title: TP53/p53 alterations and Aurora A expression in progressor and non-progressor colectomies from patients with longstanding ulcerative colitis.
abstract: Aneuploidy is a common feature in the colonic mucosa of patients suffering from the inflammatory bowel disease ulcerative colitis (UC) and often precedes the development of dysplasia and cancer. Aneuploidy is assumed to be caused by missegregation of chromosomes during mitosis, often due to a faulty spindle assembly checkpoint. p53 is a tumour suppressor protein known to regulate the spindle assembly checkpoint and is frequently mutated in aneuploid cells. Aurora A is a presumed oncoprotein, also involved in regulation of the spindle assembly checkpoint. In the present study, we examined the mutational frequency of TP53 and the protein levels of p53 in a set of 20 progressor and 10 non-progressor colectomies from patients suffering from longstanding UC. In addition, we re-examined previously published immunohistochemical data on Aurora A expression using the same material. Levels of Aurora A were re-examined with regard to DNA ploidy status and dysplasia within the progressors, as well as in relation to p53 accumulation and TP53 mutational status. We detected p53 accumulation only within the progressor colectomies, where it could be followed back 14 years prior to the colectomies, in pre-colectomy biopsies. TP53 mutations were detected in both progressors and non-progressors. Expression levels of Aurora A were similar in the progressors and non-progressors. Within the group of progressors however, low levels of Aurora A were associated with areas of DNA aneuploidy, as well as with increasing degrees of dysplasia. Our results indicate that alterations in p53 may be an early biomarker of a progressor colon, and that p53 is accumulated early in UC-related carcinogenesis. Furthermore, a decreased Aurora A expression is associated with the development of DNA aneuploidy, as well as with dysplasia in UC progressors.
authors.affiliation: Division of Diagnostics and Intervention, Department of Pathology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Mariann
authors.initials: M
authors.lastname: Friis-Ottessen
authors.affiliation: Medivir Norge, Oslo, Norway.
authors.forename: Espen
authors.initials: E
authors.lastname: Burum-Auensen
authors.affiliation: Department of Pathology, University of Oslo, Oslo, Norway.
authors.forename: Aasa R
authors.initials: AR
authors.lastname: Schjølberg
authors.affiliation: Division of Surgery and Cancer Medicine, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
authors.forename: Per Olaf
authors.initials: PO
authors.lastname: Ekstrøm
authors.affiliation: Department of Pathology, Akershus University Hospital, Division of Medicine and Laboratory Sciences, University of Oslo, Oslo, Norway.
authors.forename: Solveig N
authors.initials: SN
authors.lastname: Andersen
authors.affiliation: Department of Pathology, University of Oslo, Oslo, Norway.
authors.forename: Ole Petter
authors.initials: OP
authors.lastname: Clausen
authors.affiliation: Division of Diagnostics and Intervention, Department of Pathology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Paula M
authors.initials: PM
authors.lastname: De Angelis
mesh_terms: D000293:Adolescent; D000328:Adult; D064096:Aurora Kinase A / Q000235:genetics* / Q000378:metabolism; D063646:Carcinogenesis / Q000235:genetics; D002648:Child; D003082:Colectomy; D003093:Colitis, Ulcerative / Q000235:genetics* / Q000473:pathology* / Q000601:surgery; D004252:DNA Mutational Analysis; D018450:Disease Progression; D005091:Exons; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011003:Ploidies; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism; D055815:Young Adult
chemical_list: D016159:Tumor Suppressor Protein p53; D064096:Aurora Kinase A