The IL6ST Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human colorectal adenocarcinoma cell line HT29. These cells harbor a targeted disruption of the IL6ST gene, which encodes the common gp130 signal transducer, thereby abolishing functional gp130 expression and downstream signaling. This loss-of-function model is well-suited for investigating the roles of IL-6 family cytokines in colorectal cancer biology, including signal transduction, proliferation, and survival.
The parental HT29 cell line was established from a primary colorectal adenocarcinoma of a 44-year-old female. HT29 cells are a widely used intestinal epithelial model for colorectal cancer research, offering a well-characterized background for studying tumor cell signaling, intestinal barrier function, and epithelial-mesenchymal transition (EMT). Their robust in vitro growth and differentiation capacity make them an ideal host for genetic manipulation and functional assays.
IL6ST encodes gp130, the shared signal-transducing subunit for the IL-6 family of cytokines, including IL-6, IL-11, LIF, OSM, CNTF, CTF1, and CLCF1. Ligand binding induces receptor dimerization and activation of associated JAK1, JAK2, and TYK2 kinases, which phosphorylate tyrosine residues within the gp130 cytoplasmic domain. These phosphotyrosines serve as docking sites for STAT3 and the adaptor protein SHP2. STAT3 homodimers translocate to the nucleus and transcriptionally upregulate genes such as BCL2, BCL-XL, MYC, CCND1, VEGFA, and MMP9, while SHP2 mediates activation of the GRB2-SOS-RAS-RAF-MEK-ERK1/2 cascade and the PI3K-AKT-mTOR pathway. Negative regulation is imposed by SOCS3, a STAT3 target gene that feeds back to inhibit JAK activity. Thus, gp130 coordinates mitogenic, survival, and invasive signals through multiple parallel effector arms.
In the context of HT29 colorectal adenocarcinoma cells, gp130 signaling is frequently dysregulated and contributes to oncogenic phenotypes. Knockout of IL6ST in this cell line provides a clean background to uncouple the specific contributions of IL-6 family cytokines from other growth factor inputs. Researchers can interrogate the dependency of colorectal cancer cell proliferation, survival, and metastasis on gp130-driven STAT3, MAPK, and AKT activation. The model is particularly valuable for studying mechanisms of resistance to therapeutic agents targeting IL-6/IL-6R signaling, such as tocilizumab, and for screening small-molecule inhibitors that disrupt gp130-mediated oncogenic pathways.
Typical applications include profiling JAK/STAT and MAPK pathway activation by western blot analysis of STAT3 and ERK1/2 phosphorylation, monitoring target gene expression via RT-qPCR for SOCS3, MYC, and CCND1, and assessing functional consequences through CCK-8 proliferation assays, Annexin V apoptosis assays, and Transwell migration/invasion assays. The knockout cells are also compatible with STAT3 luciferase reporter assays for high-throughput screening and RNA-seq transcriptome analysis to define gp130-dependent gene signatures. Drug sensitivity studies with STAT3 inhibitors or anti-IL-6R biologics can be performed to evaluate therapeutic vulnerabilities. For ordering or technical inquiries, please contact Ascent Research.
