Araujo Aline N, Moraes Lais, França Maria Inez C, Hakonarson Hakon, Li Jin, Pellegrino Renata, Maciel Rui M B, Cerutti Janete M
Genetic Bases of Thyroid Tumors Laboratory (A.N.A., L.M., J.M.C.), Division of Genetics, Department of Morphology and Genetics, Universidade Federal de São Paulo, and Laboratory of Molecular and Translational Endocrinology (M.I.C.F., R.M.B.M.), Division of Endocrinology, Department of Medicine, Universidade Federal de São Paulo, São Paulo SP 04039-032, Brazil; Center for Applied Genomics (H.H., J.L., R.P.), The Children's Hospital of Philadelphia, Research Institute; and Department of Pediatrics (H.H.), The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
J Clin Endocrinol Metab. 2014 Jun;99(6):E1104-12. doi: 10.1210/jc.2013-2993. Epub 2014 Mar 6.
Our group described a p.G533C RET gene mutation in a large family with multiple endocrine neoplasia type 2 syndrome. Clinical heterogeneity, primarily associated with the presence of lymph node metastases, was observed among the p.G533C carriers.
The aim of this study was to use single-nucleotide polymorphism-array technology to identify copy number variations (CNVs), which are present in the constitutional DNA and associated with the established clinical and pathological features of aggressive medullary thyroid carcinoma (MTC), primarily the presence of lymph node metastasis.
Fifteen p.G533C carriers with MTC were chosen for the initial screening. The subjects were divided into two groups according the presence (n = 8) or absence (n = 7) of lymph node metastasis. Peripheral blood DNA was independently hybridized using a genome-wide single-nucleotide polymorphism Array 6.0 platform. The results were analyzed using both Genotyping Console and PennCNV software. To identify the possible candidate regions associated with the presence of lymph node metastasis, cases (metastatic MTC) were compared with controls (nonmetastatic MTC). The identified CNVs were validated by quantitative PCR in an extended cohort (n = 32).
Using two different algorithms, we identified nine CNV regions that may contribute to susceptibility to lymph node metastasis. The validation step confirmed that a CNV loss impacting the FMN2 gene was potentially associated with a greater predisposition to lymph node metastasis in this family (P = .0179). Finally, we sought to investigate whether the development of lymph node metastasis might not depend on a single CNV but rather a combination of various CNVs. These analyses defined a CNV pattern related to a more aggressive phenotype in this family, with CNV deletions being enriched in the metastatic group (P = .0057).
Although hereditable specific RET mutations are important to determine cancer risk, germline CNVs in disease-affected individuals may predispose them to MTC aggressiveness.
我们的研究小组在一个患有2型多发性内分泌肿瘤综合征的大家庭中描述了一种p.G533C RET基因突变。在携带p.G533C突变的个体中观察到临床异质性，主要与淋巴结转移的存在有关。
本研究的目的是使用单核苷酸多态性阵列技术来识别拷贝数变异（CNV），这些变异存在于个体DNA中，并与侵袭性甲状腺髓样癌（MTC）已确定的临床和病理特征相关，主要是淋巴结转移的存在。
选择15名携带p.G533C突变且患有MTC的患者进行初步筛查。根据有无淋巴结转移将受试者分为两组（有转移组n = 8；无转移组n = 7）。使用全基因组单核苷酸多态性Array 6.0平台对外周血DNA进行独立杂交。使用基因分型控制台和PennCNV软件对结果进行分析。为了识别与淋巴结转移存在相关的可能候选区域，将病例（转移性MTC）与对照（非转移性MTC）进行比较。通过定量PCR在一个扩大的队列（n = 32）中对鉴定出的CNV进行验证。
使用两种不同的算法，我们鉴定出9个可能与淋巴结转移易感性相关的CNV区域。验证步骤证实，影响FMN2基因的CNV缺失可能与该家族中更高的淋巴结转移易感性相关（P = 0.0179）。最后，我们试图研究淋巴结转移的发生是否可能不依赖于单个CNV，而是多种CNV的组合。这些分析确定了一种与该家族中更具侵袭性表型相关的CNV模式，CNV缺失在转移组中更为丰富（P = 0.0057）。
虽然可遗传的特定RET突变对于确定癌症风险很重要，但疾病患者个体中的种系CNV可能使他们易患侵袭性MTC。
