF-κB-Mediated Activation of the MLCK-P-MLC Signaling Pathway.

Escherichia coli Nissle 1917 (EcN), a kind of probiotic, has been reported to have a protective effect on the intestinal barrier function and can ameliorate certain gastrointestinal disorders. In this study, the potential protective effect of EcN on the intestinal barrier function in a septic mouse model induced by cecal ligation and puncture (CLP) operation was investigated. FITC-Dextran 4,000 Da (FD-4) flux and the expression levels of tight junction (TJ) proteins were measured to evaluate the protective effect of EcN on the intestinal barrier function. Then, Caco-2 monolayers were utilized to further investigate the protective effect of the EcN supernatant (EcNsup) on the barrier dysfunction induced by TNF-α and IFN-γ in vitro; the plasma level of both the cytokines increased significantly during sepsis. Transepithelial electrical resistance (TEER) and FD-4 transmembrane flux were measured, and the localization of ZO-1 and Occludin was investigated by immunofluorescence. The expression of MLCK and the phosphorylation of MLC were detected by western blot. The activation of NF-κB was explored by immunofluorescence, and CHIP assays were performed to investigate the conjunction of NF-κB with the promoter of MLCK. The results indicated that EcN protected the intestinal barrier function in sepsis by ameliorating the altered expression and localization of TJ proteins and inhibiting the NF-κB-mediated activation of the MLCK-P-MLC signaling pathway which might be one of the mechanisms underlying the effect of EcN.

Low expression of SPARC in gastric cancer-associated fibroblasts leads to stemness transformation and 5-fluorouracil resistance in gastric cancer.

BACKGROUND: The aim of the present study was to clarify the correlations between SPARC expression in gastric cancer-associated fibroblasts (GCAFs) and the prognosis of patients with gastric cancer and to elucidate the role of GCAF-derived SPARC in stemness transformation and 5-fluorouracil resistance in gastric cancer. METHODS: One hundred ninety-two patients were enrolled in the present study. SPARC expression levels were evaluated by immunohistochemical staining. Primary GCAFs were obtained and cultured from cancer patients for in vitro study, and a lentivirus infection method was employed to knock down SPARC expression in GCAFs. The stemness phenotype and 5-fluorouracil (5-FU) response of gastric cancer cells were assessed via a 3D co-culture model. The apoptotic status and stemness alterations were monitored by flow cytometry and western blotting. Additionally, label-free quantification proteomics was used to identify the differentially expressed proteins and potential pathways in gastric cancer cells treated with GCAF-derived SPARC. RESULTS: Low expression of GCAF-derived SPARC was associated with decreased differentiation and reduced 5-year overall survival and was an independent predictive factor for prognosis in gastric cancer. The 3D tumour growth and 5-FU resistance abilities of gastric cancer cells were elevated after treatment with GCAFs with SPARC knockdown relative to these abilities in negative control cells. Additionally, suppressing SPARC expression in GCAFs facilitated the phenotypic alteration of gastric cancer cells towards CD44+/CD24- cancer stem cell (CSC)-like cells. Quantification proteomics analysis revealed that the differentially expressed proteins in gastric cancer cells were mainly involved in the AKT/mTOR and MEK/ERK signalling pathways. CONCLUSIONS: SPARC expression in GCAFs is a useful prognostic factor in patients with gastric cancer. Low expression of GCAF-derived SPARC can lead to CSC transformation and 5-FU resistance. Additionally, the AKT/mTOR and MEK/ERK signalling pathways may participate in the malignant process.

1,25(OH)2D3 Attenuates IL-1ß-Induced Epithelial-to-Mesenchymal Transition Through Inhibiting the Expression of lncTCF7.

The activated form of vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], regulates numerous cellular processes, including inhibition of cancer progression. IL-1ß has been reported to facilitate cancer development, especially by inducing an epithelial-to-mesenchymal transition (EMT) in several malignant tumors. However, the underlying mechanism of 1,25(OH)2D3 and IL-1ß in colorectal cancer (CRC) still remains largely unknown. To fill in this knowledge gap, we measured cell proliferation and invasion by CCK-8 and Transwell assays after stimulation with 1,25(OH)2D3 and IL-1ß. E-cadherin and vimentin were chosen as markers of EMT measured by immunofluorescence, quantitative real-time PCR (qRT-PCR), and Western blot. The expression and function of the vitamin D receptor (VDR) was evaluated by Western blot and luciferase reporter assay. qRT-PCR and RNA-FISH were performed to detect the expression and location of lncTCF7 in vitro. The binding sites of VDR in the lncTCF7 promoter were confirmed by a chromatin immunoprecipitation assay. Based on the above experiments, we found that 1,25(OH)2D3 attenuates IL-1ß-induced increased proliferation and invasion in colorectal cancer through enhancing VDR, which inhibits the expression of lncTCF7 by directly binding to its promoter region.