SANT-1

SANT-1 inhibits wild type and oncogenic Smo with equal potency. SANT-1 counteracts SAG-induced pathway activation in Shh-LIGHT2 cells. SANT-1 is able to block BODIPY-cyclopamine binding to Smo-expressing cells, but SANT-1 is unable to inhibit completely this association to background levels. This suggests that their interactions with Smo may alter its affinity for cyclopamine rather than compete directly for cyclopamine binding. SANT-1 blocks pathway activation in SmoA1-LIGHT2 cells with potencies similar to those observed in the Shh-LIGHT2 assay. SANT-1 has disparate inhibitory activities in the Shh-LIGHT2 and BODIPY-cyclopamine assays and is unusually potent at blocking SAG-mediated pathway activation.^[1]

SANT-1 efficiently inhibited cyclopamine- and jervine- induced translocation of Smo to the primary cilium. SANT-1 inhibits PKA stimulation of Smo trafficking to the proximal cilium.^[2]

• Small Molecule Screens for Hh Pathway Modulators

  Shh-N (N-terminal fragment of Shh without cholesterol modification)-conditioned medium is obtained from an HEK 293 cell line stably transfected with Shh-N expression and neomycin resistance constructs. The Shh-N-producing HEK 293 cells are grown to 80% confluency in DMEM containing 10% (vol/vol) FBS and 400 μg/ml G418. The medium then is replaced with DMEM containing 2% (vol/vol) FBS, and after 1 day of growth, the medium is collected and filtered through a 0.22-μm membrane. Control medium is obtained from HEK 293 cells. Shh-LIGHT2 cells are then cultured to confluency in 96-well plates and treated with the small molecules (0.714 μg/mL; ≈2 μM compound in each well) in the presence of either Shh-N-conditioned medium or HEK 293 control medium (1:25 dilution into DMEM containing 0.5% bovine calf serum). After incubating the treated cells for 30 h at 37°C, cellular firefly and Renilla luciferase activities are measured.

• Animal Models

  Swiss albino male mice

• Dosages

  3.3 mg/kg

• Administration

  i.p.