Differentiation dependent matrix formation (fibronectin and laminin) in an experimental murine rhabdomyosarcoma model

Cellular differentiation processes along with formation of extracellular matrix proteins were investigated in methylcholanthrene-induced murine rhabdomyosarcomata. We used primary tumours, allotransplants in nude mice, and the respective tumour recurrences generated by repeated incomplete surgical tumour removal. The expression of the differentiation markers desmin and myoglobin as well as the presence of fibronectin and laminin was ascertained by immunohistochemical methods. The question arises, whether or not correlations between the grade of cellular differentiation (desmin, myoglobin) and extracellular matrix formation (fibronectin, laminin) exist in tumours with striated muscle cell differentiation. The constant relations between cellular differentiation and matrix formation in original tumours also applied to allotransplants and tumour recurrences in which partially modulations of differentiation in comparison with original tumours could be recognized.