Figure 6.

Mebendazole decreases HIF transcriptional activity in vivo. (a) Representative fluorescent image of full cross-sections of orthotopic mammary tumors derived from MDA-MB-231 hypoxia fate-mapping cells treated with sesame oil as vehicle control (n = 6) or 30 mg/kg of MBZ (n = 6) via oral gavage. The percentage of GFP expression in the tumors is graphed for each tumor on the right. (b–d) NSG mice were orthotopically implanted with a patient-derived xenograft model of triple-negative breast cancer, HCI-001. The mice were randomized and treated with sesame oil as a vehicle gavage (Con, n = 8) or 30 mg/kg MBZ in a sesame oil gavage (30 mg/kg; n = 9) four times per week. (b,c) Total RNA was isolated from tumor tissue and analyzed with RT-qPCR using primers specific for CA9 (b) or EPO (c) mRNA expression. The results were normalized to the mean value for tumors from vehicle-treated mice. p-values are indicated. (d–f) CA9 was immunofluorescently labeled and quantified for each tumor (d). Representative fluorescent images of sections of tumors stained for CA9 and quantified in (d) with scale bar = 3 mm (e). Enlarged insets shown in white are displayed in (f) with a scale bar = 300 µm. See Supplementary S2 for staining and imaging of each tumor as well as a methodology for quantification. Note: One sample measured for EPO mRNA expression had a result of not detected by real-time PCR, causing the control group to consist of seven replicates rather than 8.