Functional Impact of Sequence Alterations Found in BRCA1 Promoter/5'UTR Region in Breast/Ovarian Cancer Families from Upper Silesia, Poland
Functional Impact of Sequence Alterations Found in BRCA1 Promoter/5'UTR Region in Breast/Ovarian Cancer Families from Upper Silesia, Poland
复制标题
波兰上西里西亚乳腺癌/卵巢癌家族中 BRCA1 启动子/5UTR 区域中发现的序列改变的功能影响
DOI：
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发表时间：
2006
影响因子：
1.7
通讯作者：
E. Grzybowska
中科院分区：
文献类型：
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作者：
Jolanta Pamuła;Małgorzata Krześniak;H. Zientek;Wioletta Pękala;M. Rusin;E. Grzybowska
BRCA1的5'区包含多个调控序列，它们位于两个可选启动子α和β以及两个可选的非编码外显子1a和1b的两侧。BRCA1 5'区（包括两个备选启动子α和β以及外显子1a和1b）的畸变可能与乳腺癌和卵巢癌的风险增加有关。在这项研究中，我们筛选了150例BRCA1区域的多态性和突变。所有先证均来自家族性乳腺癌和/或卵巢癌，在之前的BRCA1 （185delAG, C61G, 4153delA, 532insc）或BRCA2 （6174delT, 9631delC）的始创突变中发现突变阴性。在我们的研究中，我们通过直接DNA测序和等位基因特异性PCR扩增，在BRCA1的非编码区发现了几个序列改变。BRCA1外显子1b多态性缺失的三个家族(2223delAAAAA, Acc。U37574)被发现。此外，两个连锁核苷酸取代(2642A>T, 2743T>C, Acc。在16例患者中检测到BRCA1内含子1中的U37574)。为了评估这两个序列变体的功能意义，我们构建了一个在野生型和改变的BRCA1启动子区域转录和翻译控制下编码萤火虫荧光素酶的报告载体。报告细胞试验使用肺癌细胞系（NCI-H1299）和乳腺癌细胞系（MCF7）进行。我们已经证明，分析的序列变异在我们的实验系统中没有功能意义。然而，我们发现BRCA1启动子在乳腺癌细胞系中的相对活性低于肺癌细胞系。基于我们的功能实验结果，我们得出结论，多态性缺失2223delAAAAA和两个连锁替换2642A b> T和2743T>C不会显著改变BRCA1的表达，可能不是致病突变。
The 5' region of BRCA1 contains multiple regulatory sequences flanking the two alternative promoters α and β and two alternative, non-coding exons, 1a and 1b. Aberrations within the 5' region BRCA1 (encompassing two alternative promoters α and β and exons 1a and 1b) may be associated with an increased risk of breast and ovarian cancer. In this study we screened 150 patients for polymorphism and mutations in this region of BRCA1. All probands came from familial breast and/or ovarian cancer that had been found to be mutation-negative in a previous search for founder mutations in BRCA1 (185delAG, C61G, 4153delA, 5382insC) or BRCA2 (6174delT, 9631delC). In our study we found several sequence alterations within the non-coding region of BRCA1 by using direct DNA sequencing and allele-specific PCR amplification. Three families with a polymorphic deletion in BRCA1 exon 1b (2223delAAAAA, Acc. U37574) were found. Moreover, two linked nucleotide substitutions (2642A>T, 2743T>C, Acc. U37574) in BRCA1 intron 1 were detected in 16 patients. In order to assess the functional significance of these two sequence variants, we constructed a reporter vector encoding firefly luciferase under the transcriptional and translational control of wild type and altered BRCA1 promoter region. The reporter assay was performed using a lung cancer cell line (NCI-H1299) and a breast cancer cell line (MCF7). We have demonstrated that the analysed sequence variants have no functional significance in our experimental system. However, we have found that the BRCA1 promoter has lower relative activity in the breast cancer cell line compared with the lung cancer cell line. Based on the results of our functional experiments we conclude that the polymorphic deletion 2223delAAAAA and two linked substitutions 2642A>T and 2743T>C do not significantly alter BRCA1 expression and are probably not disease-causing mutations.
影响因子：
56.9
作者：
MIKI, Y;SWENSEN, J;SKOLNICK, MH
通讯作者：
SKOLNICK, MH