Fig. 1

Inhibition of SphK1 suppressed EOC metastasis to the adipocyte-rich niche. a SphK1 IHC of paired samples from ovarian primary tumors and their corresponding metastatic omental deposits from 20 patients. Representative images are shown. The scale bar represents 60 μm. b Quantitative analysis of IHC staining for SphK1 of ovarian primary tumors and their corresponding metastatic omental deposits from 20 patients. **P < 0.01; two-tailed Student’s t test. C SKOV3 cells were transfected with negative control siRNA (si-Ctrl) or SphK1 siRNA (si-SphK1). 24 h after transfection, mRNA level of SphK1 was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and normalized to GAPDH. 48 h after transfection, protein level of SphK1 was determined by Western blot and normalized to GAPDH. Data are mean ± SD (n = 3). **P < 0.01; two-tailed Student’s t test. d Representative images of migration and invasion assays (200×). Transfected SKOV3 cells were serum starved overnight and metastasized towards serum free medium (SFM) or adipocyte CM. Migrated cells and invaded cells were photographed and calculated. Experiments have been carried out with adipocytes from 2 to 3 independent donors. Data are mean ± SD (n = 3). *P < 0.05; two-tailed Student’s t test. e Representative images of omentum in healthy mouse and representative images of EOC xenograft mouse model in the Ctrl and PF543 group. Black arrows indicated the location of the metastatic nodules. f Representative images of omental metastatic tumors in EOC mouse models of the Ctrl and PF543 group. g Quantification of tumor weight in different metastatic sites. Data are mean ± SD (n = 6). *P < 0.05 versus Ctrl group; ns, no significance; two-tailed Student’s t test. h Quantification of tumor number in different metastatic sites. Data are mean ± SD (n = 6). *P < 0.05 versus Ctrl group; ns, no significance; two-tailed Student’s t-test