The CCNT1 Knockout Huh-7 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal Huh-7 cell population in which the CCNT1 gene has been disrupted, resulting in a loss-of-function model for Cyclin T1. This polyclonal knockout product provides a heterogeneous pool of edited cells suitable for studying the functional consequences of Cyclin T1 ablation across a mixed genetic background, without clonal selection.
The Huh-7 host cell line was originally derived from a hepatocellular carcinoma of a 57-year-old Japanese male and has since become a widely employed model for hepatocyte function, liver cancer biology, and hepatitis C virus replication. As an epithelial liver cancer cell line, Huh-7 retains features of hepatocytic differentiation and is permissive for HCV infection, making it a valuable platform for both oncogenic studies and virology research.
CCNT1 encodes Cyclin T1, the regulatory subunit of the positive transcription elongation factor b (P-TEFb) complex. Cyclin T1 forms a heterodimer with CDK9 and is released from the inhibitory 7SK snRNP complex upon activation by signaling cascades such as MAPK/ERK or through recruitment by HIV-1 Tat. Active P-TEFb phosphorylates the C-terminal domain of RNA polymerase II at Ser2 and counteracts the negative elongation factors NELF and DSIF (SPT5), thereby promoting productive transcriptional elongation of cellular genes such as MYC and FOS, as well as the HIV-1 provirus. Additional interacting factors within the Super Elongation Complex include AFF4 and ELL2, which further stabilize P-TEFb on chromatin.
In the context of Huh-7 hepatocellular carcinoma cells, Cyclin T1-mediated transcriptional elongation is particularly relevant for MYC-driven oncogenic programs and the maintenance of malignant gene expression profiles. Disruption of CCNT1 in this polyclonal knockout model allows researchers to dissect the dependence of liver cancer cells on P-TEFb activity and to evaluate how tumor cell proliferation and survival are impacted by the loss of Cyclin T1 function. Moreover, because Huh-7 cells are amenable to HIV-1 Tat transactivation assays, this model enables exploration of host factor requirements for HIV-1 transcriptional activation in a hepatic cellular environment.
Typical research applications include mechanistic investigations of transcriptional elongation using chromatin immunoprecipitation?CqPCR for RNA Pol II Ser2 phosphorylation, global expression analysis via RNA-seq, and RT-qPCR quantification of target genes such as MYC and FOS. Protein-level validation can be performed by Western blotting for Cyclin T1 and CDK9, while functional studies benefit from HIV-1 LTR reporter assays and pharmacological sensitivity screens using CDK9 inhibitors. For further technical details or inquiries, please contact Ascent Research.
