Fig. 2

The angiogenic switch does not depend on hypoxia or Hif-1α. a Imaging of B16 cells incubated with hypoxia probe reagent (oxygen sensor) cultured under hypoxic or normoxia. Scale bar, 100 μm. b Imaging of the hypoxia probe reagent incubated transplant B16 microtumors under normoxia. Tumor is grey. Scale bar, 50 μm. c The length of the first vessel of the B16 microtumors under normoxia. d RT-qPCR quantification of the Hif1α expression in B16-Red cells transfected with Hif1α siRNA (50 μM) for 48 h (n = 3). NC, negative control. e Imaging of the first tumor vessel growth of Hif1α knockdown B16-Red transplant microtumors. Tumor is red. Scale bar, 50 μm. f The length of the first tumor vessel of Hif1α knockdown B16-Red transplant microtumors. g and h. RT-qPCR quantification of the Car9/CA9 and Slc2a1/GLUT1 expression in the transplant microtumors during the angiogenic switch (about 12 h and 24 h). Red fluorescence, hypoxia. ECs are green. Unpaired t-test, ns P > 0.05, *** P < 0.001 (n = 3–5)