GLI1 and colonic neoplasm: To this end, the HCT116-p53RE-Luc cell line (with wild-type p53 and multiple p53 response elements upstream of the luciferase gene), SW480 colon cancer cell line (transiently transfected with the Tcf/Lef-dependent TOPFlash construct [32]; a gift from Dr. Randall Moon) and A549 lung cancer cells (transiently transfected with the GLI-dependent GLIBS-Luc reporter construct and the GLI expression plasmid; gifts from Dr. David Robbins) were treated with Siomycin A or thiostrepton and the luciferase activity was measured 16 hours after treatment.