Fig. 1. Hypoxia stimulated exosomal miR-25-3p expression in a HIF-1α dependent manner. The protein expression of HIF-1α in normoxia, hypoxia, or HIF-1α-transfected MDA-MB-231 (A) and E0771 cells (B) was measured by western-blot assay. (C) miR-25-3p expression in normoxia, hypoxia, or HIF-1α-transfected MDA-MB-231 and E0771 cells was detected by RT-qPCR. (D) Exosome-related proteins CD81 and CD63 in normoxia or hypoxia-derived exosomes, as well as in MDA-MB-231 cells were determined by western-blot assay. (E) miR-25-3p expression in normoxia, hypoxia, or HIF-1α-derived exosome was detected by RT-qPCR. (F and G) Knockdown of HIF-1α inhibited miR-25-3p expression in hypoxia-responsive breast cancer cells and exosomes.