Evaluating genome-wide expression following the disruption of CDK12 reveals a bimodal pattern of gene regulation

We demonstrate that the loss of CDK12 protein or activity, unlike CDK9 or CDK7, significantly upregulates the expression of certain genes, including genes whose activation contributes to the anti-proliferative effects of CDK12 inhibition. In HER2+ breast cancer, a malignancy where CDK12 is almost invariably co-amplified with HER2, CDK12 inhibition drives up the expression of MYC, which is toxic to HER2+ cancer cells. This upregulation of c-myc largely mediates the killing effect of CDK12 inhibition. Therefore, we report a novel mode of regulation of gene expression via CDK12, which represents a promising target for cancer driven by HER2 gene amplification. Examination of the effects of inhibting three transcriptional kinases (CDK12, CDK9, CDK7) on genome-wide expression