The KDM4A Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the near-haploid HAP1 cell line, designed for functional studies of the KDM4A histone demethylase. This polyclonal knockout model enables robust loss-of-function analysis of KDM4A in a genetically simplified background. The knockout was generated by CRISPR/Cas9-mediated gene disruption, resulting in a heterogeneous pool of cells with inactivating mutations at the target locus. This polyclonal format preserves the genetic diversity of the knockout pool, allowing researchers to assess gene function without clonal selection bias. The product is supplied as a ready-to-use frozen vial of early-passage cells, suitable for immediate expansion and characterization in downstream experiments.
The HAP1 cell line is a near-haploid human cell line originally derived from the KBM-7 chronic myeloid leukemia (CML) line. Its near-haploid karyotype minimizes genetic redundancy, making it an ideal host for knockout studies as single-gene disruptions often yield clear phenotypes. HAP1 cells retain neoplastic myeloid progenitor features, providing a relevant context for studying hematological malignancies and cancer biology. Widely adopted in functional genomics and genetic screens, HAP1 cells offer a consistent genetic background for comparative studies across edited populations.
KDM4A encodes a Jumonji C domain-containing histone demethylase that specifically removes methyl groups from di- and tri-methylated H3K9 and H3K36, key marks associated with transcriptional repression and elongation. The enzyme??s activity is regulated by upstream signals including androgen receptor (AR), HIF1A, MYC, E2F1, and p53, integrating diverse cellular inputs. Upon activation, KDM4A demethylates H3K9me2/3 to relieve chromatin compaction, facilitating transcriptional activation of target genes such as CCND1 and E2F1, while also modulating H3K36me3 to influence RNA polymerase II elongation. KDM4A interacts with co-repressor complexes (NCoR/SMRT), histone deacetylases (HDACs), HP1, and p53, placing it at the nexus of chromatin remodeling and transcriptional regulation. Disruption of KDM4A thus leads to a global increase in H3K9me2/3 and H3K36me3, altering chromatin accessibility and gene expression programs critical for proliferation and differentiation.
In the HAP1 CML-derived near-haploid background, knockout of KDM4A provides a powerful tool to dissect the epigenetic mechanisms underlying leukemia cell proliferation and survival. The loss of KDM4A demethylase activity in these neoplastic myeloid progenitor cells results in hypermethylation of H3K9 and H3K36, leading to chromatin condensation and transcriptional dysregulation of genes involved in cell cycle control and apoptosis. This model is particularly valuable for studying the interplay between oncogenic signaling (e.g., BCR-ABL in CML) and epigenetic modifiers, as KDM4A has been implicated in hormone-dependent cancers and drug resistance. The polyclonal knockout pool allows for assessment of phenotypic heterogeneity and selection pressures, mimicking the complexity found in tumor populations.
Typical applications include chromatin biology studies using ChIP-qPCR for H3K9me2 and H3K36me3 enrichment, transcriptional profiling via RNA-seq, and validation of target gene expression by RT-qPCR and western blotting. Functional assays such as proliferation curves, colony formation, and cell cycle analysis by flow cytometry can reveal the impact of KDM4A loss on cellular growth dynamics. This knockout model also enables investigation of drug sensitivity and resistance mechanisms in leukemia, as well as genetic interaction screens with other epigenetic regulators (e.g., SUV39H1, CHD1) or AR signaling components. For further details or custom inquiries, please contact Ascent Research.
