Abstract
Effects of Sphingosine 1-Phosphate/Sphingosine-1-Phosphate Receptor on Pro-Angiogenesis in HT-29 Human Colon Cancer Cells
Department of Internal Medicine, Clinical Medical College, Changsha Health Vocational College, Changsha 410100, 1Key Laboratory of Nanobiological Technology, National Health Commission of the People’s Republic of China, Xiangya Hospital of Central South University, Changsha, Hunan 410008, PR China
Correspondence Address:
Hui Xu, Department of Internal Medicine, Clinical Medical College, Changsha Health Vocational College, Changsha 410100, PR China, E-mail: xulu434912211@163.com
To investigate the effects and mechanism of sphingosine-1-phosphate/sphingosine-1-phosphate receptor on pro-angiogenesis in human colon cancer cells is the main objective. The effects of sphingosine-1-phosphate on the pro-angiogenesis in human colon cancer cells HT-29 and SW480 were assessed by tube formation assay. Quantitative real-time polymerase chain reaction was used to detect the expression of interleukin-8, interleukin-6 and vascular endothelial growth factor in HT29 and SW480 cells after sphingosine-1-phosphate treatment. Small interfering ribonucleic acid was designed to silence the expression of sphingosine-1- phosphate receptor 1, sphingosine-1-phosphate receptor 2 and sphingosine-1-phosphate receptor 3 in HT-29 and SW480 cells. Western blot and quantitative real-time polymerase chain reaction were used to assess the down-regulation efficiency of sphingosine-1-phosphate receptor in HT-29 and SW480 cells. Later, the effects of sphingosine-1-phosphate receptor were detected by quantitative real-time polymerase chain reaction. Tube formation assay showed that the number of formed tubes in human umbilical vein endothelial cell-fused cells (EA.hy926) resuspended in the culture supernatant from HT-29 and SW480 cells treated with sphingosine-1-phosphate was significantly more than that of the control group (t=3.667 and 4.881, p=0.021 and 0.013), indicating that sphingosine-1-phosphate promoted the pro-angiogenic ability of colon cancer cells. Moreover, the messenger ribonucleic acid expression of interleukin-8, interleukin-6 and vascular endothelial growth factor were significantly increased after sphingosine-1-phosphate treatment compared to the control group (p<0.05) where sphingosine-1-phosphate receptor 1 gene silence could significantly decrease the messenger ribonucleic acid expression in HT-29 and SW480 cells (p<0.05), while sphingosine-1-phosphate receptor 2 and sphingosine-1-phosphate receptor 3 gene silence did not lead to significant messenger ribonucleic acid changes. Sphingosine-1-phosphate up-regulated the expression of interleukin-8, interleukin-6 and vascular endothelial growth factor in human colon cancer cells through sphingosine-1-phosphate receptor 1 and thereby enhancing the proangiogenic effect of colon cancer cells. The sphingosine-1-phosphate/sphingosine-1-phosphate receptor pathway is a promising novel therapeutic target for inhibiting colon cancer growth.