Novel In Vivo Mouse Cryoablation Model to Explore Unique Therapeutic Approaches for Premalignant Columnar Lesions

Abstract

Patients with epithelial metaplasias have an increased risk of developing malignancies. In Barrett’s esophagus, neo-columnar epithelium develops proximal to the squamous-columnar junction (SCJ) in the esophagus as the result of prolonged exposure to bile and acid reflux. Patients require lifetime periodic surveillance, due to lack of effective eradication therapies. The shortage of innovative treatment options is mostly attributable to the paucity of adequate in vivo models of neo-columnar epithelium regeneration. This protocol describes the generation of a cryoablation model to study regeneration of neo-epithelia at the SCJ. Cryoablation of the columnar and squamous mucosa at the SCJ was achieved through local application of liquid N2O in wild-type and reporter mice in combination with acid suppression. Acid suppression alone, showed restoration of the SCJ with normal histological features of both the neo-columnar and neo-squamous epithelium within 14 days. As a proof of principle, mice were treated with mNoggin, an inhibitor of bone morphogenetic proteins (BMPs), which are involved in the development of columnar epithelia. Local application of mNoggin to the ablated area at the SCJ significantly reduced the development of the neo-columnar mucosa. Although this model does not faithfully recapitulate the exact characteristics of Barrett’s esophagus, it is a well-suited tool to study the mechanisms of therapeutic inhibition of neo-columnar regeneration. It therefore represents an efficient and easy platform to test novel pharmacological therapies for treatment of neo-epithelial lesions at the SCJ.

Molecular Biology and Clinical Management of Esophageal Adenocarcinoma

“…The difficulty in the confirmation of the origin of BE is mainly attributed to the inability to observe metaplastic transformations in vivo due to a lack of reliable animal models [210]. Our group developed a mouse model resembling BE that regenerates the neo-columnar epithelium [211], which may accelerate the progression of this kind of study.…”

Promises and Limitations of Current Models for Understanding Barrett’s Esophagus and Esophageal Adenocarcinoma

“…As opposed to endoscopically administered ablation, the murine model involves a gastrostomy and ablation with a cryopen for application of liquid nitrogen to the inner wall of the stomach while visualizing the SCJ. 54 …”