FIG. 3.

The N terminus of LT is responsible for abrogating the additional checkpoints that enables Ras to be proliferative in the absence of anchorage. Pools of drug selected Schwann cells (4 × 10³), expressing dnp53 and the N terminus of LT together or on their own with Ras or the empty retroviral vector LXSN, were seeded in soft agar. After 2 weeks the colonies were stained with neutral red prior to being counted and photographed. Assays were carried out in duplicate, and a representative result of three independent experiments is shown.