Effect of S1P5 on proliferation and migration of human esophageal cancer cells

AIM:To investigate the sphingosine 1phosphate (S1P) receptor expression profile in human esophageal cancer cells and the effects of S1P5 on proliferation and migration of human esophageal cancer cells. METHODS: S1P receptor expression profile in human esophageal squamous cell carcinoma cell line Eca109 was detected by semiquantitative reverse trans cription polymerase chain reaction. Eca109 cells were stably transfected with S1P5EGFP or controlEGFP constructs. The relation between the responses of cell proliferationand migration to S1P and S1P5 expres sion was evaluated by 3(4,5dimethylthiazol2yl)2,5diphenyl tetrazolium bromide and migration assay, respectively. RESULTS: Both normal human esophageal mucosal epithelium and Eca109 cells expressed S1P1, S1P2, S1P3 and S1P5, respectively. Esophageal mucosal epithelium expressed S1P5 at a higher level than Eca109 cell line. S1P5 overexpressing Eca109 cells displayed spindle cell morphology with elongated and extended filopodialike projections. The proliferation response of S1P5transfected Eca109 cells was lower than that of control vectortransfected cells with or without S1P stimulation (P < 0.05 or 0.01). S1P significantly inhibited the migration of S1P5transfected Eca109 cells (P < 0.001). However, without S1P in transwell lower chamber, the number of migrated S1P5transfected Eca109 cells was greater than that of control vectortransfected Eca109 cells (P < 0.001).CONCLUSION: S1P binding to S1P5 inhibits the proliferation and migration of S1P5transfected Eca109 cells. Esophageal cancer cells may downregulate the expression of S1P5 to escape the inhibitory effect.