The CD274 Knockout SK-HEP-1 Polyclonal Cells product provides a heterogeneous population of SK-HEP-1 cells that have undergone CRISPR/Cas9-mediated gene disruption of the CD274 locus. This polyclonal knockout format preserves the genetic diversity inherent in CRISPR-edited pools and allows researchers to interrogate CD274 function without clonal selection. Unlike monoclonal cell lines, this population-level knockout model better reflects the phenotypic variability encountered in heterogeneous tumor samples, making it particularly suitable for studies in cancer biology and immune checkpoint signaling.
The SK-HEP-1 host cell line is a human adherent epithelial line originally isolated from the ascites of a patient with hepatic adenocarcinoma. Commonly employed as a model for hepatocellular carcinoma, SK-HEP-1 cells exhibit a tumorigenic phenotype and are widely used to investigate liver cancer biology, drug response, and tumor microenvironment interactions. This line provides a physiologically relevant backdrop for examining the role of immunomodulatory molecules in liver-derived malignancies.
CD274 encodes programmed death-ligand 1 (PD-L1), a critical immune checkpoint molecule that suppresses T-cell activity through engagement of the PD-1 receptor. PD-L1 expression is upregulated by interferon gamma (IFN-??), STAT3, HIF-1??, and EGFR signaling. Upon binding to PD-1 on T cells, PD-L1 recruits the SHP-2 phosphatase (PTPN11), which dephosphorylates key tyrosine residues downstream of the T-cell receptor and CD28, thereby attenuating PI3K/AKT and MAPK/ERK pathways. This blockade reduces T-cell activation, proliferation, and cytokine production, facilitating immune evasion. PD-L1 also interacts with CD80 and can form homodimers, further refining its immunoregulatory role.
Disruption of CD274 in SK-HEP-1 cells creates a loss-of-function system to dissect PD-L1-dependent immune suppression in the context of hepatic adenocarcinoma. Because SK-HEP-1 cells endogenously express PD-L1, knockout of this gene permits direct assessment of its contribution to tumor-immune cell crosstalk, particularly in co-culture experiments with human T cells. This model can reveal how PD-L1 influences signaling through PI3K, AKT, and ERK in tumor cells themselves, in addition to its paracrine effects on immune effectors, thus offering insights into both intrinsic and extrinsic tumor mechanisms.
This polyclonal knockout cell product is optimized for a broad range of research applications, including flow cytometric quantification of PD-L1 surface expression, western blotting for total protein levels, and RT-qPCR for transcript analysis. It is especially powerful for T-cell suppression assays, where loss of PD-L1 can restore T-cell cytotoxicity, and for evaluating the efficacy of anti-PD-1/PD-L1 antibodies in drug sensitivity studies. Researchers can also employ immunofluorescence to monitor PD-L1 localization and investigate compensatory signaling pathways activated upon PD-L1 loss. For more details on lot-specific performance characteristics or to inquire about custom modifications, please contact Ascent Research.
