DIFFERENTIATION MARKERS IN ORAL-CARCINOMA CELL-LINES AND TUMORS

Cell lines are useful as models if they retain the relevant characteri stics of the tissue of origin. We compared two human squamous carcinom a cell lines derived from tumors of the tongue that vary in their exte nt of differentiation, with human biopsies of carcinomas of the tongue that were either poorly or well-differentiated. The mRNA levels of su prabasal cell proteins (keratin K13, involucrin, transglutaminase) and of protein kinase C (PKC) isozymes were measured by RT-PCR. Apart fro m PKC beta and PKC delta (mostly expressed by Langerhans cells and mis sing in culture), qualitatively similar patterns were found in vitro a nd in vivo. The more differentiated cells had expression levels modera tely lower to higher than the normal controls. The poorly differentiat ed cells generally had substantially lower levels.