Biochem/physiol Actions

dBET1 is a JQ1-and-phthalimide conjugate that causes the degradation of BRD4 protein, a transcriptional coactivator that regulates the expression of genes that promote cancer cell proliferation and survival. JQ1 is a selective BET bromodomain (BRD) inihbitor. The phthalimide portion is a derivative of the drug thalidomide, which is known to bind to cereblon (CRBN), part of an ubiquitin E3 ligase complex resulting in ubiquitylation and degradation by the proteasome. The conjugate dBET1 induced highly selective cereblon-dependent BET protein degradation both in vitro and in vivo. It induced complete CRBN-dependent proteosomal degradation of BRD4 in a human acute myeloid leukaemia (AML) cell line and delayed leukemia progression in mice.