Fig. 4.

SA compounds inhibit Hh target gene activation, and SA1–10 reduce proliferation and delay progression through G1 of BCC-like cells. (A) Relative Gli1 and Ptch1 levels in ASZ1 cells treated with 25 μM compound, as measured by qRT-PCR. SA1–10 inhibit the expression of Gli1 and Ptch1 in ASZ1 cells. (B) Relative Gli-luciferase activity of Smo^−/− MEFs expressing SmoM2 and treated with 25 μM compound, showing that SA compounds inhibit SmoM2 activity. (C) Quantitation of Gli1 levels in Sufu^−/− MEFs treated with 25 μM compound, as measured by qRT-PCR. Sufu is epistatic to SA compound activity. (D) qRT-PCR measurement of relative Gli1 levels in ASZ1 cells treated with 25 μM compound. Compared with their structural analogues SA7–9, NC1 and NC2 are ineffective inhibitors of Gli1 expression. (E) Relative firefly luciferase levels of Shh-LIGHT2 cells treated with SA10 and its structural analogues NC3–5. NC3–5 did not inhibit Hh pathway activity. (F) BrdU incorporation in ASZ1 cells treated with 25 μM compound. SA1–10 reduced cell proliferation in ASZ1 cells. (G) Percentage of cells in each phase of the cell cycle as determined by flow cytometric quantitation of DNA content. ASZ1 cells treated with 25 μM SA1–10 show an increased proportion in G1 phase. Cells treated with SA5 also have an increased proportion in S phase. Data in A–E are averages of quadruplicate measurements; data in F are the average of two independent experiments in duplicate. Asterisks indicate significance according to the Student t test (P < 0.05).