The ICMT Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the human HT29 colorectal adenocarcinoma cell line. These cells feature targeted disruption of the ICMT gene via guide RNA-directed Cas9 nuclease activity, generating a heterogeneous knockout model without single-cell cloning. This format preserves genetic diversity while ablating ICMT function, providing a robust tool for studying isoprenylcysteine carboxylmethyltransferase in cancer-relevant signaling networks.
The parental HT29 cell line is a widely used epithelial model of human colorectal adenocarcinoma, retaining key features such as epithelial morphology and proliferative capacity. HT29 cells harbor mutations in tumor suppressors like APC and TP53, and exhibit active Wnt/??-catenin signaling, which cooperates with oncogenic RAS pathways. This genetic context makes HT29 an ideal background for investigating post-translational modifications that regulate RAS and other CAAX protein functions in colorectal cancer.
ICMT catalyzes the final step in CAAX protein processing, methylating the prenylated cysteine residue to enable stable membrane association of small GTPases such as KRAS, NRAS, HRAS, RAC1, and RHO proteins. This modification occurs downstream of farnesylation by farnesyltransferase or geranylgeranyltransferase type I and proteolysis by RCE1. ICMT thus regulates subcellular localization and signaling output, influencing pathways governing proliferation, migration, and survival. ICMT interacts with prenylated CAAX substrates and is integral to RAS signaling and small GTPase membrane targeting.
In HT29 cells, ICMT disruption is expected to impair membrane targeting of prenylated RAS and RHO proteins, attenuating signal transduction driving malignant phenotypes. This model allows dissection of how loss of ICMT affects RAS and RHO protein localization and function in colorectal adenocarcinoma. It enables study of post-translational methylation’s contribution to cancer cell proliferation and migration, and evaluation of synthetic lethal interactions with other pathway inhibitors. This system is valuable for probing dependency on the prenylation cycle in RAS-driven oncogenic processes.
Typical applications include investigating RAS-driven oncogenic signaling, studying post-translational modifications, screening prenylation-targeting anticancer drugs, and analyzing colorectal cancer cell migration and invasion. Compatible assays include western blotting for ICMT and substrate methylation, membrane fractionation for RAS localization, immunofluorescence for GTPase distribution, proliferation and migration assays, and drug sensitivity tests with farnesyltransferase inhibitors. The polyclonal design enables robust, reproducible analyses for high-throughput screening and mechanistic studies. For further details, contact Ascent Research.
