EFFECTS OF THE TISSUE CULTURE ENVIRONMENT ON HUMAN PRIMARY KERATINOCYTES

Abstract

CULTURED KERATINOCYTES HAVE BEEN USED EXTENSIVELY IN CLINICAL AND RESEARCH APPLICATIONS. CURRENT STANDARD CULTURE CONDITIONS RELY ON SPECIFIC CULTURE MEDIUM FORMULATIONS AND ATMOSPHERIC OXYGEN LEVELS THAT ARE WIDELY ACCEPTED AS GIVING OPTIMAL CELL GROWTH OF EARLY PASSAGE CULTURES. HOWEVER KERATINOCYTES ARE READILY TRIGGERED TO DIFFERENTIATE AND BECOME POST-MITOTIC, REDUCING THE RATE AT WHICH CELLS CAN BE AMPLIFIED FOR FURTHER USE. THEORETICALLY THIS CAN BE OVERCOME BY ACCELERATING THEIR PROLIFERATION USING GROWTH FACTOR ADDITIVES, OR DELAYING DIFFERENTIATION, OR BY INCREASING THE NUMBER OF PROGENITOR CELLS IN THE CULTURE. THE FIRST PART OF THIS WORK INVESTIGATES THE PHENOTYPIC STABILITY OF CELL MODEL LINES, USING THE WELL-ESTABLISHED BASAL KERATINOCYTE BIOMARKER, KERATIN 14 (K14) EXPRESSION. EXPERIMENTS SHOW THAT EPIDERMAL GROWTH FACTOR (EGF), A POTENT AND COMMONLY USED KERATINOCYTE CULTURE COMPONENT, IS ASSOCIATED WITH PROGRESSIVE EPIGENETIC SILENCING OF THIS MAJOR BASAL KERATINOCYTE