IRIBHM, Université Libre de Bruxelles, Campus Erasme, School of Medicine, Route de Lennik 808, Brussels B-1070, Belgium.
Br J Cancer. 2012 Sep 4;107(6):994-1000. doi: 10.1038/bjc.2012.302. Epub 2012 Jul 24.
Papillary thyroid cancer (PTC) incidence increased dramatically in children after the Chernobyl accident, providing a unique opportunity to investigate the molecular features of radiation-induced thyroid cancer. In contrast to the previous studies that included age-related confounding factors, we investigated mRNA expression in PTC and in the normal contralateral tissues of patients exposed and non-exposed to the Chernobyl fallout, using age- and ethnicity-matched non-irradiated cohorts.
Forty-five patients were analysed by full-genome mRNA microarrays. Twenty-two patients have been exposed to the Chernobyl fallout; 23 others were age-matched and resident in the same regions of Ukraine, but were born after 1 March 1987, that is, were not exposed to ¹³¹I.
A gene expression signature of 793 probes corresponding to 403 genes that permitted differentiation between normal tissues from patients exposed and from those who were not exposed to radiation was identified. The differences were confirmed by quantitative RT-PCR. Many deregulated pathways in the exposed normal tissues are related to cell proliferation.
Our results suggest that a higher proliferation rate in normal thyroid could be related to radiation-induced cancer either as a predisposition or as a consequence of radiation. The signature allows the identification of radiation-induced thyroid cancers.
切尔诺贝利事故后，儿童中甲状腺癌（PTC）的发病率显著增加，为研究放射性诱导甲状腺癌的分子特征提供了独特的机会。与之前包含年龄相关混杂因素的研究不同，我们使用年龄和种族匹配的非放射性队列，研究了暴露于和未暴露于切尔诺贝利沉降物的患者的 PTC 及正常对侧组织中的 mRNA 表达。
对 45 例患者进行全基因组 mRNA 微阵列分析。22 例患者暴露于切尔诺贝利沉降物；另外 23 例患者年龄匹配，居住在乌克兰同一地区，但出生于 1987 年 3 月 1 日之后，即未接触 ¹³¹I。
鉴定出一组 793 个探针，对应 403 个基因，可区分暴露于辐射和未暴露于辐射的患者的正常组织。通过定量 RT-PCR 验证了这些差异。暴露的正常组织中许多失调的途径与细胞增殖有关。
我们的结果表明，正常甲状腺中的更高增殖率可能与放射性诱导的癌症有关，无论是作为易感性还是辐射的结果。该特征可识别放射性诱导的甲状腺癌。
