The KDSR Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population derived from HT29 colorectal adenocarcinoma cells, with targeted disruption of the KDSR gene. This loss-of-function model is designed for investigating 3-ketodihydrosphingosine reductase function in sphingolipid metabolism.
HT29 cells originate from a primary colon adenocarcinoma of a 44-year-old female and display adherent epithelial morphology. They form polarized monolayers with tight junctions, serving as a model of human intestinal epithelium for cancer and drug absorption studies.
KDSR encodes 3-ketodihydrosphingosine reductase, which catalyzes the NADPH-dependent conversion of 3-ketodihydrosphingosine to dihydrosphingosine in the rate-limiting de novo sphingolipid biosynthesis pathway. This reaction lies downstream of the serine palmitoyltransferase complex (SPTLC1/2/3) and upstream of ceramide synthases (CERS1-6) and dihydroceramide desaturase (DEGS1). Transcription factors SREBP1 and SP1 upregulate KDSR expression, while inflammatory cytokines such as TNF-?? and growth factors EGF and IGF-1 modulate its activity. Disruption of KDSR blocks dihydrosphingosine production, depleting key metabolites including ceramides, sphingomyelin, and sphingosine-1-phosphate (S1P). Consequently, signaling via S1P receptors and sphingosine kinases (SPHK1/2) is attenuated, and apoptotic processes regulated by BAX and BAK are perturbed. Cofactors like NADPH and regulatory ORMDL proteins further integrate KDSR into cellular stress responses.
In HT29 colorectal adenocarcinoma cells, sphingolipid metabolism is tightly linked to tumor cell proliferation, survival, and therapeutic resistance. KDSR knockout disrupts sphingolipid homeostasis, potentially reducing ceramide levels and impairing S1P-mediated survival pathways, which may sensitize cells to apoptosis and modulate chemoresistance. Because HT29 cells form polarized epithelial monolayers with functional tight junctions, this knockout model also permits investigation of how sphingolipid alterations affect barrier function and cell polarity. The interaction between KDSR loss and HT29’s oncogenic mutations, including APC and TP53, provides a clinically relevant context for studying lipid-dependent cancer cell signaling.
Researchers can utilize these polyclonal knockout cells for a variety of assays, including LC-MS sphingolipid profiling, ceramide ELISA, S1P quantification, and functional studies using MTT, Annexin V apoptosis, and wound healing migration assays. Expression analysis via RT-qPCR and Western blotting for sphingolipid enzymes and immunofluorescence staining of tight junction proteins are also readily applicable. This product is particularly suited for dissecting colorectal cancer metabolism, identifying drug targets, and exploring the role of sphingolipid signaling in chemoresistance and inflammatory bowel disease. For further information, contact Ascent Research.
