The DTX3L Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-engineered polyclonal knockout cell population derived from the NCI-H1975 human lung adenocarcinoma line. Targeted disruption of the DTX3L gene yields a heterogeneous pool of cells with loss of DTX3L function, providing a robust model for studying the gene’s role in cellular signaling. This polyclonal format avoids clonal bias and is ideal for pooled functional genomics screens and bulk biochemical analyses.
The NCI-H1975 host cell line is an epithelial line established from a patient with lung adenocarcinoma, harboring EGFR T790M and L858R mutations. These activating mutations confer constitutive EGFR signaling and sensitivity to first-generation EGFR tyrosine kinase inhibitors, while the T790M mutation is associated with acquired resistance. As a well-characterized model of EGFR-mutant non-small cell lung cancer, NCI-H1975 enables investigation of oncogenic signaling and resistance mechanisms in a clinically relevant context.
DTX3L encodes an E3 ubiquitin ligase that functions in complex with PARP9 to ubiquitinate STAT1, modulating its transcriptional activity and stability. This ubiquitination event is a critical node in interferon signaling, linking type I and II interferon receptor activation (via IFNAR and JAK1/TYK2) to transcription of interferon-stimulated genes. DTX3L also participates in the DNA damage response by targeting repair factors for ubiquitination, connecting genome maintenance with innate immunity. The pathway comprises upstream regulators such as interferons and DNA damage signals, downstream targets including STAT1 and ISGs, and interacting factors like ubiquitin conjugation enzymes.
In the NCI-H1975 background, DTX3L knockout offers a unique opportunity to explore cross-talk between EGFR-driven oncogenesis, interferon signaling, and ubiquitin-mediated regulation. Given that EGFR mutations can influence immune signaling via STAT1, loss of DTX3L may reveal vulnerabilities or resistance mechanisms relevant to targeted therapies and immunotherapies. This model is particularly valuable for examining how E3 ligase-mediated ubiquitination impacts drug response and tumor cell survival under interferon stress.
Research applications include dissecting interferon-dependent antiviral responses, probing ubiquitination dynamics, investigating DNA damage repair pathways, and evaluating therapeutic targets in lung cancer. Representative assays such as western blotting for STAT1 and ubiquitin species, co-immunoprecipitation of the DTX3L-PARP9 complex, RT-qPCR for ISG induction, immunofluorescence for STAT1 translocation, and cell proliferation assays are compatible with this model. For additional information or technical support, please contact Ascent Research.
