Pharmacy and Pharmaceutical Sciences Commons^™

The Development Of Novel Cdk8 And Cdk19 Inhibitors And Degraders As Potential Anti-Cancer Agents, Li Zhang

Theses and Dissertations

CDK8 and its homolog CDK19 are essential for transcription regulation and their dysregulation has been identified in numerous diseases, especially in cancers. CDK8 and CDK19 have been implicated in cancer development through their kinase activity and kinase independent functions. Despite the existing CDK8/19 inhibitors, there is still a need to develop novel CDK8/19 inhibitors with improved potency and PK profile. It is also necessary to develop CDK8/19 degraders that are able to eliminate the kinase-independent functions. Although two CDK8-degrading PROteolysis Activating Chimeras (PROTACs) have been reported, they have limited CDK8 degradation efficacy and no effect on CDK19. PROTACs with improved …

The Role Of Cdk8 In Metastatic Growth Of Colon Cancer, Jiaxin Liang

Theses and Dissertations

Unresectable hepatic metastases of colon cancer poorly respond to existing therapies and are a major cause of colon cancer lethality. Transcription- regulating Mediator kinase CDK8, an early clinical stage drug target, is amplified or overexpressed in many colon cancers and CDK8 expression correlates with shorter patient survival. Here we show that CDK8 inhibition does not generally suppress proliferation of CDK8-overexpressing colon cancer cells but nevertheless CDK8 knockdown by shRNA or CDK8 kinase inhibition by a selective small-molecule drug candidate suppresses metastatic growth of mouse and human colon cancer cells in the liver. This effect is due at least in part …

Effects Of Dna Damage And Cdk Inhibitors On The Nucleoli, Vineet Garg

Theses and Dissertations

The nucleolus is the primary site of ribogenesis and consists of three compartments, namely, fibrillar center (FC), dense fibrillar component (DFC) and granular component (GC). Recent studies have observed a novel structure distinct from these three compartments which forms in the nucleolus upon DNA damage called Intranucleolar body (INoB). Previous studies in our laboratory have found INoBs forming in HT1080 fibrosarcoma cell lines after ectopic overexpression of damage-inducible cell cycle inhibitor p21. This INoB formation has been observed to be decreased by Senexin A which is an inhibitor of transcription regulating kinases CDK8/CDK19.

Here we show that INoB formation correlates …