The ICMT Knockout HCT 116 Polyclonal Cells provide a CRISPR/Cas9-mediated gene-disrupted polyclonal population targeting the ICMT gene in the HCT 116 colorectal carcinoma cell line. This product is designed for constitutive loss of isoprenylcysteine carboxyl methyltransferase function, enabling researchers to interrogate the enzyme’s role in protein prenylation and membrane targeting without the confounding effects of clonal selection or site-specific mutation patterns.
The host HCT 116 line is a well-established human colorectal adenocarcinoma model carrying a heterozygous KRAS G13D driver mutation and exhibiting microsatellite instability (MSI). Derived from epithelial cells of a primary tumor, these cells are extensively utilized to investigate oncogenic RAS-dependent signaling, DNA mismatch repair defects, and responses to targeted agents, making them a physiologically relevant platform for studying colorectal cancer biology and drug sensitivity.
ICMT catalyzes the S-adenosylmethionine-dependent carboxyl methylation of C-terminal prenylcysteine residues on key signaling proteins, including HRAS, NRAS, KRAS, RhoA, Rac1, CDC42, and prelamin A. This modification is essential for stable membrane association and productive signal transduction. ICMT expression is transcriptionally regulated by SP1 and NF-Y, and its activity is coupled to upstream prenylation pathway flux. Downstream, ICMT-dependent methylation facilitates activation of ERK1/2 and AKT through RAS?CRAF?CMEK and PI3K cascades, while also influencing Rho family GTPase-mediated cytoskeletal reorganization and G-protein gamma subunit function.
In the HCT 116 context, disruption of ICMT critically impairs the membrane localization and oncogenic output of mutant KRAS G13D as well as Rho GTPases, thereby attenuating proliferative and survival signals. This polyclonal knockout model enables dissection of how impaired protein methylation alters the equilibrium of RAS effector pathways and sensitizes cells to prenylation pathway inhibitors, providing a valuable system for studying synthetic lethality and adaptive resistance mechanisms within a genetically defined colorectal adenocarcinoma background.
Applications include mechanistic studies of ICMT in RAS-driven cancer, screening of ICMT and prenylation pathway inhibitors, and analysis of protein trafficking and membrane dynamics using techniques such as KRAS membrane fractionation and immunofluorescence for Ras localization. Functional readouts can be assessed via RhoA GTPase activation assays, phospho-ERK/AKT profiling, cell proliferation (MTS, colony formation), apoptosis (Annexin V), and cell migration assays. These cells are also suitable for drug sensitivity testing with farnesyltransferase inhibitors. For additional technical information or to discuss custom applications, please contact Ascent Research.
