Gain of chromosome band 7q11 in papillary thyroid carcinomas of young patients is associated with exposure to low-dose irradiation.

Abstract

The main consequence of the Chernobyl accident has been an increase in papillary thyroid carcinomas (PTCs) in those exposed to radioactive fallout as young children. Our aim was to identify genomic alterations that are associated with exposure to radiation. We used array comparative genomic hybridization to analyze a main (n = 52) and a validation cohort (n = 28) of PTC from patients aged <25 y at operation and matched for age at diagnosis and residency. Both cohorts consisted of patients exposed and not exposed to radioiodine fallout. The study showed association of a gain on chromosome 7 (7q11.22-11.23) with exposure (false discovery rate = 0.035). Thirty-nine percent of the exposed group showed the alteration; however, it was not found in a single case from the unexposed group. This was confirmed in the validation set. Because only a subgroup of cases in the exposed groups showed gain of 7q11.22-11.23, it is likely that different molecular subgroups and routes of radiation-induced carcinogenesis exist. The candidate gene CLIP2 was specifically overexpressed in the exposed cases. In addition, the expression of the genes PMS2L11, PMS2L3, and STAG3L3 correlated with gain of 7q11.22-11.23. An enrichment of Gene Ontology terms "DNA repair" (PMS2L3, PMS2L5), "response to DNA damage stimulus" (BAZ1B, PMS2L3, PMS2L5, RFC2), and "cell-cell adhesion" (CLDN3, CLDN4) was found. This study, using matched exposed and unexposed cohorts, provides insights into the radiation-related carcinogenesis of young-onset PTC and, with the exposure-specific gain of 7q11 and overexpression of the CLIP2 gene, radiation-specific molecular markers.

• Authors: Julia Hess, Gerry Thomas, Herbert Braselmann, Verena Bauer, Tatjana Bogdanova, Johannes Wienberg, Horst Zitzelsberger, Kristian Unger
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 108 Issue 23 Pg. 9595-600 (Jun 07 2011) ISSN: 1091-6490 [Electronic] United States
• PMID: 21606360 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Iodine Radioisotopes
• Microtubule-Associated Proteins
• cytoplasmic linker protein 115

Topics

• Adolescent
• Carcinoma
• Carcinoma, Papillary
• Case-Control Studies
• Cell Adhesion (genetics)
• Chernobyl Nuclear Accident
• Child
• Chromosome Aberrations (radiation effects)
• Chromosomes, Human, Pair 7 (genetics)
• Comparative Genomic Hybridization
• DNA Repair (genetics)
• Dose-Response Relationship, Radiation
• Female
• Gene Expression Regulation, Neoplastic (radiation effects)
• Humans
• In Situ Hybridization, Fluorescence
• Iodine Radioisotopes
• Male
• Microtubule-Associated Proteins (genetics)
• Neoplasms, Radiation-Induced (genetics)
• Reverse Transcriptase Polymerase Chain Reaction
• Thyroid Cancer, Papillary
• Thyroid Neoplasms (genetics)
• Young Adult