THE RET PROTOONCOGENE IN SPORADIC PHEOCHROMOCYTOMAS - FREQUENT MEN 2-LIKE MUTATIONS AND NEW MOLECULAR DEFECTS
THE RET PROTOONCOGENE IN SPORADIC PHEOCHROMOCYTOMAS - FREQUENT MEN 2-LIKE MUTATIONS AND NEW MOLECULAR DEFECTS
复制标题
DOI：
10.1210/jc.80.7.2063
复制
发表时间：
1995-07-01
影响因子：
5.8
通讯作者：
BERTAGNA, X
中科院分区：
文献类型：
--
作者：
BELDJORD, C;DESCLAUXARRAMOND, F;BERTAGNA, X
为了评估RET原癌基因在散发性嗜铬细胞瘤中的病理生理作用，我们检测了该基因的2个区域，其中分子缺陷与多发性内分泌瘤（MEN）特异性相关：2A型（由外显子10和11编码的富含半胱氨酸的区域），2B型（由外显子16编码的酪氨酸激酶区域）。通过逆转录酶-聚合酶链反应（PCR或来自肿瘤RNA和/或白细胞DNA的PCR）扩增两个区域的序列。用化学夹变性梯度凝胶电泳分析扩增片段。在28例单侧散发性肿瘤患者中，发现6例RET突变，3例位于MEN 2A区域。3个在MEN 2B区域。5例患者有错义突变：2例在MEN 2A区域C634 W和D 631 Y），3例在MEN 2B区域M91 ST。其中3例患者的白细胞DNA分析证实RET突变仅存在于肿瘤DNA中。第六位患者由于内含子9的3'剪接受体位点处的二核苷酸-AG-的缺失而丢失了肿瘤互补DNA中的外显子10;这种分子缺陷是唯一的。在肿瘤DNA中发现的。因此，MEN 2A和2B区域的RET突变也在约20%的散发性嗜铬细胞瘤中发现。我们描述了新型分子缺陷的RET原癌基因在MEN 2A区域，涉及非半胱氨酸残基和外显子10的损失。进一步的研究应该扩展到分析整个RET原癌基因。这些发现对于治疗散发性嗜铬细胞瘤患者有着深远的临床意义。
To assess the pathophysiological role of the RET protooncogene in sporadic pheochromocytomas, we examined the 2 regions of the gene in which molecular defects are specifically associated with the multiple endocrine neoplasias (MEN) type 2A the cysteine-rich domain encoded by exons 10 and 11), and type 2B the tyrosine kinase domain encoded by exon 16). The sequences of both regions were amplified by reverse transcriptase-polymerase chain reaction (PCR or PCR from tumor RNA and/or leukocyte DNA. The amplified fragments were analyzed by denaturing gradient gel electrophoresis using chemical clamps. In 28 patients with unilateral sporadic tumors, 6 RET mutations were found, 3 in the MEN 2A region. 3 in the MEN 2B region. Five patients had missense mutations: 2 in the MEN 2A region C634W and D631Y), and 3 in the MEN 2B region M91ST. Analysis of leukocyte DNA in 3 of these patients confirmed that RET mutations were only present in tumor DNA. The sixth patient had lost exon 10 in the tumor complementary DNA as a result of the deletion of the dinucleotide -AG- at the 3' splice acceptor site of intron 9; this molecular defect a as only. found in the tumor DNA. Thus RET mutations of the MEN 2A and 2B regions are also found in about 20% of sporadic pheochromocytomas. We describe new types of molecular defects of the RET protooncogene in the MEN 2A region that involve noncysteine residues and loss of exon 10. Further studies should be extended to analyze the entire RET protooncogene. These findings have a profound clinical impact For the management of patients with supposedly sporadic pheochromocytomas.