BACKGROUND/AIM In this study, sphingosine-1-phosphate receptor-1 (S1P1) and S1P3 receptors were silenced to evaluate proliferation, adhesion, viability and lateral motility in estrogen receptor-negative MCF-7 and estrogen receptor-positive MDA-MB-231 breast cancer cells. MATERIALS AND METHODS Groups of MCF-7 and MDA-MB-231 cells with: no small interfering RNA (siRNA); siRNA with no target; S1P1-silencing siRNA; S1P3-silencing siRNA; and siRNAs silencing both S1P1, and S1P3 were examined for this purpose at 24, 48 and 72 h after intervention. RESULTS Viability of cells was reduced due to suppression of S1P1/S1P3. While no change was observed in the proliferation of MCF-7 cells, the proliferation of S1P1/S1P3-suppressed MDA-MB-231 cells was reduced. S1P1/S1P3 suppression resulted in reduction of adhesion of MCF-7 cells, but to an increase of MDA-MB-231 cells. Lateral motility was reduced in all S1P1/S1P3-suppressed groups. CONCLUSION Silencing the receptors simultaneously rather than separately was more effective. Additionally, the different characteristics of cancer cells affected the proliferation and adhesion of cells differently. This difference may be associated with the estrogen receptors in the cells.
