The HS3ST1 Knockout 143B Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the 143B human osteosarcoma cell line, in which the HS3ST1 gene has been disrupted by CRISPR/Cas9-mediated targeting. This product provides a heterogeneous pool of edited cells, enabling robust loss-of-function studies without clonal selection. Disruption of HS3ST1 eliminates expression of heparan sulfate 3-O-sulfotransferase 1, a critical enzyme in the terminal modification of heparan sulfate chains.
The 143B cell line is a well-established osteosarcoma model that retains osteoblast-like characteristics, including secretion of bone matrix proteins and responsiveness to osteogenic factors. Originating from a primary bone tumor, these cells are tumorigenic in vivo and are extensively employed to investigate bone cancer biology and osteoblast function. The 143B background provides a relevant setting for examining HS3ST1 in bone malignancies, where heparan sulfate sulfation patterns influence tumor growth, metastasis, and the microenvironment.
HS3ST1 catalyzes 3-O-sulfation of glucosamine residues in heparan sulfate, generating motifs required for high-affinity antithrombin binding and subsequent inhibition of Factor Xa and thrombin. This modification also facilitates interactions with growth factors such as FGF2, VEGF, and PDGF, thereby modulating signaling through their receptors. HS3ST1 acts within a biosynthetic pathway involving EXT1, EXT2, NDST1, HS2ST1, and HS6ST1, and is regulated by upstream cues including TGF-??, Wnt ligands, and BMPs. Knockout of HS3ST1 abrogates antithrombin-mediated anticoagulant activity and attenuates FGF2-FGFR signaling, represented by reduced phospho-ERK levels. Additionally, 3-O-sulfated motifs are entry receptors for herpes simplex virus, and their absence blocks viral gD binding.
In 143B cells, HS3ST1 knockout provides a tool to dissect how specific heparan sulfate fine structures influence osteosarcoma cell behavior. Loss of 3-O-sulfation likely alters responses to growth factors abundant in the bone milieu, such as FGF2 and Wnts, impacting proliferation, migration, and invasion. This model also enables investigation of coagulation-related phenomena in the tumor stroma and viral susceptibility. The tumorigenic property of 143B permits in vivo xenograft studies to assess HS3ST1-dependent tumor progression.
Applications include heparan sulfate structure-function analysis via LC-MS disaccharide profiling, antithrombin-binding western blotting, and Factor Xa inhibition assays. Signaling studies may use phospho-ERK readouts after FGF stimulation, and viral entry assays can evaluate HSV-1 dependence on 3-O-sulfation. Standard proliferation and migration assays (MTT, scratch wound) are compatible. The polyclonal format reduces clonal artifacts and is ideal for screening. For inquiries, please contact Ascent Research.
