The JAG1 Knockout T-47D Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population designed for loss-of-function studies of the JAG1 gene in a human breast cancer background. This product is generated by disrupting the endogenous JAG1 locus in T-47D parental cells, resulting in a heterogeneous pool of edited alleles that abrogate functional Jagged1 protein production. As a polyclonal knockout model, it provides a physiologically relevant system for investigating JAG1-dependent signaling dynamics without the bottleneck effects of clonal selection, enabling robust population-level analyses of Notch pathway perturbation.
T-47D is a well-characterized human breast ductal carcinoma cell line originally isolated from a pleural effusion metastasis. These cells are estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), and HER2-negative, recapitulating the luminal A molecular subtype frequently observed in clinical breast cancer. The T-47D line retains epithelial characteristics and hormone responsiveness, making it an ideal host for examining how JAG1-mediated Notch signaling intersects with hormonal regulation and tumor progression in mammary carcinoma. Its adherent growth and ease of manipulation further support a wide range of cell-based assays.
JAG1 encodes the Notch ligand Jagged1, a type I transmembrane protein that activates signaling upon binding to NOTCH1?C4 receptors on adjacent cells. This trans-interaction triggers sequential proteolytic cleavages by ADAM17 and the ??-secretase complex, releasing the Notch intracellular domain (NICD) to translocate to the nucleus. NICD forms a transcriptional activation complex with CSL (RBP-J??) and mastermind-like (MAML) coactivators, driving expression of canonical targets such as HES1, HEY1, MYC, and CCND1 while repressing p21. Upstream regulators including TGF-??, hypoxia (HIF-1??), and Wnt/??-catenin converge on JAG1 expression, positioning it as a critical node in cross-talk between developmental cues and oncogenic pathways. Interacting partners like Mind bomb (MIB1) ubiquitin ligase further modulate ligand endocytosis and signaling strength.
In the T-47D breast cancer context, Jagged1-driven Notch activation is intimately linked to epithelial-mesenchymal transition (EMT), stemness maintenance, and pro-survival signals. Disruption of JAG1 in these cells abrogates ligand-dependent NICD generation, markedly reducing HES1 and HEY1 transcription and attenuating downstream pro-tumorigenic functions. This knockout model thus serves as a powerful tool for dissecting how JAG1-Notch signaling contributes to hormone-responsive and potentially resistant breast cancer phenotypes. It allows researchers to uncouple the effects of angiocrine, paracrine, and autocrine Notch activation in a defined cancer cell environment.
Researchers can employ these polyclonal knockout cells in diverse applications, including co-culture reporter assays to quantify Notch transactivation, migration/invasion studies to assess EMT-driven motility, and proliferation (MTT) assays to evaluate growth dependence on JAG1. Validation is routinely performed via Western blotting for JAG1, NICD, and HES1, RT-qPCR profiling of Notch target genes, and immunofluorescence to examine NICD nuclear localization. The model is also suitable for drug target validation and screening campaigns aimed at the Notch pathway. For further technical specifications and ordering details, please contact Ascent Research.
