Cyclopamine-KAAD is a potent inhibitor of hedgehog signaling with an IC50 value of 20 nM in a Shh-LIGHT2 assay. It blocks binding of BODIPY-cyclopamine to cells expressing Smoothened (Smo) in a dose-dependent manner. Cyclopamine-KAAD is cell-permeable and binds to SmoA1 to promote its exit from the endoplasmic reticulum. It inhibits the invasion and migration (45.9 and 43.3% inhibition, respectively) of Bel-7402 hepatocarcinoma cells and decreases the expression of nuclear glioma-associated oncogene 1 (Gli1) and cytosolic MMP-9, pERK1, and pERK2 proteins in a dose-dependent manner. Cyclopamine-KAAD also increases TRAIL-mediated cell death in NCH82 and NCH89 human glioblastoma cultures and upregulates expression of the death receptors DR4 and DR5 in LN229 and U251 glioma cells.
Glabrescione B is a novel compound that specifically binds to Gli1, an important modulator of the Hedgehog (Hh) signaling pathway. By disrupting the Gli1-DNA interaction, Glabrescione B effectively impairs the activity of Gli1. Moreover, Glabrescione B demonstrates potent inhibitory effects on the growth of tumor cells that rely on Hedgehog signaling, as well as on the self-renewal capacity and clonogenicity of tumor-derived stem cells.
Physalin H is an Hh signaling inhibitor blocks GLI1-DNA-complex formation, it also strong quinone reductase induction activity with IR (Induction ratio, QR induction activity) value of 3.74±0.02. Physalin H shows immunosuppressive effects on T cells both
MS-0022 is a SMO antagonist. MS-0022 showed effective Hh signaling pathway inhibition at the level of SMO in the low nM range, and Hh pathway inhibition downstream of Suppressor of fused (SUFU) in the low µM range. MS-0022 reduced growth in the tumor cell lines PANC-1, SUIT-2, PC-3 and FEMX in vitro. MS-0022 is a treatment led to a transient delay of tumor growth that correlated with a reduction of stromal Gli1 levels in SUIT-2 xenografts in vivo.