The ITPR3 Knockout NCI-H1975 Polyclonal Cells product is a CRISPR/Cas9-edited polyclonal knockout cell population featuring disruption of the ITPR3 gene in the NCI-H1975 human lung adenocarcinoma epithelial cell line. This engineered cell model provides a loss-of-function system for studying inositol 1,4,5-trisphosphate receptor type 3 (IP3R3), a critical mediator of intracellular calcium release.
NCI-H1975 is an adherent epithelial line derived from the pleural effusion of a female patient with lung adenocarcinoma. It harbors two activating EGFR mutations??L858R and T790M??making it a widely used model for EGFR-mutant non-small cell lung cancer (NSCLC) with acquired resistance to first-generation tyrosine kinase inhibitors. These cells retain EGFR-driven proliferative and survival signaling characteristic of advanced lung adenocarcinoma.
ITPR3 encodes the type 3 IP3 receptor, a ligand-gated calcium channel on the endoplasmic reticulum (ER) membrane. Activated by IP3 downstream of phospholipase C (PLC) upon EGFR or G protein-coupled receptor stimulation, IP3R3 releases ER calcium into the cytoplasm. This calcium signal regulates diverse effectors, including calmodulin-dependent kinases, the transcription factors NFAT and CREB, and mitochondrial apoptosis machinery via Bcl-2 family proteins and cytochrome c release. IP3R3 also engages in protein?Cprotein interactions with partners such as IRBIT, Bcl-2, CARF, and FKBP12, positioning it at the nexus of calcium homeostasis, ER stress responses, and survival signaling.
In the EGFR-mutant NCI-H1975 background, IP3R3-mediated calcium signaling lies at the intersection of oncogenic driver pathways and stress responses. Disruption of ITPR3 is expected to attenuate EGFR-dependent calcium mobilization, impair activation of calmodulin/NFAT and CREB transcriptional programs, and alter apoptotic thresholds governed by ER-mitochondrial calcium crosstalk. This knockout model enables dissection of how EGFR-mutant NSCLC cells rely on IP3R3 for proliferation, survival under ER stress, and communication within the tumor microenvironment. It may also reveal mechanisms by which calcium signaling modulates sensitivity to EGFR-targeted therapies.
Researchers can employ this polyclonal knockout population to investigate EGFR-calcium signaling axes, apoptosis regulation, and drug resistance in NSCLC. Functional assays include Fluo-4 AM calcium flux measurements to quantify receptor-operated calcium release, Annexin V/PI staining for apoptosis, and MTT or colony formation assays for proliferation and clonogenic survival. Western blotting for IP3R3 and its interactors, RNA-seq profiling of calcium signaling genes, and co-immunoprecipitation of IP3R3 complexes provide molecular validation. This product is suitable for screening calcium signaling modulators and exploring paracrine effects in co-culture systems. For detailed technical information or custom requests, please contact Ascent Research.
