The CBS Knockout HGC-27 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population of the HGC-27 human gastric carcinoma epithelial cell line, designed to disrupt the gene encoding cystathionine beta-synthase (CBS). This polyclonal model provides a heterogeneous loss-of-function system for investigating the transsulfuration pathway in a gastric cancer background.
HGC-27 is a poorly differentiated gastric adenocarcinoma cell line established from a lymph node metastasis. It retains epithelial morphology and serves as a widely used model for studying gastric cancer biology, including metastatic progression and metabolic adaptations. The cell line??s aggressive characteristics make it suitable for probing pathway dependencies relevant to tumor maintenance.
CBS is a rate-limiting enzyme in the transsulfuration pathway that condenses homocysteine and serine to generate cystathionine, using heme and pyridoxal phosphate as cofactors. Allosteric activation by S-adenosylmethionine and transcriptional control by Sp1, NF-Y, HIF1A, and NRF2 regulate its activity. Downstream, CTH converts cystathionine to cysteine, which feeds into glutathione synthesis via GCLC and GCLM, and is also a substrate for hydrogen sulfide (H2S) production. Key interconnected pathway components include MTR, MTRR, BHMT, MAT1A, SAHH, and xCT. Disruption of CBS impairs homocysteine clearance, reducing the cellular output of cysteine, glutathione, and H2S, thereby sensitizing cells to oxidative stress and perturbing H2S-mediated signaling events such as protein persulfidation.
In the HGC-27 gastric cancer context, loss of CBS function disrupts redox homeostasis and H2S-dependent signaling, potentially affecting cell survival, proliferation, and stress responses. Gastric tumors often exhibit altered methionine and folate cycle metabolism; this knockout model allows dissection of the transsulfuration pathway??s contribution to cancer cell redox balance and metabolic reprogramming. The polyclonal nature captures gene-disruption effects across a heterogeneous cell pool, mimicking intratumoral diversity.
This model supports diverse applications, including oxidative stress sensitivity assays (ROS measurement, viability by MTT or CCK-8, apoptosis by annexin V/caspase-3), metabolic profiling of homocysteine and glutathione by HPLC/LC-MS, and quantification of H2S production. Functional studies such as colony formation, migration, and drug sensitivity screening can reveal CBS-dependent phenotypic consequences. Complementary molecular analyses via Western blotting, RT-qPCR, and RNA-seq provide expression-level validation. For inquiries, please contact Ascent Research.
