This product consists of a CRISPR/Cas9-edited polyclonal knockout cell population derived from the NCI-H1975 human non-small cell lung cancer line, designed for targeted disruption of the IMPA1 gene. The polyclonal format provides a heterogeneous pool of edited alleles, enabling population-level analysis of IMPA1 loss-of-function without clonal selection bias. This model serves as a versatile tool for studying inositol monophosphatase 1 biology in a lung adenocarcinoma background.
The NCI-H1975 cell line is a well-characterized model of lung adenocarcinoma, established from a non-smoking female patient. It harbors activating EGFR L858R and T790M mutations, which drive constitutive PI3K/AKT and MAPK signaling, critical for tumor growth and survival. These oncogenic alterations render NCI-H1975 cells particularly dependent on downstream signaling networks, including those regulated by inositol phosphate metabolism, making it an ideal host for interrogating IMPA1 function.
IMPA1 encodes inositol monophosphatase, which hydrolyzes inositol monophosphate to free inositol, a critical step in phosphatidylinositol recycling. Free inositol is required for synthesis of PtdIns, which is phosphorylated by PIK3CA to generate PIP2 and PIP3. These second messengers activate AKT1, promoting cell survival and proliferation. IMPA1 activity is regulated by growth factor receptor stimulation, inositol availability, and is inhibited by lithium, leading to inositol depletion and attenuation of PI3K/AKT signaling. Additionally, PLC cleaves PIP2 to yield IP3, which binds IP3R to mobilize calcium, linking IMPA1 to calcium signaling. Interacting factors such as IMPA2 and INPP1 participate in parallel inositol processing steps. Thus, IMPA1 sustains both AKT and calcium pathways by maintaining cellular inositol pools.
In the context of NCI-H1975 cells with EGFR-driven PI3K/AKT activation, IMPA1 knockout provides a unique system to dissect the contribution of inositol recycling to oncogenic signaling. Loss of IMPA1 is expected to impair PtdIns synthesis, blunting PIP2 and PIP3 generation and downstream AKT phosphorylation, even in the presence of mutant EGFR. This model enables investigation of lithium sensitivity and inositol-dependent growth pathways, offering insights into how metabolic regulation of inositol pools intersects with tyrosine kinase inhibitor resistance mechanisms and potential anti-proliferative strategies.
Researchers can employ this polyclonal knockout model in assays such as western blotting for phosphorylated AKT (Ser473) and mTOR, RT-qPCR of PI3K pathway targets, and LC-MS-based quantification of inositol phosphate species. Cell viability (MTT/CCK-8) and apoptosis (Annexin V) assays assess responses to lithium or growth factor withdrawal. Dose-response experiments elucidate lithium sensitivity, while PI3K/AKT reporter assays provide dynamic readouts. Transcriptional profiling via RNA-seq further uncovers gene expression changes. For technical support and protocols, please contact Ascent Research.
