Lactosylsulfatide expression in hepatocellular carcinoma cells enhances cell adhesion to vitronectin and intrahepatic metastasis in nude mice

Abstract

Lactosylsulfatide (SM3), one of the major sulfated glycolipids, has been reported to be involved in cellular adhesion. Yet, its specific function has not been well understood in tumor biology, especially in the process of metastasis. We analyzed expression levels of sulfatide on HCC cells with different metastatic potentials and found that levels were correlated with metastatic potential. Next, the cerebroside sulfotransferase (CST) (EC2.8.2.11) gene, which synthesizes SM3 as well as galactosylsulfatide (SM4), was transfected into the HCC line Hep3B. Cell surface expression of SM3 was confirmed by thin-layer chromatogram immunostaining and flow-cytometric analyses. SM3-expressing Hep3B cells showed elevated expression of integrin αVβ3 and higher adhesive ability to vitronectin compared to mock cells. Furthermore, SM3 expression promoted intrahepatic metastasis in nude mice. Thus, SM3 may play an important role in the metastasis of HCC cells by causing the interaction of integrin αVβ3 with vitronectin. © 2004 Wiley-Liss, Inc.