Effects of SphK1 and FAK on epithelial-mesenchymal transition in colon cancer HCT116 cells

AIM: To investigate the effects of sphingosine kinase l(SphK1) and focal adhesion kinase(FAK) on the epithelial-mesenchymal transition(EMT) of human colon cancer HCT116 cells. METHODS: Human colon cancer HCT116 cells were divided into 3 groups. N, N-dimethylsphingosine(DMS) was used to suppress the activity of SphK1. PF573228 was used to suppress the activation of FAK. The cells treated with equal volume of culture medium severed as control group. The cell viability was measured by MTT assay. The protein expression of SphK1, FAK and the EMT relative protein E-cadherin, N-cadherin, vimentin and matrix metalloproteinase(MMP) 2 was analyzed by Western blot. The mRNA expression of SphK1, sphingosine-1-phosphate(S1P), FAK, E-cadherin and vimentin was detected by real-time PCR. The ability of tumor cell migration was measured by wound-healing assay. RESULTS: The cell viability of HCT116 cells was suppressed by DMS and PF573228 in dose and time dependent manners. DMS significantly suppressed the expression of SphK1, FAK, N-cadherin, vimentin and MMP2, meanwhile enhanced the expression of E-cadherin. PF573228 reduced the expression of FAK, SphK1, N-cadherin, vimentin and MMP2, meanwhile increased the expression of E-cadherin(P<0.01). In addition, the migration ability of HCT116 cells was significantly decreased by treating with DMS and PF573228(P<0.01). Compared with control group, the mRNA expression of FAK, SphK1, S1P and vimentin was decreased, while the expression of E-cadherin was increased significantly in PF573228 group and DMS group(P<0.05). CONCLUSION: SphK1 and FAK signaling pathways may play an important role in the occurrence of EMT in the colon cancer HCT116 cells.