CELLULAR EXPRESSION OF ADHESION FACTORS IN CHILDHOOD RHABDOMYOSARCOMA

Tumor invasion and metastasis are believed to involve the adhesive int eraction of tumor cells with extracellular matrix (ECM). This study re ports the expression of laminin, fibronectin, thrombospondin, tenascin , and CD44 in rhabdomyosarcoma cells taken from tumors derived from 12 pediatric patients. Twelve paraffin-embedded rhabdomyosarcomas consis ting of five alveolar, six embryonal, and one botryoid subtype were ex amined. All tumors demonstrated positive staining for tenascin and thr ombospondin, 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 rhabdomyosarcom as were positive for CD44. No association of the expression of the stu died ECM proteins and receptor with the presence of metastatic disease at clinical presentation or with the level of tumor differentiation w as found.