Figure 3.

The Hh signaling pathway and their inhibitors. The Hh-signaling pathway comprises three main components: the Hh ligand; a transmembrane receptor circuit composed of the negative regulator Ptc, and the an activator Smo; and finally a cytoplasmic complex that regulates the Ci or Gli family of transcriptional effectors. Ptc, a twelve-pass membrane protein binds Hh ligand, and in the absence of ligand, Ptc interacts with and inhibits Smo, a sevenpass membrane protein. When Hh binds Ptc, its interactions with Smo are altered, leads to Ci/Gli protein entering the nucleus and acting as a transcriptional activator for the same genes. Cur-61414, GDC-0449, BMS-833923 and IPI-926 could antagonize the smo that lead to the inhibiton of Hh-signaling pathway.