The EFNA5 Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population targeting the EFNA5 gene, which encodes the GPI-anchored ephrin-A5 ligand. This model disrupts ephrin-A5 expression, leading to loss of both reverse signaling and impaired forward signaling through Eph receptors, thereby providing a platform to dissect bidirectional Eph-ephrin interactions. The polyclonal pool retains diverse editing outcomes typical of CRISPR/Cas9-mediated gene disruption, avoiding biases introduced by single-cell cloning.
The NCI-H1975 host cell line is an epithelial model of non-small cell lung adenocarcinoma (NSCLC) with activating EGFR (L858R, T790M) and PIK3CA (G118D) mutations. Derived from a lung tumor, these cells exhibit an aggressive transformed phenotype with constitutive PI3K-Akt and MAPK pathway activity, inherent resistance to first-generation EGFR inhibitors, and high metastatic potential, making them well-suited for studying lung cancer progression.
Ephrin-A5 functions by engaging EphA receptors??principally EphA4, EphA7, and EphA3??to initiate bidirectional signaling. Forward signaling activates Rho GTPases (RhoA, Rac1, Cdc42), Src, and downstream ERK1/2 and Akt, modulating cytoskeletal dynamics and cell adhesion. Reverse signaling through ephrin-A5 involves Src-mediated phosphorylation, recruitment of adaptors Grb4 and NCK1, and regulation of FAK and paxillin. ADAM10-mediated shedding of ephrin-A5 further regulates repulsive responses. EFNA5 knockout abolishes these pathways, disrupting Rho GTPase activity, MAPK/ERK flux, and ??-catenin stability.
In NCI-H1975 cells, loss of ephrin-A5 is expected to reduce contact-mediated repulsion and dampen invasive behavior by attenuating RhoA-ROCK signaling and MMP2/MMP9 expression. The hyperactive PI3K-Akt and MAPK background may shift downstream responses, making this model valuable for dissecting ephrin-A5??s role in NSCLC metastasis and tumor-stroma interactions without clonal selection artifacts.
Applications include Western blot analysis of phospho-ERK and EphA4, RT-qPCR for EFNA5, Transwell migration/invasion assays, and immunofluorescence for ephrin-A5 and F-actin. Co-immunoprecipitation of EphA4?Cephrin-A5 confirms complex disruption, while MTS and Annexin V assays monitor proliferation and apoptosis. The polyclonal knockout cells enable studies on bidirectional Eph-ephrin signaling, drug target validation, and tumor-stroma crosstalk in NSCLC. For inquiries, please contact Ascent Research.
