OVEREXPRESSION OF PROTEIN-KINASE-C BETA-I IN A MURINE KERATINOCYTE CELL-LINE PRODUCES EFFECTS ON CELLULAR GROWTH, MORPHOLOGY AND DIFFERENTIATION

The present study demonstrates that the murine keratinocyte cell line 3PC expresses the Ca2+ insensitive isoforms of protein kinase C (PKC) delta, epsilon, zeta and (at both the mRNA and protein levels), but do es not express the Ca2+-sensitive PKC isoforms alpha, beta or gamma. R ecombinant retroviral gene transduction was used to develop derivative s of this cell line that stably express high levels of 1 PKC beta I-re lated transcripts and proteins, and have increased levels of Ca2+ stim ulated PKC enzyme activity. Functional overexpression of the PKC beta I isoform in 3PC cells enhances both 12-O-tetradecanoyl phorbol-13-ace tate-induced growth inhibition, and Ca2+-induced morphologic different iation.