The CBS Knockout HeLa Polyclonal Cells provide a CRISPR/Cas9-mediated loss-of-function model of cystathionine beta-synthase (CBS) in the HeLa human cervical adenocarcinoma line. This polyclonal cell population harbors heterogeneous gene disruptions at the CBS locus, generating a versatile knockout resource that avoids clonal bias. The model enables robust examination of transsulfuration pathway biology and CBS-dependent metabolic and signaling functions in a widely used immortalized cell background.
HeLa cells are HPV18-positive, aneuploid epithelial cells derived from a human cervical adenocarcinoma, representing one of the most extensively used cell lines in biomedical research. Their rapid proliferation, well-annotated genome, and adaptability to genetic manipulation make them an ideal host for gene knockout studies. The HeLa background offers a consistent platform to investigate metabolic pathways relevant to cancer biology, redox regulation, and amino acid metabolism, while also allowing cross-comparison with a vast body of published HeLa-based research.
CBS encodes a heme-dependent enzyme that catalyzes the condensation of homocysteine and serine to cystathionine, a pivotal transsulfuration reaction. It is allosterically activated by S-adenosylmethionine (SAM) and regulated by transcription factors SP1, NF-Y, and HSF1 in response to nitric oxide and oxidative stress. Downstream, cystathionine is converted to cysteine, glutathione, and hydrogen sulfide (H?S). CBS integrates with the methionine cycle via MAT, MTR, and BHMT, and with the folate cycle, linking it to one-carbon metabolism and redox homeostasis.
Disruption of CBS in HeLa cells abolishes transsulfuration flux, leading to homocysteine accumulation and marked reductions in cystathionine, cysteine, glutathione, and H?S. This metabolic block impairs cellular antioxidant capacity and sensitizes cells to oxidative challenge, recapitulating metabolic hallmarks of homocystinuria. In the aneuploid, HPV-driven HeLa background, CBS loss further perturbs redox control and may influence proliferation, apoptosis, and nucleotide synthesis. Thus, this knockout model provides a tractable system to dissect CBS-dependent contributions to cancer cell metabolism, redox signaling, and cardiovascular pathology.
Researchers can apply this model to quantify homocysteine via HPLC, measure cysteine and glutathione levels, detect H?S production with fluorescent probes or the monobromobimane method, and confirm CBS knockout by Western blotting. Additional utility includes cell proliferation assays, ROS detection, apoptosis analysis, and transcriptomic profiling by RNA-seq. These applications support studies of homocystinuria, cardiovascular disease, stroke, neural tube defects, and cancer metabolism. For further details, custom services, or technical assistance, please contact Ascent Research.
