The DNAJB2 Knockout NCI-H1299 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population established from the NCI-H1299 human lung adenocarcinoma epithelial cell line, designed for functional studies of the DNAJB2 co-chaperone. The polyclonal format comprises a heterogeneous mixture of cells harboring gene disruptions, reflecting the genetic diversity of the parental tumor and allowing robust interrogation of DNAJB2-dependent phenotypes without the constraints of clonal selection.
NCI-H1299 is a widely used non-small cell lung cancer (NSCLC) model derived from a lymph node metastasis. These cells carry a homozygous deletion of the TP53 tumor suppressor gene and a deletion of the CDKN2A locus, resulting in loss of functional p53, p16INK4a, and p14ARF proteins. The consequent defects in DNA repair, apoptosis, and cell cycle regulation generate a state of chronic proteotoxic stress and genomic instability, making the line particularly valuable for studying protein quality control mechanisms in an oncogenic context.
DNAJB2 encodes a member of the HSP40/DNAJ family that recruits HSP70 chaperones (HSPA1A and HSPA1B) to misfolded substrates. Under heat shock, oxidative, or proteotoxic stress, the transcription factor HSF1 activates DNAJB2 expression, and the protein forms complexes with HSP70, the co-chaperone BAG3, and the E3 ubiquitin ligase STUB1/CHIP. This triage machinery directs client proteins either toward refolding or to degradation via the ubiquitin-proteasome system, with the AAA+ ATPase VCP/p97 channeling substrates toward autophagy when proteasome capacity is exceeded. DNAJB2 loss disrupts this network, leading to accumulation of ubiquitinated aggregates, persistent heat shock response, and elevated oxidative injury.
In the NCI-H1299 background, DNAJB2 knockout exacerbates the inherent proteotoxic stress caused by TP53 and CDKN2A loss, potentially enhancing cellular sensitivity to proteasome inhibitors such as bortezomib. The polyclonal knockout cells allow assessment of DNAJB2-dependent effects on proliferation, migration, invasion, and epithelial-mesenchymal transition, as well as investigation of how impaired chaperone function influences drug resistance and the interaction between protein aggregation and immune recognition pathways.
These cells are suited for a broad array of applications, including co-immunoprecipitation of HSP70?CDNAJB2 complexes, proteasome activity and ubiquitin-proteasome flux measurements, immunofluorescence detection of protein inclusions, and cell viability assays under heat shock or proteasome inhibitor treatment. They additionally serve as a model for Charcot-Marie-Tooth disease type 2T and related neuromyopathies, and can be employed in high-content screens for modulators of HSF1 activity or HSP70?Cco-chaperone interactions. For additional details, please contact Ascent Research.
