The INPP5F Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the NCI-H1975 lung adenocarcinoma line, with targeted disruption of the INPP5F gene. This heterogeneous pool provides a loss-of-function model for studying the inositol polyphosphate 5-phosphatase INPP5F. As a polyclonal population, it captures population-averaged phenotypes and avoids clonal selection artifacts, making it suitable for signaling and functional analyses where representative knockout effects are desired.
NCI-H1975 is an epithelial cell line isolated from a non-small cell lung adenocarcinoma patient, characterized by activating EGFR kinase domain mutations (L858R/T790M). These mutations drive constitutive PI3K/AKT and MAPK pathway activation and are associated with acquired resistance to first- and second-generation EGFR inhibitors. The cell line is widely used to model EGFR-mutant lung cancer, investigate mechanisms of drug resistance, and evaluate next-generation therapeutic strategies targeting the oncogenic signaling network.
INPP5F encodes an inositol polyphosphate 5-phosphatase that hydrolyzes the 5-phosphate of PIP3 to generate PI(3,4)P2, directly opposing PI3K-mediated PIP3 production. This activity reduces AKT membrane recruitment and phosphorylation, dampening downstream signaling through mTORC1, GSK3??, and FoxO transcription factors. INPP5F function is regulated by upstream receptors such as EGFR and insulin receptor, and it interacts with PI3K regulatory subunit p85, 14-3-3 adaptor proteins, and RAB GTPases. Together with PTEN, INPP5F acts as a critical brake on PIP3-driven proliferative and survival signals.
In the context of NCI-H1975 cells with hyperactive EGFR, deletion of INPP5F is predicted to remove a key negative regulator, leading to sustained PIP3 accumulation and enhanced AKT/mTOR pathway output. This model allows investigation of cooperative effects between oncogenic EGFR and loss of tumor suppressor-like phosphatases, with implications for understanding acquired resistance to targeted therapies such as osimertinib and for identifying synthetic lethal interactions.
These polyclonal knockout cells are suitable for a variety of experimental approaches, including phospho-AKT and phospho-S6 western blotting, proliferation and colony formation assays, flow cytometric analysis of cell cycle and apoptosis, and drug sensitivity profiling with osimertinib or PI3K/mTOR inhibitors. Transcriptional readouts via RT-qPCR can monitor AKT target gene expression. The cells support research in lung cancer signaling, drug resistance mechanisms, and PI3K pathway biology. For technical support or ordering inquiries, please contact Ascent Research.
