FIG. 4.

(A) Vascular endothelial growth factor (VEGF) and CD31 immunostaining. (a) VEGF-positive margins were found surrounding CS-derived tumors at 1 week post-transplantation, ×40, scale bar is 200 μm and (b) was magnified from a small frame in (a), ×200, scale bar is 50 μm. Based on immunohistochemical expression of CD31, microvessels were displayed more densely in the CS-derived than in ICS-derived tumors at 8 weeks (c, d, respectively). At 8 weeks, 0.475%±0.113% area versus 2.420%±1.893% area displayed positively in ICS-derived tumors and CS-derived tumors, respectively (p=0.05). This finding intensified further after 12 weeks with ICS tumors exhibiting only 0.782%±0.378% area versus CS tumors exhibiting 0.979%±0.364% area (p=0.43) (e, f ). Scale bar is 50 μm (×200). (B) Microvessel density. Percentage of CD31 positive-stained areas were compared using ImageJ 1.44o software (NIH). Images of CS-derived and ICS-derived tumors were compared and analyzed. At 8 weeks, CS-derived tumors exhibited 2.420%±1.893% area versus ICS-derived tumors only showing 0.475%±0.113% area positive for CD31 (p=0.05). At 12 weeks, CS-derived tumors were 0.979%±0.364% area versus ICS-derived tumors were 0.782%±0.378% area (p=0.43). Color images available online at www.liebertpub.com/tec