The HEXIM2 Knockout SK-HEP-1 Polyclonal Cells product comprises a heterogeneous population of Homo sapiens SK-HEP-1 cells that have undergone CRISPR/Cas9-mediated disruption of the HEXIM2 gene. This polyclonal knockout format provides a robust loss-of-function model for studying HEXIM2 roles in transcription elongation and gene regulation without the clonal selection bottlenecks inherent in monoclonal lines. The edited cell population enables researchers to interrogate HEXIM2-dependent pathways in a physiologically relevant hepatic endothelial context.
The host cell line, SK-HEP-1, is an adherent, endothelial-like cell line originally derived from a human hepatic adenocarcinoma. These cells display characteristics of liver sinusoidal endothelial cells (LSECs), including fenestrated morphology and roles in filtration, endocytosis, and immune regulation. The SK-HEP-1 background is widely employed in hepatocellular carcinoma research and studies of liver vascular biology, making it an ideal platform to investigate the intersection of HEXIM2 signaling and hepatic pathophysiology.
HEXIM2 is a key component of the 7SK small nuclear ribonucleoprotein (snRNP) complex, where it directly binds 7SK snRNA and interacts with proteins such as LARP7, MePCE, and HEXIM1. In unstressed cells, the 7SK snRNP sequesters and inhibits the positive transcription elongation factor b (P-TEFb), composed of CDK9 and Cyclin T1. Upon activation by cellular stress signals, NF-??B signaling, or the inducer HMBA, HEXIM2 undergoes conformational changes that release active P-TEFb. Liberated CDK9/Cyclin T1 then phosphorylates RNA polymerase II (RNA Pol II) at serine 2 residues within the C-terminal domain, promoting productive elongation of target genes involved in growth, stress responses, and pathogenesis. Thus, HEXIM2 acts as a critical molecular switch balancing transcriptional elongation versus repression.
In the SK-HEP-1 hepatic endothelial model, disruption of HEXIM2 expression provides a unique opportunity to dissect P-TEFb-dependent transcription in the context of liver sinusoid biology. Given the gene??s relevance to hepatocellular carcinoma, cardiac hypertrophy, and HIV latency reactivation, this knockout population is particularly suited for exploring how HEXIM2 loss alters gene expression programs that drive tumor microenvironment remodeling, hypertrophic signaling, or viral transcriptional control. Furthermore, the LSEC-like phenotype allows investigation of HEXIM2-dependent endocytic and immune regulatory pathways, potentially linking transcription elongation to liver-specific functions.
Typical research applications include comprehensive characterization of HEXIM2 protein and transcript levels via western blotting and RT-qPCR, global transcriptomic profiling using RNA-seq, and assessment of RNA Pol II occupancy on target genes through ChIP-qPCR. Co-immunoprecipitation of 7SK snRNP components can validate complex integrity in HEXIM2-deficient cells. Functional assays such as cell proliferation, migration, and invasion studies, along with drug screening for transcription modulators, enable dissection of the signaling outcomes. Cellular stress response assays can further probe how HEXIM2 loss sensitizes or desensitizes cells to HMBA, NF-??B activators, or genotoxic agents. For more details or to place an order, please contact Ascent Research.
