The DNAJB2 Knockout NCI-H1975 Polyclonal Cells product provides a polyclonal population of NCI-H1975 human lung adenocarcinoma cells harboring CRISPR/Cas9-mediated disruption of the DNAJB2 gene. As a pool of edited cells, this model enables loss-of-function analysis of DNAJB2 without clonal isolation, capturing the heterogeneity of CRISPR-mediated gene knockout effects across the cell population. This format is well suited for large-scale functional genomics studies where polyclonal readouts reflect average population behaviors, and it avoids potential artifacts from clonal variation.
The NCI-H1975 cell line originated from a 62-year-old female patient with non-small cell lung carcinoma (NSCLC) of adenocarcinoma histology. These cells carry compound EGFR mutations (L858R and T790M) that are associated with both primary oncogenic signaling and acquired resistance to first-generation tyrosine kinase inhibitors. The cell line is widely employed as a model for EGFR-mutant lung cancer, particularly for investigations into mechanisms of drug resistance, epithelial-mesenchymal transition, and tumor cell adaptations to targeted therapies.
DNAJB2 encodes a J-domain co-chaperone that partners with Hsp70 family members, including HSPA1A and HSPA8, to regulate protein folding and degradation. Through stimulation of Hsp70 ATPase activity, DNAJB2 facilitates substrate binding and processing, directing client proteins either to productive folding pathways or to ubiquitin-dependent proteasomal degradation. The protein interacts with diverse cofactors such as BAG family co-chaperones and the E3 ubiquitin ligase STUB1/CHIP, positioning it at a critical node between protein quality control and proteasome-mediated clearance. Upstream signals, including heat shock factor 1 (HSF1)-mediated transcription, endoplasmic reticulum stress, and oxidative stress, modulate DNAJB2 expression levels. Disruption of DNAJB2 function compromises proteostasis, leading to accumulation of misfolded and aggregated proteins, and attenuates cellular stress responses.
In the context of NCI-H1975 cells, which exhibit constitutively active EGFR signaling and heightened anabolic demands, proteostasis networks are often rewired to support malignant growth. DNAJB2 knockout in this model can reveal dependencies on the Hsp70 chaperone system for maintaining protein homeostasis under oncogenic stress. Furthermore, these cells provide a platform to examine how chaperone-mediated quality control influences responses to proteasome inhibition or other proteotoxic insults, linking protein metabolism to drug sensitivity. This polyclonal knockout population is thus a valuable tool for dissecting the contribution of DNAJB2 to cancer cell fitness and stress resilience.
Researchers can apply this knockout model to a broad range of experimental areas, including the study of Charcot-Marie-Tooth type 2 and related peripheral neuropathies, cellular mechanisms of neurodegeneration, and the role of co-chaperones in cancer biology. Representative assays include Western blotting for ubiquitylated protein aggregates and stress markers, proteasome activity measurements, co-immunoprecipitation to assess Hsp70 interactions, and immunofluorescence for stress granule formation. This tool also supports drug screening efforts aimed at targeting proteostasis vulnerabilities in EGFR-mutant NSCLC. Researchers interested in this model are encouraged to contact Ascent Research for additional information.
