SU056 potentiates SULF2 antibody in suppressing cholangiocarcinoma metastasis via SULF2-YBX1-CXCR4 signaling axis.

Intrahepatic cholangiocarcinoma (iCCA), the second most common subtype of primary liver cancer around the world, is an aggressive neoplasm with high metastastic potential, which leads to a low rate of curative resections and dismal prognosis. In previous studies, Sulfatase 2 (SULF2) has been reported to regulate various important oncogenic signaling pathways and promote iCCA progression. Further research is needed to explore the role of SULF2 in iCCA metastasis. In this study, we verified the overexpression of SULF2 in iCCA tissues and its positive correlation with advanced stage and poor prognosis. Trans-well migration and invasion assay and mouse models explored the impact of SULF2 on iCCA metastasis in vitro and in vivo. We also demonstrated that SULF2 facilitated iCCA metastasis through upregulating CXCR4 transcription mediated by the transcription factor YBX1. Moreover, SULF2 could recruit USP7 to interact with YBX1 and inhibit Lys48-polyubiquitination of YBX1, stabilizing YBX1 and promoting a functional YBX1/CXCR4 axis. Combining SULF2 monoclonal antibody with SU056 had a synergistic effect in suppressing iCCA progression and metastasis of mouse models. In conclusion, SULF2 promotes iCCA progression and metastasis through an intracellular SULF2-YBX1-CXCR4 axis, and SULF2 monoclonal antibody combined with YBX1 inhibitor SU056 may be a potentially promising treatment strategy for iCCA.