ANTISENSE C-MYC OLIGONUCLEOTIDE PROMOTES CHONDROGENESIS AND ENHANCES RA RESPONSIVENESS OF MOUSE LIMB MESENCHYMAL CELLS IN-VITRO

To examine the role of c-myc protein during chondrogenesis, we exposed 11 day p.c. mouse limb mesenchymal cells to the antisense c-myc oligo nucleotide in micromass culture. The antisense oligonucleotide inhibit ed the c-myc protein expression, and intensely promoted chondrogenesis in the exposed cells. Most of the cells differentiated into cartilagi nous cells, whereas they differentiated into cartilaginous and fibrous cells under the control conditions. The antisense oligonucleotide inc reased the inhibitory efficiency of all-trans retinoic acid (RA) to th e chondrogenesis. These results suggest that the c-myc protein suppres s the chondrogenesis and reduces RA responsiveness in the limb mesench ymal cells.