The HSPBP1 Knockout NCI-H1975 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout population derived from the NCI-H1975 human lung adenocarcinoma cell line, featuring targeted disruption of the HSPBP1 gene. This tool provides a loss-of-function model for investigating the biological roles of the Hsp70 co-chaperone HSPBP1 in a non-small cell lung cancer (NSCLC) background. The polyclonal nature ensures population-level heterogeneity that mirrors native tumor heterogeneity, while the CRISPR/Cas9-mediated gene disruption eliminates HSPBP1 protein expression, enabling functional studies of chaperone-mediated proteostasis.
NCI-H1975 is a well-established human lung adenocarcinoma epithelial cell line harboring EGFR L858R and T790M mutations, which confer oncogenic signaling and resistance to first-generation tyrosine kinase inhibitors. This genetic background renders the cells dependent on stress response pathways for survival, making it an ideal host for studying how co-chaperone regulation influences cancer cell fitness. The cell line is widely used as a model for NSCLC, particularly for investigating mechanisms of acquired drug resistance and apoptotic signaling.
HSPBP1 functions as a nucleotide-exchange inhibitor that directly binds the ATPase domain of HSPA1A (Hsp70), suppressing its chaperone activity and shifting the balance from protein refolding toward client degradation via the ubiquitin-proteasome system. Upstream regulators include heat shock, oxidative stress, and chemotherapeutic drugs, while downstream targets encompass Hsp70 client proteins, Bcl-2 family members, and apoptosis effectors. HSPBP1 interacts with key co-chaperones such as STUB1 (CHIP) and BAG family proteins, including BAG3, and operates within a network that also involves HSP90. Loss of HSPBP1 removes this inhibitory constraint, enhancing Hsp70-mediated refolding and potentially altering the turnover of critical oncogenic and tumor-suppressive proteins.
In the NCI-H1975 lung adenocarcinoma model, disruption of HSPBP1 is expected to potentiate Hsp70 chaperone activity, thereby modifying proteostasis and stress signaling networks. Given the EGFR mutation-driven dependency on stress adaptation, HSPBP1 knockout may sensitize cells to proteotoxic stress or alter apoptosis thresholds, providing a unique platform to dissect the interplay between oncogenic signaling and chaperone regulation. This model enables the exploration of how co-chaperone dynamics influence drug resistance, particularly in the context of EGFR-targeted therapies and chemotherapeutic agents that induce oxidative stress.
Researchers can employ these polyclonal HSPBP1 knockout cells to study chaperone-mediated protein quality control, stress response mechanisms, and apoptosis regulation. Representative assays include western blotting for HSPBP1 and Hsp70, caspase-3 activation assays, cell viability measurements under drug treatment, co-immunoprecipitation to assess protein?Cprotein interactions, and ATPase activity assays to quantify Hsp70 function. These applications support investigations into the molecular basis of NSCLC progression and the development of novel therapeutic strategies targeting the proteostasis network. For further technical details or custom requirements, please contact Ascent Research.
