Keratinocyte-based cell assays: their potential pitfalls.

As an in vitro model system, patient-derived epidermolysis bullosa simplex keratinocytes have had an immense impact on what we know today about keratin filament function and their role in disease development. In the absence of gene therapy, screening compound libraries for new or better drugs is another approach to improve existing treatments for genodermatoses. However in this study, we report of the potential pitfalls when using this type of cell lines as a "reporter" system. When cell lines with different genetic backgrounds are being used in cell-based assays, the greatest obstacle is to determine the most appropriate culture conditions (i.e., the composition of medium, number of cells plated and number of days in culture). We demonstrate how culture conditions can greatly interfere with the cellular response in cell-based assays (cell proliferation, metabolic activity and migration), potentially also giving rise to misleading data.