The ISOC1 Knockout NCI-H1975 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population engineered for targeted disruption of the ISOC1 gene in the NCI-H1975 human lung adenocarcinoma cell line. This loss-of-function model provides a powerful tool for dissecting ISOC1-dependent mitochondrial functions, apoptotic regulation, and redox homeostasis in a clinically relevant oncogenic background. The polyclonal format ensures a heterogeneous knockout pool, enabling robust population-level analyses without clonal selection artifacts.
The parental NCI-H1975 cell line is an adherent epithelial line derived from the pleural effusion of a 62-year-old female nonsmoker diagnosed with non-small cell lung adenocarcinoma. These cells harbor activating EGFR L858R and gatekeeper T790M mutations, conferring resistance to first- and second-generation EGFR tyrosine kinase inhibitors. As such, NCI-H1975 serves as a well-established model for investigating EGFR TKI resistance mechanisms and signaling networks in non-small cell lung cancer (NSCLC).
ISOC1 encodes a mitochondrial isochorismatase domain-containing protein that localizes to the inner mitochondrial membrane and supports respiratory chain complex integrity while suppressing intrinsic apoptosis. Mechanistically, ISOC1 is transcriptionally regulated by PPARGC1A (PGC-1??) and NRF1, linking it to mitochondrial biogenesis programs, and its expression is modulated by HIF1A and TP53 under stress conditions. ISOC1 interacts with the mitochondrial import machinery components TOMM20 and TIMM23, and with chaperones HSPD1 and HSPA9, facilitating proper protein folding and respiratory complex assembly. Downstream, ISOC1 functions upstream of CYCS (cytochrome c), BAX, and BAK1, maintaining mitochondrial outer membrane integrity and preventing apoptogenic factor release. Knockout-mediated ISOC1 depletion disrupts electron transport chain function, elevates reactive oxygen species (ROS) levels, and primes cells for cytochrome c release and caspase-3 (CASP3) activation, thereby sensitizing them to intrinsic apoptosis. Key pathway components impacted include SDHA, UQCRC2, COX4I1, ATP5A1, SOD2, and PRDX3.
In the NCI-H1975 background, ISOC1 knockout is particularly informative for studying the interplay between oncogenic EGFR signaling and mitochondrial metabolism. The combination of EGFR-driven proliferation and mitochondrial dysfunction creates a synthetic vulnerability that may heighten sensitivity to metabolic inhibitors or pro-apoptotic agents. This model allows researchers to interrogate how mitochondrial respiratory chain disruption??via ISOC1 loss??influences EGFR TKI response, apoptotic threshold, and redox adaptation in lung adenocarcinoma cells. It also provides a platform for evaluating the role of mitochondrial unfolded protein response and ROS-mediated signaling in drug resistance.
Research applications include functional genomics of cancer metabolism, elucidation of apoptosis evasion mechanisms, and drug target discovery for NSCLC. This product is suitable for a wide range of assays, including Western blotting and RT-qPCR for expression analysis, ATP bioluminescence assays and Seahorse metabolic flux analysis for bioenergetic profiling, JC-1 or TMRM staining for mitochondrial membrane potential, DCFDA-based cellular ROS detection, Annexin V/PI flow cytometry for apoptosis, cell viability (MTS) assays, and transmission electron microscopy for mitochondrial ultrastructure. For additional information, please contact Ascent Research.
