Cellular expression of adhesion factors in childhood rhabdomyosarcoma

Tumor invasion and metastasis are believed to involve the adhesive interaction of tumor cells with extracellular matrix (ECM). This study reports the expression of laminin, fibronectin, thrombospondin, tenascin, and CD44 in rhabdomyosarcoma cells taken from tumors derived from 12 pediatric patients. Twelve paraffin-embedded rhabdomyosarcomas consisting of five alveolar, six embryonal, and one botryoid subtype were examined. All tumors demonstrated positive staining for tenascin and thrombospondin, 10 were positive for fibronectin, 5 positive for laminin, and 4 positive for CD44. Both specimens without cellular staining for fibronectin were of embryonal subtype and no alveolar rhabdomyosarcomas were positive for CD44. No association of the expression of the studied ECM proteins and receptor with the presence of metastatic disease at clinical presentation or with the level of tumor differentiation was found.