Reduction of pl-CSA through ChSy-2 knockout inhibits tumorigenesis and metastasis of choriocarcinoma in JEG3 cells.

Placental-like chondroitin sulfate A (pl-CSA) is exclusively expressed in cancerous and placental tissues and is highly correlated with the degree of malignancy. However, the mechanism through which pl-CSA regulates tumorigenesis and metastasis in choriocarcinoma remains unclear. Stable transfectants of the JEG3 choriocarcinoma cell line, including a negative control (NC) line and a cell line with knockout of the biosynthetic enzyme CS synthase-2 (ChSy-2) (ChSy-2), were obtained using CRISPR/Cas9 systems and identified by immunofluorescence, flow cytometry, western blots and enzyme-linked immunosorbent assays (ELISAs). The proliferation, migration, invasion and colony formation of the cells were determined by a cell counting kit, scratch-wound assays, transwell assays and soft agar colony formation assays , respectively. The tumorigenesis and metastasis of choriocarcinoma were also investigated through two xenograft models . The ChSy-2 protein in the ChSy-2group was below the detection threshold, which was accompanied a significant reduction in the pl-CSA level. Reducing pl-CSA through ChSy-2 knockout significantly inhibited cell proliferation, migration, invasion and colony formation and tumorigenesis and metastasis of choriocarcinoma, with deceases in tumor volume and metastatic foci and a high percent survival compared to the NC . pl-CSA, as a necessary component of JEG-3 cells, was efficiently reduced through ChSy-2 knockout, which significantly inhibited the tumorigenesis and metastasis of choriocarcinoma. ChSy-2/pl-CSA could be alternative targets for tumor therapy.