title: Absence of a specific radiation signature in post-Chernobyl thyroid cancers.
abstract: Thyroid cancers have been the main medical consequence of the Chernobyl accident. On the basis of their pathological features and of the fact that a large proportion of them demonstrate RET-PTC translocations, these cancers are considered as similar to classical sporadic papillary carcinomas, although molecular alterations differ between both tumours. We analysed gene expression in post-Chernobyl cancers, sporadic papillary carcinomas and compared to autonomous adenomas used as controls. Unsupervised clustering of these data did not distinguish between the cancers, but separates both cancers from adenomas. No gene signature separating sporadic from post-Chernobyl PTC (chPTC) could be found using supervised and unsupervised classification methods although such a signature is demonstrated for cancers and adenomas. Furthermore, we demonstrate that pooled RNA from sporadic and chPTC are as strongly correlated as two independent sporadic PTC pools, one from Europe, one from the US involving patients not exposed to Chernobyl radiations. This result relies on cDNA and Affymetrix microarrays. Thus, platform-specific artifacts are controlled for. Our findings suggest the absence of a radiation fingerprint in the chPTC and support the concept that post-Chernobyl cancer data, for which the cancer-causing event and its date are known, are a unique source of information to study naturally occurring papillary carcinomas.
authors.affiliation: Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Campus Erasme, route de Lennik 808, B-1070 Brussels, Belgium.
authors.forename: V
authors.initials: V
authors.lastname: Detours
authors.forename: S
authors.initials: S
authors.lastname: Wattel
authors.forename: D
authors.initials: D
authors.lastname: Venet
authors.forename: N
authors.initials: N
authors.lastname: Hutsebaut
authors.forename: T
authors.initials: T
authors.lastname: Bogdanova
authors.forename: M D
authors.initials: MD
authors.lastname: Tronko
authors.forename: J E
authors.initials: JE
authors.lastname: Dumont
authors.forename: B
authors.initials: B
authors.lastname: Franc
authors.forename: G
authors.initials: G
authors.lastname: Thomas
authors.forename: C
authors.initials: C
authors.lastname: Maenhaut
mesh_terms: D000236:Adenoma / Q000145:classification / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002291:Carcinoma, Papillary / Q000145:classification / Q000235:genetics*; D047852:Chernobyl Nuclear Accident; D002648:Child; D005260:Female; D015870:Gene Expression / Q000528:radiation effects*; D020869:Gene Expression Profiling; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013964:Thyroid Neoplasms / Q000145:classification / Q000235:genetics*