The DNAJA2 Knockout NCI-H1299 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human non-small cell lung carcinoma (NSCLC) line NCI-H1299, with targeted disruption of the DNAJA2 gene. This polyclonal knockout format provides a genetically heterogeneous population that avoids clonal biases and better represents the complexity of a polyclonal tumor environment. The cells serve as a powerful tool for dissecting the functional roles of co-chaperones in cellular proteostasis and cancer stress responses.
The NCI-H1299 host cell line is a well-established model of metastatic lung adenocarcinoma, originally isolated from a lymph node metastasis of a lung adenocarcinoma patient. These cells are p53-null, harboring a homozygous deletion of TP53, which renders them defective in DNA damage-induced apoptosis and cell cycle arrest. This genetic background creates a heightened dependence on stress-adaptive mechanisms, including chaperone-mediated protein quality control, making the line particularly sensitive to perturbations in the proteostasis network.
DNAJA2 belongs to the Hsp40/DnaJ family of co-chaperones and contains a conserved J-domain that recruits and activates Hsc70/Hsp70 ATPase activity, driving client protein folding, translocation, and degradation. Under basal and stress conditions, its expression is transcriptionally regulated by heat shock factor 1 (HSF1) in response to heat shock, oxidative stress, and oncogenic signals. DNAJA2 physically interacts with Hsc70/Hsp70, Hsp90, and co-chaperones such as BAG family proteins, as well as with the E3 ubiquitin ligase CHIP, thereby linking the Hsp70 cycle to ubiquitin-proteasomal degradation. Consequently, DNAJA2 knockout impairs substrate recognition and ATP hydrolysis, resulting in defective protein folding, accumulation of misfolded proteins, and dysregulation of the unfolded protein response and chaperone-mediated autophagy pathways.
In p53-null NCI-H1299 cells, loss of DNAJA2 compounds inherent proteotoxic stress and may unmask synthetic lethal interactions exploitable for cancer therapy. NSCLC tumors frequently upregulate chaperone machinery to survive oncogenic stress; thus, this model enables investigation of co-chaperone dependencies in drug sensitivity, particularly to proteasome inhibitors and Hsp90-targeted agents. Furthermore, it provides a system to study p53-independent stress adaptation and the contribution of chaperone networks to metastatic potential and apoptosis resistance.
Researchers can employ these cells in a variety of assays: immunoblotting for Hsp70 and client protein levels, luciferase refolding assays to quantify chaperone activity, cell viability assays under proteotoxic or oxidative stress, proteasome activity measurements, immunofluorescence microscopy for protein aggregate detection, co-immunoprecipitation for chaperone-client interactions, and whole transcriptome analysis via RNA-seq to profile stress response pathways. Together, these applications support detailed mechanistic studies of protein quality control and the identification of novel treatment strategies in lung adenocarcinoma. For additional technical specifications or support, please contact Ascent Research.
