ABSTRACT
@#[Abstract] Objective: To investigate the effect of sphingosine kinase 1 (SphK1) knockdown on the proliferation and migration of colon cancer RKO cells induced by mesenchymal stem cells (MSCs). Methods: RKO cells were treated with MSCs conditioned medium (MSC-CM) or control medium (Control-CM), respectively. Cell proliferation was detected by CCK-8 assay. Cell migration ability was tested by Transwell chamber assay. The proteins expression of Ki-67, MMP-2/9, CD44 and CD133 was detected by Western blotting. Then, the expression of SphK1 in RKO cells was suppressed by targeted gene lentivirus shRNA vector transfection. The effects of SphK1 knockdown on the proliferation, migration and protein expressions of Ki-67, MMP-2/9, CD44 and CD133 of RKO cells induced by MSC-CM were observed. Results: The RKO cells proliferation was promoted by MSC-CM in a time-dependent manner; moreover (P<0.05), the migration ability of cells was significantly enhanced after being treated with MSC-CM(P<0.01). In addition, MSC-CM significantly increased the protein expressions of Ki-67, MMP-2/9, CD44 and CD133(all P<0.05 or P<0.01). Lentiviral ShRNA vector transfection could significantly inhibit the expression of SphK1. Down-regulation of SphK1 significantly inhibited the proliferation, migration and protein expressions of Ki-67, MMP-2/9, CD44 and CD133 of RKO cells induced by MSC-CM(all P<0.05 or P<0.01). Conclusion: MSC-CM promotes the proliferation and migration of colon cancer RKO cells. Down-regulation of SphK1 reverses the cell proliferation and migration induced by MSC-CM via inhibiting the expression of MMP-2/9, CD44 and CD133.