Figure 2.

Positive regulation of BCL6 transcription by DNA methylation. (A) The Raji, HsSultan, and EB1 Burkitt lymphoma cell lines were treated with 5-Aza-C for 24 h, and BCL6 and actin mRNA abundance was determined by quantitative RT-PCR. The bar graph depicts the BCL6 to actin ratio from three independent replicates. Error bars indicate standard deviation. The value from untreated cells for each replicate was arbitrarily set to 1. (B) Raji cells were treated with 5-Aza-C for the indicated times. BCL6, IRF4, and PRDM1 mRNA abundance was determined by quantitative RT-PCR. The bar graphs depict the ratio of each transcript to GAPDH mRNA, with the value from untreated cells (day 0) arbitrarily set to 1. Data represent the mean of three independent replicates. Error bars indicate standard deviation. (C) The diagram depicts the basic features of the BCL6 locus 5′ end along with the approximate locations of primer sets used to analyze the chromatin immunoprecipitated with the indicated antibodies in each panel. Each ChIP primer was analyzed by quantitative PCR with the graph depicting the percentage of input chromatin recovered in the immunoprecipitation for each primer set. The data represent the mean of two independent biological replicates.