Sequence analysis of the ATM gene in 20 patients with RTOG Grade 3 or 4 acute and or late tissue radiation side effects
Sequence analysis of the ATM gene in 20 patients with RTOG Grade 3 or 4 acute and or late tissue radiation side effects
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DOI：
10.1016/s0360-3016(99)00108-x
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发表时间：
1999-07-15
影响因子：
7
通讯作者：
Flentje, M
中科院分区：
文献类型：
--
作者：
Oppitz, U;Bernthaler, U;Flentje, M
目的：共济失调-毛细血管扩张症（A-T）患者表现出极大的放射敏感性和癌症易感性。家族研究表明，这种常染色体隐性遗传病的其他临床沉默杂合子发生癌症的风险高3.5至3.8。体外研究表明A-T携带者的细胞辐射敏感性适度增加。它们也可能显示出升高的临床放射敏感性。我们回顾性地检查了在标准放射治疗期间或之后出现严重不良反应的患者的A-T、ATM基因突变，考虑了未来前瞻性地识别放射敏感个体以调整剂量方案的潜在手段。（乳腺，11例;直肠，2例;耳鼻喉科，2例;膀胱，1例;前列腺，1例;肛门，1例;星形细胞瘤，1例;霍奇金斯淋巴瘤，1例），按反应严重程度列出的3 - 4级（RTOG）急性和/或晚期组织放射副作用。从患者的外周血中分离DNA。所有66个外显子和相邻的ATM基因内含子区域进行PCR扩增和突变检测相结合的琼脂糖凝胶电泳，单链构象多态性（SSCP）分析，和外显子扫描直接测序。后者包括在不同内含子中的两个单碱基缺失，在外显子中引起氨基酸取代的单碱基变化，以及在另一个内含子中的大插入。单碱基缺失和单碱基改变都代表已知的多态性。大的插入是一个Alu重复，显示不会引起改变的基因product.Conclusions：尽管高技术的努力，没有明确的ATM突变检测。然而，类似的研究扩展到更大的和不同组成的队列的患者遭受严重的不良反应的放射治疗，并应用新的技术进行突变检测可能是值得的，以评估明确的患病率显着ATM突变组的放射治疗患者的不良反应。到目前为止，必须认识到，我们目前的结果并不表明杂合ATM突变参与临床观察到的放射敏感性，而是调用不同的遗传易感性或迄今未知的外源性因素。(C)1999 Elsevier Science Inc.
Purpose: Patients with ataxia-telangiectasia (,A-T) show greatly increased radiation sensitivity and cancer predisposition. Family studies imply that the otherwise clinically silent heterozygotes of this autosomal recessive disease run a 3.5 to 3.8 higher risk of developing cancer. In vitro studies suggest moderately increased cellular radiation sensitivity of A-T carriers. They may also show elevated clinical radiosensitivity. We retrospectively examined patients who presented with severe adverse reactions during or after standard radiation treatment for mutations in the gene responsible for A-T, ATM, considering a potential means of future identification of radiosensitive individuals prospectively to adjust dosage schedules.Material and Methods: We selected 20 cancer patients (breast, 11; rectum, 2; ENT, 2; bladder, 1; prostate, 1; anus, 1; astrocytoma, 1; Hodgkins lymphoma, 1) with Grade 3 to 4 (RTOG) acute and/or late tissue radiation side effects by reaction severity. DNA from the peripheral blood of patients was isolated. All 66 exons and adjacent intron regions of the ATM gene were PCR-amplified and examined for mutations by a combination of agarose gel electrophoresis, single-stranded conformational polymorphism (SSCP) analysis, and exon-scanning direct sequencing.Results: Only 2 of the patients revealed altogether four heteroallelic sequence variants. The latter included two single-base deletions in different introns, a single-base change causing an amino acid substitution in an exon, and a large insertion in another intron. Both the single-base deletions and the single-base change represent known polymorphisms. The large insertion was an Alu repeat, shown not to give rise to altered gene product.Conclusions: Despite high technical efforts, no unequivocal ATM mutation was detected. Nevertheless, extension of similar studies to larger and differently composed cohorts of patients suffering severe adverse effects of radiotherapy, and application of new technologies for mutation detection may be worthwhile to assess the definite prevalence of significant ATM mutations within the group of radiotherapy patients with adverse reactions. To date, it must be recognized that our present results do not suggest that heterozygous ATM mutations are involved in clinically observed radiosensitivity but, rather, invoke different genetic predisposition or so far unknown exogenous factors. (C) 1999 Elsevier Science Inc.