A method for studying epithelial-mesenchymal interactions in human oral mucosal lesions.

A system has been developed for examining connective tissue influence on keratinization of normal and leukoplakic human oral epithelia. Paired biopsy specimens of normal and leukoplakic mucosa were left intact or were incubated in 1 mM EDTA to permit epithelial-connective tissue separation and various recombinations of the epithelium and connective tissue. The tissues were transplanting to subdermal sites of "nude" (nu/nu) mice and were protected by polyethylene capsules. 44% of implants performed were recovered apparently vital. Preexisting structure was retained after epithelial-connective tissue separation and self-recombination. Cross-recombined specimens showed changes in patterns of keratinization including changes of keratinized leukoplakic epithelium to a non-keratinized type.