The KMT2C Knockout NCI-H1975 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal population of human NCI-H1975 lung adenocarcinoma epithelial cells harboring a targeted disruption of the KMT2C gene. This loss-of-function model was generated using CRISPR/Cas9-mediated gene disruption, resulting in a heterogeneous pool of KMT2C-targeted cells that enables robust functional analysis while avoiding clonal artifacts. The polyclonal format is particularly valuable for studying the collective impact of KMT2C knockout on enhancer biology and cancer cell behavior in a more physiologically representative cellular context.
The NCI-H1975 host cell line is a well-characterized model of non-small cell lung cancer (NSCLC) derived from a female non-smoker. It harbors activating EGFR L858R and secondary T790M gatekeeper mutations, which confer primary and acquired resistance to first-generation EGFR tyrosine kinase inhibitors (TKIs), respectively, and also carries a PIK3CA mutation. These genetic features make NCI-H1975 an essential system for investigating mechanisms of TKI resistance and identifying synthetic lethal partners that can overcome therapeutic evasion.
KMT2C encodes histone-lysine N-methyltransferase 2C, the catalytic subunit of the MLL3/4 COMPASS-like complex. It interacts with core components WDR5, RBBP5, ASH2L, and DPY30, as well as cofactors UTX (KDM6A), PAXIP1, and NCOA6, to mono-methylate histone H3 at lysine 4 (H3K4me1) at enhancer regions. This modification is critical for enhancer activation and chromatin remodeling. KMT2C activity is regulated by upstream signals including p53, nuclear receptors such as ESR1, TGF?? receptor signaling, and Wnt/??-catenin pathway components, while its stability is modulated by ubiquitin ligases like UBR5. Disruption of KMT2C abrogates H3K4me1 deposition, leading to altered transcription of downstream targets such as CDKN1A (p21) and HOX gene clusters, thereby impairing tumor suppressor programs and differentiation-associated gene expression.
In the NCI-H1975 background, KMT2C knockout disrupts enhancer function specifically at loci critical for tumor suppressor activation and growth control, sensitizing cells to EGFR inhibition and highlighting the enzyme’s role in epigenetic resistance mechanisms. The loss of KMT2C-mediated H3K4me1 can impair cancer cell fitness and modulate transcriptional responses to targeted therapies, making this model ideal for synthetic lethality screens and studies aimed at re-activating silenced tumor suppressors.
Researchers can utilize these polyclonal KMT2C knockout cells in applications such as ChIP-seq to map genome-wide H3K4me1 distribution, RNA-seq-based differential expression analysis to identify KMT2C-dependent genes, and western blotting to assess global histone methylation changes. Functional assays??including MTT-based proliferation measurement, colony formation, caspase-3/7 apoptosis detection, and EGFR TKI dose?Cresponse analysis??enable dissection of the epigenetic contribution to drug sensitivity. Additionally, enhancer luciferase reporters and transwell invasion/migration assays can be employed to interrogate enhancer activity and metastatic potential. For further information, contact Ascent Research.
