Tissue Culture Studies of Human Oral Carcinoma III. Ultrastructure Comparisons of Epithelial-like and Fibroblast-like Cells Derived from Malignant and Nonmalignant Oral Explants

¹ School of Dentistry, University of California, San Francisco, California

Ten explants derived from nonmalignant and malignant human oral tissue were studied. Six were epithelial-like and four were fibroblast-like in appearance. These findings could not be correlated with tissue source or time in culture.

All epithelial cultures contained some cells with desmosomal attachments, while none of the fibroblast-like cultures had cells with desmosomes. All cultures had cells with similar variations in organelles and could not be differentiated on this basis. Also, each culture contained cells displaying multilaminated and multivesicular lysosomelike structures, which have not been observed with human oral nonmalignant or malignant specimens prepared directly from biopsy and before culture. These structures may represent various stages of organelle ganelle degradation, storage, or synthesis. The cells appear to be an intermediate type more consistent with their in vitro environment than their original explant source.