The EFNA4 Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population targeting the EFNA4 gene in the near-haploid HAP1 cell line. This polyclonal knockout pool provides a genetically heterogeneous loss-of-function model for studying ephrin-A4 biology. Through CRISPR/Cas9-mediated gene disruption, the expression of functional EFNA4 protein is abrogated, enabling researchers to dissect its roles in signal transduction and cellular behavior without clonal isolation.
HAP1 cells are a chronic myeloid leukemia (CML)-derived near-haploid cell line originating from the KBM-7 patient sample. Their near-haploid karyotype simplifies genetic manipulation and phenotypic interpretation, making them an ideal host for haploid genetic screens and targeted knockout studies. The HAP1 background retains cancer-relevant signaling networks, thus providing a relevant context for investigating oncogenic mechanisms and therapeutic vulnerabilities.
EFNA4 encodes ephrin-A4, a glycosylphosphatidylinositol (GPI)-anchored ligand that engages EphA receptor tyrosine kinases (EphA1?C8) to initiate bidirectional signaling. Forward signaling through EphA receptors activates SRC family kinases, focal adhesion kinase (FAK), and Rho GTPases (RhoA, Rac1), leading to modulation of cytoskeletal dynamics and cell adhesion. Reverse signaling via ephrin-A4 involves recruitment of SH2 adaptor proteins such as Grb2 and Nck, and is influenced by metalloprotease-mediated shedding by ADAM10/17. EFNA4 expression is transcriptionally regulated by HOXA9 and PAX6, as well as by retinoic acid signaling, positioning it within pathways controlling cell migration, axon guidance, and cancer invasion. These molecular interactions link ephrin-A4 to downstream effectors including ERK1/2 and AKT, thereby coupling extracellular cues to cell adhesion and migratory responses.
In the HAP1 near-haploid background, disruption of the single EFNA4 allele results in a complete loss of ephrin-A4 function, offering a powerful system for unambiguous genotype?Cphenotype correlations. This knockout model is particularly valuable for interrogating the role of ephrin-A4 in cancer cell adhesion, migration, and invasion, processes frequently deregulated in hematological and solid malignancies. Coupled with the HAP1 cell line??s utility in drug sensitivity assays, the EFNA4 knockout population enables systematic investigation of how ephrin-A4 signaling influences therapeutic response and resistance mechanisms.
These polyclonal knockout cells are suitable for a broad range of applications including cell adhesion assays, Boyden chamber migration and invasion studies, and immunofluorescence-based analyses of cytoskeletal organization. Co-immunoprecipitation and Western blotting can be employed to assess changes in EphA receptor activation, SRC/FAK phosphorylation, and interaction with adaptor proteins. RNA-sequencing and quantitative proteomics allow global profiling of EFNA4-dependent transcriptional and signaling networks. Furthermore, the knockout cells facilitate haploid genetic modifier screens and drug target validation studies aimed at identifying synthetic lethal interactions or novel inhibitors of the ephrin?CEph system. For additional technical information, please contact Ascent Research.
