The ALAS1 Knockout HT29 Polyclonal Cells represent a ready-to-use, CRISPR/Cas9-edited polyclonal knockout cell population designed for targeted disruption of the ALAS1 gene in a human colorectal adenocarcinoma background. This heterogeneous population, derived via electroporation of sequence-specific guide RNA and Cas9 nuclease, provides a robust loss-of-function model without clonal selection, preserving biological variability while eliminating the time and resource demands of single-cell cloning. Users gain immediate access to a genetically modified pool for functional genomics, pathway dissection, and phenotypic screening, ensuring reliable target-gene inactivation across a majority of cells.
These cells are built on the well-characterized HT29 cell line, a human colorectal adenocarcinoma model isolated from a primary tumor of a 44-year-old female. HT29 cells are adherent, epithelial in morphology, and harbor a mutant TP53 gene, rendering them an established system for studying intestinal epithelial biology, oncogenic signaling, and drug response. Their robust growth and amenability to genetic manipulation make them a versatile host for genome editing, particularly suitable for investigating metabolic pathways, mitochondrial function, and apoptosis in a cancer context. The mutant p53 background further enables exploration of genotype-specific vulnerabilities and therapeutic sensitivities.
ALAS1 (5-aminolevulinate synthase 1) encodes the mitochondrial rate-limiting enzyme in heme biosynthesis, catalyzing the condensation of glycine and succinyl-CoA to 5-aminolevulinate, a reaction requiring pyridoxal phosphate as a cofactor. This enzyme sits at the apex of the porphyrin synthesis pathway and is subject to tight feedback repression by heme, its end product. Upstream regulation includes transcriptional activation by PGC-1??, insulin, and glucagon, as well as induction through phenobarbital-mediated activation of the constitutive androstane receptor (CAR/NR1I3). Downstream, ALAS1 activity directly influences cellular heme pools, thereby modulating cytochrome P450 enzymes, hemoglobin assembly, and the activity of mitochondrial respiratory chain complexes. Within the pathway, succinyl-CoA synthetase provides substrate, and heme oxygenase controls heme degradation, creating a tightly regulated network linking amino acid metabolism, mitochondrial energy production, and oxidative stress responses.
In the HT29 model, ALAS1 knockout disrupts the primary route for heme synthesis, leading to heme insufficiency that broadly affects cellular physiology. Cytochrome P450-mediated drug metabolism is compromised, oxidative phosphorylation becomes less efficient, and the synthesis of hemoproteins such as respiratory chain components is impaired. This metabolic vulnerability renders knockout cells dependent on exogenous hemin for survival and proliferation, establishing a tractable system for studying heme-dependent processes in cancer. The HT29 background also permits assessment of how heme deficiency interacts with mutant TP53 signaling, influencing tumor metabolism, ferroptosis susceptibility, and mitochondrial stress adaptation, thus providing a platform for novel anticancer therapeutic targeting.
Typical research applications include investigating heme and porphyrin metabolism, modeling acute hepatic porphyrias, and evaluating the role of heme in drug metabolism and toxicity. The knockout cells are ideal for cytochrome P450 activity assays, mitochondrial respiration measurements via Seahorse analysis, and RT-qPCR or Western blot profiling of heme biosynthesis enzymes. Viability assays under hemin-depleted conditions identify compensatory pathways or synthetic lethal interactions. Researchers can use this model to study iron homeostasis, oxidative phosphorylation dysfunction, and cancer cell metabolic reprogramming. For detailed technical information, including validation data and protocol recommendations, please contact Ascent Research.
