Fig. 4

Ex vivo analysis of tumor metabolism during tumor progression. a Representative sections of 4T1 and 67NR tumors after 4-channel staining of GLUT1 (red), GLUT3 (turquoise), CD3 (green) and nuclei (blue) with correlating merged images. During progression of 4T1 tumors, a decrease in GLUT1, an increase in CD3 as well as an increase in GLUT3 expression were observed. In contrast, 67NR tumors showed increased GLUT1 expression from day three to day nine, with constantly low expression of GLUT3 and CD3. Scale bars indicate 100 µm. b Exemplary images of MALDI-2-MS with corresponding H&E stainings showing decreased intratumoral glucose accumulation during progression of 4T1 tumors, in contrast to 67NR tumors exhibiting increased glucose accumulation over time. Tumor contours are marked with dashed red lines