Histologic examination of subcutaneous tumor tissues.

Tumor tissues were harvested, fixed in 10% buffered formalin, processed, embedded in paraffin, and sectioned with a microtome. Sections were stained with hematoxylin and eosin or with Factor VIII. (A) Hematoxylin-eosin–stained section from MCA205WT (original magnification × 150). (B) Hematoxylin-eosin–stained section from MCA205IL-17 (original magnification × 150). (C) Hematoxylin-eosin–stained section from MC38WT (original magnification × 150). (D) Hematoxylin-eosin–stained section from MC38IL-17 (original magnification × 150). Note: IL-17 transfectants were markedly infiltrated with neutrophils and were edematous. (E) Factor VIII–stained section from MCA205WT (original magnification × 80). (F) Factor VIII–stained section from MCA205IL-17 (original magnification × 80). (G) Factor VIII–stained section from MC38WT (original magnification × 100). (H) Factor VIII–stained section from MC38IL-17 (original magnification × 100). Note: Immunostaining for the presence of Factor VIII showed that tumors transduced with IL-17 were more markedly vascularized when compared with parental tumors. (I) Factor VIII–stained sections were evaluated by quantifying the number of stained blood vessels in 5 randomly chosen HPFs (× 200) per tumor. Bars represent mean number of vessels ± SD per square millimeter considering the area of HPF (n = 25). The result is a representative of 2 independent experiments. *P < .001; **P < .0001; ***P < .01.