EVALUATION OF EPITHELIAL STEM CELLS IN ORAL VS. ESOPHAGEAL MUCOSA OF RAT

Aims:

We have successfully developed new regenerative medical approach for ectopic transplantation of autologous cultured oral epithelial cell sheets to prevent stenosis after extended esophageal endoscopic submucosal dissection (ESD). The ectopic transplantation with oral mucosa is considered to be acceptable because the histological high affinity is found between oral and esophageal epithelia. However, the property of epithelial stem/progenitor cells (ESPC) of both mucosae have not been fully investigated. The middle esophagus is well known to be common site of esophageal cancer. Therefore, the oral mucosae may be safe since the oral cavity is far enough from the primary tumor in the esophagus. The aims of this study are to evaluate the safety of ectopic cultured epithelial cells in the transplantation and to clarify the difference of ESPC between esophageal and oral mucosae.

Methods:

The epithelial tissue was taken from each part of the oral cavity, cervical, thoracic, and abdominal esophagus of rats. The proliferative potentials of cultured ESPC was evaluated by using colony forming assay. The label retaining cells (LRC) assay was used to detect quiescent stem cells that are viable for long time in vivo. The number of LRC and the expression of p63, suggestive of ESPC markers, were also investigated by immunohistochemical staining.

Results:

The rat oral and esophageal epithelia were histologically similar to the human ones. The distributions of LRC and p63 positive cells were almost equal in each part. The colony-forming efficiency of the oral epithelium was comparatively higher than those of the esophagus, although no significant difference was observed (oral 6.3%, cervical 5.0%, thoracic 5.4%, abdominal 5.0%, P = 0.405).

Conclusions:

The oral epithelial cells may be feasible and safe as a source of cell transplantation for the ulcer after esophageal ESD.