Sphingosine-1-phosphate receptor subtype-specific positive and negative regulation of Rac and haematogenous metastasis of melanoma cells

Biochem J. 2003 Sep 15;374(Pt 3):715-22. doi: 10.1042/BJ20030381.

Abstract

We have recently reported that S1P (sphingosine-1-phosphate) differentially regulates cellular Rac activity and cell migration in either a positive or a negative direction via distinct G-protein-coupled receptor subtypes, i.e. S1P1/Edg1 (endothelial differentiation gene) and S1P2/Edg5 respectively, when each of the S1P receptor subtypes is expressed in CHO (Chinese-hamster ovary) cells. In B16F10 mouse melanoma cells, in which S1P2, but not the other S1P receptor subtypes, is endogenously expressed, S1P inhibited cell migration with concomitant inhibition of Rac and stimulation of RhoA in dose-dependent manners. Overexpression of S1P2 in the melanoma cells resulted in potentiation of S1P inhibition of both Rac and cell migration. In contrast, overexpression of S1P1 led to stimulation of cell migration, particularly at the lower S1P concentrations. Treatment of B16F10 cells with S1P inhibited lung metastasis 3 weeks after injection into mouse tail veins. Intriguingly, overexpression of S1P2 greatly potentiated the inhibition of metastasis by S1P, whereas that of S1P1 resulted in aggravation of metastasis. Suppression of cellular Rac activity by adenovirus-transduced expression of N17Rac, but not N19RhoA, strongly inhibited cell migration in vitro and lung metastasis in vivo. These results provide the first evidence that G-protein-coupled receptors could participate in the regulation of metastasis, in which ligand-dependent, subtype-specific regulation of the cellular Rac activity is probably critically involved as a mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Calcium Signaling / genetics
  • Cell Migration Inhibition*
  • Cricetinae
  • Down-Regulation* / genetics
  • Gene Expression Regulation, Neoplastic
  • Lysophospholipids*
  • Male
  • Melanoma, Experimental / genetics
  • Melanoma, Experimental / metabolism
  • Melanoma, Experimental / pathology
  • Melanoma, Experimental / secondary*
  • Mice
  • Mice, Inbred C57BL
  • Neoplasm Transplantation
  • Neoplastic Cells, Circulating / metabolism
  • Neoplastic Cells, Circulating / pathology
  • Receptors, Cell Surface / physiology*
  • Receptors, G-Protein-Coupled*
  • Receptors, Lysophospholipid
  • Sphingosine / analogs & derivatives*
  • Sphingosine / physiology*
  • Tumor Cells, Cultured
  • Up-Regulation* / genetics
  • rac GTP-Binding Proteins / antagonists & inhibitors*
  • rac GTP-Binding Proteins / biosynthesis*
  • rac GTP-Binding Proteins / physiology

Substances

  • Lysophospholipids
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • Receptors, Lysophospholipid
  • sphingosine 1-phosphate
  • rac GTP-Binding Proteins
  • Sphingosine