Sitravatinib combined with PD-1 blockade enhances cytotoxic T-cell infiltration by M2 to M1 tumor macrophage repolarization in esophageal adenocarcinoma.

Esophageal adenocarcinoma (EAC) is a leading cause of cancer-related mortality. Sitravatinib is a novel multi-gene tyrosine kinase inhibitor (TKI) that targets tumor-associated macrophage (TAM) receptors, VEGF, PDGF and c-Kit. Currently, sitravatinib is actively being studied in clinical trials across solid tumors and other TKIs have shown efficacy in combination with immune checkpoint inhibitors (ICI) in cancer models. In this study, we investigated the anti-tumor activity of sitravatinib alone and in combination with PD-1 blockade in an EAC rat model. Treatment response was evaluated by mortality, pre- and post-treatment MRI, gene expression, immunofluorescence and immunohistochemistry. Our results demonstrated adequate safety and significant tumor shrinkage in animals treated with sitravatinib, and more profoundly, sitravatinib and PD-1 inhibitor, AUNP-12 (P < 0.01). Suppression of TAM receptors resulted in increased gene expression of pro-inflammatory cytokines and decreased expression of anti-inflammatory cytokines, enhanced infiltration of CD8+ T cells, and M2 to M1 macrophage phenotype repolarization in the tumor microenvironment of treated animals (P < 0.01). Moreover, endpoint immunohistochemistry staining corroborated the anti-tumor activity by downregulation of Ki67 and upregulation of Caspase-3 in the treated animals. Additionally, pretreatment gene expression of TAM receptors and PD-L1 were significantly higher in major responders compared with the non-responders, in animals that received sitravatinib and AUNP-12 (P < 0.02), confirming that TAM suppression enhances the efficacy of PD-1 blockade. In conclusion, this study proposes a promising immunomodulatory strategy using a multi-gene TKI to overcome developed resistance to an ICI in EAC, establishing rationale for future clinical development.

Comparing Survival After Resection, Ablation, and Radiation in Small Intrahepatic Cholangiocarcinoma.

BACKGROUND: Hepatectomy is the cornerstone of curative-intent treatment for intrahepatic cholangiocarcinoma (ICC). However, in patients unable to be resected, data comparing efficacy of alternatives including thermal ablation and radiation therapy (RT) remain limited. Herein, we compared survival between resection and other liver-directed therapies for small ICC within a national cancer registry. PATIENTS AND METHODS: Patients with clinical stage I-III ICC < 3 cm diagnosed 2010-2018 who underwent resection, ablation, or RT were identified in the National Cancer Database. Overall survival (OS) was compared using Kaplan-Meier and multivariable Cox proportional hazards methods. RESULTS: Of 545 patients, 297 (54.5%) underwent resection, 114 (20.9%) ablation, and 134 (24.6%) RT. Median OS was similar between resection and ablation [50.5 months, 95% confidence interval (CI) 37.5-73.9; 39.5 months, 95% CI 28.7-58.4, p = 0.14], both exceeding that of RT (20.9 months, 95% CI 14.1-28.3). RT patients had high rates of stage III disease (10.4% RT vs. 1.8% ablation vs. 11.8% resection, p < 0.001), but the lowest rates of chemotherapy utilization (9.0% RT vs. 15.8% ablation vs. 38.7% resection, p < 0.001). In multivariable analysis, resection and ablation were associated with reduced mortality compared with RT [hazard ratio (HR) 0.44, 95% CI 0.33-0.58 and HR 0.53, 95% CI 0.38-0.75, p < 0.001, respectively]. CONCLUSION: Resection and ablation were associated with improved survival in patients with ICC < 3 cm compared with RT. Acknowledging confounders, anatomic constraints of ablation, limitations of available data, and need for prospective study, these results favor ablation in small ICC where resection is not feasible.

The effect of normal, metaplastic, and neoplastic esophageal extracellular matrix upon macrophage activation.

INTRODUCTION: Macrophages are capable of extreme plasticity and their activation state has been strongly associated with solid tumor growth progression and regression. Although the macrophage response to extracellular matrix (ECM) isolated from normal tissue is reasonably well understood, there is a relative dearth of information regarding their response to ECM isolated from chronically inflamed tissues, pre-neoplastic tissues, and neoplastic tissues. Esophageal adenocarcinoma (EAC) is a type of neoplasia driven by chronic inflammation in the distal esophagus, and the length of the esophagus provides the opportunity to investigate macrophage behavior in the presence of ECM isolated from a range of disease states within the same organ. METHODS: Normal, metaplastic, and neoplastic ECM hydrogels were prepared from decellularized EAC tissue. The hydrogels were evaluated for their nanofibrous structure (SEM), biochemical profile (targeted and global proteomics), and direct effect upon macrophage (THP-1 cell) activation state (qPCR, ELISA, immunolabeling) and indirect effect upon epithelial cell (Het-1A) migration (Boyden chamber). RESULTS: Nanofibrous ECM hydrogels from the three tissue types could be formed, and normal and neoplastic ECM showed distinctive protein profiles by targeted and global mass spectroscopy. ECM proteins functionally related to cancer and tumorigenesis were identified in the neoplastic esophageal ECM including collagen alpha-1(VIII) chain (COL8A1), lumican, and elastin. Metaplastic and neoplastic esophageal ECM induce distinctive effects upon THP-1 macrophage signaling compared to normal esophageal ECM. These effects include activation of pro-inflammatory IFNγ and TNFα gene expression and anti-inflammatory IL1RN gene expression. Most notably, neoplastic ECM robustly increased macrophage TNFα protein expression. The secretome of macrophages pre-treated with metaplastic and neoplastic ECM increases the migration of normal esophageal epithelial cells, similar behavior to that shown by tumor cells. Metaplastic ECM shows similar but less pronounced effects than neoplastic ECM suggesting the abnormal signals also exist within the pre-cancerous state. CONCLUSION: A progressively diseased ECM, as exists within the esophagus exposed to chronic gastric reflux, can provide insights into novel biomarkers of early disease and identify potential therapeutic targets.

Intratumoral immunotherapy with STING agonist, ADU-S100, induces CD8+ T-cell mediated anti-tumor immunity in an esophageal adenocarcinoma model.

BACKGROUND: Esophageal adenocarcinoma (EAC) is a deadly disease with limited treatment options. STING is a transmembrane protein that activates transcription of interferon genes, resulting in stimulation of APCs and enhanced CD8+ T-cell infiltration. The present study evaluates STING agonists, alone and in combination with radiation to determine durable anticancer activity in solid tumors. MATERIALS AND METHODS: Esophagojejunostomy was performed on rats to induce reflux leading to the development of EAC. At 32 weeks post operatively, rats received intratumorally either 50 µg STING (ADU-S100) or placebo (PBS), +/- 16Gy radiation. Drug activity was evaluated by pre- and post- treatment MRI, histology, immunofluorescence and RT-PCR. RESULTS: Mean MRI tumor volume decreased by 30.1% and 50.8% in ADU-S100 and ADU-S100 + radiation animals and increased by 76.7% and 152.4% in placebo and placebo + radiation animals, respectively (P < 0.0001). Downstream gene expression, pre- to on- and post- treatment, demonstrated significant upregulation of IFNß, TNFα, IL-6, and CCL-2 in the treatment groups vs. placebo. On- or post- treatment, radiation alone, ADU-S100 alone, and ADU-S100 + radiation groups demonstrated enhanced PD-LI expression, induced by upregulation of CD8+ T-cells (p < 0.01). CONCLUSIONS: ADU-S100 +/- radiation exhibits potent antitumor activity and a promising immunomodulatory profile in a de novo EAC.

Prognostic immune markers for recurrence and survival in locally advanced esophageal adenocarcinoma.

Treatment options and risk stratification for esophageal adenocarcinomas (EAC) currently rely on pathological criteria such as tumor staging. However, with advancement in immune modulated treatments, there is a need for accurate predictive biomarkers that will help identify high-risk patients and provide novel therapeutic targets. Hence, we analyzed as prognostic classifiers a host of histopathological parameters in conjunction with novel immune biomarkers. Specifically, gene expression levels for CXCL9, IDO1, LAG3, and TIM3 were established in treatment naïve samples. Additionally, PD-L1 and CD8 positivity was determined by immunohistochemical staining. Based on our finding, a Cox model consisting of pathological complete response (CR), LAG3, and CXCL9 provided improved predictability for disease-free survival (DFS) compared to CR alone, and it demonstrated statistical significance for predictability of recurrence (p=0.0001). Likewise, for overall survival (OS), a Cox model constituted of TIM3, CR, and IDO1 performed better than CR alone, and it demonstrated statistical significance for predictability of survival (p = 0.0004). TIM3 was identified as the best predictor for OS (HR=4.43, p=0.0023). In conclusion, given the paucity of treatment options for EAC, evaluation of these biomarkers early in the disease course will lead to better risk stratification of patients and much needed alternatives for improved therapy.

Extracellular Matrix Degradation Products Downregulate Neoplastic Esophageal Cell Phenotype.

IMPACT STATEMENT: Extracellular matrix (ECM) biomaterials were used to treat esophageal cancer patients after cancer resection and promoted regrowth of normal mucosa without recurrence of cancer. The present study investigates the mechanisms by which these materials were successful to prevent the cancerous phenotype. ECM downregulated neoplastic esophageal cell function (proliferation, metabolism), but normal esophageal epithelial cells were unaffected in vitro, and suggests a molecular basis (downregulation of PI3K-Akt, cell cycle) for the promising clinical results. The therapeutic effect appeared to be enhanced using homologous esophageal ECM. This study suggests that ECM can be further investigated to treat cancer patients after resection or in combination with targeted therapy.

Serial Endoscopic Evaluation of Esophageal Disease in a Cancer Model: A Paradigm Shift for Esophageal Adenocarcinoma (EAC) Drug Discovery and Development.

A rat model of surgically induced reflux recapitulates the development and progression of human esophageal adenocarcinoma (EAC). In this study, reflux was induced in rats followed by postoperative endoscopy with biopsy, to diagnose and monitor disease progression. Overall, percentage agreement between visual endoscopy and gold standard histology was 95%, with disease-specific classification accuracies of 100% and 75% for Barrett's with dysplasia and EAC, respectively. Additionally, the percentage agreement for biopsy in tumors >4 mm was 75%. Thereby, establishing endoscopic evaluation as a reliable tool to assess disease progression and provide biopsies for downstream correlates in a de novo EAC model.

The Potential Clinical Utility of Circulating Tumor DNA in Esophageal Adenocarcinoma: From Early Detection to Therapy.

Esophageal adenocarcinoma (EAC) is a lethal cancer requiring improved screening strategies and treatment options due to poor detection methods, aggressive progression, and therapeutic resistance. Emerging circulating tumor DNA (ctDNA) technologies may offer a unique non-invasive strategy to better characterize the highly heterogeneous cancer and more clearly establish the genetic modulations leading to disease progression. The presented review describes the potential advantages of ctDNA methodologies as compared to current clinical strategies to improve clinical detection, enhance disease surveillance, evaluate prognosis, and personalize treatment. Specifically, we describe the ctDNA-targetable genetic markers of prognostic significance to stratify patients into risk of progression from benign to malignant disease and potentially offer cost-effective screening of established cancer. We also describe the application of ctDNA to more effectively characterize the heterogeneity and particular mutagenic resistance mechanisms in real-time to improve prognosis and therapeutic monitoring strategies. Lastly, we discuss the inconsistent clinical responses to currently approved therapies for EAC and the role of ctDNA to explore the dynamic regulation of novel targeted and immunotherapies to personalize therapy and improve patient outcomes. Although there are clear limitations of ctDNA technologies for immediate clinical deployment, this review presents the prospective role of such applications to potentially overcome many of the notable hurdles to treating EAC patients. A deeper understanding of complex EAC tumor biology may result in the progress toward improved clinical outcomes.

Sep70/Pepsin expression in hypopharynx combined with hypopharyngeal multichannel intraluminal impedance increases diagnostic sensitivity of laryngopharyngeal reflux.

BACKGROUND: Improved methods of diagnosis of laryngopharyngeal reflux (LPR) would enable surgeons to better identify patients who may benefit from antireflux surgery (ARS). The objective of the present study was to assess if hypopharyngeal Pepsin and Sep70 expression combined with hypopharyngeal multichannel intraluminal impedance (HMII) has the potential to increase diagnostic sensitivity of LPR. METHODS: This study was performed on patients who underwent unsedated transnasal endoscopy with hypopharyngeal biopsy and 24-h HMII to determine abnormal proximal exposure (APE) and DeMeester score (DMS) from 2013 to 2016. Pepsin and Sep70 protein expression was assessed by Western blots of biopsy specimens. The outcomes of ARS were assessed using reflux symptom index (RSI). HMII APE classification, Sep 70, and Pepsin protein levels were compared in normative and symptomatic LPR patients and further analyzed alongside quality of life changes following ARS. RESULTS: Of 30 subjects enrolled, 23 were excluded for abnormal HMII results or endoscopic evidence of esophagitis. Seven subjects and 105 patients were included in the normative and symptomatic groups, respectively. Compared to the normative group, only Pepsin expression was significantly higher in the symptomatic group [APE+/LPR+ (p = 0.000), APE+/LPR- (p = 0.001), and APE- (p = 0.047)]. Further, the ratio of Sep70/Pepsin was significantly lower in the symptomatic group [APE+/LPR+ (p = 0.008), APE+/LPR- (p = 0.000), and APE- (p = 0.050)], and a cutoff ratio for a diagnosis of LPR was established as < 158. Of 105 symptomatic patients, 48 patients underwent ARS. Of these, 17 patients had complete pre- and post-RSI questionnaires. LPR symptoms improved in 15 (88%), of whom 2 were APE- but met criteria for a diagnosis of LPR based on the Sep70/Pepsin cutoff. CONCLUSIONS: The identified Sep70/Pepsin ratio may serve as a reliable biomarker for the diagnosis of LPR. As a result, this may help identify additional patients who have a false-negative HMII result due to the 24-h testing window.

The Dynamic and Transient Immune Microenvironment in Locally Advanced Esophageal Adenocarcinoma Post Chemoradiation.

OBJECTIVE: The aim of this study was to assess the impact of chemoradiation on the immune microenvironment to influence and optimally design future neoadjuvant clinical trials. SUMMARY BACKGROUND DATA: Programmed death (PD)-1 inhibitors in metastatic gastroesophageal cancer have demonstrated response rates of approximately 25% in programmed death ligand-1 (PD-L1+) tumors. Unfortunately, the majority of patients do not respond. Therefore, a rationale strategy of combining immunotherapeutic agents with chemoradiation in earlier stage esophageal cancer may prevent metastatic disease in patients. METHODS: To determine the effects of chemoradiation on resected esophageal adenocarcinomas, we examined the immune microenvironment pre- and post-chemoradiation using immunohistochemistry, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), and functional analysis of tumor-infiltrating lymphocytes. Additionally, to assess the duration and dependency of radiation-induced PD-L1 upregulation, a surgical rat reflux model of esophageal adenocarcinoma is used. First, tumor-bearing animals were dosed with single-fraction 13Gy or 16Gy radiation to determine safety, dose correlation, and PD-L1 upregulation using qRT-PCR post-radiation. Next, longitudinal PD-L1 expression levels within individual animals were determined using serial endoscopic biopsies at baseline, 1, 5, and 9 weeks post 16Gy radiation. RESULTS: The majority of cancers displayed enhanced interferon γ and activated CD8+ T lymphocytes at the tumor stroma interface. These tumors also demonstrated enhanced upregulation of PD-L1 and multiple other immune checkpoints including TIM3, GITR, IDO1, LAG3, OX40, and KIR. The animal model results indicated PD-L1 upregulation is dose-dependent and transiently elevated post radiation exposure. CONCLUSIONS: Collectively, these findings provide insights into the evolving immune landscape after chemoradiation and have significant implications for neoadjuvant trial designs that will combine radiotherapy with immune checkpoint inhibitors.

CDK4/6 dual inhibitor abemaciclib demonstrates compelling preclinical activity against esophageal adenocarcinoma: a novel therapeutic option for a deadly disease.

Esophageal adenocarcinoma (EAC) is a deadly disease with limited therapeutic options. In the present study, we determined the preclinical efficacy of CDK4/6 inhibitor abemaciclib for treatment of EAC. In vitro, apoptosis, proliferation, and pathway regulation were evaluated in OE19, OE33, and FLO1 EAC cell lines. In vivo, esophagojejunostomy was performed on rats to induce EAC. At 36 weeks post-surgery, MRI and endoscopic biopsy established baseline tumor volume and molecular correlates, respectively. Next, the study animals were randomized to 26mg/kg intraperitoneal abemaciclib treatment or vehicle control for 28 days. Pre and post treatment MRIs, histopathology, and qRT-PCR were utilized to determine response. Our results demonstrated treatment with abemaciclib lead to increased apoptosis, and decreased proliferation in OE19 (p=0.185), OE33 (p=0.048), and FLO1 (p=0.043) with anticipated downstream molecular inhibition. In vivo, 78.9% of treatment animals demonstrated >20% tumor volume decrease (placebo 0%). Mean tumor volume changed in the treatment arm by -65.5% (placebo +133.5%) (p<0.01), and prevalence changed by -37.5% (placebo +16.7%) (p<0.01). Pre vs post treatment qRT-PCR demonstrated significant inhibition of all downstream molecular correlates. Overall our findings suggest potent antitumor efficacy of abemaciclib against EAC with evident molecular pathway inhibition and reasonable safety, establishing the rationale for future clinical development.

High yield reproducible rat model recapitulating human Barrett's carcinogenesis.

AIM: To efficiently replicate the biology and pathogenesis of human esophageal adenocarcinoma (EAC) using the modified Levrat model of end-to-side esophagojejunostomy. METHODS: End-to-side esophagojejunostomy was performed on rats to induce gastroduodenoesophageal reflux to develop EAC. Animals were randomly selected and serially euthanized at 10 (n = 6), 17 (n = 8), 24 (n = 9), 31 (n = 6), 38 (n = 6), and 40 (n = 6) wk postoperatively. The esophagi were harvested for downstream histopathology and gene expression. Histological evaluation was completed to determine respective rates of carcinogenic development. Quantitative reverse transcription-polymerase chain reaction was performed to determine gene expression levels of MUC2, CK19, and CK20, and results were compared to determine significant differences throughout disease progression stages. RESULTS: The overall study mortality was 15%. Causes of mortality included anastomotic leak, gastrointestinal hemorrhage, stomach ulcer perforation, respiratory infection secondary to aspiration, and obstruction due to tumor or late anastomotic stricture. 10 wk following surgery, 100% of animals presented with esophagitis. Barrett's esophagus (BE) was first observed at 10 wk, and was present in 100% of animals by 17 wk. Dysplasia was confirmed in 87.5% of animals at 17 wk, and increased to 100% by 31 wk. EAC was first observed in 44.4% of animals at 24 wk and increased to 100% by 40 wk. In addition, two animals at 38-40 wk post-surgery had confirmed macro-metastases in the lung/liver and small intestine, respectively. MUC2 gene expression was progressively down-regulated from BE to dysplasia to EAC. Both CK19 and CK20 gene expression significantly increased in a stepwise manner from esophagitis to EAC. CONCLUSION: Esophagojejunostomy was successfully replicated in rats with low mortality and a high tumor burden, which may facilitate broader adoption to study EAC development, progression, and therapeutics.

PI3K/mTOR Dual Inhibitor, LY3023414, Demonstrates Potent Antitumor Efficacy Against Esophageal Adenocarcinoma in a Rat Model.

OBJECTIVE: The purpose of the current study is to determine the efficacy of a PI3K/mTOR dual inhibitor, LY3023414, on established EAC in an in vivo model. BACKGROUND: Esophageal adenocarcinoma (EAC) is a highly lethal cancer with limited treatment options. The PI3K/mTOR pathway is upregulated in EAC and may be a target for novel therapies. METHODS: Esophagojejunostomy was performed on Sprague-Dawley rats to induce carcinogenesis, and LY3023414 was cyclically administered intraperitoneally between 32 and 40 weeks postsurgery to treatment animals. Magnetic resonance imaging (MRI) and histology were used to determine clinical response. Immunohistochemistry, immunofluorescence, and Western blot were used to validate apoptosis by cleaved caspase-3, proliferation by Ki67, and pathway inhibition, respectively. RESULTS: Mean MRI tumor volume increased by 109.2% in controls (n = 32) and decreased by 56.8% in treatment animals (n=17) (P < 0.01). Treatment with LY3023414 demonstrated tumor volume increase in 0% (control = 46.4%) (P < 0.01), decrease in 58.8% (control = 7.1%) (P < 0.01), and stable volume in 41.2% (control = 46.4%) (P = 0.77). EAC prevalence in controls increased by 25%; whereas, prevalence in treatment animals decreased by 29.4% (P < 0.01). Approximately, 75% of treatment animals presenting with residual masses on MRI had a histological response >50%. Increased apoptosis by cleaved caspase-3 (P = 0.03) and decreased proliferation by Ki67 (P < 0.01) were demonstrated in the treatment arm, when compared with the control arm. On Western blot analysis of pathway checkpoints, p-mTOR (p=0.03) and PI3K-α (P = 0.04) were downregulated in treatment responsive residual tumors, when compared with controls. CONCLUSIONS: LY3023414 demonstrates efficacy against EAC in a preclinical model, establishing the rationale for clinical testing.

Primary tumor microRNA signature predicts recurrence and survival in patients with locally advanced esophageal adenocarcinoma.

Esophageal adenocarcinoma (EAC) is an aggressive cancer necessitating the development of improved risk stratification tools for personalized care. Previously, microRNAs have been shown to correlate with the progression and prognosis of various cancer types; however, the value in EAC remains largely unexplored. We performed global microRNA profiling on 32 formalin-fixed, paraffin-embedded EAC specimens to identify microRNAs associated with progression. Literature search and pathway analysis further refined output to five significantly deregulated candidate biomarkers. Four of the five microRNAs (miR-652-5p, miR-7-2-3p, miR-3925-3p, and miR-219-3p) were validated by qRT-PCR. Survival outcomes were evaluated in testing set of 26 stage II/III EAC patients to determine the prognostic relevance of the selected microRNAs. In the testing set, miR-652-5p and miR-7-2-3p expressions were significantly associated with progression-free survival (p-value = .00771 and p-value = .00293). The highest area under receiver operating characteristic (ROC) curve was 0.8212 for the combination of miR-652-5p and miR-7-2-3p. Collectively, our findings demonstrated that the miR-652-5p/miR-7-2-3p signature may serve as a promising prognostic marker in patients with locally advanced EAC.

Preclinical Study of AUY922, a Novel Hsp90 Inhibitor, in the Treatment of Esophageal Adenocarcinoma.

OBJECTIVE: To assess the efficacy of heat-shock protein 90 (Hsp90) inhibitor, NVP-AUY922-AG (AUY922), in the treatment of esophageal adenocarcinoma (EAC) in vitro and in vivo. BACKGROUND: EAC is a leading cause of cancer death, and current treatment options are limited. Hsp90, a chaperone protein that regulates several oncoproteins, is upregulated in EAC, and may be a novel target for therapy. METHODS: In vitro, EAC cell lines were utilized to evaluate AUY922, alone and in combination with 5-fluorouracil (5-FU) and cisplatin. BrdU ELISA and flow cytometry were used to assess proliferation and measure apoptosis, respectively. Western blot and RT-PCR were performed to quantitate Hsp90 pathway expression. In vivo, esophagojejunostomy was performed on rats and treatment animals received AUY922 32 to 40 weeks postoperatively. Drug efficacy was evaluated with magnetic resonance imaging (MRI), endoscopic biopsy, gross histological evaluation, and Hsp90 pathway expression. RESULTS: In vitro, AUY922 demonstrated antiproliferative activity in both cell lines and showed enhanced efficacy with cisplatin and 5-FU. Western Blot and RT-PCR demonstrated downregulation of CDK1 and CDK4 and upregulation of Hsp72. In vivo, AUY922 showed decrease in tumor volume in 36.4% of rats (control = 9.4%), increase in 9.1% (control = 37.5%), and stable disease in 54.5% (control = 43.7%). Necropsy confirmed the presence of EAC in 50% of treatment animals and 75% of control animals. mRNA expression, pre- and posttreatment, demonstrated significant downregulation of MIF, Hsp70, Hsp90ß, and CDK4, and upregulation of Hsp72. CONCLUSIONS: AUY922 exhibits antitumor efficacy in vitro and in vivo for EAC, suggesting the need for human clinical trials.

MicroRNA signature characterizes primary tumors that metastasize in an esophageal adenocarcinoma rat model.

OBJECTIVE: To establish a miRNA signature for metastasis in an animal model of esophageal adenocarcinoma (EAC). BACKGROUND: The incidence of esophageal adenocarcinoma (EAC) has dramatically increased and esophageal cancer is now the sixth leading cause of cancer deaths worldwide. Mortality rates remain high among patients with advanced stage disease and esophagectomy is associated with high complication rates. Hence, early identification of potentially metastatic disease would better guide treatment strategies. METHODS: The modified Levrat's surgery was performed to induce EAC in Sprague-Dawley rats. Primary EAC and distant metastatic sites were confirmed via histology and immunofluorescence. miRNA profiling was performed on primary tumors with or without metastasis. A unique subset of miRNAs expressed in primary tumors and metastases was identified with Ingenuity Pathway Analysis (IPA) along with upstream and downstream targets. miRNA-linked gene expression analysis was performed on a secondary cohort of metastasis positive (n=5) and metastasis negative (n=28) primary tumors. RESULTS: The epithelial origin of distant metastasis was established by IF using villin (VIL1) and mucin 5AC (MUC5AC) antibodies. miRNome analysis identified four down-regulated miRNAs in metastasis positive primary tumors compared to metastasis negative tumors: miR-92a-3p (p=0.0001), miR-141-3p (p=0.0022), miR-451-1a (p=0.0181) and miR133a-3p (p=0.0304). Six target genes identified in the top scoring networks by IPA were validated as significantly, differentially expressed in metastasis positive primary tumors: Ago2, Akt1, Kras, Bcl2L11, CDKN1B and Zeb2. CONCLUSION: In vivo metastasis was confirmed in the modified Levrat's model. Analysis of the primary tumor identified a distinctive miRNA signature for primary tumors that metastasized.

Hypopharyngeal pepsin and Sep70 as diagnostic markers of laryngopharyngeal reflux: preliminary study.

INTRODUCTION: The management of laryngopharyngeal reflux (LPR) has been challenging. Hypopharyngeal multichannel intraluminal impedance (HMII) has shown to increase the sensitivity in diagnosing LPR. The objective of this study is to investigate the potential use of pepsin and Sep70 as diagnostic tools for detection of LPR in combination with HMII. MATERIALS AND METHODS: Tissue samples of hypopharynx, distal esophagus, and gastric cardia were collected from patients with LPR symptoms regardless of gastroesophageal reflux (GERD) diagnosis and underwent HMII to detect LPR and high esophageal reflux (HER: reflux 2 cm distal to upper esophageal sphincter) events. Patients were classified into two groups based on the presence of abnormal proximal exposure (APE), which was defined as LPR ≥1/day and/or HER ≥5/day: (1) positive-APE and (2) negative-APE. Patients with typical GERD symptoms without LPR symptoms who did not undergo HMII were used as a "control" GERD group. Protein was isolated from tissue samples and Western blot analysis of pepsin and Sep70 was performed. Pepsinogen was used as a control to differentiate pepsin from pepsinogen. Relative quantitation was performed using Image Studio Lite Software with normalization against the internal actin of each blot. RESULTS: From October 2012 to September 2013, 55 patients underwent HMII. Of 55, 20 patients underwent biopsies from hypopharynx (17 positive-APE and 3 negative-APE). Ten patients with typical GERD symptoms were identified from tissue bank as a "control" GERD group. Pepsin was detected in distal esophagus and hypopharynx in all groups without significant difference among groups. However, Sep70 in distal esophagus and hypopharynx was significantly depleted in the positive-APE group compared to the other groups (p = 0.032 and 0.002, respectively). CONCLUSION: Depletion of Sep70 with the presence of pepsin in the hypopharynx may indicate cellular injury in laryngopharynx due to constant proximal reflux. However, the normative data for these markers have to be validated.

Establishing magnetic resonance imaging as an accurate and reliable tool to diagnose and monitor esophageal cancer in a rat model.

OBJECTIVE: To assess the reliability of magnetic resonance imaging (MRI) for detection of esophageal cancer in the Levrat model of end-to-side esophagojejunostomy. BACKGROUND: The Levrat model has proven utility in terms of its ability to replicate Barrett's carcinogenesis by inducing gastroduodenoesophageal reflux (GDER). Due to lack of data on the utility of non-invasive methods for detection of esophageal cancer, treatment efficacy studies have been limited, as adenocarcinoma histology has only been validated post-mortem. It would therefore be of great value if the validity and reliability of MRI could be established in this setting. METHODS: Chronic GDER reflux was induced in 19 male Sprague-Dawley rats using the modified Levrat model. At 40 weeks post-surgery, all animals underwent endoscopy, MRI scanning, and post-mortem histological analysis of the esophagus and anastomosis. With post-mortem histology serving as the gold standard, assessment of presence of esophageal cancer was made by five esophageal specialists and five radiologists on endoscopy and MRI, respectively. RESULTS: The accuracy of MRI and endoscopic analysis to correctly identify cancer vs. no cancer was 85.3% and 50.5%, respectively. ROC curves demonstrated that MRI rating had an AUC of 0.966 (p<0.001) and endoscopy rating had an AUC of 0.534 (p = 0.804). The sensitivity and specificity of MRI for identifying cancer vs. no-cancer was 89.1% and 80% respectively, as compared to 45.5% and 57.5% for endoscopy. False positive rates of MRI and endoscopy were 20% and 42.5%, respectively. CONCLUSIONS: MRI is a more reliable diagnostic method than endoscopy in the Levrat model. The non-invasiveness of the tool and its potential to volumetrically quantify the size and number of tumors likely makes it even more useful in evaluating novel agents and their efficacy in treatment studies of esophageal cancer.

Prognostic value and targeted inhibition of survivin expression in esophageal adenocarcinoma and cancer-adjacent squamous epithelium.

BACKGROUND: Survivin is an inhibitor of apoptosis and its over expression is associated with poor prognosis in several malignancies. While several studies have analyzed survivin expression in esophageal squamous cell carcinoma, few have focused on esophageal adenocarcinoma (EAC) and/or cancer-adjacent squamous epithelium (CASE). The purpose of this study was 1) to determine the degree of survivin up regulation in samples of EAC and CASE, 2) to evaluate if survivin expression in EAC and CASE correlates with recurrence and/or death, and 3) to examine the effect of survivin inhibition on apoptosis in EAC cells. METHODS: Fresh frozen samples of EAC and CASE from the same patient were used for qRT-PCR and Western blot analysis, and formalin-fixed, paraffin-embedded tissue was used for immunohistochemistry. EAC cell lines, OE19 and OE33, were transfected with small interfering RNAs (siRNAs) to knockdown survivin expression. This was confirmed by qRT-PCR for survivin expression and Western blot analysis of cleaved PARP, cleaved caspase 3 and survivin. Survivin expression data was correlated with clinical outcome. RESULTS: Survivin expression was significantly higher in EAC tumor samples compared to the CASE from the same patient. Patients with high expression of survivin in EAC tumor had an increased risk of death. Survivin expression was also noted in CASE and correlated with increased risk of distant recurrence. Cell line evaluation demonstrated that inhibition of survivin resulted in an increase in apoptosis. CONCLUSION: Higher expression of survivin in tumor tissue was associated with increased risk of death; while survivin expression in CASE was a superior predictor of recurrence. Inhibition of survivin in EAC cell lines further showed increased apoptosis, supporting the potential benefits of therapeutic strategies targeted to this marker.