The GNS Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population generated by disruption of the GNS gene in the HT29 human colorectal adenocarcinoma cell line. This loss-of-function model eliminates glucosamine-6-sulfatase (GNS) activity, impairing heparan sulfate and keratan sulfate degradation. As polyclonal cells, they offer a heterogeneous knockout population suitable for functional studies without clonal selection. This system enables investigation of lysosomal glycosaminoglycan catabolism and lysosomal storage disorders in a cancer-relevant background.
The host HT29 line is a widely used model of human colorectal cancer, featuring oncogenic BRAF V600E, APC, and TP53 mutations with mismatch repair proficiency. Its adherent epithelial-like morphology and preserved colonocyte characteristics render it ideal for studies of intestinal epithelial biology, oncogenesis, and cancer signaling. The genetic background provides a relevant setting to investigate the interplay between lysosomal dysfunction and colorectal cancer pathways.
GNS encodes glucosamine-6-sulfatase, a lysosomal enzyme that hydrolyzes sulfate from the 6-position of N-acetylglucosamine-6-sulfate in heparan sulfate and keratan sulfate, a critical step in glycosaminoglycan degradation. Its activity is post-translationally activated by SUMF1, and its expression is regulated by TFEB and MITF transcription factors downstream of mTORC1 and hypoxia. In the heparan sulfate degradation sequence, GNS acts downstream of heparanase and SGSH, and upstream of NAGLU, interacting with HGSNAT and other lysosomal glycosidases. GNS knockout causes accumulation of sulfated glycosaminoglycans, lysosomal enlargement, and autophagy flux impairment, mimicking mucopolysaccharidosis type IIID.
In the HT29 colorectal cancer background, GNS deficiency introduces lysosomal stress that may influence tumor cell behavior. Accumulated glycosaminoglycans can modify the tumor microenvironment and interact with pathways affected by the host cell??s BRAF/APC/TP53 mutations. This model enables dissection of how lysosomal dysfunction impacts colorectal cancer phenotypes, including proliferation, survival, and therapy responses, while also serving as a tool for Sanfilippo syndrome type D research.
Applications include modeling mucopolysaccharidosis type IIID, evaluating substrate reduction or chaperone therapies, and studying the role of glycosaminoglycan accumulation in colorectal cancer. Typical assays measure GNS enzymatic activity with fluorogenic substrates, sulfated GAGs via DMMB assay, gene/protein expression by RT-qPCR and western blot, lysosomal changes by LAMP1/2 immunofluorescence, storage vacuoles by electron microscopy, and autophagy flux by LC3-I/II analysis. These applications support drug discovery and mechanistic studies. For ordering and support, please contact Ascent Research.
