Expression Of Sphingosine Kinase 1 In Tongue Squamous Cell Carcinoma And Effects On The Proliferation,migration And Invasion Of Tca8113P160 Cell In Vitro

Objective: To detect the expression of Sph K1(sphingosine kinase 1)in TSCC(tongue squamous cell carcinoma)and analyse the relationship with clinicopathological features and lymphangiogenesis,we also investigated the role of Sph K1 in the progression of TSCC and attempted to reveal the underlying mechanisms.Methods: 1.The expression of Sph K1 and LVD(lymphatic vessel density)were evaluated by immunohistochemistry in 50 cases of TSCC,and analyse the relationship between expression of Sph K1 and clinicopathological features and lymphangiogenesis;2.As an inhibitor of Sph K1,DMS(N,N-dimethylsphingosine)was used to suppress the expression of Sph K1.Cell proliferation was detected by CCK-8 assay,cell migration and invasion capabilities were assessed in Transwell chambers,the expression of Sph K1,FAK,p-FAK,E-cadherin and N-cadherin were evaluated by Western blot.As an inhibitor of FAK,PF573228 was used to suppress the activity of FAK.Cell proliferation was detected by CCK-8 assay,cell migration and invasion capabilities were assessed in Transwell chambers,the expression of E-cadherin and N-cadherin were evaluated by Western blot.Results: 1.The rate of Sph K1 high expression in TSCC(62.0 %)was significant higher than that in leukoplakia(42.9 %)and normal tongue mucosa(0 %),with statistical significance between them(P<0.05).The expression of Sph K1 was associated with clinical stage(P=0.002),lymph node metastasis(P=0.001),T stage(P=0.019)and histological grade(P=0.024)(P<0.05),but not associated with gender(P=0.341),age(P=0.786),smoking(P=0.547)and alcohol(P=0.566)(P>0.05);LVD in metastatic lymph nodes group(10.76±3.33)was higher than that in non-metastatic lymph nodes group(7.84±2.53),with statistical significance between them(P<0.05);LVD in Sph K1 high expression group(10.81±2.86)was higher than that in Sph K1 low expression group(6.84±2.32),with statistical significance between them(P<0.05).2.The cell viability of Tca8113P160 cells was suppressed by DMS and PF573228 in time and dose dependent manners;cell migration and invasion capabilities were suppressed by DMS and PF573228 assessed in Transwell chambers(P<0.05);Western blot showed that DMS suppressed the expression of Sph K1 and downregulated the expression of FAK?p-FAK?N-cadherin,meanwhile upregulated the expression of E-cadherin(P<0.05),PF573228 downregulated the expression of N-cadherin,upregulated the expression of E-cadherin(P<0.05).Conclusion: 1.Sph K1 was closely correlated with the progression and metastasis of TSCC,we speculate that Sph K1 may promote lymphangiogenesis to affect the cervical lymph node metastasis of TSCC.2.Sph K1 regulates EMT(epithelial-mesenchymal transition)via FAK signaling pathway,which then participates in invasion and migration of Tca8113P160 cells.