目的： 探讨鞘氨醇激酶1 （sphigosine kinase 1, SphK1）基因下调对间充质干细胞（mesenchymal stem cell, MSC）诱导的 结肠癌RKO细胞增殖和迁移的影响。 方法： 采用MSC条件培养液（MSC-CM）和对照培养液（Control-CM）分别干预RKO细胞， CCK-8法检测细胞的增殖能力，Transwell实验检测细胞的迁移能力，Western blotting法检测Ki-67抗原（Ki-67）、MMP-2/9、肿瘤干 细胞标志物CD44和CD133蛋白的表达。用慢病毒shRNA载体转染RKO细胞抑制SphK1的表达，观察抑制SphK1的表达对 MSC-CM诱导的RKO细胞增殖、迁移以及MMP-2/9、CD44和CD133蛋白表达的影响。 结果： MSC-CM可时间依赖性促进RKO 细胞的增殖(P<0.05)，并明显增强细胞的迁移能力(P<0.01)和细胞中Ki-67、MMP-2/9、CD44和CD133蛋白的表达(均P<0.05或P< 0.01)。慢病毒shRNA转染明显抑制RKO细胞SphK1的表达，抑制SphK1的表达可显著抑制MSC-CM对RKO细胞增殖和迁移的 促进作用(均P<0.05或P<0.01)，且明显抑制MSC-CM诱导的Ki-67、MMP-2/9、CD44和CD133蛋白的表达。 结论： MSC-CM可 促进RKO细胞的增殖和迁移，下调SphK1可通过抑制MMP-2/9、CD44和CD133的表达逆转MSC-CM诱导的细胞增殖和迁移。

Objective: To investigate the effect of sphingosine kinase 1 (SphK1) knockdown on the proliferation and migration of co- lon 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, mi- gration and protein expressions of Ki-67, MMP-2/9, CD44 a D133 of RKO cells induced by MSC-CM(all P<0.05 or P<0.01). Con- clusion: 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.

国家自然科学基金资助项目（No.81460380）；广西自然科学基金项目（No.2017GXNSFAA198019）；广西研究生教育创新计划项目 （No.YCBZ2017035）