Fig. 2

mRNA expression of ion transport-related molecules in non-CSCs normoxia (white bars), non-CSCs hypoxia (gray bars), and CSCs normoxia (black bars). CA9 and CA12 transcripts were upregulated by hypoxia in U251-MG and U87-MG cell lines. CA9, CA12, and MCT1 transcripts were upregulated by CSCs in these cell lines (n = 3–5, mean ± SEM; *p < 0.05, **p < 0.01 vs. non-CSC normoxia. ^† p < 0.05, ^†† p < 0.01 vs. non-CSC hypoxia). CSC cancer stem cell, CA carbonic anhydrase, NHE Na⁺–H⁺ exchanger, MCT monocarboxylate transporter