Figure 2.
Role of NR4A1/Sp in regulation of PD-L1 in MDA-MB-231 and 4T1 cells. MDA-MB-231 (A) and 4T1 (B) cells were transfected with two different oligonucleotides targeting Sp1 (iSp1), and NR4A1 (iNR4A1) and a control non-specific oligonucleotide (siCtl) and whole cell lysates were analyzed by western blots. MDA-MB-231 (C) and 4T1 cells (D) were treated with CDIM-8 or Cl-OCH3 for 3 hours and protein interactions with the PD-L1 promoter were analyzed by ChIP assays using primers encompassing GC-rich region of the PD-L1 promoter. E. Model of NR4A1/Sp1 complex that regulates PD-L1 expression in breast cancer cells. Quantitation of the results of Sp1 knockdown in 4T1 and MDA-MB-231 cells are summarized in Supplementary Figure 3A.