Rhabdomyosarcoma-derived cell lines exhibit aberrant expression of the cell-cell adhesion molecules N-CAM, N-cadherin, and cadherin-associated proteins.

Many cancer cells show aberrant adhesion properties that likely contribute to tumorigenesis, invasion, and metastasis. Here, we examine three MyoD-expressing, rhabdomyosarcoma-derived human cell lines (RD, A-204, and HS 729) for their expression of the neural cell adhesion molecule (N-CAM), N-cadherin, and the cadherin-associated proteins, alpha-catenin, beta-catenin, and plakoglobin, using specific antibodies and immunoblotting and immunocytochemical methods. Normally, during the formation of skeletal muscle, both N-CAM and N-cadherin are expressed and participate in mediating myoblast adhesion accompanying cell fusion. RD cells express N-CAM, N-cadherin, and the cadherin-associated proteins; however, N-CAM is expressed as a highly sialylated isoform that functions poorly in promoting Ca(2+)-independent cell aggregation. HS 729 cells express N-cadherin and its associated intracellular proteins but have no detectable N-CAM. A-204 cells express no detectable N-CAM or N-cadherin but do express cadherin-associated proteins. Thus, all three rhabdomyosarcoma cell lines exhibit some abnormality in the expression of adhesion molecules known to participate in skeletal myogenesis; however, no common defect was observed that might be considered as a characteristic marker for rhabdomyosarcomas.