Figure 2-4244.

Histological analysis and tPA expression in tumors from Ela1-TAg and Ela1-myc transgenic mice. Sections of paraffin-embedded pancreatic tissue from 1-month (A and D), 3-month (B and E), and 5-month-old (C and F) mice were analyzed for tPA expression as described in Materials and Methods. tPA expression is restricted to ductal cells in tumors from late stages of Ela1-myc mice (F, arrowheads and inset). There was no reactivity with dysplastic acini (A and D) nor with acinar tumors (B, C, E, and F) arising in both mouse strains. Inset of F shows tPA expression in tumor cells displaying ductal differentiation. Original magnification; ×100 (A–F), ×400 (F, inset).