The KSR1 Knockout HT29 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout population engineered to disrupt the KSR1 gene in the human HT29 colorectal adenocarcinoma cell line. This product provides a genetically heterogeneous pool of cells with targeted disruption of KSR1, enabling functional studies of scaffold protein-mediated signal transduction. The polyclonal format allows researchers to interrogate KSR1-dependent processes while averaging clonal variation, making it suitable for population-based assays that recapitulate tumor heterogeneity.
HT29 is an epithelial cell line derived from a human colorectal adenocarcinoma, widely utilized as a model for colorectal cancer research. These cells carry well-characterized mutations, including those in APC, TP53, and BRAF (V600E), which drive constitutive MAPK pathway activation. Consequently, HT29 cells are employed to investigate oncogenic signaling, epithelial biology, and therapeutic responses in a colon cancer context. Their stable growth characteristics and tumorigenic potential in xenograft models further extend their utility in preclinical drug discovery and cancer cell biology.
KSR1 (Kinase Suppressor of Ras 1) serves as a scaffold protein that co-localizes RAF, MEK, and ERK kinases downstream of activated RAS. It directly binds RAS isoforms (HRAS, KRAS, NRAS) and facilitates the sequential phosphorylation of BRAF/CRAF, MEK1/2, and ERK1/2. Interaction with 14-3-3 proteins and HSP90 regulates KSR1??s scaffolding activity and subcellular localization. This assembly ensures efficient signal transduction from upstream receptors like EGFR to the activation of transcription factors ELK1, c-FOS, and c-JUN. Additionally, KSR1 indirectly influences the PI3K/AKT pathway, coordinating cell proliferation and survival signals.
In the HT29 colorectal cancer background, which harbors an oncogenic BRAF V600E mutation, KSR1 is critical for sustaining elevated ERK activity. Disruption of KSR1 gene function in this model attenuates the scaffold-dependent assembly of RAF-MEK-ERK complexes, leading to reduced ERK phosphorylation and impaired downstream transcriptional programs. This functional loss highlights KSR1 as a key node in MAPK-driven proliferation and survival of colorectal cancer cells. Consequently, the KSR1 knockout HT29 polyclonal cells offer a valuable system for dissecting scaffold-dependent contributions to tumorigenesis and for investigating mechanisms of adaptive resistance to RAF or MEK inhibitors.
Typical experimental applications of this polyclonal knockout population include western blot analysis of phospho-ERK and other MAPK effectors, RT-qPCR quantification of ERK target gene expression, and cell proliferation or colony formation assays. The cells are also used in flow cytometric cell cycle analysis and inhibitor response studies with MEK inhibitors to evaluate drug sensitivity. Additionally, these cells can be employed in xenograft tumor models to examine the role of KSR1 in in vivo growth. For further product information, researchers may contact Ascent Research.
