Vitamin C downregulates yes-associated protein 1 (YAP1) expression. (A) q-RT-PCR shows that YAP1 RNA level is decreased in MDA-MB-231 cells after treatment with vitamin C; (B,C) immunoblot and semi-quantification show decreased YAP1 protein in MDA-MB-231 cells after vitamin C treatment; (D,E) vitamin C treatment reduces YAP1 immunofluorescence signal in MDA-MB-231 cells, as shown by imaging and semi-quantification. Bar = 20 µm; (F,G) The level of YAP1 protein is lower in MDA-MB-231 xenografts from NSG mice supplemented with vitamin C (3.3 g/L) compared to mice without supplementation, as shown by immunostaining (40×) and semi-quantification.