HERC5 Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed for targeted disruption of the HERC5 gene. This product provides a heterogeneous pool of NCI-H1975 human lung adenocarcinoma epithelial cells carrying diverse loss-of-function mutations at the HERC5 locus, enabling population-level analysis of gene function without single-cell cloning. The polyclonal knockout approach maintains the intrinsic genetic variability of the parental line while ablating HERC5 expression through CRISPR/Cas9-mediated gene disruption.
The parental NCI-H1975 cell line originates from the metastatic pleural effusion of a female patient with non-small cell lung adenocarcinoma. These cells harbor both the L858R activating mutation and the T790M gatekeeper mutation in the epidermal growth factor receptor (EGFR), rendering them resistant to first-generation EGFR tyrosine kinase inhibitors. NCI-H1975 serves as a well-characterized model for studying acquired drug resistance, oncogenic signaling, and therapeutic vulnerabilities in EGFR-mutant non-small cell lung cancer.
HERC5 encodes an interferon-inducible HECT-type E3 ubiquitin ligase that mediates ISG15 conjugation (ISGylation) to lysine residues on target proteins. Its expression is transcriptionally upregulated by type I interferons (IFN-??/??) through the JAK-STAT pathway, with IRF3 and IRF7 acting as key upstream regulators. HERC5 functions within the ISGylation cascade alongside the E1 enzyme UBE1L and the E2 enzyme UBE2L6 (UbcH8). Key substrates include filamin B, STAT1, p53, PKR, MxA, viral replication machinery, and ribosomal proteins. Through these modifications, HERC5 coordinates antiviral innate immunity, modulates protein translation fidelity, and participates in ribosome-associated quality control.
In the context of EGFR-mutant NCI-H1975 lung adenocarcinoma, HERC5 inactivation offers a powerful system to examine the impact of ISGylation on tumor cell biology. Interferon signaling and ISG15 conjugation have been linked to tumor immune surveillance, proliferation, and responses to immunotherapy; therefore, this knockout model enables dissection of how HERC5-mediated post-translational modifications intersect with oncogenic EGFR signaling. It is particularly suited to probe potential crosstalk between JAK-STAT-dependent antiviral programs and EGFR-driven pathways that regulate cell survival and drug sensitivity.
Research applications include dissecting interferon-induced ISGylation in lung cancer, evaluating HERC5 as a therapeutic target or predictive biomarker, and performing drug sensitivity assays with EGFR inhibitors or immune checkpoint modulators. Typical experimental readouts encompass Western blotting for ISG15 conjugates, RT-qPCR quantification of interferon-stimulated genes, cell proliferation and viability measurements, and flow cytometry for surface markers such as PD-L1. Transcriptomic profiling via RNA-seq can further elucidate global transcriptional changes upon HERC5 loss. For additional information or custom requests, please contact Ascent Research.
