The HLCS Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population in which the HLCS gene has been disrupted across the NCI-H1975 human lung adenocarcinoma cell line. Rather than an isolated clone, this product provides a heterogeneous pool of cells uniformly lacking functional holocarboxylase synthetase, preserving the genetic background of the parental line while eliminating target gene expression. This population-based knockout format enables robust, statistically powered functional analyses and minimizes bias from clonal variation, making it particularly suitable for metabolic and epigenetic studies where population-level responses are critical.
The NCI-H1975 host cell line originates from the pleural effusion of a patient with non-small cell lung adenocarcinoma and carries well-characterized EGFR mutations (L858R and T790M). These mutations render the line sensitive to EGFR tyrosine kinase inhibitors and make it a standard model for investigating drug resistance mechanisms and oncogenic signaling. The epithelial phenotype and stable growth properties of NCI-H1975 provide a reliable platform for interrogating gene function in lung cancer, especially in contexts where metabolic adaptation influences therapeutic response.
HLCS encodes the essential holocarboxylase synthetase that covalently attaches biotin to specific lysine residues of carboxylase apoenzymes??acetyl-CoA carboxylase, pyruvate carboxylase, propionyl-CoA carboxylase, and methylcrotonyl-CoA carboxylase??as well as to histones H2A, H3, and H4. This ATP- and magnesium-dependent modification activates carboxylases for central metabolic pathways including gluconeogenesis, fatty acid synthesis, and branched-chain amino acid catabolism, while histone biotinylation influences chromatin structure and gene expression. HLCS activity is regulated upstream by biotin availability, EGFR/PI3K/AKT signaling, insulin, and glucocorticoids. The enzyme interacts directly with apocarboxylases and histone substrates, placing it at a node linking nutrient sensing, metabolism, and epigenetic control.
In the context of NCI-H1975 cells, disruption of HLCS expression abrogates biotinylation of its substrate proteins, resulting in impaired flux through multiple carboxylase-dependent metabolic pathways. Given the reliance of EGFR-mutant lung adenocarcinomas on reprogrammed anabolic metabolism, this knockout model offers a powerful system to dissect how loss of biotin-dependent enzyme activity alters cellular energetics, proliferation, and drug sensitivity. Additionally, potential changes in histone biotinylation may affect gene expression programs involved in tumor maintenance and progression.
This polyclonal knockout cell population is optimized for a variety of downstream applications, including western blotting for HLCS and biotinylated proteins, RT-qPCR validation of gene disruption, Seahorse metabolic flux analysis to assess oxidative phosphorylation and glycolysis, and cell proliferation assays. Researchers can employ the model to investigate biotin metabolism, cancer epigenetics, and the impact of carboxylase inactivation on sensitivity to EGFR inhibitors. For further information or assistance with experimental design, please contact Ascent Research.
