Altered patterns of gene expression distinguishing ascending aortic aneurysms from abdominal aortic aneurysms: Complementary DNA expression profiling in molecular characterization of aortic disease Absei TS, Sundt TM III, Tung WS, et al. J Thorac Cardiovasc Surg 2003;126:344-57

AbstractConclusionThoracic aortic aneurysms (TAAs) and abdominal aortic aneurysms (AAAs) are characterized by significant molecular heterogeneity, suggesting different pathophysiologic mechanisms of aortic and thoracic aneurysm disease.SummaryThe authors compared patterns of gene expression in normal thoracic and abdominal aortas and in TAAs and AAAs. Aortic tissue was obtained during surgical repair of TAAs and infrarenal AAAs (n = 4 each). Normal thoracic and abdominal aortic control tissue was obtained from organ donors. Radiolabeled complementary DNA (cDNA) was prepared for each specimen. This was hybridized to cDNA microarrays, and levels of gene expression were determined for each site.There were 1185 genes examined, with 112 genes differentially expressed between normal thoracic aorta and TAAs (P < 0.05). In a comparison of infrarenal AAAs and normal abdominal aortas, 104 genes were differentially expressed. Quantitative increases in gene expression unique for TAAs occurred for 97 genes. Quantitative increases in gene expression that were unique for infrarenal AAAs occurred for 61 genes. Only four directionally concordant alterations in gene products occurred in both TAAs and infrarenal AAAs: matrix metalloproteinase 9/gelatinase b, V-yes-1 oncogene, mitogen-activated protein kinase 9, and intracellular adhesion molecule 1/cd 54.CommentThe authors examined end-stage aneurysm tissue and compared it with normal control tissue. Differences in genetic expression delineated in this study may reflect age differences, changes resulting from aneurysm degeneration, and other factors that differ between patients and control subjects. It cannot be determined whether differential gene expressions represent cause or effect