Sox9 Is Upstream of MicroRNA-140 in Cartilage.

MicroRNA-140 (miR-140) is specifically expressed in developing cartilage tissues. We have previously reported that miR-140 plays an important role during palatal cartilage development by modulating platelet- derived growth factor receptor alpha ( pdgfra) in zebrafish. However, the regulatory mechanism of miR-140 in cartilage is still unknown. Using developing zebrafish, sox9a mutant ( sox9a−/−) and sox9b mutant ( sox9b−/−) zebrafish and SOX9 small interfering RNA in human chondrocytes, T/C-28 cells, we found that miR-140 is regulated by the cartilage master transcription regulator Sox9 in zebrafish and mammalian cells. [ABSTRACT FROM AUTHOR]