PMC

Glutamine synthetase immunoreactivity of dysplastic and neoplastic hepatocytes from FGF19 transgenics. A: Neoplastic cells are strongly glutamine synthetase-positive. B: Liver from a wild-type mouse showing normal perivenular glutamine synthetase immunostaining. C: Dysplastic hepatocytes are strongly glutamine synthetase-positive. D: Normal glutamine synthetase immunoreactivity of perivenular hepatocytes. Original magnifications: ×40 (A and B); ×400 (C and D).

FGFR4 expression in murine liver. Bright-field (A) and dark-field (B) illumination of in situ hybridization with a murine FGFR4 riboprobe showing expression in perivenular and random hepatocytes. C and D: Higher magnification of bright-field demonstrating silver grains over random small hepatocytes. Original magnifications: ×100 (A and B); ×400 (C and D).

Expression of AFP by neoplastic and dysplastic hepatocytes. Increased expression of AFP mRNA in FGF19 transgenic liver compared to wild-type liver at 2 to 4 months of age (A) and 7 to 9 months of age (B). *, P < 0.05. Bright-field (C) and dark-field (D) illumination of in situ hybridization with AFP riboprobe showing expression of AFP by pericentral dysplastic hepatocytes (arrows). Bright-field (E) and dark-field (F) illumination of in situ hybridization with AFP riboprobe showing expression of AFP by neoplastic hepatocytes (arrows). Original magnifications, ×100.

Hepatocellular neoplasia in FGF19 transgenic mice. A: Multiple, large, raised tumors protrude from the hepatic surface of the liver from a 10-month-old FGF19 transgenic mouse (arrows). B: Histologically, neoplastic cells invade and replace normal hepatic architecture and are arranged in solid sheets or cords. Arrows mark the border of the tumor and adjacent normal liver. C: Pleomorphism of neoplastic hepatocytes and atypical mitotic figures (arrows). Original magnifications: ×40 (B); ×400 (C).

β-Catenin immunoreactivity of neoplastic hepatocytes from FGF19 transgenics. A: Strong nuclear staining of neoplastic cells compared with surrounding liver. Arrows mark the border of the tumor and adjacent normal liver. B: Neoplastic hepatocytes with nuclear immunoreactivity for β-catenin. C: Amino acid sequence alignment of the N-terminal region of β-catenin from wild-type (top) and mutant clones with amino acid substitutions (bold) in and adjacent to the GSK-3B phosphorylation domain (red). D: Sequencing data for DNA from normal liver and HCC with nucleotide substitutions at codon 34 (shaded). Original magnifications: ×200 (A); ×400 (B).

Increased proliferation of pericentral hepatocytes in FGF19 transgenics. Immunostaining for BrdU after a 5-day infusion by osmotic minipump of liver from a wild-type (A) and a FGF19 transgenic mouse (B). Morphometric analysis of BrdU-immunostained sections from FGF19 transgenics compared to wild-type mice: 2 to 4 months (C), 7 to 9 months (D), and FGF19-injected mice (E). The labeling index denotes the number of BrdU-positive hepatocytes divided by the total number of cells counted and indicated as a percentage. *, P < 0.05. Original magnifications: ×200 (A and B); ×600 (inset in B).

Preneoplastic hepatocellular changes in FGF19 transgenic mice. As early as 14 weeks of age pericentral hepatocytes formed a dense cluster around the central veins (arrows) with polarization of nuclei of the innermost hepatocytes away from the vessel lumen in FGF19 transgenics (A) that was not present in liver from nontransgenic littermate mice (B). Pericentral small dysplastic hepatocytes (C) were the predominant type of hepatocellular dysplasia although foci of large dysplastic hepatocytes (D) were occasionally noted. Arrows delineate areas of altered hepatocellular foci (shown at higher magnification in the insets). Original magnifications: ×100 (A and B); ×400 (C and D). Inset original magnifications: ×400 (A and B); ×600 (C and D).