Figure 6. APC or CTNNB1 silencing alters transcriptional activity from elements in the PHLDB2 and MALL loci.

Ten genomic sequences associated with APC and two positive control sequences (from AXIN2 intron 1 and MYC promoter, indicated by red arrows) were PCR-amplified, cloned into the pGL3-promoter firefly luciferase vector and transfected into HCT-116 cells previously transfected with either scrambled siRNA (purple) or siRNA targeting APC (red, panel A) or CTNNB1 (blue, panel B). The PHLDB2 intron 1 construct was more active following APC silencing (panel A) and less active following CTNNB1 silencing (panel B), similar to the pTOPFLASH positive control. The MALL intron 1 construct was less active following APC silencing and more active following CTNNB1 silencing. Errors bars are based on standard deviation, and FDR values lower than 0.05 are indicated (1-tailed Student's t-test).