Conservation of the class I beta-tubulin gene in human populations and lack of mutations in lung cancers and paclitaxel-resistant ovarian cancers.
Conservation of the class I beta-tubulin gene in human populations and lack of mutations in lung cancers and paclitaxel-resistant ovarian cancers.
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发表时间：
2002
影响因子：
5.7
通讯作者：
S. Šale;Raphael K. Sung;P. Shen;Kristine M. Yu;Yan Wang;G. Duran;Jong-Hyeok Kim;T. Fojo;P. Oefner;B. Sikic
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文献类型：
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作者：
S. Šale;Raphael K. Sung;P. Shen;Kristine M. Yu;Yan Wang;G. Duran;Jong-Hyeok Kim;T. Fojo;P. Oefner;B. Sikic
本研究的目的是确定I类β-微管蛋白（克隆m40）基因序列变异的发生率及其在人类肿瘤和癌细胞系中的发生率。从93个代表各种种族的对照个体、49个紫杉醇初治标本（16个卵巢癌、17个非小细胞肺癌和16个卵巢癌细胞系）和30个紫杉醇耐药标本（9个卵巢癌、9个卵巢癌细胞系和12个裸鼠卵巢癌异种移植物）中分离DNA。变性高效液相色谱和直接测序分析检测到两个沉默的多态性外显子4，Leu 217 Leu（CTG/CTA）和Gly 400 Gly（GGC/GGT），与次要等位基因频率分别为17和0.5%。在内含子1、2、3和3'非翻译区检测到5个核苷酸替换和1个单碱基缺失。对49例紫杉醇初治和30例紫杉醇耐药标本的分析显示，编码区没有额外的多态性。此外，与人类相比，在黑猩猩、大猩猩和猩猩中没有发现氨基酸替换。我们的数据表明，在I类β-微管蛋白的序列保守性非常高，这表明所有的残基是重要的微管蛋白的结构和功能。对紫杉醇治疗反应的个体差异不太可能由β-微管蛋白药物靶点的遗传变异引起。此外，获得性I类β-微管蛋白突变不太可能是耐药性的临床相关原因。
The goal of this study was to determine the prevalence of sequence variants in the class I beta-tubulin (clone m40) gene and their occurrence in human tumors and cancer cell lines. DNA was isolated from 93 control individuals representing a wide variety of ethnicities, 49 paclitaxel-naive specimens (16 ovarian cancers, 17 non-small cell lung cancers, and 16 ovarian cancer cell lines), and 30 paclitaxel-resistant specimens (9 ovarian cancers, 9 ovarian cancer cell lines, and 12 ovarian cancer xenografts in nude mice). Denaturing high-performance liquid chromatography and direct sequence analysis detected two silent polymorphisms in exon 4, Leu217Leu (CTG/CTA) and Gly400Gly (GGC/GGT), with minor allele frequencies of 17 and 0.5%, respectively. Five nucleotide substitutions and one single-base deletion were detected in introns 1, 2, and 3 and in the 3' untranslated region. Analysis of 49 paclitaxel-naive and 30 paclitaxel-resistant specimens revealed no additional polymorphisms in the coding region. In addition, no amino acid replacements were found in chimpanzee, gorilla, and orangutan in comparison to human. Our data demonstrate a very high degree of sequence conservation in class I beta-tubulin, suggesting that all residues are important in tubulin structure and function. Individual variation in response to treatment with paclitaxel is not likely to be caused by genetic variations in the beta-tubulin drug target. Moreover, acquired mutations in class I beta-tubulin are unlikely to be a clinically relevant cause of drug resistance.