Cell adhesion and tumor progression in mouse skin carcinogenesis: increased synthesis and organization of fibronectin is associated with the undifferentiated spindle phenotype.

The expression and organization of the extracellular matrix component fibronectin has been analyzed in a collection of murine epidermal keratinocyte cell lines representative of different stages of mouse skin carcinogenesis. The fibroblastoid phenotype of spindle cells has been found to be associated with high levels of fibronectin expression and the ability to organize this molecule in an extracellular matrix. These observations, together with our previous analysis on the expression of cadherins, alpha 6 beta 4 integrin and the proteoglycan syndecan, indicate that profound alterations in cell adhesion behaviour occur in the last stages of tumor progression in this system. These alterations could favor the migratory and invasive phenotype of spindle cells.