12hr 5-FU treatment vs. DMSO in SJSA cells (from 'A kinase independent role for CDK19 in p53 response')

ABSTRACT: The human Mediator complex regulates RNA Polymerase II transcription genomewide. A general factor that regulates Mediator function is the four-subunit Mediator kinase module, which contains either CDK8 or CDK19. Whereas CDK8 has been linked to specific signaling cascades and oncogenesis, the cellular roles of its paralog, CDK19, are poorly studied. To define cellular roles for CDK19, we used osteosarcoma cells (SJSA) that naturally lack endogenous CDK8 protein. Although stable CDK19 knockdown was tolerated in SJSA cells, it caused reduced proliferation vs. control shRNA cells. Global gene expression analyses (RNA-Seq) suggested that defects in cholesterol biosynthesis contributed to reduced proliferation in CDK19 knockdown cells (vs. shCTRL). Notably, proliferation defects were rescued with transient expression of wild-type or kinase-dead CDK19. Using RNA-Seq and other assays, we established a general role for CDK19 in the transcriptional response to 5-fluorouracil (5-FU), an inducer of genotoxic and metabolic stress. These experiments also implicated CDK19 in activation of p53 target genes during 5-FU treatment. To further probe a potential role for CDK19 in the p53 response, SJSA cells (shCDK19 vs. shCTRL) were treated with the p53 activator Nutlin-3. Remarkably, CDK19 was required for SJSA cells to return to a proliferative state following Nutlin-3 treatment, and this effect was kinase-independent. These results implicate CDK19 as a regulator of p53 stress responses and suggest a manifestation of CDK19 knockdown—potentially reduced levels of cholesterol metabolites—blocks cellular resistance to Nutlin-3.

ORGANISM(S): Homo sapiens

PROVIDER: GSE89807 | GEO | 2017/05/09

SECONDARY ACCESSION(S): PRJNA353364

REPOSITORIES: GEO