The DPYD Knockout HCT 116 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population in which the DPYD gene has been disrupted. This product is composed of a heterogeneous pool of HCT 116 cells harboring targeted gene modifications introduced by CRISPR/Cas9 technology, resulting in a loss-of-function model without clonal selection. The polyclonal nature ensures preservation of genetic diversity and avoids artifacts from single-cell isolation, making it suitable for experiments where population-level responses are paramount.
The host cell line, HCT 116, is a human colorectal carcinoma epithelial cell line featuring microsatellite instability-high (MSI-H) due to MLH1 mutation and a KRAS G13D oncogenic mutation. These genetic aberrations make HCT 116 a standard model for colorectal cancer, particularly for chemosensitivity, DNA mismatch repair, and KRAS signaling studies. Its epithelial origin also renders it suitable for investigating pyrimidine metabolism within intestinal tumorigenesis.
DPYD encodes dihydropyrimidine dehydrogenase, the rate-limiting enzyme in pyrimidine catabolism that facilitates the reduction of uracil and thymine to dihydrouracil and dihydrothymine, respectively, using NADPH and FAD as cofactors. This enzymatic step initiates the breakdown of pyrimidine bases, leading to the formation of ??-alanine and ??-aminoisobutyrate via the subsequent actions of dihydropyrimidinase (DPYS) and ??-ureidopropionase (UPB1). In addition to its role in endogenous pyrimidine degradation, DPYD is the primary metabolic detoxification pathway for the chemotherapeutic agent 5-fluorouracil (5-FU). DPYD expression is transcriptionally regulated by multiple upstream factors, including p53, NF-??B, HIF-1??, and circadian clock proteins BMAL1/CLOCK, with DPYD protein functioning as a homodimer and interacting with DPYS. Disruption of DPYD in HCT 116 cells abrogates pyrimidine catabolism, leading to elevated intracellular uracil and 5-FU levels, thereby potentiating 5-FU cytotoxicity.
In the HCT 116 colorectal carcinoma background, DPYD knockout provides a powerful tool to dissect the interplay between pyrimidine metabolism and chemoresistance. The MSI-H status and KRAS mutation of HCT 116 are known to influence 5-FU sensitivity; therefore, ablating DPYD in this genetic context allows researchers to evaluate how defective pyrimidine degradation synergizes with mismatch repair deficiency and oncogenic KRAS signaling to drive drug toxicity. This model facilitates the investigation of DPYD as a predictive biomarker for fluoropyrimidine-based chemotherapy, including 5-FU and capecitabine, and supports studies on hereditary DPYD deficiency syndromes that manifest as thymine-uraciluria.
Researchers can employ DPYD Knockout HCT 116 Polyclonal Cells in a range of functional assays, including 5-FU cytotoxicity assays to quantify chemosensitivity, liquid chromatography?Cmass spectrometry (LC-MS) for uracil and metabolite profiling, DPYD enzymatic activity measurements using radiolabeled substrates, and Western blot or RT-qPCR to verify DPYD protein and transcript ablation. These applications are critical for drug toxicity screening, modeling DPYD deficiency, and investigating fluoropyrimidine adverse reactions. For additional information on this product, please contact Ascent Research.
