Searching for non-RET molecular alterations in medullary thyroid carcinoma: Expression analysis by mRNA differential display
Searching for non-RET molecular alterations in medullary thyroid carcinoma: Expression analysis by mRNA differential display
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DOI：
10.1007/s00268-004-7748-y
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发表时间：
2005-04-01
影响因子：
2.6
通讯作者：
Musholt, PB
中科院分区：
文献类型：
--
作者：
Musholt, TJ;Hanack, J;Musholt, PB
大约25%-70%的散发性甲状腺髓样癌（MTCs）与RET原癌基因的体细胞突变有关。然而，在相当数量的MTC中，没有检测到这样的遗传变异，这意味着替代的致病分子改变。为了评估RET突变特异性基因表达的改变，并确定参与MTC肿瘤发生的未知基因转录本，我们通过mRNA差异显示（RT-DD）进行了表达分析。8例MTC患者（6例散发性肿瘤，2例遗传性肿瘤）的快速冷冻肿瘤组织和相应的正常甲状腺组织被纳入研究; 5/8例MTC携带RET点突变（密码子618、634、918）。通过使用荧光标记的任意寡核苷酸，在自动测序仪上电泳，以及利用高性能荧光扫描仪的新型片段回收技术，改进了RT-DD方法。超过400个差异表达的mRNA转录，代表上调或下调的基因在比较组织中检测。总共回收、克隆、测序并鉴定了28个选择的片段。观察到与细胞增殖或肿瘤进展相关的基因转录本的差异表达，如膜联蛋白A2、Rab 11 a、三叶蛋白、超氧化物歧化酶（SOD 1）、线粒体置换环（D环）和G蛋白亚基γ 11以及神经内分泌标志物嗜铬粒蛋白。此外，几个mRNA转录的未知基因显示突变特异性上调或下调MTC。照明的分子基础，特别是C-细胞癌的RET受体酪氨酸激酶没有可检测到的变化，将需要为先进的肿瘤，不能单独通过手术干预的抑制或治愈的治疗策略的发展。
Some 25%-70% of sporadic medullary thyroid carcinomas (MTCs) are associated with somatic mutations within the RET protooncogene. In a significant number of MTCs, however, no such genetic variations can be detected, which implies alternative pathogenic molecular alterations. To assess altered RET mutation-specific gene expression, and to identify yet unknown gene transcripts involved in the tumorigenesis of MTC, we performed an expression analysis by mRNA differential display (RT-DD). Snap-frozen tumor tissues and corresponding normal thyroid tissues of 8 patients suffering from MTC (6 sporadic, 2 hereditary tumors) were included in the study; 5/8 MTCs harbored RET point mutations (codons 618, 634, 918). The RT-DD method was refined by use of fluorescence-labeled arbitrary oligonucleotides, electrophoresis on an automated sequencer, and a novel fragment-recovery technique utilizing a high-performance fluorescence scanner. More than 400 differentially expressed mRNA transcripts-representing upregulated or downregulated genes in the compared tissues-were detected. In all, 28 selected fragments were recovered, cloned, sequenced, and identified. Differential expression of gene transcripts with known association to cell proliferation or tumor progress ion-such as annexin A2, Rab11a, trefoil proteins, superoxide dismutase (SOD1), mitochondrial displacement loop (D-loop), and G protein subunit gamma11-as well as of the neuroendocrine marker chromogranin was observed. Furthermore, several mRNA transcripts of yet unknown genes displayed mutation-specific upregulation or downregulation in MTC. Illumination of the molecular basis especially of C-cell carcinomas without detectable alterations of the RET receptor tyrosine kinase will be required for the development of therapeutic strategies for advanced tumors that cannot be bridled or cured by surgical interventions alone.