Cell lines and reagents

SF-295 cells were obtained from Addex Bio (San Diego, CA) and cultured in Roswell Park Memorial Institute 1640 (RPMI 1640) medium (Gibco, Waltham, MA) with 10% fetal bovine serum (FBS) added (Hyclone, from ThermoFisher Scientific, Waltham, MA). A549 cells were obtained from ATCC (Manassas, VA) and were cultured in F-12 medium (Gibco, Waltham, MA) with 10% FBS. All cells were maintained at 37 °C and 5% CO₂ and used within 20 passages.

MG and TTI-3066 was obtained from Terpenoid Therapeutics, Incorporated (Coralville, IA). They were dissolved in dimethylsulfoxide (DMSO) to 100 mM and stored in the dark at − 20 °C before use. This stock was then diluted to 10 mM immediately before dilution to final concentration in complete cell culture media, as above. Cyclopamine (Fig. 1C, SelleckChem, Houston, TX) was dissolved in DMSO to mM before dilution to final concentration in complete cell culture media.