The KNSTRN Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the KNSTRN gene in the NCI-H1975 human non-small cell lung carcinoma (NSCLC) cell line. This polyclonal model provides a heterogeneous pool of cells with KNSTRN gene disruption, enabling functional studies of kinastrin (SKAP) without clonal selection. The knockout product is generated through CRISPR/Cas9-mediated gene targeting, resulting in a loss-of-function model for investigating mitotic regulation and chromosome dynamics in a lung adenocarcinoma context.
The parental NCI-H1975 cell line originates from a female patient with lung adenocarcinoma and harbors EGFR L858R and T790M mutations, making it a widely accepted model for EGFR-mutant NSCLC with acquired resistance to first-generation tyrosine kinase inhibitors. These epithelial cells retain key oncogenic signaling features and are routinely employed to explore mechanisms of drug resistance, test next-generation EGFR inhibitors, and evaluate combination therapies. The cell line’s well-characterized genetic background supports reproducible investigations into tumor cell biology.
KNSTRN encodes kinastrin (SKAP), a kinetochore-localized protein critical for chromosome alignment and mitotic fidelity. Kinastrin interacts directly with the NDC80 complex, CENP-E, and Aurora B kinase, recruiting PP1 phosphatase to antagonize Aurora B-mediated phosphorylation at kinetochore-microtubule attachment sites. This activity stabilizes attachments and promotes chromosome congression. Upstream, KNSTRN function is regulated by CDK1/cyclin B and spindle assembly checkpoint kinases such as BUB1, BUBR1, and Aurora B. Downstream, it facilitates activation of the anaphase-promoting complex/cyclosome (APC/C) and cohesion cleavage, ensuring accurate chromosome segregation. Disruption of KNSTRN impairs these processes, likely causing mitotic delay, missegregation, and aneuploidy.
Within the NCI-H1975 background, KNSTRN knockout provides a unique tool to explore mitotic vulnerabilities in EGFR-mutant lung adenocarcinoma. The oncogenic EGFR signaling may intersect with spindle checkpoint pathways, and KNSTRN loss could reveal synthetic lethality relationships or enhance sensitivity to spindle poisons and EGFR inhibitors. This model enables dissection of chromosome instability mechanisms in a clinically relevant setting, supporting the development of novel therapeutic strategies for drug-resistant NSCLC. The polyclonal format preserves genetic heterogeneity found in tumors, offering a complementary system to monoclonal knockouts.
Typical research applications include immunofluorescence staining for mitotic spindle and kinetochore markers, live-cell imaging of mitotic progression and chromosome dynamics, flow cytometry for cell cycle distribution, and Western blotting for phospho-Histone H3 as a mitotic index readout. The cells are well suited for colony formation assays and drug sensitivity screens with agents targeting EGFR or mitotic checkpoints. RNA sequencing can uncover transcriptional changes following KNSTRN loss. For further technical information, please contact Ascent Research.
