The DNPH1 Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the human DNPH1 gene in the NCI-H1975 lung adenocarcinoma background. This product comprises a pool of edited cells with heterogeneous gene disruption, providing a robust loss-of-function model without clonal selection. The polyclonal format preserves population-level heterogeneity and is suitable for studying gene function in cancer nucleotide metabolism and genome stability.
The NCI-H1975 cell line is an EGFR-mutant human lung adenocarcinoma epithelial model established from the pleural effusion of a female patient with non-small cell lung cancer (NSCLC). These cells harbor an activating exon 19 deletion in the epidermal growth factor receptor (EGFR), conferring constitutive oncogenic signaling and dependency on EGFR-driven pathways. NCI-H1975 is widely used for studying EGFR-targeted therapies, drug resistance, and tumor biology in lung cancer.
DNPH1 encodes a deoxynucleoside triphosphate hydrolase that catalyzes the hydrolysis of canonical and non-canonical dNTPs, preventing their incorporation into DNA and maintaining nucleotide pool homeostasis. DNPH1 functions downstream of the MYC transcription factor, which transcriptionally regulates its expression, and acts as a key node in the nucleotide salvage pathway. The enzyme operates as a homodimer and interacts directly with substrate dNTPs. Loss of DNPH1 activity leads to imbalanced dNTP pools, misincorporation of abnormal nucleotides, and replication stress, ultimately affecting genome stability and cell cycle progression. In the broader pathway, DNPH1 coordinates with ribonucleotide reductase, dUTPase, and DNA polymerases to regulate dNTP supply and ensure replication fidelity.
In EGFR-mutant NCI-H1975 cells, DNPH1 depletion disrupts nucleotide metabolism, exacerbating replication stress and DNA damage. Given that EGFR signaling drives proliferation and may influence nucleotide biosynthesis, the combination of oncogenic EGFR and DNPH1 loss creates a synthetic vulnerability. This model is instrumental for investigating how nucleotide pool imbalances contribute to chemoresistance, particularly to agents targeting DNA replication or repair. Furthermore, it allows dissection of the interplay between EGFR signaling and genome maintenance, providing a platform to identify synergistic drug combinations or synthetic lethal interactions.
Researchers can employ these polyclonal knockout cells in a range of assays, including dNTP quantification to assess nucleotide pool changes, DNA damage assays (e.g., ??H2AX foci), proliferation assays, and drug sensitivity screening with EGFR inhibitors or chemotherapeutic agents. The model supports transcriptomic analysis via RNA-seq and validation of target disruption by Western blotting and RT-qPCR. Applications include exploring mechanisms of chemoresistance in NSCLC, screening for synthetic lethal partners, and studying DNA damage responses. For further information or to discuss custom research applications, please contact Ascent Research.
