ChIP analysis of RAR isoforms on the <i>PTGDR</i> promoter.

A. KU812 cells were exposed to 1μM ATRA or DMSO for 24h. ChIP assays were performed with antibodies against RARα and RARβ. Normal Rabbit IgG was used as the negative control for immunoprecipitation. Immunoprecipitated DNA was amplified by qPCR using primers spanning the polymorphic variant -549T>C in the proximal region of the PTGDR promoter or using the distal PTGDR intron region (negative primers). Results are presented as the fold enrichment of chromatin DNA precipitated by the specific antibody compared with normal rabbit IgG. ATRA data were normalized versus DMSO. Values are means from three independent experiments. **PPTGDR (negative control), n = 3. B. PBMCs isolated from subject bearing the CTCT, CCCC or TCCC-PTGDR haplotype variants were subject to ChIP assays with anti-RARα and RARβ antibodies as previously described, n = 1.