Figure 3: (a) MTT assay showing decrease in proliferating cells after treatment with 20  𝜇 M cyclopamine for 48 hours. Data is expressed as % of control (ethanol treatment only). (b) Western blot showing decrease in PTCH-1 expression in SKBR3 cells treated with 20  𝜇 M cyclopamine as compared to cells treated with ethanol only. (c) Immunofluorescence showing decrease in PTCH-1 and Gli-1 (nuclear and cytoplasmic) 24 hours after treatment with cyclopamine. (d) Scatchard analysis of 131I-SHH binding to the surface of SKBR3 cell lines with and without treatment with 10  𝜇 M cyclopamine. There is a 5-fold decrease in surface PTCH-1 receptor expression 48 hours after treatment. (e) Reduced cellular uptake of 131I-SHH in the PTCH-1 receptor positive breast cancer cell line SKBR3 with and without treatment with the HH inhibitor cyclopamine.