The CBX8 Knockout NCI-H1299 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal cell population with targeted disruption of the CBX8 gene in the NCI-H1299 human non-small cell lung carcinoma (NSCLC) cell line. This heterogeneous pool of edited cells avoids the limitations of single-clone selection, providing a biologically representative loss-of-function model to interrogate CBX8-dependent epigenetic regulatory networks. The polyclonal format retains population-level diversity and is suitable for robust, reproducible functional assays.
NCI-H1299 is an adherent epithelial cell line derived from a lymph node metastasis of a 43-year-old male with lung adenocarcinoma. It is a widely employed model in NSCLC research due to its well-characterized oncogenic profile, including activating mutations in KRAS and inactivating mutations in the tumor suppressors STK11 and TP53. This genetic background renders the line highly tumorigenic and metastatic, and it is extensively used to study signaling pathways, cellular senescence, and mechanisms of drug resistance. The line??s consistent growth characteristics and ease of genetic manipulation make it an optimal host for polyclonal knockout generation.
CBX8 is a chromodomain-containing protein that functions as a core subunit of the polycomb repressive complex 1 (PRC1). Its chromodomain specifically binds trimethylated lysine 27 on histone H3 (H3K27me3), a repressive mark deposited by the PRC2 complex (comprising EZH2, SUZ12, and EED). This interaction tethers PRC1 to chromatin, where the catalytic subunit RING1B (RING1A/RING1B) catalyzes monoubiquitination of histone H2A at lysine 119 (H2AK119ub). Together with scaffolding factors such as BMI1 and PHC1/2/3, CBX8 promotes chromatin compaction and long-term gene silencing. CBX8 activity is regulated by cell cycle and oncogenic inputs, including E2F transcription factors, MYC, and CDK-cyclin complexes. Its silencing targets encompass critical tumor suppressors like CDKN2A/p16 and PTEN, as well as HOX gene clusters, thereby linking epigenetic regulation to proliferation control, cellular senescence, and WNT/??-catenin signaling.
In the NCI-H1299 background, disruption of CBX8 impairs PRC1 recruitment and reduces H2AK119ub deposition at target loci, leading to derepression of CBX8-repressed genes. This knockout model enables precise dissection of CBX8-specific contributions to epigenetic silencing, distinguishing its roles from those of other PRC1 components. Given the line??s KRAS/STK11/TP53 mutant status, CBX8 loss permits investigation of how polycomb-mediated repression cooperates with oncogenic drivers to maintain the malignant phenotype. Researchers can examine consequences on tumor suppressor reactivation, cell cycle checkpoint control, senescence bypass, and sensitivity to targeted therapies or cytotoxic agents.
This product supports a broad spectrum of research applications, including chromatin immunoprecipitation followed by qPCR (ChIP-qPCR) for H2AK119ub and H3K27me3 profiling, quantitative RT-PCR and western blot analysis of CBX8, CDKN2A, PTEN, and HOX expression, and functional assays such as MTT, BrdU, and colony formation to assess proliferation and clonogenicity. Flow cytometry facilitates cell cycle distribution analysis, while RNA-seq enables transcriptome-wide identification of CBX8-dependent gene programs. The polyclonal nature captures cell-to-cell variability, enhancing the physiological relevance of findings. For technical support or detailed protocols, please contact Ascent Research.
