The ICMT Knockout SK-HEP-1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population in the SK-HEP-1 hepatic adenocarcinoma line, designed for functional studies of isoprenylcysteine carboxyl methyltransferase (ICMT) in protein prenylation and hepatocellular carcinoma. The polyclonal format provides a heterogeneous gene-disrupted pool suitable for pooled screening and assays where clonal isolation is not required.
SK-HEP-1 cells, derived from ascites of a liver adenocarcinoma patient, model hepatocellular carcinoma with adherent epithelial morphology. They retain dysregulated growth factor signaling and metastatic features, enabling investigation of liver cancer biology and therapeutic responses in a human context.
ICMT catalyzes the carboxyl methylation of prenylated CAAX-motif proteins, including K-Ras, H-Ras, N-Ras, RhoA, Rac1, and Cdc42, completing their post-translational modification after farnesyltransferase or geranylgeranyltransferase I lipidation and RCE1 endoproteolysis. This methylation is required for stable membrane targeting and full signaling output of these small GTPases, which regulate proliferation, migration, and survival. ICMT activity is constitutively present but modulated by prenylation substrate availability, linking protein methylation to cellular isoprenoid pathways.
In SK-HEP-1 cells, ICMT disruption impairs membrane localization and signaling of prenylated GTPases, potentially attenuating oncogenic Ras and Rho pathways frequently activated in hepatocellular carcinoma. This model helps dissect the dependency of liver tumor cells on ICMT-mediated methylation and can reveal vulnerabilities to prenylation inhibitors, including farnesyltransferase inhibitors, as single agents or in combination.
Applications include western blot analysis of ICMT and unprenylated proteins, Ras activity pulldown, MTT proliferation, transwell migration, colony formation, and drug sensitivity assays. The polyclonal population enables assessment of heterogeneous knockout effects and is suited for screening novel ICMT inhibitors or chemical modulators of the prenylation pathway. For support, contact Ascent Research.
