The CD274 Knockout UM-UC-3 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt CD274 gene expression. This product provides a heterogeneous pool of UM-UC-3 cells with targeted disruption of PD-L1, a critical immune checkpoint molecule. The polyclonal format captures diverse editing events, offering a robust loss-of-function model for studying PD-L1 biology. The CRISPR/Cas9-mediated gene disruption eliminates functional PD-L1 protein, enabling investigation of its roles in immune evasion and signal transduction.
The UM-UC-3 parental cell line is a widely utilized human bladder transitional cell carcinoma line derived from a male patient. As an adherent epithelial cell line, UM-UC-3 retains key hallmarks of bladder tumorigenicity, including invasive potential and molecular signatures relevant to urothelial cancer. This cell line serves as an established in vitro model for dissecting molecular mechanisms of bladder carcinogenesis, metastasis, and drug resistance. Its origin from a high-grade transitional cell carcinoma makes it particularly appropriate for studying immune checkpoint pathways, as these tumors frequently exhibit PD-L1 upregulation.
CD274 encodes PD-L1, a transmembrane ligand that delivers inhibitory signals upon engaging its receptor PD-1 on activated T cells. Mechanistically, PD-L1 binding to PD-1 recruits and activates the SHP-2 phosphatase, which dephosphorylates crucial T cell receptor (TCR)-proximal kinases including ZAP70, LCK, and CD3??, thereby attenuating downstream signaling cascades such as PI3K/AKT/mTOR and RAS/MAPK/ERK. PD-L1 expression is transcriptionally regulated by interferon-gamma (IFN-??) via STAT1 and IRF1, and is also modulated by oncogenic drivers such as EGFR, ALK, MYC, and HIF-1??, as well as by PI3K/AKT activation or PTEN loss. Additional upstream regulators include TNF-?? and IL-6, further embedding PD-L1 within a complex cytokine and growth factor network. PD-L1 also interacts with CD80 (B7-1), expanding its immunomodulatory reach. Consequently, PD-L1 functions as a key node in the PD-1/PD-L1 checkpoint axis, promoting T cell exhaustion, regulatory T cell induction, and tumor immune escape.
In bladder cancer, PD-L1 overexpression is a frequent mechanism of immune evasion, correlating with poor prognosis and aggressive disease. The CD274 Knockout UM-UC-3 Polyclonal Cells offer a genetically defined platform to mimic loss of PD-L1 function in a clinically representative tumor background. By comparing knockout and wild-type UM-UC-3 cells, researchers can dissect PD-L1-dependent signaling, identify compensatory resistance pathways, and evaluate the cell-intrinsic effects of PD-L1 ablation on tumor proliferation, survival, and metastatic capacity. This model is instrumental for validating the specificity of anti-PD-1/PD-L1 therapeutics and for probing crosstalk between PD-L1 and other oncogenic pathways active in bladder carcinoma.
This product supports a broad range of experimental workflows. Flow cytometry and immunoblotting confirm PD-L1 loss and assess downstream targets such as SHP-2, ZAP70, and LCK phosphorylation. Co-culture with T cells evaluates PD-L1-mediated immunosuppression and checkpoint blockade effects. Transcriptomic profiling via RNA-seq or RT-qPCR identifies global gene expression changes, while migration, invasion, and apoptosis assays reveal phenotypic outcomes. High-throughput screening with anti-PD-1/PD-L1 antibodies can identify novel modulators. For further technical details, please contact Ascent Research.
