The DLGAP4 Knockout NCI-H1975 Polyclonal Cell product consists of a pool of NCI-H1975 human lung adenocarcinoma cells that have been subjected to CRISPR/Cas9-mediated gene disruption targeting the DLGAP4 locus. This polyclonal knockout population provides a robust loss-of-function model for investigating DLGAP4-dependent signaling in a well-characterized non-small cell lung cancer (NSCLC) background. Unlike monoclonal lines, the polyclonal format preserves the heterogeneous genetic background inherent to the parental line while ablating the target gene, enabling studies that minimize clonal artifacts. The cells are delivered as a ready-to-use heterogeneous pool, suitable for direct functional assays and comparative analyses.
The parental NCI-H1975 cell line was originally derived from the pleural effusion of a 62-year-old female never-smoker diagnosed with lung adenocarcinoma. This line harbors an activating EGFR exon 19 deletion (E746-A750) together with the secondary T790M gatekeeper mutation, a combination that confers acquired resistance to first-generation EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib. Consequently, NCI-H1975 serves as a widely accepted model for studying mechanisms of EGFR-TKI resistance and for evaluating next-generation therapeutics in NSCLC. The dual mutation status makes it particularly valuable for interrogating signaling crosstalk between EGFR and scaffolds like DLGAP4.
DLGAP4 encodes SAPAP4, a postsynaptic density scaffolding protein that directly interacts with DLG family members, most notably DLG4 (PSD-95). Through this interaction, SAPAP4 helps organize multi-protein complexes at sites of cell-cell adhesion and may coordinate receptor clustering and downstream signal transduction. In the context of NCI-H1975 cells, DLGAP4 is implicated in the regulation of ERK1/2, JNK, and ??-catenin signaling, potentially via its interaction with DLG4 and SHANK1, and through effects on actin cytoskeleton dynamics mediated by Rac1. Known protein partners include DLG1, DLG2, DLG3, and GRIN2B, placing DLGAP4 at an intersection between cell adhesion, MAPK/ERK, and RAP1 pathways.
Disruption of DLGAP4 in NCI-H1975 cells is expected to perturb the assembly of junctional signaling complexes, thereby altering downstream MAPK pathway activity and cytoskeletal organization. Given the established role of EGFR signaling in driving NSCLC proliferation and survival, loss of a scaffold that modulates EGFR-associated signaling nodes could modify cellular responses to TKIs. This knockout model thus provides a platform to dissect how scaffold proteins influence drug sensitivity, cell migration, and invasive potential in lung adenocarcinoma. Importantly, because DLGAP4 is not typically considered an oncogene, its knockdown may reveal context-specific vulnerabilities or adaptive resistance mechanisms in EGFR-mutant NSCLC.
Researchers can employ this polyclonal knockout cell population in a broad array of functional assays. Typical applications include examining the impact of DLGAP4 loss on gefitinib sensitivity using CCK-8 viability assays, assessing migratory and invasive properties via wound healing and Transwell assays, and characterizing alterations in the phosphoproteome through phospho-kinase arrays. Co-immunoprecipitation experiments can validate disrupted DLGAP4?CDLG4 complexes, while RT-qPCR and Western blotting confirm target gene knockout and downstream effector changes. RNA-seq transcriptomic profiling and flow cytometric cell cycle analysis further support systems-level investigation. For further information, please contact Ascent Research.
