Cytokine levels released by cell lines established from autochthonous tumors and in the serum of tumor-bearing mice. (A-C) VEGF and IL-6 are secreted by oncogene-driven autochthonous tumors. VEGF, IL-6, and GM-CSF levels were determined in cell culture supernatants of cell lines established from Tg mice bearing sporadic tumors (9.27, 9.29, 16.30, 16.113), HCC-bearing Tg x Alb-Cre mice (Alb.7, Alb.14, Alb.347), and Tg/Ad.Cre mice bearing virus-induced HCC (Ad.56, Ad.434). Retrovirally transduced 16.113 cells (16.113-GM) were tested for GM-CSF levels only. (D, E) VEGF and IL-6 were determined in sera of young Tg mice (n = 5 and n = 4), Tg mice (n = 8 and n = 38), Tg x Alb-Cre mice (n = 10 and n = 4), and Tg/Ad.Cre mice (n = 4 and n = 13). Note that no GM-CSF could be detected in sera of the mice shown above (data not shown). (F) TGF-β1 levels were determined in sera of young Tg mice (n = 4), Tg mice (n = 7), Tg × Alb-Cre mice (n = 4), and Tg/Ad.Cre mice (n = 4). Bars indicate means; error bars represent SEM; n.d. = not detected.