The IDO1 Knockout SK-HEP-1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the IDO1 gene in a loss-of-function model. This product comprises a heterogeneous pool of edited cells derived from the SK-HEP-1 hepatic adenocarcinoma line, enabling robust assessment of IDO1-dependent phenotypes without reliance on a single clonal isolate. The polyclonal format captures a spectrum of genetic disruptions, reflecting population-level responses and minimizing clonal bias in functional studies.
The SK-HEP-1 host cell line was established from the ascites of a patient with liver adenocarcinoma and exhibits characteristics of neoplastic liver epithelial cells. Widely used in hepatocellular carcinoma research, this adherent line is a well-characterized model for tumor biology, drug metabolism, and immune evasion. Its genomic background provides a relevant context for interrogating the role of IDO1 in a liver cancer microenvironment.
IDO1 encodes the enzyme indoleamine 2,3-dioxygenase 1, which catalyzes the first and rate-limiting step of tryptophan degradation along the kynurenine pathway. This reaction depletes local tryptophan and produces kynurenine, a ligand for the aryl hydrocarbon receptor (AHR). IDO1 expression is strongly induced by interferon-gamma (IFNG), interleukin-1 beta (IL1B), and tumor necrosis factor (TNF) via JAK-STAT signaling, involving STAT1 and IRF1. The enzyme functions as a heme-containing protein and can be modulated by nitric oxide. Downstream, kynurenine activates AHR and, together with tryptophan depletion sensed by GCN2 kinase, suppresses effector T cells and promotes FOXP3-positive regulatory T-cell differentiation. IDO1 also intersects with mTORC1, integrating metabolic and immune regulatory signals.
In SK-HEP-1 hepatic adenocarcinoma cells, IDO1 overexpression facilitates immune escape by inhibiting T-cell proliferation and fostering a tolerogenic milieu. CRISPR/Cas9-mediated disruption of IDO1 in this polyclonal population allows dissection of tumor-intrinsic contributions to immune suppression, proliferation, and drug sensitivity. Compared with monoclonal knockouts, the polyclonal format better mirrors intratumoral heterogeneity, enabling studies on how IDO1 loss affects population-level behaviors in the context of liver cancer.
This knockout cell pool supports diverse applications, including tumor immunology, immune checkpoint research, and drug screening. Researchers can employ Western blotting to confirm IDO1 ablation, HPLC-based measurement of tryptophan and kynurenine in conditioned media, T-cell proliferation assays to evaluate functional immune modulation, and flow cytometry for immune checkpoint markers. RNA-seq and RT-qPCR enable transcriptomic profiling of IDO1-dependent pathways. These tools facilitate investigation of the kynurenine pathway in hepatic adenocarcinoma and evaluation of novel IDO1-targeted therapies. For further details and technical support, contact Ascent Research.
