The CD274 Knockout KYSE-30 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the CD274 gene in the human KYSE-30 esophageal squamous cell carcinoma line. This polyclonal knockout pool provides a heterogeneous cell population with targeted gene disruption, enabling functional studies without the need for clonal selection. The loss-of-function model eliminates PD-L1 (programmed death-ligand 1) expression, offering a versatile tool for investigating immune checkpoint biology in a cancer context.
KYSE-30 is a well-differentiated esophageal squamous cell carcinoma cell line originally established from a Japanese patient. As an epithelial cancer model, it retains characteristics relevant to esophageal tumor biology, including adherent growth and typical squamous carcinoma morphology. The cell line serves as a robust platform for studying oncogenic signaling, tumor microenvironment interactions, and therapeutic responses, particularly in the context of immune evasion mechanisms prevalent in esophageal cancers.
CD274 encodes PD-L1, a transmembrane immune checkpoint ligand that binds to the PD-1 receptor (PDCD1) on T cells, as well as CD80 (B7-1). Upon PD-1 engagement, PD-L1 triggers recruitment of SHP-2 phosphatase, which dephosphorylates key T-cell receptor (TCR) signaling components, including ZAP-70 and LCK, thereby inhibiting proximal TCR signaling. This cascade leads to reduced IL-2 production and upregulation of T-cell exhaustion markers such as PD-1, TIM-3, and LAG-3. CD274 expression is tightly regulated by multiple upstream signals: interferon-gamma (IFNG) activates JAK1/STAT1 and STAT3 pathways, while oncogenic transcription factors including MYC, HIF1A, AP-1, and NF-??B, and kinases such as EGFR and oncogenic RAS, converge to drive CD274 transcription. Loss of the tumor suppressor PTEN further potentiates PD-L1 expression via PI3K-AKT signaling, highlighting the integration of immune checkpoint regulation with hallmark cancer pathways.
In the KYSE-30 esophageal squamous cell carcinoma model, CD274 knockout disrupts the PD-L1/PD-1 immune checkpoint axis, potentially restoring T-cell-mediated anti-tumor immunity. This polyclonal knockout population allows researchers to dissect the direct contribution of tumor-intrinsic PD-L1 to immune evasion without confounding factors from single-cell clonal variation. The model is particularly valuable for investigating how PD-L1 loss impacts downstream signaling networks within the tumor cell and in co-cultured immune cells, providing insights into the role of CD274 in driving T-cell exhaustion and suppressing effector functions in the esophageal cancer microenvironment.
This knockout product is well-suited for a broad range of functional assays. Western blotting and flow cytometry can confirm abolition of PD-L1 protein expression, while RT-qPCR quantifies CD274 mRNA levels. Co-culture systems with human T cells enable analysis of cytokine secretion profiles (e.g., IL-2 by ELISA), T-cell proliferation, and cytotoxicity assays to assess restoration of immune effector functions. Immunofluorescence localization studies and RNA-seq transcriptomic profiling further characterize phenotypic changes. Additionally, the cells facilitate drug sensitivity screening with PD-1/PD-L1 inhibitors and evaluation of novel combination immunotherapies aimed at overcoming immune resistance in esophageal squamous cell carcinoma. For further technical details, please contact Ascent Research.
