The HCCS Knockout NCI-H1975 Polyclonal Cells product comprises a CRISPR/Cas9-edited polyclonal knockout cell population derived from the NCI-H1975 human lung adenocarcinoma cell line. This loss-of-function model targets the HCCS gene, which encodes holocytochrome c synthase, through CRISPR/Cas9-mediated gene disruption, resulting in a heterogenous pool of cells with targeted genomic modifications. This polyclonal format preserves genetic complexity and enables robust assessment of HCCS-dependent biological processes without clonal selection bias.
The parental NCI-H1975 cell line, an epithelial line established from the pleural effusion of a female lung adenocarcinoma patient, serves as a widely used non-small cell lung carcinoma (NSCLC) model. It harbors activating EGFR L858R and T790M mutations that drive constitutive tyrosine kinase signaling, making the line highly relevant for studying EGFR-mediated oncogenic pathways and therapeutic resistance, particularly in relation to mitochondrial metabolism.
HCCS encodes a mitochondrial holocytochrome c synthase that catalyzes covalent heme attachment to apocytochrome c, generating mature holocytochrome c, a critical electron carrier in the respiratory chain and a key trigger of intrinsic apoptosis. Its expression is regulated by mitochondrial biogenesis factors PGC-1?? and NRF1, and the enzyme interacts with apocytochrome c, heme, and the TOM/TIM translocation machinery. Mature holocytochrome c shuttles electrons between Complex III and Complex IV, coupling oxidative phosphorylation to ATP production. Upon apoptotic stimuli, cytochrome c release into the cytosol promotes APAF1-dependent activation of initiator caspase-9 and executioner caspase-3. Therefore, HCCS disruption abolishes cytochrome c function, impairing respiratory chain efficiency and dampening the apoptotic response.
In the NCI-H1975 EGFR-mutant lung adenocarcinoma background, HCCS knockout offers a powerful platform to dissect the interplay between oncogenic signaling and mitochondrial homeostasis. EGFR-driven metabolic reprogramming often heightens mitochondrial dependence, and the loss of holocytochrome c synthase perturbs respiratory chain integrity, potentially shifting cellular metabolism toward glycolysis. This model enables the investigation of how mitochondrial dysfunction??mediated through defective cytochrome c maturation??affects tumor cell proliferation, drug sensitivity, and apoptotic plasticity in an NSCLC-relevant genotype.
This polyclonal knockout cell population enables detailed mitochondrial dysfunction studies, including Complex III activity assays, ATP measurement, and Seahorse respirometry to evaluate oxidative phosphorylation. Western blotting and immunofluorescence for cytochrome c allow examination of its maturation and submitochondrial distribution, while Annexin V apoptosis assays detect alterations in caspase-dependent cell death. Additional applications cover mitochondrial heme metabolism, cytochrome c biogenesis pathways, and therapeutic target validation in EGFR-mutant NSCLC. For technical specifications or further inquiries, please contact Ascent Research.
