Fig. 2

SphK1 modulates adipocyte-induced E/N-cadherin switch through Twist1. a SKOV3 and HEY cells were transfected with negative control siRNA or SphK1 siRNA. Cells were serum starved overnight and cultured in SFM or adipocyte CM for 48 h. Expression levels of SphK1, E-cadherin and N-cadherin were determined by Western blot and normalized to GAPDH. Densitometric analyses of E-cadherin and N-cadherin were shown on the right. Experiments have been carried out with adipocytes from 2 to 3 independent donors. Data are mean ± SD (n = 3). *P < 0.05 versus control; ^#P < 0.05 versus adipocyte CM alone; two-tailed Student’s t test. b SKOV3 and HEY cells were transfected with negative control siRNA or SphK1 siRNA. Cells were serum starved overnight and cultured in SFM or adipocyte CM for 48 h. Expression level of SphK1 and Twist1 was determined by Western blot and normalized to GAPDH. Densitometric analysis of Twist1 was shown on the right. Experiments have been carried out with adipocytes from 2 to 3 independent donors. Data are mean ± SD (n = 3). *P < 0.05 versus control; ^#P < 0.05 versus adipocyte CM alone; two-tailed Student’s t test. C IHC staining of E-cadherin, N-cadherin and Twist1 in the omental metastatic tumor tissue of mouse models. The scale bar represents 20 μm. Statistical analysis of integrated optical density (IOD)/area was shown on the right. Data are mean ± SD (n = 6). *P < 0.05 versus Ctrl group; two-tailed Student’s t-test. d Expression levels of SphK1, E-cadherin, N-cadherin and Twist1 in omental metastatic tumor tissue of mouse models were determined by Western blot and normalized to GAPDH. Densitometric analyses of E-cadherin, N-cadherin and Twist1 were shown on the right. Data are mean ± SD (n = 6). *P < 0.05 versus Ctrl group; two-tailed Student’s t test. e Model of adipocyte-induced omental metastasis of EOC cells. Adipocytes are capable of activating SphK1, leading to the release of S1P. SphK1/S1P signaling may subsequently activate Twist1 through S1P receptor (S1PR) pathway and/or intracellular pathway, which drives E/N-cadherin switch