The IGFBP4 Knockout HCT 116 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of HCT 116 human colorectal carcinoma cells with disruption of the IGFBP4 gene. This heterogeneous pool comprises various loss-of-function mutations introduced by non-homologous end joining, providing a biologically relevant model to study the consequences of IGFBP4 loss without clonal selection biases.
HCT 116 is a widely used colon cancer cell line derived from a male patient, characterized by MLH1 mutation-driven microsatellite instability (MSI-H). It harbors wild-type KRAS and TP53 alleles. These features make it an ideal platform for investigating colorectal tumorigenesis, metastatic mechanisms, and therapeutic responses in a genetically defined background with intact p53 and Ras signaling.
IGFBP4 acts as a negative regulator of insulin-like growth factor (IGF) signaling by binding IGF1 and IGF2, thereby preventing their interaction with IGF1R. Knockout of IGFBP4 increases free IGF ligands, leading to enhanced IGF1R phosphorylation and activation of downstream PI3K-AKT and MAPK/ERK cascades, with key effectors AKT1 and MAPK3 (ERK1). This results in reduced expression of the cyclin-dependent kinase inhibitors CDKN1A (p21) and CDKN1B (p27), driving cell cycle progression. Upstream regulators include TP53 and TGF-beta, and the protease PAPP-A can cleave IGFBP4 to liberate IGFs.
In the HCT 116 background, IGFBP4 ablation removes a critical checkpoint on IGF-driven proliferation and survival. Combined with the cell line??s MSI-H status and wild-type p53, this model enables dissection of how enhanced IGF1R signaling cooperates with genomic instability to promote colorectal cancer progression, suppress senescence, and potentially influence drug sensitivity.
These polyclonal knockout cells support diverse applications such as western blotting for phosphorylated IGF1R, AKT, and ERK; RT-qPCR for IGF1, IGF2, and IGFBP4; MTT and colony formation assays; annexin V apoptosis measurements; and transwell migration/invasion studies. They are suitable for ligand stimulation experiments and PAPP-A digestion assays, facilitating drug screening for IGF pathway inhibitors and functional analysis of senescence pathways in colorectal cancer. For additional information, contact Ascent Research.
