HT1080 tumours are highly angiogenic and show presence of <i>in situ</i> hypoxia. A.

<p>An image of a haematoxylin and eosin (HE)-stained section of HT1080 tumours showing the presence of abundant vascular channels containing red blood cells is illustrated. A magnified image of these vascular channels is depicted on the right hand side. (Original magnifications 100X and 400X respectively) <b>B.</b> Paraffin sections of HT1080 tumours were subjected to immuno histochemistry (IHC) analyses using antibodies to various angiogenic markers. The tumour cells were positive for PECAM, VE-Cadherin, VEGF, NRP-1, VEGF₁₆₅ and VEGFR-2 (violet colour). PECAM positive micro-vessel formation is indicated by a black arrow (top layer, right panel). <b>C.</b> Nuclear localization of HIF-1α in the tumour cells confirms the presence of <i>in situ</i> hypoxia. The sections were counterstained with hematoxylin to demarcate the nuclei (blue).