The HSPA4L Knockout NCI-H1975 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the NCI-H1975 human non-small cell lung adenocarcinoma cell line. This product provides a loss-of-function model of the HSPA4L gene, which encodes a molecular chaperone involved in protein folding and stress response. The polyclonal knockout format ensures a heterogeneous population of cells with target-gene disruption, enabling robust functional genomic studies without the clonal selection artifacts that can arise in monoclonal knockout lines. The cells are supplied as a polyclonal pool, ideally suited for investigating HSPA4L-dependent signaling pathways and stress-related phenotypes.
The NCI-H1975 cell line was established from the pleural effusion of a female patient with non-small cell lung adenocarcinoma and is a well-characterized model of EGFR-mutant lung cancer. These cells harbor activating EGFR L858R and T790M resistance mutations, making them valuable for studying mechanisms of acquired resistance to EGFR tyrosine kinase inhibitors. The NCI-H1975 line is widely employed in drug sensitivity assays, signaling studies, and investigations into apoptosis and proliferation in the context of mutant EGFR-driven NSCLC. Its epithelial morphology and adherent growth properties facilitate a range of in vitro assays, including migration and invasion studies.
HSPA4L functions as an ATP-dependent molecular chaperone within the heat shock protein 70 family, playing a critical role in protein folding, refolding, and degradation under both basal and stress conditions. Its activity is primarily regulated by heat shock transcription factors HSF1 and HSF2 and is induced by thermal stress, oxidative stress, and endoplasmic reticulum (ER) stress. HSPA4L interacts with co-chaperones such as BAG1, BAG3, DNAJB1, HSP90, and STUB1, thereby modulating client protein maturation and targeting misfolded proteins for degradation. Downstream, HSPA4L influences anti-apoptotic proteins BCL2 and BCL-XL as well as pro-apoptotic factors BAX and BAD, linking chaperone function to cell survival. In the context of the MAPK signaling pathway, HSPA4L has been shown to interact with components including MAPK1 (ERK2) and MAPK3 (ERK1), affecting their stability and downstream phosphorylation events. Furthermore, it intersects with the AKT signaling axis, which is frequently activated in cancer, thereby contributing to the regulation of proliferation and apoptosis.
Disruption of HSPA4L in NCI-H1975 cells is expected to impair cellular protein folding capacity under stress conditions, potentially leading to increased proteotoxic stress and reduced viability. Given the reliance of cancer cells on chaperone networks to sustain oncogenic signaling, loss of HSPA4L may sensitize the EGFR-mutant lung adenocarcinoma cells to targeted therapies. Specifically, the knockout model is predicted to alter the balance between pro-survival and pro-apoptotic signals mediated by BCL2 family members and to attenuate MAPK pathway activation, as HSPA4L contributes to the proper folding and function of kinases such as ERK1/2. This polyclonal knockout therefore provides a physiologically relevant tool for dissecting the contribution of chaperone-mediated protein homeostasis to therapeutic resistance and tumor cell adaptation.
This product is well-suited for a broad range of experimental applications, including the elucidation of HSPA4L’s role in the NSCLC stress response, examination of its impact on EGFR-targeted therapy resistance, and assessment of its influence on apoptosis and proliferation. Typical validation assays include Western blotting for HSPA4L protein, RT-qPCR for knockdown confirmation, and Sanger sequencing to verify gene disruption. Functional studies can incorporate cell viability assays under stress conditions, Annexin V/PI apoptosis assays, phospho-ERK signaling analysis, migration and invasion assays, and drug sensitivity profiling. The polyclonal knockout cells also serve as a valuable resource for functional genomics screens aimed at identifying synthetic lethal interactions or modulators of resistance pathways. For additional specifications, custom formulations, or technical inquiries, please contact Ascent Research.
