Fig. 1. Sphingosine-1-phosphate receptor 1 (S1PR1) expression correlates with vasculogenic mimicry (VM) and endothelium-dependent vessel (EDV) in human breast cancer tissues.

a CD31/PAS double staining shows the VM channels in human breast cancer specimens. The channels (red arrowhead) lined with tumor cells contained red blood cells and were CD31 negative and PAS positive ( × 200, bars 20 µm). The EDVs were CD31-positive (black arrowhead) ( × 200, bars 20 µm). b Quantification of EDV counts per × 40 fields is presented. c Kaplan–Meier analysis showed that S1PR1-positive non-TNBC patients had a poorer prognosis. d Survival of S1PR1-positive TNBC patients was not significantly affected. e Human breast cancer specimens were analyzed by immunohistochemistry. Positive expression and negative expression of S1PR1 (a, b), VE-cadherin (c, d), β-catenin (e, f) ( × 200, bars 20 µm). *p < 0.05