(A) Heatmap depicting the relative expression of the indicated genes involved in fatty acid synthesis from APC−/− tumors (n = 16) and intestinal epithelial cells (IECs, n = 16) using RNA-seq data. (B) Relative abundance of saturated and unsaturated 16- and 18-carbon fatty acid species in APC−/− tumors treated daily with water (Con, n = 14) or HFCS (n = 9). Groups compared by Student’s t test with correction for multiple comparisons using the Holm-Sidak method. ****P < 0.0001. (C) Schematic depicting key enzymes, genes, and metabolites in the de novo lipogenesis pathway. Red, enzyme name; red in parentheses, gene name. (D) APC−/−; FASN−/− mice were treated with a daily oral gavage containing water (Con, n = 9) or HFCS (n = 10) starting the day after tamoxifen injection and killed at 8 weeks. The size of each tumor (diameter) in the intestine was determined in whole-mount tissue after methylene blue staining, using a dissecting microscope. Data represent the number of tumors >3 mm in diameter in Con and HFCS-treated mice. Groups compared by Student’s t test. NS, not significant. (E) Percentage of high-grade tumors (n = 11 per group) from Con and HFCS-treated APC−/−; FASN−/− mice. Student’s t test. NS, not significant. All data represent means ± SEM.