The IMPDH1 Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population generated by disruption of the IMPDH1 gene in the NCI-H1975 human lung adenocarcinoma cell line. This knockout model provides a valuable tool for investigating loss-of-function effects of IMPDH1, the rate-limiting enzyme in de novo guanine nucleotide biosynthesis. The polyclonal nature of these cells reflects a heterogeneous mixture of gene-disrupted alleles, enabling robust assessment of population-level phenotypes without clonal selection bias. Researchers can utilize this system to interrogate metabolic vulnerabilities and signaling dependencies in a well-characterized oncogenic background.
The NCI-H1975 parental line is derived from a non-small cell lung adenocarcinoma and harbors the EGFR L858R/T790M double mutation, which confers constitutive kinase activity and resistance to first-generation tyrosine kinase inhibitors. As an adherent epithelial cell line with tumorigenic properties, it is widely employed for studying EGFR-driven oncogenesis and targeted therapy resistance. The introduction of IMPDH1 knockout into this genetic context allows exploration of the interplay between oncogenic signaling and nucleotide metabolism in a physiologically relevant human cancer model.
IMPDH1 catalyzes the NAD+-dependent oxidation of inosine monophosphate (IMP) to xanthosine monophosphate (XMP), the first committed step in GTP biosynthesis. It functions downstream of growth-promoting transcription factors MYC and E2F1, and its activity is enhanced by mTORC1 signaling to meet the increased nucleotide demand of proliferating cells. IMPDH1 physically interacts with IMPDH2, CTPS, and polyribosomal components, forming a multienzyme complex that channels substrates into GTP production. GTP is an essential substrate for DNA and RNA synthesis and activates Ras/Rho GTPases, linking IMPDH1 activity to cytoskeletal dynamics and cell cycle progression. Depletion of guanine nucleotide pools by IMPDH1 knockout impairs these fundamental processes and can trigger AMPK signaling as cellular energy charge decreases.
In the NCI-H1975 background, IMPDH1 disruption is expected to profoundly affect nucleotide homeostasis, rendering cells dependent on salvage pathways or external nucleosides. Given the heightened metabolic demands of EGFR-mutant lung adenocarcinoma, this knockout model allows dissection of how oncogene-driven proliferation intersects with purine metabolism. It may reveal synthetic lethal relationships or expose vulnerabilities exploitable by nucleotide-depleting chemotherapies such as mycophenolic acid, an IMPDH inhibitor. This polyclonal population is particularly suitable for studying adaptive responses and resistance mechanisms that arise under chronic nucleotide stress in a tumor-relevant setting.
This product supports a broad range of functional studies, including cancer metabolism, immunosuppression, nucleotide biosynthesis, and drug target validation. Representative applications encompass cell proliferation assays (MTS), HPLC-based nucleotide quantification, IMPDH enzymatic activity measurements, immunoblotting, RT-qPCR, RNA-seq, colony formation, apoptosis analysis, and cell cycle profiling. The knockout model also serves as a platform for investigating retinitis pigmentosa 10-associated mechanisms, albeit in a non-retinal lineage. For additional details and technical support, please contact Ascent Research.
The IMPDH1 Knockout NCI-H1975 Polyclonal Cells provide a genetic tool to study purine metabolism and GTP-dependent processes in a lung adenocarcinoma background with EGFR L858R/T790M mutations. IMPDH1, regulated by MYC and mTORC1, controls de novo GTP synthesis; its knockout depletes guanine nucleotides and impairs proliferation.
Applications include nucleotide measurement by HPLC, cell cycle analysis, and RNA-seq to assess transcriptional consequences of nucleotide stress. This model is ideal for drug target validation and exploring metabolic adaptation in cancer.
