The KCTD3 Knockout NCI-H1975 Polyclonal Cells comprise a CRISPR/Cas9-edited polyclonal cell population featuring targeted disruption of the KCTD3 gene in the human NCI-H1975 non-small cell lung cancer (NSCLC) cell line. This polyclonal knockout model provides a heterogeneous loss-of-function system for investigating KCTD3-dependent molecular mechanisms.
The NCI-H1975 cell line is derived from a female non-smoker with lung adenocarcinoma and harbors an activating EGFR L858R point mutation. As an established NSCLC epithelial model, these cells recapitulate key oncogenic signaling features, including constitutive EGFR and downstream MAPK/PI3K pathway activation, making them widely used in lung cancer research.
KCTD3 encodes a substrate adaptor for the Cullin3-RING E3 ubiquitin ligase complex, interacting directly with Cullin3 and RBX1 to mediate ubiquitination and proteasomal degradation of ??-catenin (CTNNB1). By promoting ??-catenin turnover, KCTD3 negatively regulates Wnt/??-catenin signaling, suppressing the transcriptional activity of TCF/LEF factors and reducing expression of pro-proliferative target genes. This tumor-suppressive function is further modulated by upstream transcriptional regulators such as SP1 and possibly p53, as well as epigenetic silencing through promoter methylation. Consequently, KCTD3-deficient cells exhibit stabilized ??-catenin and enhanced Wnt pathway output, providing a defined system to dissect ubiquitin-dependent control of oncogenic signaling.
In the NCI-H1975 background, where EGFR L858R drives sustained proliferation and survival signals, disruption of KCTD3 is expected to potentiate Wnt/??-catenin signaling, thereby exacerbating tumorigenic phenotypes. This polyclonal knockout population thus serves as a relevant model to examine the interplay between EGFR-driven growth pathways and Wnt/??-catenin dysregulation, and to evaluate KCTD3??s role as a potential tumor suppressor in lung adenocarcinoma. Moreover, the isogenic nature??comparison with parental NCI-H1975 cells??enables precise assessment of how KCTD3 loss influences apoptosis, colony formation, and global gene expression programs.
Researchers can employ this knockout model in a variety of experimental contexts, including western blotting for KCTD3 and ??-catenin, co-immunoprecipitation of Cullin3 complexes, in vivo ubiquitination assays, cycloheximide chase experiments to measure ??-catenin stability, Wnt reporter luciferase assays, cell proliferation and apoptosis analyses, colony formation assays, and transcriptomic profiling via RNA-seq. These tools are instrumental for investigating ubiquitin-mediated proteostasis in lung cancer, elucidating signaling crosstalk, conducting functional screens for tumor suppressors, and advancing drug discovery targeting the ubiquitin-proteasome system or Wnt pathway. For inquiries or technical assistance, please contact Ascent Research.
