Figure 5:

A, Images demonstrate that normalization of extracellular tumor pH (pH_e) neutralizes inherent tumor acidosis and restores immune permissiveness after conventional transarterial chemoembolization (TACE) (cTACE). Top, peaks from extracellular pH spectroscopy are shown in red, overlaid on the corresponding anatomic T1-weighted axial MRI scans (repetition time msec/echo time msec, 5.2/2.5). Color map overlays illustrate extracellular tumor pH. Middle, Hematoxylin-eosin (H&E) and, bottom, human leukocyte antigen–DR isotope (HLA-DR) receptor staining reveals peritumoral immune cell infiltration in acidic untreated tumors. While extracellular tumor pH changes after conventional TACE remained insignificant and immune cell infiltrates were similar to or decreased compared with untreated tumors, conventional TACE with bicarbonate (cTACE w/bicarb) significantly increased extracellular pH of the tumor and tumor edge, boosting peritumoral immune cell infiltration. B, Box-and-whisker plots indicate extracellular (pH_e) differences in control rabbits and those treated with conventional TACE (cTACE) and conventional TACE with bicarbonate (cTACE w/bicarb). Data are medians (lines in boxes) and 25th to 75th percentiles (bottom and top of boxes) and ranges (whiskers) (Mann-Whitney U, Kruskal-Wallis test).