The CBX3 Knockout NCI-H1975 Polyclonal Cells (Homo sapiens) is a CRISPR/Cas9-edited polyclonal knockout cell population targeting the CBX3 gene, which encodes heterochromatin protein 1?? (HP1??). This model enables functional studies of HP1?? without clonal isolation, preserving the heterogeneous background of the parental line. The polyclonal nature yields diverse knockout alleles, suitable for pooled screens and bulk biochemical analyses.
The NCI-H1975 cell line originates from a female non-smoker??s pleural effusion and represents a metastatic lung adenocarcinoma with wild-type EGFR and KRAS. These epithelial cells retain invasive properties and are a standard model for studying NSCLC progression and metastasis in the absence of common driver mutations.
CBX3 (HP1??) is a key reader of histone H3 lysine 9 di- and trimethylation (H3K9me2/3), mediating heterochromatin formation and gene silencing. It is recruited by SUV39H1 and G9a/EHMT2, and interacts with HP1?? (CBX5), HP1?? (CBX1), LBR, and DNMT1 to maintain repressive chromatin. Regulated transcriptionally by MYC and E2F1, CBX3 represses CDKN1A (p21) and CDH1 (E-cadherin), promoting cell cycle progression and epithelial-mesenchymal transition. CBX3 also modulates Wnt and TGF-?? signaling, and its disruption affects downstream targets such as SPARC and Cyclin D1.
In NCI-H1975 lung adenocarcinoma cells, CBX3 presumably maintains H3K9me3-enriched heterochromatin at tumor suppressor genes, contributing to unchecked proliferation and metastatic potential. CRISPR/Cas9-mediated disruption is predicted to relieve this silencing, upregulating CDKN1A and CDH1, which may induce cell cycle arrest and impair invasion. This model is particularly useful for studying epigenetic mechanisms of NSCLC progression independent of EGFR/KRAS mutations and for evaluating CBX3 as a therapeutic target.
Applications include dissecting HP1??-mediated chromatin regulation in NSCLC, screening for synthetic lethal interactions or drug sensitivities, studying epithelial-mesenchymal transition, and testing HDAC inhibitor effects. Compatible assays encompass western blotting, ChIP-qPCR, RNA-seq, viability/invasion assays, flow cytometry, and immunofluorescence. For further information, please contact Ascent Research.
