Calcium Modulation of Growth and Differentiation of Immortal Human Oral Keratinocytes

다국어 초록 (Multilingual Abstract)

Modification of the medium calcium concentration markedly modulates the pattern of proliferation and differentiation of cultured epidermal cells in human and murine. Correlation of the differences in the molecular weights of some of the keratins with those of NBT reduction abilities of human oral keratinocytes was studied in relation to its differentiation. Immortal human oral keratinocytes were grown in a serumfree keratinocyte growth medium containing 0.15, 0.3, 0.6 or 1.2 mM calcium for 3 days and assayed for the DNA synthesis, NBT reduction, and keratin profiles. The addition of calcium in culture medium produced altered morphology. enhanced percentage of NBT-positive cells and inhibited de novo DNA synthesis showing that extracellular calcium induced the differentiation of immortal oral keratinocytes. In low-calcium-grown cells the low molecular weight keratins were observed. however, the addition of calcium to low-calcium-grown cells resulted in induction of the high molecular weight keratins. These results indicate that the increase of the molecular weights of some of the keratins correlates with the degree of the differentiation of oral keratinocytes. We suggest a possibility that the change of keratin profiles may be used as a molecular marker of calcium-induced keratinocyte differentiation.