Ceramide promotes lytic reactivation of Epstein-Barr virus in gastric carcinoma.

Epstein-Barr virus (EBV) has a lifelong latency period after initial infection. Rarely, however, when the EBV immediate early gene BZLF1 is expressed by a specific stimulus, the virus switches to the lytic cycle to produce progeny viruses. We found that EBV infection reduced levels of various ceramide species in gastric cancer cells. As ceramide is a bioactive lipid implicated in the infection of various viruses, we assessed the effect of ceramide on the EBV lytic cycle. Treatment with C6-ceramide (C6-Cer) induced an increase in the endogenous ceramide pool and increased production of the viral product as well as BZLF1 expression. Treatment with the ceramidase inhibitor ceranib-2 induced EBV lytic replication with an increase in the endogenous ceramide pool. The glucosylceramide synthase inhibitor Genz-123346 inhibited C6-Cer-induced lytic replication. C6-Cer induced extracellular signal-regulated kinase 1/2 (ERK1/2) and CREB phosphorylation, c-JUN expression, and accumulation of the autophagosome marker LC3B. Treatment with MEK1/2 inhibitor U0126, siERK1&2, or siCREB suppressed C6-Cer-induced EBV lytic replication and autophagy initiation. In contrast, siJUN transfection had no impact on BZLF1 expression. The use of 3-methyladenine (3-MA), an inhibitor targeting class III phosphoinositide 3-kinases (PI3Ks) to inhibit autophagy initiation, resulted in reduced beclin-1 expression, along with suppressed C6-Cer-induced BZLF1 expression and LC3B accumulation. Chloroquine, an inhibitor of autophagosome-lysosome fusion, increased BZLF1 protein intensity and LC3B accumulation. However, siLC3B transfection had minimal effect on BZLF1 expression. The results suggest the significance of ceramide-related sphingolipid metabolism in controlling EBV latency, highlighting the potential use of drugs targeting sphingolipid metabolism for treating EBV-positive gastric cancer.IMPORTANCEEpstein-Barr virus remains dormant in the host cell but occasionally switches to the lytic cycle when stimulated. However, the exact molecular mechanism of this lytic induction is not well understood. In this study, we demonstrate that Epstein-Barr virus infection leads to a reduction in ceramide levels. Additionally, the restoration of ceramide levels triggers lytic replication of Epstein-Barr virus with increase in phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and CREB. Our study suggests that the Epstein-Barr virus can inhibit lytic replication and remain latent through reduction of host cell ceramide levels. This study reports the regulation of lytic replication by ceramide in Epstein-Barr virus-positive gastric cancer.

Differentiation of Prior SARS-CoV-2 Infection and Postacute Sequelae by Standard Clinical Laboratory Measurements in the RECOVER Cohort.

BACKGROUND: There are currently no validated clinical biomarkers of postacute sequelae of SARS-CoV-2 infection (PASC). OBJECTIVE: To investigate clinical laboratory markers of SARS-CoV-2 and PASC. DESIGN: Propensity score-weighted linear regression models were fitted to evaluate differences in mean laboratory measures by prior infection and PASC index (≥12 vs. 0). (ClinicalTrials.gov: NCT05172024). SETTING: 83 enrolling sites. PARTICIPANTS: RECOVER-Adult cohort participants with or without SARS-CoV-2 infection with a study visit and laboratory measures 6 months after the index date (or at enrollment if >6 months after the index date). Participants were excluded if the 6-month visit occurred within 30 days of reinfection. MEASUREMENTS: Participants completed questionnaires and standard clinical laboratory tests. RESULTS: Among 10 094 participants, 8746 had prior SARS-CoV-2 infection, 1348 were uninfected, 1880 had a PASC index of 12 or higher, and 3351 had a PASC index of zero. After propensity score adjustment, participants with prior infection had a lower mean platelet count (265.9 × 109 cells/L [95% CI, 264.5 to 267.4 × 109 cells/L]) than participants without known prior infection (275.2 × 109 cells/L [CI, 268.5 to 282.0 × 109 cells/L]), as well as higher mean hemoglobin A1c (HbA1c) level (5.58% [CI, 5.56% to 5.60%] vs. 5.46% [CI, 5.40% to 5.51%]) and urinary albumin-creatinine ratio (81.9 mg/g [CI, 67.5 to 96.2 mg/g] vs. 43.0 mg/g [CI, 25.4 to 60.6 mg/g]), although differences were of modest clinical significance. The difference in HbA1c levels was attenuated after participants with preexisting diabetes were excluded. Among participants with prior infection, no meaningful differences in mean laboratory values were found between those with a PASC index of 12 or higher and those with a PASC index of zero. LIMITATION: Whether differences in laboratory markers represent consequences of or risk factors for SARS-CoV-2 infection could not be determined. CONCLUSION: Overall, no evidence was found that any of the 25 routine clinical laboratory values assessed in this study could serve as a clinically useful biomarker of PASC. PRIMARY FUNDING SOURCE: National Institutes of Health.

Discovering cancer stem-like molecule, nuclear factor I X, using spatial transcriptome in gastric cancer.

Gastric cancer (GC) is characterized by significant intratumoral heterogeneity, and stem cells are promising therapeutic targets. Despite advancements in spatial transcriptome analyses, unexplored targets for addressing cancer stemness remain unknown. This study aimed to identify Nuclear Factor IX (NFIX) as a critical regulator of cancer stemness in GC and evaluate its clinicopathological significance and function. Spatial transcriptome analysis of GC was conducted. The correlation between NFIX expression, clinicopathological factors, and prognosis was assessed using immunostaining in 127 GC cases. Functional analyses of cancer cell lines validated these findings. Spatial transcriptome analysis stratified GC tissues based on genetic profiles, identified CSC-like cells, and further refined the classification to identify and highlight the significance of NFIX, as validated by Monocle 3 and CytoTRACE analyses. Knockdown experiments in cancer cell lines have demonstrated the involvement of NFIX in cancer cell proliferation and kinase activity. This study underscores the role of spatial transcriptome analysis in refining GC tissue classification and identifying therapeutic targets, highlighting NFIX as a pivotal factor. NFIX expression is correlated with poor prognosis and drives GC progression, suggesting its potential as a novel therapeutic target for personalized GC therapies.

Kinesin Family Member B18 Is Related to Gastric Mucin Phenotype and Contributes to Gastric Cancer Progression by Regulating Epithelial-Mesenchymal Transition.

INTRODUCTION: Gastric cancer (GC) remains a common health concern worldwide and is the third leading cause of death in Japan. It can be broadly classified into gastric and intestinal mucin phenotypes using immunohistochemistry. We previously reported numerous associations of kinesin family member (KIF) genes and mucin phenotypes with GC. However, no previous studies have reported on the importance of KIF18B in GC using immunostaining. Thus, in this study, we investigated the expression and functions of KIF18B, which is highly expressed in gastric mucin phenotype GC. METHODS: We performed RNA-seq of gastric and intestinal mucin type GCs, and clinicopathological studies of the KIF18B we found were performed using 96 GC cases. We also performed functional analysis using GC-derived cell lines. RESULT: RNA-seq showed the upregulation of matrisome-associated genes in gastric mucin phenotype GC and a high expression of KIF18B. KIF18B was detected in 52 of the 96 GC cases (54%) through immunohistochemistry. Low KIF18B expression was significantly associated with poor overall survival (p < 0.01). Other molecules that were significantly associated with KIF18B were MUC5AC and claudin 18; these were also significantly associated with the gastric mucin phenotype. KIF18B small interfering RNA (siRNA)-transfected GC cells showed greater growth and spheroid colony formation than the negative control siRNA-transfected cells. Furthermore, expression of snail family transcriptional repressor 1 and cadherin 2 was significantly increased and that of cadherin 1 was significantly decreased in KIF18B siRNA-transfected GC cells. CONCLUSION: These findings not only suggest that KIF18B may be a useful prognostic marker, but also provide insight into the pathogenesis of the GC phenotype.

Gastrointestinal Manifestations and Their Association with Neurologic and Sleep Problems in Long COVID-19 Minority Patients: A Prospective Follow-Up Study.

BACKGROUND: Long-COVID is a condition post SARS-CoV-2 infection with persistent or recurring symptoms affecting multiple organs, and may involve viral persistence, changes to the microbiome, coagulopathies, and alterations to neuro-immune interactions. These factors can disrupt the Gut-Brain Axis, which is a complex system involving bidirectional communication between the central nervous system and the gastrointestinal (GI) system. As a result of these disruptions, individuals with long-COVID may develop post-infectious functional GI disorders, which can cause a range of symptoms affecting the digestive system. AIM: To understand frequency of GI manifestations of Long-COVID and to determine association with sleep or neurological symptoms in a predominantly minority population. METHODS: We included patients with positive SARS-CoV-2 PCR (n = 747) who were hospitalized from Feb. 2020 to May 2021 at Howard University Hospital and followed between 6 and 12 months from discharge. GI, sleep, and neurological symptoms (via the Montreal Cognitive Assessment (MoCA) scoring system) were assessed using a standardized questionnaire. Linear regression analysis, χ2 and Fisher's exact test were utilized to determine the statistical significance of correlations of GI/Neuro/COVID. RESULTS: The mean age of patients was 58, with 51.6% females and a predominant African American ethnicity (73.6%, n = 550). A total of 108 patients died during their initial hospital stay, with the remaining 639 patients followed-up. Three hundred fifty (350) patients responded to the questionnaire (57 patients died during the follow-up period). Overall, 39 (13.3%) patients reported GI-related symptoms, out of which 19 (6.4%) had persistent symptoms and 20 (6.8%) developed new onset GI symptoms. Nausea and vomiting were the most common 24/39 (61.5%), followed by abdominal pain 7/39 (18%), diarrhea 5/39 (12.8%), and others 3/39 (7.6%). Patients who presented with vomiting during acute SARS-CoV-2 infection were more likely to have Long-COVID GI manifestations (P = 0.023). Use of ACE inhibitors, abnormal lymphocyte count and elevated ferritin are other variables that showed significant associations with Long-COVID GI manifestations (P = 0.03, 0.006 and 0.03, respectively). During follow-up, a total of 28 (9.5%) patients reported difficulty with sleep and 79 (27%) patients had abnormal MoCA assessment. With further analysis, there was a trend between presentation of GI symptoms on admission with abnormal MoCA assessment, and an association between abnormal LFTs and history of liver disease during hospitalization with subsequent sleep problems. Baseline characteristics, clinical comorbidities, other laboratory values, hospital length of stay, mechanical ventilation, medications during hospitalization, re-admission and Flu or COVID-19 vaccination have not shown any association with Long-COVID GI symptoms in our cohort. CONCLUSION: Dyspeptic symptoms were common GI manifestations in the acute and post COVID periods. GI symptoms, abnormal LFTs and a history of liver disease during the acute infectious phase associates with abnormal MoCA and sleep problems during follow-up. Further large population studies are needed to determine if COVID-19 leads to a GI symptoms-associated Long-COVID phenotypes and other symptoms through the Gut-Brain-Axis.

Comprehensive molecular phenotyping of ARID1A-deficient gastric cancer reveals pervasive epigenomic reprogramming and therapeutic opportunities.

OBJECTIVE: Gastric cancer (GC) is a leading cause of cancer mortality, with ARID1A being the second most frequently mutated driver gene in GC. We sought to decipher ARID1A-specific GC regulatory networks and examine therapeutic vulnerabilities arising from ARID1A loss. DESIGN: Genomic profiling of GC patients including a Singapore cohort (>200 patients) was performed to derive mutational signatures of ARID1A inactivation across molecular subtypes. Single-cell transcriptomic profiles of ARID1A-mutated GCs were analysed to examine tumour microenvironmental changes arising from ARID1A loss. Genome-wide ARID1A binding and chromatin profiles (H3K27ac, H3K4me3, H3K4me1, ATAC-seq) were generated to identify gastric-specific epigenetic landscapes regulated by ARID1A. Distinct cancer hallmarks of ARID1A-mutated GCs were converged at the genomic, single-cell and epigenomic level, and targeted by pharmacological inhibition. RESULTS: We observed prevalent ARID1A inactivation across GC molecular subtypes, with distinct mutational signatures and linked to a NFKB-driven proinflammatory tumour microenvironment. ARID1A-depletion caused loss of H3K27ac activation signals at ARID1A-occupied distal enhancers, but unexpectedly gain of H3K27ac at ARID1A-occupied promoters in genes such as NFKB1 and NFKB2. Promoter activation in ARID1A-mutated GCs was associated with enhanced gene expression, increased BRD4 binding, and reduced HDAC1 and CTCF occupancy. Combined targeting of promoter activation and tumour inflammation via bromodomain and NFKB inhibitors confirmed therapeutic synergy specific to ARID1A-genomic status. CONCLUSION: Our results suggest a therapeutic strategy for ARID1A-mutated GCs targeting both tumour-intrinsic (BRD4-assocatiated promoter activation) and extrinsic (NFKB immunomodulation) cancer phenotypes.

Microbiomic and Metabolomic Analyses Unveil the Protective Effect of Saffron in a Mouse Colitis Model.

Despite the existence of effective drugs used to treat inflammatory bowel disease (IBD), many patients fail to respond or lose response over time. Further, many drugs can carry serious adverse effects, including increased risk of infections and malignancies. Saffron (Crocus sativus) has been reported to have anti-inflammatory properties. Its protective role in IBD and how the microbiome and metabolome play a role has not been explored extensively. We aimed to establish whether saffron treatment modulates the host microbiome and metabolic profile in experimental colitis. Colitis was induced in C57BL/6 mice with 3% DSS and treated with either saffron in a dose of 20 mg/kg body weight or vehicle through daily gavage. On day 10, stool pellets from mice were collected and analyzed to assess saffron's effect on fecal microbiota and metabolites through 16S rRNA sequencing and untargeted primary metabolite analysis. Saffron treatment maintained gut microbiota homeostasis by counter-selecting pro-inflammatory bacteria and maintained Firmicutes/Bacteroides ratio, which was otherwise disturbed by DSS treatment. Several metabolites (uric acid, cholesterol, 2 hydroxyglutaric acid, allantoic acid, 2 hydroxyhexanoic acid) were altered significantly with saffron treatment in DSS-treated mice, and this might play a role in mediating saffron's colitis-mitigating effects. These data demonstrate saffron's therapeutic potential, and its protective role is modulated by gut microbiota, potentially acting through changes in metabolites.

Development of a Definition of Postacute Sequelae of SARS-CoV-2 Infection.

Importance: SARS-CoV-2 infection is associated with persistent, relapsing, or new symptoms or other health effects occurring after acute infection, termed postacute sequelae of SARS-CoV-2 infection (PASC), also known as long COVID. Characterizing PASC requires analysis of prospectively and uniformly collected data from diverse uninfected and infected individuals. Objective: To develop a definition of PASC using self-reported symptoms and describe PASC frequencies across cohorts, vaccination status, and number of infections. Design, Setting, and Participants: Prospective observational cohort study of adults with and without SARS-CoV-2 infection at 85 enrolling sites (hospitals, health centers, community organizations) located in 33 states plus Washington, DC, and Puerto Rico. Participants who were enrolled in the RECOVER adult cohort before April 10, 2023, completed a symptom survey 6 months or more after acute symptom onset or test date. Selection included population-based, volunteer, and convenience sampling. Exposure: SARS-CoV-2 infection. Main Outcomes and Measures: PASC and 44 participant-reported symptoms (with severity thresholds). Results: A total of 9764 participants (89% SARS-CoV-2 infected; 71% female; 16% Hispanic/Latino; 15% non-Hispanic Black; median age, 47 years [IQR, 35-60]) met selection criteria. Adjusted odds ratios were 1.5 or greater (infected vs uninfected participants) for 37 symptoms. Symptoms contributing to PASC score included postexertional malaise, fatigue, brain fog, dizziness, gastrointestinal symptoms, palpitations, changes in sexual desire or capacity, loss of or change in smell or taste, thirst, chronic cough, chest pain, and abnormal movements. Among 2231 participants first infected on or after December 1, 2021, and enrolled within 30 days of infection, 224 (10% [95% CI, 8.8%-11%]) were PASC positive at 6 months. Conclusions and Relevance: A definition of PASC was developed based on symptoms in a prospective cohort study. As a first step to providing a framework for other investigations, iterative refinement that further incorporates other clinical features is needed to support actionable definitions of PASC.

COVID-19 and Gastrointestinal Tract: From Pathophysiology to Clinical Manifestations.

Background: Since its first report in Wuhan, China, in December 2019, COVID-19 has become a pandemic, affecting millions of people worldwide. Although the virus primarily affects the respiratory tract, gastrointestinal symptoms are also common. The aim of this narrative review is to provide an overview of the pathophysiology and clinical manifestations of gastrointestinal COVID-19. Methods: We conducted a systematic electronic search of English literature up to January 2023 using Medline, Scopus, and the Cochrane Library, focusing on papers that analyzed the role of SARS-CoV-2 in the gastrointestinal tract. Results: Our review highlights that SARS-CoV-2 directly infects the gastrointestinal tract and can cause symptoms such as diarrhea, nausea/vomiting, abdominal pain, anorexia, loss of taste, and increased liver enzymes. These symptoms result from mucosal barrier damage, inflammation, and changes in the microbiota composition. The exact mechanism of how the virus overcomes the acid gastric environment and leads to the intestinal damage is still being studied. Conclusions: Although vaccination has increased the prevalence of less severe symptoms, the long-term interaction with SARS-CoV-2 remains a concern. Understanding the interplay between SARS-CoV-2 and the gastrointestinal tract is essential for future management of the virus.

Symptomatic, clinical and biomarker associations for mortality in hospitalized COVID-19 patients enriched for African Americans.

BACKGROUND AND AIMS: Initial reports on US COVID-19 showed different outcomes in different races. In this study we use a diverse large cohort of hospitalized COVID-19 patients to determine predictors of mortality. METHODS: We analyzed data from hospitalized COVID-19 patients (n = 5852) between March 2020- August 2020 from 8 hospitals across the US. Demographics, comorbidities, symptoms and laboratory data were collected. RESULTS: The cohort contained 3,662 (61.7%) African Americans (AA), 286 (5%) American Latinx (LAT), 1,407 (23.9%), European Americans (EA), and 93 (1.5%) American Asians (AS). Survivors and non-survivors mean ages in years were 58 and 68 for AA, 58 and 77 for EA, 44 and 61 for LAT, and 51 and 63 for AS. Mortality rates for AA, LAT, EA and AS were 14.8, 7.3, 16.3 and 2.2%. Mortality increased among patients with the following characteristics: age, male gender, New York region, cardiac disease, COPD, diabetes mellitus, hypertension, history of cancer, immunosuppression, elevated lymphocytes, CRP, ferritin, D-Dimer, creatinine, troponin, and procalcitonin. Use of mechanical ventilation (p = 0.001), shortness of breath (SOB) (p < 0.01), fatigue (p = 0.04), diarrhea (p = 0.02), and increased AST (p < 0.01), significantly correlated with death in multivariate analysis. Male sex and EA and AA race/ethnicity had higher frequency of death. Diarrhea was among the most common GI symptom amongst AAs (6.8%). When adjusting for comorbidities, significant variables among the demographics of study population were age (over 45 years old), male sex, EA, and patients hospitalized in New York. When adjusting for disease severity, significant variables were age over 65 years old, male sex, EA as well as having SOB, elevated CRP and D-dimer. Glucocorticoid usage was associated with an increased risk of COVID-19 death in our cohort. CONCLUSION: Among this large cohort of hospitalized COVID-19 patients enriched for African Americans, our study findings may reflect the extent of systemic organ involvement by SARS-CoV-2 and subsequent progression to multi-system organ failure. High mortality in AA in comparison with LAT is likely related to high frequency of comorbidities and older age among AA. Glucocorticoids should be used carefully considering the poor outcomes associated with it. Special focus in treating patients with elevated liver enzymes and other inflammatory biomarkers such as CRP, troponin, ferritin, procalcitonin, and D-dimer are required to prevent poor outcomes.

Non-steroidal anti-inflammatory drugs and acetylsalicylic acid increase the risk of complications of diverticular disease: a meta-analysis of case-control and cohort studies.

BACKGROUND: The role of non-steroidal anti-inflammatory drugs (NSAIDs) and acetylsalicylic acid in the occurrence of diverticular bleeding (DB), complicated diverticulitis (CD), and acute diverticulitis (AD) is not yet defined. AIM: Update a systematic review and meta-analyses of case-control and cohort studies to evaluate the association between NSAIDs or acetylsalicylic acid with DB, CD, or AD. METHODS: The study included were identified through MEDLINE, Scopus, Web of Science, and Cochrane Library databases. Sizes were pooled across studies to obtain the overall effect size. A random-effects model was used to account for different sources of variation among studies. Odds ratio (OR) with 95% confidence interval (CI) was used as a measure of effect size. RESULTS: Thirteen studies were included in the systematic review and meta-analysis. NSAIDs and acetylsalicylic acid use were associated with an increased risk of DB (OR: 6.90, 95% CI 3.86 to 12.35, P ˂ 0.00001, and OR 2.84, 95% CI 2.19 to 3.67, P < 0.00001, respectively). NSAIDs and acetylsalicylic acid use were also associated with increased risk of CD occurrence (OR 3.13, 95% CI 1.73 to 5.68, P = 0.0002, and OR 1.49, 95% CI 1.02 to 2.17, P = 0.04, respectively). The only study found about AD occurrence showed that NSAIDs use was not associated with AD and acetylsalicylic acid use had a low risk of AD. CONCLUSION: NSAIDs and acetylsalicylic acid significantly increase the risk of DB and CD. Further studies are needed to clarify the role of NSAIDs and acetylsalicylic acid in AD. However, increasing evidence suggests caution in the use of such medications in patients with colonic diverticula.

Protective Effect of Saffron in Mouse Colitis Models Through Immune Modulation.

BACKGROUND: People with inflammatory bowel disease (IBD) including ulcerative colitis are at risk for colorectal cancer. Despite available effective drugs used to treat IBD, many patients fail or lose response over time with some displaying drug-induced adverse events. Saffron (Crocus sativus) has been reported to have anti-inflammatory properties. Its protective role in IBD has not been explored extensively. AIM: To establish whether saffron treatment alleviates inflammation in experimental colitis. METHODS: Colitis was induced in C57BL/6 mice with 3% DSS and treated with either saffron doses (7.5, 15, 20, 25 mg/kg body weight) or vehicle through daily gavage. On day 11, mice were euthanized and analyzed for gross and microscopic inflammation. Distal colon segments were collected for mRNA and protein expression of HO-1 protein and GPX2, (the downstream targets of NRF-2). Nrf-2 translocation from cytosol to nucleus was confirmed by immunofluorescence, and further Nrf-2 protein expression in nuclear and cytosolic fraction of colon was analyzed by immunoblot. Immune cells were isolated from the lamina propria of mouse colon for flow cytometry-based immunophenotyping. Colitis was also induced in C57BL/6 Ahr knockout and wild type mice to explore the involvement of Ahr-dependent pathways in saffron's protective effect(s). The therapeutic effect of saffron was further validated in another TNBS model of colitis. RESULTS: Saffron 20 mg/kg body weight showed improved colon gross and histology features and led to better body weight, colon length, histology score, and reduced disease activity index (DAI). Saffron significantly decreased pro-inflammatory macrophages (M1), while increasing anti-inflammatory macrophages (M2) and IL10 + dendritic cells. Saffron treatment also enhanced CD3 + T and CD3 + CD8 + T cells followed by increase in different CD3 + CD4 + T cells subsets like CD25 + T cells, FoxP3 + CD25 + regulatory T cells, and CD4 + FOXP3 + CD25-regulatory T cells. Immunoblot analysis showed a significant increase in HO-1/GPX2 protein expression. With saffron treatment, Nrf-2 translocation into nucleus from cytosol also supports the involvement of Nrf-2 and its downstream targets in the protective effect of saffron. Further, we demonstrated that saffron in part exert anti-inflammatory effect through activation of aryl hydrocarbon receptor (AhR)-nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent pathways. CONCLUSION: These data demonstrate saffron's therapeutic potential and its protective role in part via Ahr/Nrf-2 pathways and regulatory innate and adaptive immune cells.

WITHDRAWN: FOXC1 modulates stem-like cell properties and chemoresistance through hedgehog and EMT signaling in gastric adenocarcinoma.

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A novel protein AXIN1-295aa encoded by circAXIN1 activates the Wnt/ß-catenin signaling pathway to promote gastric cancer progression.

BACKGROUND: Circular RNA (circRNA), a subclass of non-coding RNA, plays a critical role in cancer tumorigenesis and metastasis. It has been suggested that circRNA acts as a microRNA sponge or a scaffold to interact with protein complexes; however, its full range of functions remains elusive. Recently, some circRNAs have been found to have coding potential. METHODS: To investigate the role of circRNAs in gastric cancer (GC), parallel sequencing was performed using five paired GC samples. Differentially expressed circAXIN1 was proposed to encode a novel protein. FLAG-tagged circRNA overexpression plasmid construction, immunoblotting, mass spectrometry, and luciferase reporter analyses were applied to confirm the coding potential of circAXIN1. Gain- and loss-of-function studies were conducted to study the oncogenic role of circAXIN1 and AXIN1-295aa on the proliferation, migration, invasion, and metastasis of GC cells in vitro and in vivo. The competitive interaction between AXIN1-295aa and adenomatous polyposis coli (APC) was investigated by immunoprecipitation analyses. Wnt signaling activity was observed using a Top/Fopflash assay, real-time quantitative RT-PCR, immunoblotting, immunofluorescence staining, and chromatin immunoprecipitation. RESULTS: CircAXIN1 is highly expressed in GC tissues compared with its expression in paired adjacent normal gastric tissues. CircAXIN1 encodes a 295 amino acid (aa) novel protein, which was named AXIN1-295aa. CircAXIN1 overexpression enhances the cell proliferation, migration, and invasion of GC cells, while the knockdown of circAXIN1 inhibits the malignant behaviors of GC cells in vitro and in vivo. Mechanistically, AXIN1-295aa competitively interacts with APC, leading to dysfunction of the "destruction complex" of the Wnt pathway. Released ß-catenin translocates to the nucleus and binds to the TCF consensus site on the promoter, inducing downstream gene expression. CONCLUSION: CircAXIN1 encodes a novel protein, AXIN1-295aa. AXIN1-295aa functions as an oncogenic protein, activating the Wnt signaling pathway to promote GC tumorigenesis and progression, suggesting a potential therapeutic target for GC.

Hyperactivation of MEK/ERK pathway by Ca2+ /calmodulin-dependent protein kinase kinase 2 promotes cellular proliferation by activating cyclin-dependent kinases and minichromosome maintenance protein in gastric cancer cells.

Although CAMKK2 is overexpressed in several cancers, its role and relevant downstream signaling pathways in gastric cancer (GC) are poorly understood. Treatment of AGS GC cells with a CAMKK2 inhibitor, STO-609, resulted in decreased cell proliferation, cell migration, invasion, colony-forming ability, and G1/S-phase arrest. Quantitative phosphoproteomics in AGS cells with the CAMKK2 inhibitor led to the identification of 9603 unique phosphosites mapping to 3120 proteins. We observed decreased phosphorylation of 1101 phosphopeptides (1.5-fold) corresponding to 752 proteins upon CAMKK2 inhibition. Bioinformatics analysis of hypo-phosphorylated proteins revealed enrichment of MAPK1/MAPK3 signaling. Kinase enrichment analysis of hypo-phosphorylated proteins using the X2K Web tool identified ERK1, cyclin-dependant kinase 1 (CDK1), and CDK2 as downstream substrates of CAMKK2. Moreover, inhibition of CAMKK2 and MEK1 resulted in decreased phosphorylation of ERK1, CDK1, MCM2, and MCM3. Immunofluorescence results were in concordance with our mass spectroscopy data and Western blot analysis results. Taken together, our data reveal the essential role of CAMKK2 in the pathobiology of GC through the activation of the MEK/ERK1 signaling cascade.

Helicobacter pylori-induced gastric cancer is orchestrated by MRCKß-mediated Siah2 phosphorylation.

BACKGROUND: Helicobacter pylori-mediated gastric carcinogenesis is initiated by a plethora of signaling events in the infected gastric epithelial cells (GECs). The E3 ubiquitin ligase seven in absentia homolog 2 (Siah2) is induced in GECs in response to H. pylori infection. Posttranslational modifications of Siah2 orchestrate its function as well as stability. The aim of this study was to evaluate Siah2 phosphorylation status under the influence of H. pylori infection and its impact in gastric cancer progression. METHODS: H. pylori-infected various GECs, gastric tissues from H. pylori-infected GC patients and H. felis-infected C57BL/6 mice were evaluated for Siah2 phosphorylation by western blotting or immunofluorescence microscopy. Coimmunoprecipitation assay followed by mass spectrometry were performed to identify the kinases interacting with Siah2. Phosphorylation sites of Siah2 were identified by using various plasmid constructs generated by site-directed mutagenesis. Proteasome inhibitor MG132 was used to investigate proteasome degradation events. The importance of Siah2 phosphorylation on tumorigenicity of infected cells were detected by using phosphorylation-null mutant and wild type Siah2 stably-transfected cells followed by clonogenicity assay, cell proliferation assay, anchorage-independent growth and transwell invasion assay. RESULTS: Siah2 was phosphorylated in H. pylori-infected GECs as well as in metastatic GC tissues at residues serine6 (Ser6) and threonine279 (Thr279). Phosphorylation of Siah2 was mediated by MRCKß, a Ser/Thr protein kinase. MRCKß was consistently expressed in uninfected GECs and noncancer gastric tissues but its level decreased in infected GECs as well as in metastatic tissues which had enhanced Siah2 expression. Infected murine gastric tissues showed similar results. MRCKß could phosphorylate Siah2 but itself got ubiquitinated from this interaction leading to the proteasomal degradation of MRCKß and use of proteasomal inhibitor MG132 could rescue MRCKß from Siah2-mediated degradation. Ser6 and Thr279 phosphorylated-Siah2 was more stable and tumorigenic than its non-phosphorylated counterpart as revealed by the proliferation, invasion, migration abilities and anchorage-independent growth of stable-transfected cells. CONCLUSIONS: Increased level of Ser6 and Thr279-phosphorylated-Siah2 and downregulated MRCKß were prominent histological characteristics of Helicobacter-infected gastric epithelium and metastatic human GC. MRCKß-dependent Siah2 phosphorylation stabilized Siah2 which promoted anchorage-independent survival and proliferative potential of GECs. Phospho-null mutants of Siah2 (S6A and T279A) showed abated tumorigenicity.

COVID-19 and gastrointestinal symptoms in Mexico, a systematic review: does location matter?

BACKGROUND: Covid-19 in Mexico is on the rise in different parts of the country. We aimed to study the symptoms and comorbidities that associate with this pandemic in 3 different regions of Mexico. METHODS: We analyzed data from SARS-CoV-2 positive patients evaluated at healthcare centers and hospitals of Mexico (n = 1607) including Northwest Mexico (Sinaloa state), Southeast Mexico (Veracruz state) and West Mexico (Jalisco state) between March 1 and July 30, 2020. Mexico consists of a total population that exceeds 128 million. Demographics, comorbidities and clinical symptoms were collected. Statistical descriptive analysis and correlation analyses of symptoms, comorbidities and mortality were performed. RESULTS: A total of 1607 hospitalized patients positive for COVID-19 across all 3 regions of Mexico were included. The average age was 54.6 years and 60.4% were male. A mortality rate of 33.1% was observed. The most common comorbidities were hypertension (43.2%), obesity (30.3%) and diabetes (31.4%). Hypertension was more frequent in West (45%), followed by Northwest (37%) and Southeast Mexico (29%). Obesity was around 30% in Northwest and West whereas an 18% was reported in Southeast. Diabetes was most common in West (34%) followed by Northwest (22%) and Southeast (13%). This might be related to the highest mortality rate in Northwest (31%) and West (37%) when compared to Southeast. Most common symptoms in our overall cohort were fever (80.8%), cough (79.8%), headache (66%), dyspnea (71.1%), myalgia (53.8%), joints pain (50.8%) and odynophagia (34.8%). Diarrhea was the main gastrointestinal (GI) symptom (21.3%), followed by abdominal pain (18%), and nausea/ vomiting (4.5%). Diarrhea and abdominal pain were more common in West (23.1 and 21%), followed by Southeast (17.8, and 9.8%) and Northwest (11.4 and 3.1%). CONCLUSION: Our study showed a high mortality rate likely related to high frequencies of comorbidities (hypertension, obesity and diabetes). Mortality was different across regions. These discrepancies might be related to the differences in the frequencies of comorbidities, and partially attributed to differences in socio-economic conditions and quality of care. Thus, our findings stress the need for improved strategies to get better outcomes in our population.

Saffron and Its Major Ingredients' Effect on Colon Cancer Cells with Mismatch Repair Deficiency and Microsatellite Instability.

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide. One of its subtypes is associated with defective mismatch repair (dMMR) genes. Saffron has many potentially protective roles against colon malignancy. However, these roles in the context of dMMR tumors have not been explored. In this study, we aimed to investigate the effects of saffron and its constituents in CRC cell lines with dMMR. METHODS: Saffron crude extracts and specific compounds (safranal and crocin) were used in the human colorectal cancer cell lines HCT116, HCT116+3 (inserted MLH1), HCT116+5 (inserted MSH3), and HCT116+3+5 (inserted MLH1 and MSH3). CDC25b, p-H2AX, TPDP1, and GAPDH were analyzed by Western blot. Proliferation and cytotoxicity were analyzed by MTT. The scratch wound assay was also performed. RESULTS: Saffron crude extracts restricted (up to 70%) the proliferation in colon cells with deficient MMR (HCT116) compared to proficient MMR. The wound healing assay indicates that deficient MMR cells are doing better (up to 90%) than proficient MMR cells when treated with saffron. CDC25b and TDP1 downregulated (up to 20-fold) in proficient MMR cells compared to deficient MMR cells, while p.H2AX was significantly upregulated in both cell types, particularly at >10 mg/mL saffron in a concentration-dependent manner. The reduction in cellular proliferation was accompanied with upregulation of caspase 3 and 7. The major active saffron compounds, safranal and crocin reproduced most of the saffron crude extracts' effects. CONCLUSIONS: Saffron's anti-proliferative effect is significant in cells with deficient MMR. This novel effect may have therapeutic implications and benefits for MSI CRC patients who are generally not recommended for the 5-fluorouracil-based treatment.

Saffron Pre-Treatment Promotes Reduction in Tissue Inflammatory Profiles and Alters Microbiome Composition in Experimental Colitis Mice.

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with an incompletely understood pathogenesis. Long-standing colitis is associated with increased risk of colon cancer. Despite the availability of various anti-inflammatory and immunomodulatory drugs, many patients fail to respond to pharmacologic therapy and some experience drug-induced adverse events. Dietary supplements, particularly saffron (Crocus sativus), have recently gained an appreciable attention in alleviating some symptoms of digestive diseases. In our study, we investigated whether saffron may have a prophylactic effect in a murine colitis model. Saffron pre-treatment improved the gross and histopathological characteristics of the colonic mucosa in murine experimental colitis. Treatment with saffron showed a significant amelioration of colitis when compared to the vehicle-treated mice group. Saffron treatment significantly decreased secretion of serotonin and pro-inflammatory cytokines, such as TNF-α, IL-1ß, and IL-6, in the colon tissues by suppressing the nuclear translocation of NF-κB. The gut microbiome analysis revealed distinct clusters in the saffron-treated and untreated mice in dextran sulfate sodium (DSS)-induced colitis by visualization of the Bray-Curtis diversity by principal coordinates analysis (PCoA). Furthermore, we observed that, at the operational taxonomic unit (OTU) level, Cyanobacteria were depleted, while short-chain fatty acids (SCFAs), such as isobutyric acid, acetic acid, and propionic acid, were increased in saffron-treated mice. Our data suggest that pre-treatment with saffron inhibits DSS-induced pro-inflammatory cytokine secretion, modulates gut microbiota composition, prevents the depletion of SCFAs, and reduces the susceptibility to colitis.

Association of Patients' Perception of Quality of Healthcare Received and Colorectal Cancer Screening Uptake: An Analysis of 2 National Surveys in the USA.

OBJECTIVE: It is not known whether patients' ratings of the quality of healthcare services they receive truly correlate with the quality of care from their providers. Understanding this association can potentiate improvement in healthcare delivery. We evaluated the association between patients' ratings of the quality of healthcare services received and uptake of colorectal cancer (CRC) screening. SUBJECTS AND METHODS: We used 2 iterations of the Health Information National Trends Survey (HINTS) of adults in the USA. HINTS 2007 (4,007 respondents; weighted population = 75,397,128) evaluated whether respondents were up to date with CRC screening while HINTS 4 cycle 3 (1,562 respondents; weighted population = 76,628,000) evaluated whether participants had ever received CRC screening in the past. All included respondents from both surveys were at least 50 years of age, had no history of CRC, and had rated the quality of healthcare services that they had received at their healthcare provider's office in the previous 12 months. RESULTS: HINTS 2007 data showed that respondents who rated their healthcare as good or fair/poor were significantly less likely to be up to date with CRC screening compared to those who rated their healthcare as excellent. We found comparable results from analysis of HINTS 4 cycle 3 data with poorer uptake of CRC screening as the healthcare quality ratings of respondents reduced. CONCLUSION: Our study suggests that patients who reported receiving lower quality of healthcare services were less likely to have undergone and be compliant with CRC screening recommendations. It is important to pay close attention to patient feedback surveys in order to improve healthcare delivery.