Induction of transgenes causes rapid oncogenic transformation of normal zebrafish liver cells into HCC cells. Representative histological cross sections of 3-month post-fertilization (mpf) DOX-treated zebrafish liver tissue from 1.5 to 7.5 dpt. Images were taken at 40× magnification. A x−m−, non-transgenic control; B x+m−, xmrk oncogene expression; C x−m+, Myc oncogene expression; D x+m+, xmrk and Myc oncogene expression. Key: black arrows, apoptotic cells; black boxes, syncytial cells with multiple nuclei indicating abnormal mitosis. Error bars = 20 μm

Lipid levels increase in zebrafish liver HCC tissue. Representative images of Oil-Red-O stained zebrafish tissue taken from three mpf DOX-treated zebrafish (1.5 to 7.5 dpt). Lipid droplets are stained in red and nuclei are counterstained in blue. A x−m−, non-transgenic control; B x+m−, xmrk oncogene expression; C x−m+, Myc oncogene expression; D x+m+, xmrk and Myc oncogene expression. Key: black arrows indicate large lipid droplets. Error bars = 20 μm

Total lipid class abundance during HCC transgene expression. Many lipid classes exhibited altered levels in three mpf DOX-treated zebrafish tissue samples from 1.5 to 7.5 dpt. A DHC, PC(O), GM3, and PS levels. B PE, PI, and TG levels. Color key: x−m−, brown column; x−m+, blue column; x+m−, red column; x+m+, green column. *p < 0.05; **p < 0.01

Relative lipid class abundance changes in zebrafish liver tumor tissue. Abundance of 24 lipid classes in three mpf DOX-treated zebrafish from 1.5 to 7.5 dpt (see text for lipid class abbreviation definition). Key: x+m−, xmrk oncogene expression; x−m+, Myc oncogene expression; x+m+, xmrk and Myc oncogene expression; red (upregulated), black (unchanged), green (downregulated). Data expressed as log2 transformation of value of lipid species/value of control lipid species

Expression profiles for lipid metabolism genes. The expression of lipogenic factors, enzymes, and lipid β-oxidation genes is altered in x−m+, x+m−, and x+m+ tumors at 3, 4.5, and 6 dpt. A Lipogenic factors expression profiles. B Lipogenic enzyme expression profiles. C Lipid β-oxidation gene expression profiles (see text for gene definitions). N = 3; *p < 0.05

Total lipid class level association with HCC disease stage. Univariate modeling shows the probability that individual total lipid class levels are associated with normal or disease stage phenotypes. Plots show total lipid levels versus probability of disease progression. A DHC, GM3, PC(O), and PI plot. B PE, PS, and TG plot. X-axis units: pmol/mg. Key: “OR” (odds ratio); dark blue lines (normal); dark red lines (hyperplasia/ adenoma); green lines (HCC stage I); orange lines (HCC stage II)