GSE119863
BCL6 confers KRAS-mutant NSCLCs resistance to BET inhibitors [ChIP-Seq]
We report that BCL6 interacts with BRD3 and that BRD3 inhibition upregulates BCL6. By obtaining sequence from chromatin immunoprecipitated DNA of A549 cells, we generated genome-wide binding gene spectrums of BCL6 and BRD3. By locating -3000 to +200 bps around TSS, we find that BRD3 binds to the promoters of 2470 genes and that BCL6 binds to the promoters of 694 genes, with 82 genes shared by BRD3 and BCL6. Interestingly, BCL6 itself is one of these 82 shared genes, implying that BCL6 mediated self-repression may require the participation of BRD3. Other shared genes includes SGK2, IDH2, HOXB6, SIRT1, SOCS3 and ZFNs, demonstrating the widely involvement of BRD3 in the regulatory role of BCL6. To examine the dependency of BCL6 on BRD3, we also compared BCL6-binding spectrums with or without a BET inhibitor, OTX015. The ChIP-seq data with BCL6 antibody exhibited a diverse BCL-binding spectrum composed of 731 genes in OTX015 treatment, with only 117 genes overlapped with that of DMSO treatment. These data demonstrates that BET inhibition is sufficient to change BCL6-binding spectrum. This study provides a new insight of BCL6 regulatory roles in KRAS-mutant NSCLCs, where BRD3 is recruited by BCL6 and affect BCL6 binding preference as a cofactor. Overall design: Examination of BCL6 and BRD3 binding spectrums in unstressed conditions. 2. Comparation of BCL6-binding genes with or without a BET inhibitor, OTX015 (1 µM for 6 hr), by ChIP-seq assay.