The CCNT2 Knockout Huh-7 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from Huh-7 human hepatocellular carcinoma cells. This loss-of-function model features targeted disruption of the CCNT2 gene across a pooled cell population, avoiding clonal artifacts. The polyclonal format ensures robust representation of knockout phenotypes for functional genomics studies.
Huh-7 is an epithelial cell line from a well-differentiated liver tumor of a Japanese male. Widely used in hepatocyte biology, it supports research on drug metabolism, viral hepatitis, and oncogenic signaling. The cells carry a p53 mutation and active PI3K/AKT and MAPK pathways, providing a relevant context for studies of transcriptional dysregulation in hepatocellular carcinoma.
CCNT2 encodes Cyclin T2, the regulatory subunit of positive transcription elongation factor b (P-TEFb). Within P-TEFb, Cyclin T2 partners with cyclin-dependent kinase 9 (CDK9) and is normally held inactive by the 7SK small nuclear ribonucleoprotein (7SK snRNP) complex, which includes HEXIM1 and 7SK RNA. Release from this inhibitory complex is facilitated by bromodomain protein BRD4 and the super elongation complex components AFF1/AFF4. Once free, P-TEFb phosphorylates serine 2 of the RNA polymerase II C-terminal domain (CTD), triggering productive transcriptional elongation. Key downstream targets regulated by this mechanism include the oncogenes MYC and CCND1, and the anti-apoptotic factor BCL2, which promote cell proliferation and survival. Additionally, the HIV-1 Tat protein exploits Cyclin T2?CCDK9 to drive viral gene expression. Upstream signals through the PI3K/AKT and NF-??B pathways converge on P-TEFb to control its activity, linking extracellular stimuli to transcriptional output.
CCNT2 knockout in Huh-7 cells impairs P-TEFb-dependent elongation of growth and survival genes, likely reducing proliferation and sensitizing cells to apoptosis. This model is valuable for dissecting Cyclin T2-specific functions distinct from Cyclin T1, and for studying HIV-1 transcription in liver cells. The polyclonal design ensures phenotypic consistency across experiments.
Applications include transcriptional elongation analysis by RNA-seq and ChIP-PCR, CDK9 inhibitor screening, and HIV-1 infection assays. Downstream effects can be assessed via western blotting for Pol II Ser2 phosphorylation and RT-qPCR for target genes. Functional studies may use proliferation, colony formation, and apoptosis assays. These cells enable exploration of P-TEFb regulation in hepatocellular carcinoma. For technical inquiries, please contact Ascent Research.
