The EIF2AK3 Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population from the HT29 human colorectal adenocarcinoma line, with targeted disruption of the EIF2AK3 gene encoding PERK kinase. This heterogeneous knockout pool enables loss-of-function studies of the unfolded protein response (UPR) without clonal selection bias.
The HT29 parental line is a well-studied human colorectal adenocarcinoma cell model with epithelial morphology. Isolated from a primary tumor, it carries mutations in APC, TP53, and SMAD4, with wild-type KRAS. HT29 cells maintain features of intestinal epithelial differentiation, forming polarized monolayers useful for barrier function, tumorigenicity, and stress adaptation studies.
PERK is an ER-resident transmembrane kinase activated by accumulation of misfolded proteins. Upon ER stress (caused by glucose deprivation, hypoxia, oxidative stress, or calcium imbalance), PERK dissociates from GRP78/BiP, oligomerizes, and autophosphorylates. Activated PERK directly phosphorylates eIF2?? at serine 51, resulting in a global reduction of cap-dependent translation while enhancing translation of select mRNAs such as ATF4. ATF4 transcriptionally upregulates genes involved in amino acid metabolism, redox homeostasis, and apoptosis, including CHOP (DDIT3), GADD34 (PPP1R15A), and NRF2 (NFE2L2). PERK signaling intersects with the other UPR branches through IRE1 and ATF6, and its activity is regulated by 14-3-3 proteins and cytosolic chaperones. This pathway is fundamental to ER stress adaptation and has been widely linked to cancer cell survival in adverse microenvironments.
In the context of HT29 colorectal cancer cells, loss of PERK function profoundly disrupts the UPR, impairing the cell’s ability to cope with proteotoxic stress. Given the mutational landscape of HT29??including TP53 deficiency??PERK knockout may shift the balance toward apoptosis under ER stress or alter adaptive responses that support tumor growth in nutrient-deprived microenvironments. This model is therefore particularly valuable for dissecting how PERK-dependent signaling contributes to colorectal cancer progression, chemoresistance, and metabolic adaptation. It enables researchers to explore whether PERK inhibition synergizes with standard chemotherapies or targeted agents in p53-mutant contexts.
The EIF2AK3 Knockout HT29 Polyclonal Cells enable a broad array of experimental approaches. Typical assays include western blotting for phospho-eIF2??, ATF4, and CHOP, RT-qPCR profiling of UPR targets, RNA-seq under ER stress, flow cytometry for apoptosis (Annexin V), viability assays with tunicamycin or thapsigargin, colony formation, migration, and drug sensitivity screens. Metabolic analyses (Seahorse) and co-immunoprecipitation of PERK interactors are also feasible. This model is ideal for studying PERK-dependent UPR, ER stress-induced apoptosis, and chemoresistance in colorectal cancer, as well as for inhibitor screening. For further details, contact Ascent Research.
