Upregulation of HIF-1α/2α by vGPCR paracrine secretions.
(A) HMEC1s were exposed to media conditioned by control (Control CM) or vGPCR-expressing cells (vGPCR CM), in the presence of vehicle or Rapamycin (50 µM). mRNA levels of HIF-1α and HIF-2α and protein levels of HIF-1α, HIF-2α and VEGF are shown. (B) HMEC1s were transfected with increasing doses (20, 40 and 80 nM) of HIF-1β siRNA or Scrambled siRNA. Cells were then exposed to media conditioned by vGPCR-expressing cells. VEGF mRNA levels are shown. (C) Immunohistochemical analysis of HIF-1α and HIF-2α, and staining using an isotype-matched control antibody, in vGPCR tumor and human KS.