Figure 7.

Ad L4-100K increases dl922-947 activity in vitro and in vivo. (a) ID8 (left) and MOVCAR7 (right) cells were infected with dl922-947 in the presence or absence of Ad 100K. Cell survival was assessed 120 hours later by MTT assay. Data for dual-infected cells are normalized to survival following infection with Ad 100K alone. (b) Infectious intracellular virions generated 48 hours postinfection in ID8 cells were titered by TCID₅₀ assay (as shown in b). *P < 0.05, dotted line indicates input MOI of dl922-947. BLD = below limit of detection. (c,d) Subcutaneous ID8 tumors were grown on the left flank of ICRF nude female mice. Once tumors reached ~7 mm in diameter, dl922-947 was injected intratumorally (5 × 10⁹ particles in 50 µl PBS on days 1–3 inclusive). Mice also received a single intratumoral dose of Ad 100K (3 × 10⁹ particles in 50 µl PBS) or PBS alone on day 4. Tumors were excised on day 5, dissected in two and either snap frozen in dry ice or fixed in 5% formaldehyde. Expression of adenovirus structural proteins was assessed by IHC (c; bars represent 200 µm). The number of Hexon transcripts was measured using quantitative reverse transcription PCR (as shown in d). IHC, immunohistochemistry; MOI, multiplicity of infection; MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide; pfu, plaque-forming unit; PBS, phosphate-buffered saline.