The IMPACT Knockout SK-HEP-1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the SK-HEP-1 human liver adenocarcinoma cell line, featuring targeted disruption of the IMPACT gene (also known as Imprinted and Ancient Gene Protein). This pooled population provides a loss-of-function model to study the role of IMPACT in translational control and the integrated stress response.
SK-HEP-1 cells were originally isolated from the ascites of a patient with liver adenocarcinoma and exhibit an adherent, aneuploid phenotype with notable endothelial-like characteristics, making them a valuable dual model for hepatocellular carcinoma (HCC) biology and liver endothelial cell function.
IMPACT functions as a negative regulator of the integrated stress response (ISR) by binding GCN1 and preventing GCN2 kinase-mediated phosphorylation of the eukaryotic translation initiation factor 2?? (eIF2??). Under amino acid deprivation, IMPACT acts downstream of mTORC1 signaling and upstream of GCN2, eIF2?? phosphorylation, and ATF4 transcription. IMPACT physically interacts with GCN1, GCN2, and the ribosome, and its disruption releases GCN2-dependent signaling, leading to increased eIF2?? phosphorylation, ATF4 translation, and expression of downstream effectors such as CHOP and GADD34, ultimately suppressing global protein synthesis.
In the SK-HEP-1 background, knockout of IMPACT provides a physiologically relevant system to interrogate how deregulated ISR contributes to hepatocellular carcinoma progression and the endothelial-like behavior of these tumor cells. The model enables dissection of amino acid sensing and translational reprogramming in the context of liver cancer cell survival, proliferation, and metabolic adaptation under nutrient-limited conditions typically encountered in solid tumors.
These polyclonal knockout cells are suitable for a range of functional assays, including western blotting for phospho-eIF2?? and ATF4, luciferase reporter assays for ISR activity, RT-qPCR profiling of ATF4/CHOP/GADD34 induction under amino acid starvation, co-immunoprecipitation of IMPACT-GCN1 complexes (in wild-type controls), cell viability measurements under nutrient stress, and puromycin incorporation assays to monitor translational output. They serve as a robust platform for studying integrated stress response signaling, translational control in cancer, and for screening small molecules that modulate the GCN2?CeIF2???CATF4 axis. For additional details, technical support, or custom cell engineering services, please contact Ascent Research.
