Gene expression alteration in chondrocyte by A-CEBP overexpression.

To investigate loss-of-function of the C/EBP family members, we used A-CEBP which exerts a dominant-negative effect against all CEBPs. DOX-inducible overexpression of A-CEBP into mouse chondrocyte cell line ATDC5 increased expressions of early differentiation markers, decreased those of late differentiation markers. In addition, A-CEBP altered many genes related with skeletal development, cartilage, cell cycle, inflammation and apoptosis. We established stable ATDC5 cells which express GFP or A-CEBP by DOX induction. We started differentiation of these cells by ITS supplement immediately after DOX induction, harvested mRNA after 3 weeks, and performed microarray analysis.