Positive correlation of image analysis by mini-endoscopy with micro-PET scan and histology in rats after esophagoduodenal anastomosis

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.

Gold nanorods and curcumin-loaded nanomicelles for efficient in vivo photothermal therapy of Barrett's esophagus

Aim: Provide an enhanced local drug delivery, nanoparticle(s) to minimize systemic effects and achieve enhanced permeability and drug retention into abnormal cells and stroma. Materials & methods: Here a simultaneous loading of lipophilic gold nanorods (GNRs) and curcumin into polymeric nanomicelles made of biocompatible PLGA-b-PEG copolymer through a double re-emulsification process has been developed. Results: Initial results in vitro on Barrett's esophagus and esophageal adenocarcinoma cell lines demonstrated a significant reduction in cell viability with curcumin and GNRs exposure (p < 0.05). In vivo Barrett's-associated animal model confirmed these results with successful in vivo demonstrated eradication of all high-grade dysplastic premalignant cancer cells. Conclusion: The synthesis of this novel nanosystem containing GNRs and curcumin is safe and effective in treating and eradicating premalignant esophageal adenocarcinoma.

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.

Infrared light-absorbing gold/gold sulfide nanoparticles induce cell death in esophageal adenocarcinoma

Gold nanoparticles and near infrared-absorbing light are each innocuous to tissue but when combined can destroy malignant tissue while leaving healthy tissue unharmed. This study investigated the feasibility of photothermal ablation therapy for esophageal adenocarcinoma using chitosan-coated gold/gold sulfide (CS-GGS) nanoparticles. A rat esophagoduodenal anastomosis model was used for the in vivo ablation study, and three human esophageal cell lines were used to study the response of cancer cells and benign cells to near infrared light after treatment with CS-GGS. The results indicate that both cancerous tissue and cancer cells took up more gold nanoparticles and were completely ablated after exposure to near infrared light. The benign tissue and noncancerous cells showed less uptake of these nanoparticles, and remained viable after exposure to near infrared light. CS-GGS nanoparticles could provide an optimal endoluminal therapeutic option for near infrared light ablation of esophageal cancer.

The association of manganese superoxide dismutase expression in Barrett's esophageal progression with MnTBAP and curcumin oil therapy

BACKGROUND

The aim of this study was to investigate the relationship between reflux induced bile insult and MnSOD expression, as well as to examine therapies to preserve MnSOD expression. Additionally, we sought to examine the relationship between MnSOD protein expression and MnSOD enzymatic activity.

METHODS

MnSOD protein expression was determined by Western blot assay and enzymatic activity was determined by SOD assay. The enzymatic activity of the Het-1A and Bar-T cells were compared both before and after treatments.

RESULTS

MnSOD expression in Het-1A cells was decreased after bile salt exposure. The cells that received MnTBAP or curcumin oil pretreatment showed increased MnSOD expression compared with control untreated cells. The Bar-T cells showed an increase in MnSOD expression after treatment with bile salts. The cells that were pretreated with MnTBAP displayed a larger increase in MnSOD expression compared with the cells that were not pretreated prior to bile salt exposure. The MnSOD activity was significantly different between the untreated cell lines (P = 0.01) and after treatment with bile salt (P = 0.03). Additionally, Bar-T cells had significantly less MnSOD activity than Het-1A cells after each of the pretreatments.

CONCLUSIONS

We demonstrated preservation of MnSOD expression in Het-1A cells that were pretreated with antioxidants including MnTBAP, curcumin oil, and certain berry extracts. Additionally, we demonstrated that Bar-T cells have significantly less MnSOD activity than Het-1A cells. These finding have important implications for future studies regarding chemoprevention and the treatment of esophageal cancer.