The HOMEZ Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the NCI-H1975 human lung adenocarcinoma cell line. These cells harbor a disrupted HOMEZ gene generated by CRISPR/Cas9-mediated gene editing, producing a heterogeneous loss-of-function model that reflects the diverse edits within the cell population. This polyclonal format avoids clonal selection bias and provides a robust tool for studying HOMEZ-dependent transcriptional regulation.
The host NCI-H1975 cell line is a widely used model of non-small cell lung cancer (NSCLC), originating from pleural effusion of a female patient with lung adenocarcinoma. These epithelial cells carry two mutations in the epidermal growth factor receptor (EGFR): L858R, which promotes constitutive kinase activity, and T790M, which confers resistance to first-generation EGFR tyrosine kinase inhibitors. Consequently, NCI-H1975 cells are instrumental in research on EGFR-driven oncogenesis, targeted therapy resistance, and tumor microenvironment signaling.
HOMEZ encodes a homeodomain transcription factor with a leucine zipper domain that functions as a transcriptional repressor, primarily through interaction with HOX11 (TLX1) and other homeobox proteins. This repression likely involves recruitment of TLE/Groucho corepressors. HOMEZ is regulated upstream by retinoic acid signaling through RAR/RXR receptors, Wnt/??-catenin pathway activity, and EGFR signaling. It also responds to developmental morphogens such as FGF and BMP. Downstream, HOMEZ modulates the expression of cell cycle regulators (CDKN1A, CCND1), pro- and anti-apoptotic genes (BCL2, BAX), and EGFR pathway components, thereby linking developmental cues to cellular proliferation and survival decisions.
In the NCI-H1975 EGFR-mutant lung adenocarcinoma context, HOMEZ knockout provides a powerful system to examine how this repressor influences transcriptional programs underlying tumor malignancy. Given the convergence of EGFR, Wnt, and retinoic acid pathways in NSCLC, loss of HOMEZ may dysregulate cell cycle progression, apoptosis, and differentiation, directly affecting drug sensitivity. This polyclonal knockout model is especially valuable for dissecting mechanisms of resistance to EGFR inhibitors like gefitinib and osimertinib, as HOMEZ targets include BCL2 family members that govern apoptotic thresholds.
Typical applications include transcriptomic profiling (RNA-seq) to identify HOMEZ-regulated gene networks, quantitative PCR and Western blotting for target validation, and chromatin immunoprecipitation (ChIP-seq) to map DNA binding sites. Functional assays such as MTT proliferation, Annexin V apoptosis, and migration/invasion studies can quantify the impact of HOMEZ loss on cellular behavior. Additionally, these cells enable EGFR inhibitor sensitivity screens, assessing how HOMEZ deficiency alters therapeutic response in a T790M-positive background. For further details, please contact Ascent Research.
