Figure 4.

c-MYC represses expression of the CCL5 chemokine, which promotes the migration of MCF-7 cells. (A) Microarray expression profile (mean±s.e.m. from independent replicates) of CCL5 in control and c-MYC^KD (knockdown) cells. (B) CCL5 gene expression, normalized by 18S ribosomal RNA, was quantified by real-time reverse transcription–PCR analysis in control, c-MYC^KD, MIZ-1^KD or c-MYC/MIZ-1^DKD (double knockdown) MCF-7 cells. (C) Chromatin immunoprecipitations (ChIPs) were carried out with antibodies against c-MYC and MIZ-1, or a pre-immune serum (Ctrl). ChIP was evaluated using quantitative real-time PCR analysis, with primers in the CCL5 gene regulatory region. (D) Parental control and c-MYC^KD MCF-7 cells were treated with fetal calf serum (FCS) and recombinant CCL5 or an anti-CCL5-blocking antibody or left untreated and assayed for migration.