Establishing the protein MIA (melanoma inhibitory activity) as a marker for chondrocyte differentiation.

Melanoma inhibitory activity (MIA), also referred to as cartilage derived retinoic acid-sensitive protein (CD-RAP), is detected physiologically in cartilage tissue and pathologically in malignant melanomas. To measure MIA/CD-RAP quantitatively we developed a sensitive ELISA system. Recently, we described diagnostic applications of the MIA-ELISA in patients with cartilage diseases. The study described herein was performed to determine whether there is any relation between MIA/CD-RAP levels and the degree of chondrocyte differentiation in tissue culture and to analyse whether MIA/CD-RAP may serve as a useful marker to control chondrocyte differentiation in in vitro tissue engineering. Our data provide evidence that measuring MIA in tissue culture supernatant by a quantitative ELISA can be used as a marker for differentiated chondrocytes.