The EGFR Knockout HT29 Polyclonal Cells product from Ascent Research is a CRISPR/Cas9-edited polyclonal knockout cell population, featuring targeted disruption of the epidermal growth factor receptor (EGFR) gene in the HT29 human colorectal adenocarcinoma cell line. This pooled knockout population, generated via CRISPR/Cas9 ribonucleoprotein delivery, provides a robust and genetically diverse cell model for studying EGFR function without clonal selection. The polyclonal composition retains the inherent genetic background of the HT29 parental line while ablating EGFR expression, making it suitable for bulk population studies and high-throughput screening applications.
The HT29 cell line, derived from a primary colorectal adenocarcinoma of a 44-year-old female, is a widely used epithelial model in biomedical research. These cells exhibit an undifferentiated phenotype under standard culture conditions but can undergo enterocytic differentiation upon appropriate stimuli, making them a valuable tool for studying intestinal epithelial biology, barrier function, and colorectal cancer pathogenesis. The HT29 background is particularly relevant for investigating EGFR-driven signaling events in the context of colorectal tumorigenesis, as EGFR overexpression and constitutive activation are common features in colorectal cancers.
EGFR (ErbB1/HER1) is a 170-kDa receptor tyrosine kinase that, upon binding to ligands such as EGF, TGF??, amphiregulin, epiregulin, betacellulin, or HB-EGF, undergoes dimerization and autophosphorylation. This initiates multiple downstream cascades: the GRB2/SOS/RAS/RAF/MEK/ERK (MAPK/ERK) pathway, the PI3K/AKT pathway, the JAK/STAT pathway, and the PLC??/PKC pathway. EGFR also interacts with coreceptors like HER2 and HER3, and adaptor proteins including GRB2, SHC, and CBL, which modulate signal transduction and receptor ubiquitination. Downstream targets include ERK1/2, AKT, STAT3, PLC??, ELK1, mTOR, MYC, and CCND1, collectively regulating cell proliferation, survival, motility, and differentiation. SRC-mediated transactivation further diversifies EGFR signaling.
In HT29 cells, EGFR signaling drives key oncogenic processes. Disruption of EGFR in this polyclonal knockout population abolishes EGF-induced receptor tyrosine kinase activity, leading to impaired activation of the MAPK/ERK and PI3K/AKT pathways, as described in the mechanistic summary. Consequently, the cells exhibit reduced proliferation, survival, and migration, mirroring the effects of pharmacological EGFR inhibition. This model thus enables dissection of EGFR-dependent signaling from compensatory mechanisms, providing a clean loss-of-function system to evaluate therapeutic targets and resistance mechanisms in colorectal cancer.
Typical research applications include investigating the role of EGFR in colorectal cancer cell signaling, drug response to monoclonal antibodies (e.g., cetuximab) or tyrosine kinase inhibitors, mechanisms of invasiveness and metastasis, and the impact on intestinal epithelial differentiation and barrier function. Representative assays cover western blotting for EGFR, phospho-ERK, and phospho-AKT; RT-qPCR for EGFR mRNA; MTT proliferation assay; scratch wound migration assay; cetuximab sensitivity testing; annexin V apoptosis assay; and immunofluorescence for EGFR localization. For additional product details, technical support, or to place an order, please contact Ascent Research.
