ALDH18A1 Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population derived from the human HT29 colorectal adenocarcinoma line, designed for loss-of-function studies of aldehyde dehydrogenase 18 family member A1 (ALDH18A1). This polyclonal knockout model, generated through CRISPR/Cas9-mediated gene disruption, offers a heterogeneous population with diverse editing events at the ALDH18A1 locus, enabling robust interrogation of gene function while averaging out potential clonal artifacts. The product provides a genetically defined system for dissecting the role of P5C synthase in amino acid metabolism, collagen biosynthesis, and cancer cell homeostasis. Researchers can leverage this tool to explore proline dependency mechanisms in colorectal cancer, validate metabolic vulnerabilities, and model ALDH18A1-related pathologies without the constraints of single-clone isolation.
The parental HT29 cell line is a well-established epithelial model derived from a human colorectal adenocarcinoma, widely employed in cancer biology, drug discovery, and intestinal physiology studies. HT29 cells retain key characteristics of intestinal epithelial differentiation and are capable of forming polarized monolayers, making them suitable for investigating processes such as extracellular matrix remodeling, metabolic reprogramming, and tumor microenvironment interactions. Their colorectal origin positions them as a relevant context for examining ALDH18A1 function, given the increasing recognition of proline metabolism in gastrointestinal malignancies. The use of this host line thus provides a clinically pertinent platform for functional genomics and pharmacological screening.
ALDH18A1 encodes ??1-pyrroline-5-carboxylate synthase (P5CS), a bifunctional enzyme that catalyzes the ATP-dependent phosphorylation of glutamate to ??-glutamyl phosphate and its subsequent NADPH-dependent reduction to pyrroline-5-carboxylate (P5C). P5C serves as a common intermediate for the biosynthesis of proline, ornithine, and downstream metabolites including arginine, polyamines, and collagen. The enzymatic activity of P5CS is transcriptionally regulated by upstream factors such as ATF4, MYC, and p53, and is integrated with mTORC1 signaling to couple amino acid availability with cell growth and stress responses. P5CS directly interacts with cofactors ATP and NADPH, and its product P5C is further metabolized by pyrroline-5-carboxylate reductase (PYCR) to proline or by ornithine aminotransferase (OAT) to ornithine. Disruption of ALDH18A1 therefore impairs proline and ornithine production, with downstream consequences on collagen synthesis, polyamine availability, and cellular redox balance.
In the context of HT29 colorectal cancer cells, ALDH18A1 knockout has profound implications for metabolic reprogramming and tumor cell fitness. Colorectal tumors often exhibit altered proline metabolism, with P5CS activity contributing to increased collagen deposition in the tumor stroma and supporting rapid proliferation under nutrient stress. By abrogating P5CS function, these polyclonal knockout cells are expected to exhibit reduced proline pools, defective collagen maturation, and heightened sensitivity to metabolic perturbations such as glutamine deprivation or oxidative stress. This model is particularly valuable for studying the intersection of amino acid metabolism and cancer cell survival, as well as for investigating the molecular basis of ALDH18A1-linked genetic disorders including autosomal recessive cutis laxa type 3A (ARCL3A), autosomal dominant cutis laxa 3 (ADCL3), and spastic paraplegia 9B (SPG9B).
Typical research applications encompass a broad range of experimental strategies, including Western blotting and RT-qPCR to assess P5CS expression and downstream effectors like collagen and PYCR, RNA-seq for transcriptomic profiling, and metabolic assays quantifying proline and ornithine levels. Functional studies may involve immunofluorescence for collagen deposition, cell proliferation and viability assays, flow cytometric analysis of cell cycle distribution, and drug sensitivity screens targeting proline metabolism. This polyclonal knockout population is ideally suited for metabolic flux analyses, CRISPR-based synthetic lethality screens, and investigation of extracellular matrix remodeling in 3D culture systems. For further details or technical consultation, please contact Ascent Research.
