The role of CDK12 in tumor bio­logy

Physiological function of cyclin-dependent kinase 12 (CDK12) is crucial for several cellular processes, including regulation of transcription, RNA splicing, transcription termination and polyadenylation. It is well documented by now that CDK12 controls transcription of the unique set of genes involved in DNA-damage response, replication of DNA and response to cellular stress. Just recently, a key function of CDK12 in the induction of tandem duplication of specific DNA sequences within the metastatic castrate resistant prostate tumors has been documented. Therefore, it is possible to recognize CDK12 as a tumor suppressor; nevertheless, there is a growing body of evidence that CDK12 can support tumor growth under specific circumstances and thus act as a tumor oncogene. CDK12 therefore represents an alternative dia-gnostic approach for breast, ovarian and prostate tumors, especially when conventional treatment is not active and there is a need for more effective approaches, such as concept of synthetic lethality.