Carotid atherosclerotic plaques from symptomatic stroke patients share the molecular fingerprints to develop in a neoplastic fashion: A microarray analysis study

Identification of genetic mechanisms that promote the onset of stroke and transient cerebral ischemic attack symptoms in carotid atherosclerotic patients would further our understanding of the pathophysiology of this disease and could lead to new pharmacological and molecular therapies. Using Affymetrix Human Genome 230 GeneChip set, the present study evaluated the gene expression differences in geometrically similar carotid artery plaque samples extricated from six symptomatic stroke patients and four asymptomatic patients. There was no significant difference in the degree of stenosis between the two groups. Of the 44,860 transcripts analyzed, 289 (approximately 0.6% of the total transcripts) were differentially expressed between the plaques from the symptomatic and asymptomatic groups (236 were expressed more abundantly and 53 were expressed less abundantly in the symptomatic group). Of the 236 transcripts expressed more abundantly in the symptomatic plaques, 71% (167 transcripts) indicate an active cell proliferation and neoplastic process. These include oncogenes, growth factors, tumor promoters, tumor markers, angiogenesis promoters, transcription factors, RNA splicing factors, RNA processing proteins, signal transduction mediators and those that control the metabolism. Real-time polymerase chain reaction confirmed the increased expression of 63 transcripts in the symptomatic plaques. The other groups of transcripts expressed more abundantly in the symptomatic plaques are those that control ionic homeostasis, those that participate in the progression of degenerative neurological diseases (Alzheimer’s disease, amyotrophic lateral sclerosis and Huntington’s disease) and epilepsy. This indicates that symptomatic plaques are molecularly and biochemically more active than the asymptomatic plaques, or active plaque growth precipitates stroke symptoms.