title: Coding Microsatellite Frameshift Mutations Accumulate in Atherosclerotic Carotid Artery Lesions: Evaluation of 26 Cases and Literature Review.
abstract: Somatic DNA alterations are known to occur in atherosclerotic carotid artery lesions; however, their significance is unknown. The accumulation of microsatellite mutations in coding DNA regions may reflect a deficiency of the DNA mismatch repair (MMR) system. Alternatively, accumulation of these coding microsatellite mutations may indicate that they contribute to the pathology. To discriminate between these two possibilities, we compared the mutation frequencies in coding microsatellites (likely functionally relevant) with those in noncoding microsatellites (likely neutral). Genomic DNA was isolated from carotid endarterectomy (CEA) specimens of 26 patients undergoing carotid surgery and from 15 nonatherosclerotic control arteries. Samples were analyzed by DNA fragment analysis for instability at three noncoding (BAT25, BAT26, CAT25) and five coding (AIM2, ACVR2, BAX, CASP5, TGFBR2) microsatellite loci, with proven validity for detection of microsatellite instability in neoplasms. We found an increased frequency of coding microsatellite mutations in CEA specimens compared with control specimens (34.6 versus 0%; p = 0.0013). Five CEA specimens exhibited more than one frameshift mutation, and ACVR2 and CASP5 were affected most frequently (5/26 and 6/26). Moreover, the rate of coding microsatellite alterations (15/130) differed significantly from that of noncoding alterations (0/78) in CEA specimens (p = 0.0013). In control arteries, no microsatellite alterations were observed, neither in coding nor in noncoding microsatellite loci. In conclusion, the specific accumulation of coding mutations suggests that these mutations play a role in the pathogenesis of atherosclerotic carotid lesions, since the absence of mutations in noncoding microsatellites argues against general microsatellite instability, reflecting MMR deficiency.
authors.affiliation: Department of Neurology, Technical University Munich, Munich, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Kurz
authors.affiliation: Department of Vascular and Endovascular Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Maani
authors.initials: M
authors.lastname: Hakimi
authors.affiliation: Applied Tumor Biology, Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kloor
authors.affiliation: Department of Neurology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Caspar
authors.initials: C
authors.lastname: Grond-Ginsbach
authors.affiliation: General Pathology, Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.|Pathologie Heidelberg, Heidelberg, Germany.
authors.forename: Marie-Luise
authors.initials: ML
authors.lastname: Gross-Weissmann
authors.affiliation: Department of Vascular and Endovascular Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Dittmar
authors.initials: D
authors.lastname: Böckler
authors.affiliation: Applied Tumor Biology, Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Magnus
authors.initials: M
authors.lastname: von Knebel Doeberitz
authors.affiliation: Department of Vascular and Endovascular Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Dihlmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000235:genetics* / Q000473:pathology; D002339:Carotid Arteries / Q000473:pathology; D053843:DNA Mismatch Repair / Q000235:genetics; D005260:Female; D016368:Frameshift Mutation / Q000235:genetics*; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D016366:Open Reading Frames / Q000235:genetics