The DNAJC3 Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the DNAJC3 gene in the NCI-H1975 human lung adenocarcinoma epithelial cell line. This product supplies a heterogeneous mixture of cells carrying loss-of-function edits, enabling functional studies without clonal selection biases. The pooled knockout format provides a reliable loss-of-function model for investigating DNAJC3-dependent processes in cancer biology.
The parental NCI-H1975 cell line is a widely used model of non-small cell lung cancer (NSCLC), originally established from the pleural effusion of a female patient with lung adenocarcinoma. These cells harbor activating EGFR L858R and T790M mutations, the latter conferring resistance to first-generation tyrosine kinase inhibitors. Consequently, NCI-H1975 is a pertinent system for exploring oncogenic signaling, drug resistance mechanisms, and the tumor microenvironment in EGFR-mutant adenocarcinoma.
DNAJC3, encoding the co-chaperone P58IPK, serves as an endogenous inhibitor of the stress-activated kinases PKR and PERK. Under ER stress, DNAJC3 transcription is induced by ATF4 and XBP1, and its protein product associates with BiP/GRP78 and the Hsp70 chaperone machinery. P58IPK directly binds and represses PERK and PKR, thereby attenuating eIF2?? phosphorylation and suppressing downstream ATF4/CHOP-mediated apoptotic signaling. This negative feedback loop supports proteostasis and promotes cell survival during unfolded protein response (UPR) activation.
In the NCI-H1975 background, DNAJC3-mediated regulation of PERK and PKR is particularly relevant due to the elevated ER stress often observed in EGFR-driven adenocarcinomas. Aberrant UPR signaling contributes to chemoresistance and adaptive protection against targeted therapies. Disruption of DNAJC3 in this polyclonal knockout population enables researchers to assess how loss of P58IPK sensitizes lung cancer cells to ER stress-inducing agents, alters translation control, and modulates sensitivity to EGFR inhibitors, thereby illuminating therapeutic vulnerabilities.
Typical applications include immunoblotting for eIF2?? phosphorylation, ATF4, CHOP, and DNAJC3 itself; RT-qPCR profiling of UPR target genes; cell viability and apoptosis assays following tunicamycin-induced ER stress; drug sensitivity testing with EGFR tyrosine kinase inhibitors; and co-immunoprecipitation to verify disrupted interactions with PERK and PKR. Transcriptomic analysis via RNA-seq can further capture broad UPR reprogramming. These tools support mechanistic dissection of the PERK-eIF2??-ATF4 pathway and evaluation of DNAJC3 as a target for combinatorial strategies. For further information, please contact Ascent Research.
