Table 3

Immunohistochemical evaluation of GEO xenografts

Mice bearing GEO tumor xenografts were treated as described in “Materials and Methods” and in the legend to Fig. 4<$REFLINK> . Treatment was started on day 7 after tumor cell injection, when tumor volume was ∼0.2–0.3 cm3. Mice were treated i.p. daily from day 1 to day 5 with ZD1839 (2.5-mg/dose) and/or received RT treatment (10 Gy/dose daily, days 1 to 4 of the first week). Analysis was performed on day 21 after tumor cell injection. The percent (±SD) of specifically stained GEO cancer cells for Ki67, TGFα, bFGF, or VEGF was recorded. To determine the percentage of positive cells, ∼1000 cancer cells were scored. The number of microvessels for field (±SD) was measured using a mAb raised against the human Factor VIII-related antigen and was scored by averaging five field counts of three individual tumors for each group.

TreatmentTumor size cm3Proliferative activity (Ki67)TGFαbFGFVEGFMicrovessel counts
Control1.7 (±0.2)70 (±5)%65 (±7)%55 (±5)%60 (±4)%18 (±3)
RT0.26 (±0.08)45 (±5)%65 (±10)%50 (±5)%55 (±7)%15 (±2)
ZD18390.24 (±0.05)25 (±5)%30 (±5)%15 (±4)%20 (±5)%10 (±1)
Combination0.05 (±0.01)10 (±3)%8 (±2)%6 (±2)%5 (±1)%1 (±1)