The epidermis consists of multiple layers of keratinocytes. Stem cells reside in the basal layer and cells that exit that layer undergo terminal differentiation as they move through the suprabasal layers. Under normal conditions the rate of production of new cells in the basal layer balances the rate of shedding of differentiated cells from the outermost epidermal layers. However, in tumours of the epidermis this balance is disturbed. Too many undifferentiated cells are produced, too few cells undergo terminal differentiation and the normal architecture of the tissue is lost.
My lab has developed a number of tools that allow us to examine the behaviour of human epidermal keratinocytes in vitro at single cell resolution and to compare their properties with those of keratinocytes from squamous cell carcinomas. Our results reveal how interactions with the niche are disturbed in cancer and suggest that specific genetic lesions have specific effects on those interactions.