Cell culture models for studying the development of Barrett's esophagus: a systematic review

Predicting Regression of Barrett's Esophagus-Can All the King's Men Put It Together Again?

The primary pre-neoplastic lesion of the lower esophagus in the vicinity of the gastroesophageal junction (GEJ) is any Barrett's esophageal lesions (BE), and esophageal neoplasia has increased in the US population with predispositions (Caucasian males, truncal obesity, age, and GERD). The responses to BE are endoscopic and screening cytologic programs with endoscopic ablation of various forms. The former have not been proven to be cost-effective and there are mixed results for eradication. A fresh approach is sorely needed. We prospectively followed 2229 mostly male veterans at high risk for colorectal cancer in a 27-year longitudinal long-term study, collecting data on colorectal neoplasia development and other preneoplastic lesions, including BE and spontaneous regression (SR). Another cross-sectional BE study at a similar time period investigated antigenic changes at the GEJ in both BE glandular and squamous mucosa immunohistochemistry and the role of inflammation. Ten of the prospective cohort (21.7%) experienced SR out of a total of forty-six BE patients. Significant differences between SR and stable BE were younger age (p < 0.007); lower platelet levels (p < 0.02); rectal p87 elevation in SR (p < 0.049); a reduced innate immune system (InImS) FEREFF ratio (ferritin: p87 colonic washings) (p < 0.04). Ancillary testing showed a broad range of neoplasia biomarkers. InImS markers may be susceptible to intervention using commonplace and safe medical interventions and encourage SR.

Enhancement of DNA hypomethylation alterations by gastric and bile acids promotes chromosomal instability in Barrett's epithelial cell line

Gastric and bile acid reflux leads to chronic inflammation, resulting in methylation alterations in Barrett's esophagus (BE) together with chromosomal instability (CIN). We investigated DNA hypomethylation following acid exposure and confirmed its significance in BE-related carcinogenesis by inducing CIN in vitro. OACP4C, an esophageal cancer cell line, and CP-A, a non-dysplastic cell line originating from BE, were exposed to acidic conditions using deoxycholic acid. CP-A exhibited substantially increased DNA hypomethylation of alpha satellite sequences in the centromere region, as well as increased levels of alpha satellite transcripts, but no changes were observed in the long interspersed nucleotide element-1 sequences distributed throughout the entire genome. These changes were not clearly found in OACP4C. Copy number changes at specific chromosomes were identified in CP-A, along with an increased number of cells exhibiting abnormal segregations, whereas these changes were rarely observed in OACP4C. The changes were maintained after several cell divisions. These findings suggest that alpha satellites are likely targets of DNA hypomethylation induced by acid exposure. CP-A was more sensitive to acid exposure than OACP4C, indicating that acid-induced DNA hypomethylation is involved in cancer development rather than progression, which could be involved in the underlying mechanism of esophagogastric junction carcinoma development.

A Systematic Review on Attenuation of PCSK9 in Relation to Atherogenesis Biomarkers Associated with Natural Products or Plant Bioactive Compounds in In Vitro Studies: A Critique on the Quality and Imprecision of Studies

A systematic review was performed to identify all the related publications describing PCSK9 and atherogenesis biomarkers attenuation associated with a natural product and plant bioactive compounds in in vitro studies. This review emphasized the imprecision and quality of the included research rather than the detailed reporting of the results. Literature searches were conducted in Scopus, PubMed, and Science Direct from 2003 until 2021, following the Cochrane handbook. The screening of titles, abstracts, and full papers was performed by two independent reviewers, followed by data extraction and validity. Study quality and validity were assessed using the Imprecision Tool, Model, and Marker Validity Assessment that has been developed for basic science studies. A total of 403 articles were identified and 31 of those that met the inclusion criteria were selected. 13 different atherogenesis biomarkers in relation to PCSK9 were found, and the most studied biomarkers are LDLR, SREBP, and HNF1α. In terms of quality, our review suggests that the basic science study in investigating atherogenesis biomarkers is deficient in terms of imprecision and validity.

Increased PXR and Suppressed T-Cell Signaling Are Associated With Malignant Degeneration of Barrett's Esophagus

Background and Aims

Barrett's esophagus (BE) is the precursor lesion for esophageal adenocarcinoma (EAC). To detect EAC in early stage, patients with BE undergo endoscopic surveillance. Surveillance cohorts largely consist of nondysplastic BE (NDBE) patients with a low annual progression risk (<0.5%). Predictive biomarkers for malignant progression of NDBE could improve efficacy of surveillance. Biomarker research has mostly focused on aberrant protein expression on BE epithelial cells. Moreover, insight in cell signaling driving malignant transformation is unknown. This study uses a data-driven approach to analyze tumor-stroma interaction in NDBE which progressed to high-grade dysplasia or EAC.

Methods

In this case-control study, we performed RNA sequencing analysis on index NDBE biopsies from 6 patients who, during long-term follow-up, progressed and 7 who did not progress to high-grade dysplasia/EAC. For control samples, squamous and duodenum tissues from BE patients were analyzed. For validation, we used quantitative PCR.

Results

Significant differences in BE transcriptomic profiles between progressors and nonprogressors were found by principal component and differential expression analyses. Ingenuity pathway analysis indicated that 8 cell signaling pathways were significantly upregulated in the progressors, and 14 pathways were significantly downregulated. The most interesting finding was the upregulation of the xenobiotic metabolism pregnane X receptor signaling pathway in the progressor cohort, while of the downregulated pathways in progressors, several were related to the immune system.

Conclusion

These novel transcriptomic insights are fundamental for developing (chemo-)preventive therapies. These could be therapies, which protect against toxins, including biles, responsible for pregnane X receptor activation or which enhance protective immune mechanisms. The identified RNA markers are promising biomarkers for improving risk stratification in surveillance programs.

Barrett's Metaplasia Progression towards Esophageal Adenocarcinoma: An Attempt to Select a Panel of Molecular Sensors and to Reflect Clinical Alterations by Experimental Models

The molecular processes that predispose the development of Barrett’s esophagus (BE) towards esophageal adenocarcinoma (EAC) induced by gastrointestinal reflux disease (GERD) are still under investigation. In this study, based on a scientific literature screening and an analysis of clinical datasets, we selected a panel of 20 genes covering BE- and EAC-specific molecular markers (FZD5, IFNGR1, IL1A, IL1B, IL1R1, IL1RN, KRT4, KRT8, KRT15, KRT18, NFKBIL1, PTGS1, PTGS2, SOCS3, SOX4, SOX9, SOX15, TIMP1, TMEM2, TNFRSF10B). Furthermore, we aimed to reflect these alterations within an experimental and translational in vitro model of BE to EAC progression. We performed a comparison between expression profiles in GSE clinical databases with an in vitro model of GERD involving a BE cell line (BAR-T) and EAC cell lines (OE33 and OE19). Molecular responses of cells treated with acidified bile mixture (BM) at concentration of 100 and 250 μM for 30 min per day were evaluated. We also determined a basal mRNA expression within untreated, wild type cell lines on subsequent stages of BE and EAC development. We observed that an appropriately optimized in vitro model based on the combination of BAR-T, OE33 and OE19 cell lines reflects in 65% and more the clinical molecular alterations observed during BE and EAC development. We also confirmed previous observations that exposure to BM (GERD in vitro) activated carcinogenesis in non-dysplastic cells, inducing molecular alternations in the advanced stages of BE. We conclude that it is possible to induce, to a high extent, the molecular profile observed clinically within appropriately and carefully optimized experimental models, triggering EAC development. This experimental scheme and molecular marker panel might be implemented in further research, e.g., aiming to develop and evaluate novel compounds and prodrugs targeting GERD as well as BE and EAC prevention and treatment.

DNA methylation markers in esophageal cancer: an emerging tool for cancer surveillance and treatment

Esophageal carcinoma (EC) is one of the most pervasive cancers in the world, with upwards of 500,000 new diagnoses, annually. Despite its prominence, advancements in the detection and treatment of EC have been marginal over the past 30 years and the survival rate continues to stay below 20%. This is due to the uncommonly heterogeneous presentation of EC which presents unprecedented challenges in improving patient survival and quality of care. However, distinct epigenetic alterations to the DNA methylome may provide an avenue to drastically improve the detection and treatment of EC. Specifically, the creation of novel biomarker panels that consist of EC-specific methylation markers have shown promise as a potential alternative to the more invasive, contemporary diagnostic methods. Additionally, growing insight into the biological and clinical properties of EC-specific methylation patterns have opened a window of opportunity for enhanced treatment; of growing interest is the application of "DNMT inhibitors" - a class of drugs which inhibit excessive methylation and have been shown to re-sensitize chemoresistant tumors. Here we provide a comprehensive review of the current advancements in EC DNA methylation to underscore a potential approach to its detection and treatment.

Barrett's Epithelium to Esophageal Adenocarcinoma: Is There a "Point of No Return"?

Background: Esophageal adenocarcinoma (EA) arises from Barrett's epithelium (BE), and chronic gastroesophageal reflux disease is considered the strongest risk factor for disease progression. All BE patients undergo acid suppressive therapy, surveillance, and BE removal by surgery or endoscopic ablation, yet the incidence of EAC continues to increase. Despite the known side effects and mortality, the one-size-fits-all approach is the standard clinical management as there are no reliable methods for risk stratification. Methods: Paired-end Illumina NextSeq500 RNA sequencing was performed on total RNA extracted from 20-week intervals (0, 20, 40, and 60 W) of an in vitro BE carcinogenesis (BEC) model to construct time series global gene expression patterns (GEPs). The cells from two strategic time points (20 and 40 W) based on the GEPs were grown for another 20 weeks, with and without further acid and bile salt (ABS) stimulation, and the recurrent neoplastic cell phenotypes were evaluated. Results: Hierarchical clustering of 866 genes with ≥ twofold change in transcript levels across the four time points revealed maximum variation between the BEC20W and BEC40W cells. Enrichment analysis confirmed that the genes altered ≥ twofold during this window period associated with carcinogenesis and malignancy. Intriguingly, the BEC20W cells required further ABS exposure to gain neoplastic changes, but the BEC40W cells progressed to malignant transformation after 20 weeks even in the absence of additional ABS. Discussion: The transcriptomic gene expression patterns in the BEC model demonstrate evidence of a clear threshold in the progression of BE to malignancy. Catastrophic transcriptomic changes during a window period culminate in the commitment of the BE cells to a "point of no return," and removal of ABS is not effective in preventing their malignant transformation. Discerning this "point of no return" during BE surveillance by tracking the GEPs has the potential to evaluate risk of BE progression and enable personalized clinical management.

Bile reflux and hypopharyngeal cancer (Review)

Laryngopharyngeal reflux, a variant of gastroesophageal reflux disease, has been considered a risk factor in the development of hypopharyngeal cancer. Bile acids are frequently present in the gastroesophageal refluxate and their effect has been associated with inflammatory and neoplastic changes in the upper aerodigestive tract. Recent in vitro and in vivo studies have provided direct evidence of the role of acidic bile refluxate in hypopharyngeal carcinogenesis and documented the crucial role of NF-κB as a key mediator of early oncogenic molecular events in this process and also suggested a contribution of STAT3. Acidic bile can cause premalignant changes and invasive squamous cell cancer in the affected hypopharynx accompanied by DNA damage, elevated p53 expression and oncogenic mRNA and microRNA alterations, previously linked to head and neck cancer. Weakly acidic bile can also increase the risk for hypopharyngeal carcinogenesis by inducing DNA damage, exerting anti-apoptotic effects and causing precancerous lesions. The most important findings that strongly support bile reflux as an independent risk factor for hypopharyngeal cancer are presented in the current review and the underlying mechanisms are provided.

PDZK1 induces resistance to apoptosis in esophageal adenocarcinoma cells

BACKGROUND

Esophageal cancer is a lethal malignancy with a poor prognosis. The incidence of esophageal adenocarcinoma, which develops from Barrett's esophagus (BE), has recently been increasing. In a previous study, we found that PDZK1 expression is higher in long segment BE compared to that in short-segment BE. However, the function of PDZK1 in the mucosa of BE is unclear.

AIMS

Clarify the role of PDZK1 in BE mucosa using PDZK1 overexpressed cells.

METHODS

Human adenocarcinoma-derived OE33 cells were used as a parental cell line and transfected to generate PDZK1 overexpressed OE33 cells (PC cells) or transfected with empty vector as control cells (NC cells). Cell growth of NC and PC cells in 10% fetal bovine serum was evaluated by cell counting. The effect of PDZK1 on proteasome inhibitor (PSI)-induced apoptosis was qualified by fluorescence microscopy and quantified by flow cytometry. Expression of apoptosis-related proteins was evaluated by western blotting.

RESULTS

There were no significant differences in cell growth between NC and PC cells. PSI significantly increased apoptosis in NC cells, but not in PC cells. In response to PSI, increased levels of cleaved-caspase3 and decreased pro-caspase3 levels were found in NC cells, but not in PC cells. In NC cells, PSI significantly decreased Bcl-2 expression without affecting Bax levels. In contrast, high expression of both Bcl-2 and Bax was observed in PC cells.

CONCLUSION

Overexpression of PDZK1 protein induces an apoptosis-resistant phenotype in BE cells, which may be a potential therapeutic target.

Forkhead box F1 induces columnar phenotype and epithelial-to-mesenchymal transition in esophageal squamous cells to initiate Barrett's like metaplasia

Multiple genome-wide association studies (GWAS) have linked Forkhead Box F1 (FOXF1) to Barrett's esophagus (BE). Understanding whether FOXF1 is involved in initiation of Barrett's metaplasia could allow FOXF1 to be used for risk stratification and for therapy. Two-dimensional cell cultures and three-dimensional organoid cultures and well-annotated human biopsies were used to determine the role of FOXF1 in BE pathogenesis. Multiple established esophageal squamous and BE cell lines were tested in gain- and loss-of-function studies. Initiation of a BE-like metaplastic change was evaluated by measuring characteristic cytokeratins and global gene expression profiling and by culturing organoids. Epithelial-mesenchymal transition (EMT) was evaluated by immunostaining for E-cadherin, vimentin and Snail, and by cell motility assay. Columnar esophageal epithelium of BE patients exhibited higher expression of FOXF1 compared to normal squamous esophageal epithelium of GERD patients (P < 0.001). Acidic bile salts induced nuclear FOXF1 in esophageal squamous cells. FOXF1 overexpression in normal esophageal squamous cells: (a) increased columnar cytokeratins and decreased squamous cytokeratins, (b) converted squamous organoids to glandular organoids, and (c) switched global gene profiles to resemble that of human BE epithelium (P = 2.1685e - 06 for upregulated genes and P = 8.3378e - 09 for downregulated genes). FOXF1 inhibition in BE cell lines led to loss of BE differentiation markers, CK7, and mucin 2. Also, FOXF1 induced EMT and promoted cell motility in normal esophageal squamous epithelial cells. FOXF1-induced genes mapped to pathways such as Cancer, Cellular Assembly and Organization, DNA Replication, Recombination, and Repair. In conclusion, FOXF1 promotes a BE-like columnar phenotype and cell motility in esophageal squamous epithelial cells, which may have a critical role in BE development. FOXF1 should be studied further as a biomarker for BE and as a target for BE treatment.

Weakly Acidic Bile Is a Risk Factor for Hypopharyngeal Carcinogenesis Evidenced by DNA Damage, Antiapoptotic Function, and Premalignant Dysplastic Lesions In Vivo

Simple Summary

The etiologic role of biliary reflux in hypopharyngeal cancer is supported by clinical data. Although, reflux episodes often occur at pH 4.0, they can also occur at weakly acidic pH (5.5–6.0). The carcinogenic effect of bile at strongly acidic pH (pH 3.0) was recently documented in vivo. Here, we provide novel in vivo evidence that a weakly acidic pH of 5.5, similarly to a strongly acidic pH of 3.0, increases the risk of bile-related hypopharyngeal neoplasia. We document that chronic exposure of hypopharyngeal mucosa to bile at pH 5.5 promotes premalignant lesions with DNA damage, NF-κB activation, and deregulated mRNA and miRNA phenotypes, including Bcl-2 and miR-451a. The oncogenic effects of bile over a wider pH range suggests that antacid therapy may be insufficient to fully modify the effects of a bile induced oncogenic effect.

Abstract

Background: There is recent in vivo discovery documenting the carcinogenic effect of bile at strongly acidic pH 3.0 in hypopharynx, while in vitro data demonstrate that weakly acidic bile (pH 5.5) has a similar oncogenic effect. Because esophageal refluxate often occurs at pH > 4.0, here we aim to determine whether weakly acidic bile is also carcinogenic in vivo. Methods: Using 32 wild-type mice C57B16J, we performed topical application of conjugated primary bile acids with or without unconjugated secondary bile acid, deoxycholic acid (DCA), at pH 5.5 and controls, to hypopharyngeal mucosa (HM) twice per day, for 15 weeks. Results: Chronic exposure of HM to weakly acidic bile, promotes premalignant lesions with microinvasion, preceded by significant DNA/RNA oxidative damage, γH2AX (double strand breaks), NF-κB and p53 expression, overexpression of Bcl-2, and elevated Tnf and Il6 mRNAs, compared to controls. Weakly acidic bile, without DCA, upregulates the “oncomirs”, miR-21 and miR-155. The presence of DCA promotes Egfr, Wnt5a, and Rela overexpression, and a significant downregulation of “tumor suppressor” miR-451a. Conclusion: Weakly acidic pH increases the risk of bile-related hypopharyngeal neoplasia. The oncogenic properties of biliary esophageal reflux on the epithelium of the upper aerodigestive tract may not be fully modified when antacid therapy is applied. We believe that due to bile content, alternative therapeutic strategies using specific inhibitors of relevant molecular pathways or receptors may be considered in patients with refractory GERD.

Lipid droplet biogenesis and COX-2 pathway activation are triggered by Barrett's esophagus and adenocarcinoma, but not esophageal squamous cell carcinoma risk factors

Esophageal cancer (EC) is an aggressive disease, presenting two main histological subtypes: adenocarcinoma (EAC) and squamous cell carcinoma (ESCC). The two EC subtypes widely differ concerning virtually all factors. ESCC development is mainly associated with tobacco and alcohol abuse, whereas obesity and chronic gastroesophageal reflux disease (GERD) are important risk factors not only for EAC, but also for for Barrett’s esophagus (BE), an intestinal metaplasia that precedes EAC. Obesity triggers ectopic lipid droplets (LD) accumulation in non-adipose tissues. LD are organelles involved in cell metabolism, signaling, proliferation and production of inflammatory mediators. Therefore, the aim of this work was to investigate LD occurrence and role in EC. This study shows progressive LD levels increase along EAC development, in esophageal samples from non-obese through obese individuals, as well as BE, and EAC patients, whereas no significant changes were observed in ESCC samples, when compared to non-tumor samples. Additionally, in order to mimic BE and EAC risk factors exposure, a non-tumor esophageal cell line was incubated with oleic acid (OA) and acidified medium and/or deoxycholic acid (DCA), revealing a significant increment in LD amount as well as in COX-2 and CXCL-8 expression, and in IL-8 secretion. Further, COX-2 expression and LD amount presented a significant positive correlation and were detected co-localized in EAC, but not in ESCC, suggesting that LD may be the site for eicosanoid production in EAC. In conclusion, this study shows that obesity, and BE- and EAC-associated inflammatory stimuli result in a gradual increase of LD, that may be responsible for orchestrating inflammatory mediators’ production and/or action, thus contributing to BE and EAC genesis and progression.

Molecular Profile of Barrett's Esophagus and Gastroesophageal Reflux Disease in the Development of Translational Physiological and Pharmacological Studies

Barrett's esophagus (BE) is a premalignant condition caused by gastroesophageal reflux disease (GERD), where physiological squamous epithelium is replaced by columnar epithelium. Several in vivo and in vitro BE models were developed with questionable translational relevance when implemented separately. Therefore, we aimed to screen Gene Expression Omnibus 2R (GEO2R) databases to establish whether clinical BE molecular profile was comparable with animal and optimized human esophageal squamous cell lines-based in vitro models. The GEO2R tool and selected databases were used to establish human BE molecular profile. BE-specific mRNAs in human esophageal cell lines (Het-1A and EPC2) were determined after one, three and/or six-day treatment with acidified medium (pH 5.0) and/or 50 and 100 µM bile mixture (BM). Wistar rats underwent microsurgical procedures to generate esophagogastroduodenal anastomosis (EGDA) leading to BE. BE-specific genes (keratin (KRT)1, KRT4, KRT5, KRT6A, KRT13, KRT14, KRT15, KRT16, KRT23, KRT24, KRT7, KRT8, KRT18, KRT20, trefoil factor (TFF)1, TFF2, TFF3, villin (VIL)1, mucin (MUC)2, MUC3A/B, MUC5B, MUC6 and MUC13) mRNA expression was assessed by real-time PCR. Pro/anti-inflammatory factors (interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, tumor necrosis factor α, interferon γ, granulocyte-macrophage colony-stimulating factor) serum concentration was assessed by a Luminex assay. Expression profile in vivo reflected about 45% of clinical BE with accompanied inflammatory response. Six-day treatment with 100 µM BM (pH 5.0) altered gene expression in vitro reflecting in 73% human BE profile and making this the most reliable in vitro tool taking into account two tested cell lines. Our optimized and established combined in vitro and in vivo BE models can improve further physiological and pharmacological studies testing pathomechanisms and novel therapeutic targets of this disorder.

Glyco-conjugated bile acids drive the initial metaplastic gland formation from multi-layered glands through crypt-fission in a murine model

Bile acid reflux is known to be associated with the development of Barrett’s esophagus and esophageal adenocarcinoma (EAC), yet the role of specific bile acids and the mechanism behind the metaplastic changes is unclear. Here, we demonstrate that multi-layered glandular structures at the squamo-columnar junction in mice contain multiple cell lineages, which resemble the human esophageal submucosal gland ducts. Exposing mice to patient’s refluxates induced expansion of multi-layered glandular structures and development of columnar metaplasia at the squamo-columnar junction. The glycine conjugated bile acids induced an intestinal type of metaplasia more typical for Barrett’s esophagus. Through lineage tracing, we excluded the involvement of K5⁺, DCLK1⁺, and LGR5⁺ progenitor cells as the primary source in the development of the glandular metaplastic epithelium. We show that the mechanism behind development of metaplasia involves crypt fission and may be independent of stem cell proliferation. Our findings support the hypothesis that in humans, BE arises from non-squamous cells residing in submucosal gland ducts and that induction of intestinal type of metaplasia is most effectively induced by glycine-conjugated bile acids. These novel insights may lead to more effective strategies to prevent development of Barrett’s esophagus and esophageal adenocarcinoma.

Preclinical models for the study of Barrett's carcinogenesis

Barrett's esophagus (BE) is clinically significant, as it is the only known precursor lesion for esophageal adenocarcinoma. To develop improved therapies for the treatment of BE, a greater understanding of the disease process at the molecular genetic level is needed. However, achieving a greater understanding will require improved preclinical models so that the disease process can be more closely studied and novel therapies can be tested. Our concise review highlights progress in the development of preclinical models for the study of BE and identifies the most suitable model in which to test novel therapies.

Bile acid and cigarette smoke enhance the aggressive phenotype of esophageal adenocarcinoma cells by downregulation of the mitochondrial uncoupling protein-2

Limited information is available regarding mechanisms that link the known carcinogenic risk factors of gastro-esophageal reflux and cigarette smoking to metabolic alterations in esophageal adenocarcinoma (EAC). In the present study, we utilized a novel in-vitro model to examine whether bile acid and cigarette smoke increase the aggressiveness of EAC and whether these changes are associated with metabolic changes. EAC cells (EACC) were exposed to 10 μg/ml cigarette smoke condensate (CSC) and/or 100 μM of the oncogenic bile acid, deoxycholic acid (DCA), for 5 days. These exposure conditions were chosen given their lack of effect on proliferation or viability. DCA and CSC increased invasion, migration, and clonogenicity in EAC cells. These changes were associated with concomitant increases in ATP, ROS, and lactate production indicative of increased mitochondrial respiration as well as glycolytic activity. DCA and CSC exposure significantly decreased expression of uncoupling protein-2 (UCP2), a mitochondrial inner membrane protein implicated in regulation of the proton gradient. Knockdown of UCP2 in EACC phenocopied DCA and CSC exposure as evidenced by increased cell migration, invasion, and clonogenicity, whereas over-expression of UCP2 had an inverse effect. Furthermore, over-expression of UCP2 abrogated DCA and CSC-mediated increases in lactate and ATP production in EACC. DCA and CSC promote the aggressive phenotype of EACC with concomitant metabolic changes occurring via downregulation of UCP2. These results indicate that UCP2 is integral to the aggressive phenotype of EACC. This mechanism suggests that targeting alterations in cellular energetics may be a novel strategy for EAC therapy.

A systematic review of the asymmetric inheritance of cellular organelles in eukaryotes: A critique of basic science validity and imprecision

We performed a systematic review to identify all original publications describing the asymmetric inheritance of cellular organelles in normal animal eukaryotic cells and to critique the validity and imprecision of the evidence. Searches were performed in Embase, MEDLINE and Pubmed up to November 2015. Screening of titles, abstracts and full papers was performed by two independent reviewers. Data extraction and validity were performed by one reviewer and checked by a second reviewer. Study quality was assessed using the SYRCLE risk of bias tool, for animal studies and by developing validity tools for the experimental model, organelle markers and imprecision. A narrative data synthesis was performed. We identified 31 studies (34 publications) of the asymmetric inheritance of organelles after mitotic or meiotic division. Studies for the asymmetric inheritance of centrosomes (n = 9); endosomes (n = 6), P granules (n = 4), the midbody (n = 3), mitochondria (n = 3), proteosomes (n = 2), spectrosomes (n = 2), cilia (n = 2) and endoplasmic reticulum (n = 2) were identified. Asymmetry was defined and quantified by variable methods. Assessment of the statistical reliability of the results indicated only two studies (7%) were judged to have low concern, the majority of studies (77%) were 'unclear' and five (16%) were judged to have 'high concerns'; the main reasons were low technical repeats (<10). Assessment of model validity indicated that the majority of studies (61%) were judged to be valid, ten studies (32%) were unclear and two studies (7%) were judged to have 'high concerns'; both described 'stem cells' without providing experimental evidence to confirm this (pluripotency and self-renewal). Assessment of marker validity indicated that no studies had low concern, most studies were unclear (96.5%), indicating there were insufficient details to judge if the markers were appropriate. One study had high concern for marker validity due to the contradictory results of two markers for the same organelle. For most studies the validity and imprecision of results could not be confirmed. In particular, data were limited due to a lack of reporting of interassay variability, sample size calculations, controls and functional validation of organelle markers. An evaluation of 16 systematic reviews containing cell assays found that only 50% reported adherence to PRISMA or ARRIVE reporting guidelines and 38% reported a formal risk of bias assessment. 44% of the reviews did not consider how relevant or valid the models were to the research question. 75% reviews did not consider how valid the markers were. 69% of reviews did not consider the impact of the statistical reliability of the results. Future systematic reviews in basic or preclinical research should ensure the rigorous reporting of the statistical reliability of the results in addition to the validity of the methods. Increased awareness of the importance of reporting guidelines and validation tools is needed for the scientific community.

Gastro-duodenal fluid induced nuclear factor-κappaB activation and early pre-malignant alterations in murine hypopharyngeal mucosa

We recently described the role of gastro-duodenal fluids (GDFs) in generating changes consistent with hypopharyngeal neoplasia through activation of NF-κB pathway, using an in vitro model of human hypopharyngeal normal keratinocytes. Here, we further provide evidence that gastro-duodenal reflux is a risk factor for early pre-malignant alterations in hypopharyngeal mucosa (HM) related to an activated NF-κB oncogenic pathway, using both an in vitro and a novel in vivo model of C57Bl/6J mice. Histological, immunohistochemical and automated quantitative analysis documents significant NF-κB activation and early pre-malignant alterations in HM topically exposed to GDFs, compared to acid alone and other controls. Early pre-malignant histologic lesions exhibited increased Ki67, CK14 and ΔNp63, cell proliferation markers, changes of cell adhesion molecules, E-Cadherin and β-catenin, and STAT3 activation. The in vivo effect of NF-κB activation is positively correlated with p-STAT3, Ki67, CK14 or β-catenin expression, while GDFs induce significant transcriptional activation of RELA(p65), bcl-2, TNF-α, STAT3, EGFR and wnt5A, in vivo. Our in vivo model demonstrates selectively activated NF-κB in response to topically administrated GDFs, leading to early pre-malignant events in HM.

The cancer genome: from structure to function

The 2014 joint meeting of the International Society for Cellular Oncology (ISCO) and the European Workshop on Cytogenetics and Molecular Genetics of Solid Tumors (EWCMST), organized by Nick Gilbert, Juan Cigudosa and Bauke Ylstra, was held from 11 to 14 May in Malaga, Spain. Since the previous meeting in 2012, the ever increasing availability of new sequencing technologies has enabled the analysis of cancer genomes at an increasingly greater detail. In addition to structural changes in the genome (i.e., translocations, deletions, amplifications), frequent mutations in important regulatory genes have been found to occur, as also frequent alterations in a large number of epigenetic factors. The challenge now is to relate structural changes in cancer genomes to the underlying disease mechanisms and to reveal opportunities for the design of novel (targeted) therapies. During the meeting, various topics related to these challenges and opportunities were addressed, including those dealing with functional genomics, genome instability, biomarkers and diagnostics, cancer genetics and epigenomics. Special attention was paid to therapy-driven cancer evolution (keynote lecture) and relationships between DNA repair, cancer and ageing (Prof. Ploem lecture). Based on the information presented at the meeting, several aspects of the cancer genome and its functional implications are provided in this report.

Upregulation of miRNA-143, -145, -192, and -194 in esophageal epithelial cells upon acidic bile salt stimulation

Barrett's esophagus (BE) is a metaplastic condition of the distal esophagus that occurs because of chronic gastroesophageal reflux. Previous studies have identified BE-specific microRNAs (miRNAs) in comparison with normal squamous epithelium (SQ). We hypothesized that BE-specific miRNAs could be induced in esophageal SQ cells by exposure to acid and/or bile salts. We aimed to determine whether BE-specific miRNAs are upregulated in an esophageal SQ cell line (Het-1A) in an environment with acid and/or bile salts and whether this is nuclear factor-κB (NF-κB) dependent. Acid and/or bile salt incubations were performed in Het-1A cells. Experiments were performed with or without inhibiting the NF-κB pathway. Quantitative reverse transcriptase polymerase chain reaction was performed to determine expression of miRNA-143, -145, -192, -194, cyclo-oxygenase-2 (COX2), mucin 2 (MUC2), and sex determining region Y-box 9. For validation, we determined levels of these miRNAs in biopsies from patients with reflux esophagitis and normal SQ. Significantly increased expression levels of miRNA-143 (2.7-fold), -145 (2.6-fold), -192 (2.0-fold), -194 (2.2-fold), COX2, MUC2, and sex determining region Y-box 9 were found upon acidic bile salt incubation, but not upon acid or bile salt alone. NF-κB pathway inhibition significantly decreased miRNA-143, -192, -194, COX2, and MUC2 expression. Additionally, miRNA-143, -145 and -194 expression was increased in reflux esophagitis biopsies compared with normal SQ, but no changes were found in miRNA-192 expression. Our findings suggest that upregulation of BE-specific miRNAs by acidic bile may be an early event in the transition of SQ to BE and that their expression is partly regulated by the NF-κB pathway.