FIG 5.

Inactivation of activinB restores insulin expression in βMen1 insulinomas and increases survival. (A) Measurements of islet cell surface during the course of tumorigenesis. Endocrine surface were calculated using H&E-stained whole pancreatic sections at the indicated ages. The graph shows the percentage of endocrine surface normalized to exocrine surfaces. Numbers of analyzed pancreases per genotype and age are indicated (n). Data are represented as mean of mouse surface ± SEM. (B) Immunohistochemical analysis of insulin expression in 14-month-old pancreas from animals of the indicated genotype. (C) Morphometric measurements of tumor versus insulin-immunoreactive (Ins⁺) β-cell surfaces observed in 14-month-old InhβB-βMen1 and control mice. Data represent the mean of surface ± SEM. **, P < 0.01 by the Student t test. (D) Survival curve of βMen1 (n = 16), InhβB-βMen1 (n = 14), and control (n = 14) mice. **, P < 0.01; ***, P < 0.001 (by the Mantel-Cox test). (E) Ki67 proliferative index of Ins⁺ lesions and control β cells at 14 months of age. Data represent the mean of the number of Ki67⁺/Ins⁺ cells found in mutant and control animals ± SEM. NS, not significant the Student t test.