Figure 6.

Visualizing the “reverse Warburg effect” by double labeling with MCT4 and COX activity staining. Frozen sections of human breast cancer-positive lymph nodes were subjected to COX activity staining (brown color) and immunostaining with MCT4 antibodies (red color). Slides were then counterstained with hematoxylin (blue color). Note that MCT4 staining is predominantly localized to the cancer-associated lymph node stroma. In contrast, COX activity is strongly associated with the metastatic breast cancer cells. Two representative images are shown. Original magnification, 40x.