The INPP5K Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population engineered for targeted gene disruption of the INPP5K locus. This product offers a heterogenous pool of NCI-H1975 cells harboring diverse loss-of-function edits, providing a robust model to ablate INPP5K function without clonal selection. The polyclonal format captures a broad spectrum of genetic perturbations, enabling population-level studies of INPP5K-dependent phenotypes while mitigating clonal artifacts. Researchers can utilize this knockout model to investigate the multifaceted roles of INPP5K in signal transduction, cytoskeletal organization, and cellular stress responses within a defined genetic background.
NCI-H1975 is a human lung adenocarcinoma epithelial cell line established from the metastatic pleural effusion of a 77-year-old female with non-small cell lung cancer. It harbors activating EGFR mutations (L858R and T790M) and MET amplification, which drive constitutive PI3K/AKT signaling and confer resistance to first-generation EGFR tyrosine kinase inhibitors. This genetic profile renders NCI-H1975 an ideal host for dissecting oncogenic signaling networks and evaluating therapeutic interventions targeting the PI3K/AKT axis. Combined with INPP5K knockout, the cell model permits detailed interrogation of how phosphoinositide metabolism intersects with oncogenic drivers in a therapeutically resistant context.
INPP5K encodes a phosphoinositide phosphatase that preferentially hydrolyzes the 5-phosphate from phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3), thereby counteracting PI3K-mediated membrane signaling. Through this activity, INPP5K directly antagonizes AKT activation and downstream insulin and growth factor responses. Its expression is transcriptionally regulated by the spliced form of XBP1, a key effector of the unfolded protein response (UPR), placing INPP5K at a convergence point between endoplasmic reticulum (ER) stress sensors such as IRE1?? and PERK and actin cytoskeleton dynamics. Biochemically, INPP5K associates with actin filaments, insulin receptor substrate 1 (IRS1), and 14-3-3 adaptor proteins, forming complexes that coordinate signal transduction with cytoskeletal reorganization. Disruption of INPP5K thus impacts multiple nodes, from PIP3 homeostasis to ER stress adaptation and actin polymerization.
In the NCI-H1975 background, loss of INPP5K is expected to amplify PI3K/AKT pathway output, potentially exacerbating phospho-AKT levels and altering cellular responses to metabolic or proteostatic stress. Given the inherent ER stress burden in cancer cells and the reliance of EGFR/MET-driven tumors on AKT survival signals, INPP5K knockout cells serve as a platform to explore feedback regulation of PI3K signaling, UPR modulation, and actin-dependent processes like migration and invasion. The model is particularly suited for dissecting how the XBP1?CINPP5K axis influences drug sensitivity and for identifying synthetic lethal interactions in the setting of EGFR TKI resistance.
Typical applications include mechanistic studies of insulin resistance and PI3K/AKT pathway regulation using insulin stimulation assays, Western blotting for phospho-AKT, and PIP3 mass quantitation. The knockout cells are also invaluable for investigating ER stress and UPR dynamics via qPCR for XBP1 splicing or IRE1??/PERK activation markers. Actin cytoskeleton alterations can be visualized through immunofluorescence, and protein?Cprotein interactions involving 14-3-3 or IRS1 can be assessed by immunoprecipitation. This model supports target validation campaigns, muscular dystrophy research exploiting INPP5K??s role in actin dynamics, and cancer biology studies centered on oncogenic signaling cross-talk. For further information or to discuss customization, please contact Ascent Research.
