Research Paper Volume 12, Issue 10 pp 9275—9291

NAC1 attenuates BCL6 negative autoregulation and functions as a BCL6 coactivator of FOXQ1 transcription in cancer cells

Figure 3. BCL6 activates FOXQ1 promoter activity in a NAC1-dependent fashion. (A) Chromatin immunoprecipitation of BCL6 in HeLa tTa cells expressing active NAC1 (off) and after NAC1 inactivation by N130 truncated NAC1 expression induction (on). qPCR with three different primer sets flanking three different regions, which contain the putative BCL6 binding motifs of FOXQ1 promoter: A (-1000), B (-800), and C (-150). BCL6 binding to each region is represented as percentage of the input. (B) Luciferase reporter assay of FOXQ1 promoter activity in HeLa cells transfected with NAC1 and BCL6 specific siRNA. Data show relative luciferase activity normalized to Renilla luciferase activity from each experimental condition; (C) HeLa cells were transfected with BCL6-Flag or control plasmid. The relative luciferase activities of wide type FOXQ1 promoter and three deletion mutant promoters (FOXQ1-del A -1000, del B -800, and del C -150) were determined. ***P<0.001.