Brd4 knockout colonic epithelial organoids are partially resistant to IFNg-induced cell death.
To identify the role of Brd4 in colorectal cancer (CRC) development , we performed Sleeping Beauty (SB) transposon mutagenesis in mice. We identified several candidate genes including Brd4.  To provide functional validation, we knocked out Brd4 in mouse tumor organoids carrying an activating KrasG12D, and an inactivating ApcD716 allele, and performed RNAseq. Brd4 knockout colonic organoids showed deregulation of genes in IFNg signaling. We treated Brd4 knockout organoids with IFNg and found that Brd4 konckout organoids showed partial resistance  to IFNg-induce cell death. The mechanism may explain the function of Brd4 in colon cancer development. Overall design: Brd4 was knocked out by CRISPR-Cas9 in mouse colon tumor organoids carrying an activating KrasG12D, and an inactivating ApcD716 allele. RNA was collected from control (4 replicates) and Brd4 KO (3 replicates). Also, IFNg was treated with control organoids  and Brd4 KO organoids, and RNA was collected from IFNg-treated conrol organoids (3 replicates) and IFNg-treated Brd4 KO organoids to perform RNA-seq.