Filter-grown TR146 cells as an in vitro model of human buccal epithelial permeability

Use of a cell culture model of a specific epithelium requires documentation of its differentiation. This study reports permeability of mannitol concur rent with a profile of differentiation markers of filter-grown TR146 cells, a cell line originating from a human buccal carcinoma, cultivated submerge d or at the air-liquid interface for 23 to 31 d. A multilayered squamous ep ithelial-like tissue was found. The maximal permeability barrier and the mo st distinct stratification were obtained at day 23, when cultured submerged (apparent permeability coefficient 4.08+/-0.15 (x 10(-6)) cm/s; transepith elial electrical resistance 102+/-5 Ohm x cm(2)). The profile of differenti ation markers demonstrated similarities to normal human buccal epithelium b y expression of K3, K10, K13, K16, and K19 keratins, plasma membrane-associ ated transglutaminase, involucrin, and epidermal growth factor receptor. Un iform expression of K5, K8 and K18 was consistent with the carcinogenic ori gin of TR146 cells. Identical profiles of differentiation markers were obta ined irrespective of method or time of culture. Karyotyping proved the huma n origin of TR146 cells. Three different passages had near triploid (3n+-) chromosome compliments and consistent occurrence of four marker chromosomes [mar4, mar5, mar9, and add(5)(p)], while differences between them defined them as subclones. The results indicate that a submerged filter-grown TR146 cell culture at day 23 of culture has the potential to model the human buc cal epithelial barrier for permeation of drugs.