Figure 8.

Specific transgene expression driven by a PSA promoter in prostate cancer cells. Xenograft tumors were established by subcutaneous injection of cancer cells into the flank of nude mice. When tumors reached about 50 mm³, each of the adenoviral constructs was injected directly into the tumor. The tumors were harvested 72 hr later and processed to cryosections. Shown is X-gal staining of tumor sections derived from prostate cancer PPC-1 cells ((a), (c), and (e)) and bladder cancer RT4 cells ((b), (d), and (f)). (a) and (b) are untreated control tumors to serve as negative controls. (c) and (d) are tumors transduced by AdPSAlacZ (1 × 10¹⁰ pfu). (e) and (f) are tumors transduced by AdRSVlacZ (5 × 10⁹ pfu) to serve as positive controls.