FIGURE 4.

Trypanosome ODC protects against the antiproliferative effect of induced Az. A construct encoding Az1 cDNA cloned downstream of a Tet-responsive promoter was transfected into NIH3T3 cells previously transformed with a plasmid encoding a Tet-controlled transactivator and a trypanosome ODC (trpODC)-encoding construct (B) or the compatible empty vector (A). Successful induction of Az was demonstrated by inhibition of ODC activity in cells transformed with the empty vector (insets). The growth rates of the various cells was determined by cell counting at days 7, 8, and 9 following seeding and induction. *, significant difference from control cells using Student's t test (p < 0.02).