CRISPR/Cas9-mediated disruption of the ARHGAP18 gene in HT29 colorectal adenocarcinoma cells yields a polyclonal knockout cell population for loss-of-function studies of this Rho GTPase-activating protein. This heterogeneous pool of edited cells provides a versatile model to examine ARHGAP18??s role in actin cytoskeleton regulation, cell migration, and adhesion without clonal selection bias.
The HT29 cell line, derived from a primary colorectal adenocarcinoma, is a widely used model of intestinal epithelial barrier function and cancer biology. These cells form polarized monolayers with functional tight junctions and can undergo enterocytic differentiation under glucose depletion. The background includes mutations in APC, KRAS, and TP53, which are relevant to colorectal cancer and influence Rho GTPase signaling.
ARHGAP18 encodes a RhoGAP domain protein that inactivates RhoA and Cdc42 by accelerating GTP hydrolysis, thereby limiting actin stress fiber formation and focal adhesion assembly. Its activity is regulated by upstream signals including KRAS?CMEK/ERK, ETS1, SP1, TGF-??, and hypoxia. In HT29 cells, ARHGAP18 interacts with focal adhesion components (paxillin, talin, integrin ??1), actin regulators (filamin A), and adaptors (14-3-3??). Loss of ARHGAP18 is predicted to sustain RhoA/Cdc42 activity, leading to ROCK-mediated MLC phosphorylation, enhanced actin stress fibers, and altered focal adhesion dynamics. ARHGAP18 also modulates E-cadherin and ??-catenin, linking it to adherens junction integrity and Wnt pathway cross-talk.
In HT29 colorectal cancer cells, ARHGAP18 knockout likely amplifies Rho-driven contractility and migration, potentially promoting invasive behavior and disrupting epithelial barrier function. This polyclonal knockout population is ideal for investigating how ARHGAP18 loss influences colorectal cancer cell behavior, including EMT-like changes, altered adhesion, and migration. The model is well-suited for studying junctional integrity via TEER measurements and E-cadherin localization, and for evaluating Rho GTPase signaling in tumor progression.
Applications include RhoA-GTP/Cdc42-GTP quantification, phalloidin staining for actin visualization, immunofluorescence for paxillin and vinculin, Transwell migration/invasion assays, wound healing, TEER-based barrier assays, and Rho GTPase activation assays. Co-immunoprecipitation and RNA sequencing can further define ARHGAP18??s interactome and transcriptional impact. These cells also support inhibitor screening for ROCK and other Rho pathway targets. For further details, please contact Ascent Research.
