An investigation into the involvement of angiopoietins in the development of colorectal cancer
We have recently undertaken a successful pilot study investigating the distribution of the angiopoietins in both colorectal tumour and adjacent non-malignant colorectal tissue. Tissue microarrays have been used to assess the expression profiles of a number of factors in over 600 matched normal and Dukes’ B colorectal samples from the national QUASAR study (QUASAR study group). These experiments have shown that: first both the angiopoietins, as well as Tie2, are significantly upregulated in tumours in comparison to normal colon (Ang1 94.3% vs 78.5%; Ang2 92.2% vs 51.9%; Tie-2 86% vs 72.1%). Secondly, there is a 6-fold increase in [Ang2+ Ang1-] expression in tumours as compared to normal tissue (p<0.001). Thirdly, both tumour vascularity (p<0.001) and cellular proliferation (p<0.02) are significantly increased in tumours positive for Ang-2. Correlation of vascularity and expression of angiopoietins with both survival and recurrence will be determined as soon as these data are released from the QUASAR study.
We have refined our methods to study microarrays of colorectal adenomas. These are the precursors of colorectal cancer and so are the earliest stages of colorectal tumourigenesis. We will correlate angiopoietin data with clinicopathological features of the adenoma to assess the role of angiopoietins at this stage.
Figure 1.
Bach F, Uddin FJ, Burke D. Angiopoietins in malignancy Eur J Surg Oncol, (2007) 33:7-15
MERCURY Study Group Diagnostic accuracy of preoperative magnetic resonance imaging in predicting curative resection of rectal cancer: prospective observational study Group BMJ 2006;333:779
The Effect of Faecal Diversion on Human Ileum. (2007) L Williams, M Armstrong, P Finan, P Sagar, D Burke. GUT Jun 2007; 56: 796 - 801