Delineating genetic alterations for tumor progression in the MCF10A series of breast cancer cell lines.
Delineating genetic alterations for tumor progression in the MCF10A series of breast cancer cell lines.
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DOI：
10.1371/journal.pone.0009201
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发表时间：
2010-02-15
期刊：
影响因子：
3.7
通讯作者：
Lee MP
中科院分区：
文献类型：
--
作者：
Kadota M;Yang HH;Gomez B;Sato M;Clifford RJ;Meerzaman D;Dunn BK;Wakefield LM;Lee MP
为了深入了解基因组改变在乳腺癌进展中的作用，我们对来自MCF10A的一系列四个细胞系进行了全面的基因特征分析。MCF10A是永生化乳腺上皮细胞系(MEC)；MCF10AT是由MCF10A转化活化的HRAS基因形成的癌前细胞系；MCF10CA1h和MCF10CA1a均来源于MCF10AT异种移植瘤，在异种移植模型中分别形成高分化和低分化恶性肿瘤。我们使用Affymetrix 500K SNP阵列分析DNA拷贝数变异，目的是识别基因特异的扩增和缺失事件。除了先前提到的CDKN2A基因缺失外，我们的研究还发现在所有四种细胞系中都存在MYC扩增。此外，我们还发现了MCF10CA1h和MCF10CA1a中的LRP1B、MCF10CA1h中的FHIT和CDH13以及MCF10CA1a中的RUNX1等基因的基因内缺失。通过DNA和RNA分析，我们证实了MCF10CA1a中RUNX1的缺失，以及该细胞系中RUNX1蛋白的缺失。此外，我们还发现RUNX1在高级别原发乳腺肿瘤中的表达低于低/中级别肿瘤。突变分析证实在MCF10CA1h和MCF10CA1a中有一个激活的PIK3CA突变H1047R，这与Ser473和Thr308处AKT1磷酸化的增加有关。此外，我们还发现，随着拷贝数的增加，位于基因组区域的基因表达水平增加。因此，我们的基因分析揭示了描述乳腺肿瘤进展的连续分子事件。这些事件包括永生化中的CDKN2A缺失和MYC扩增，转化中的HRAS激活，恶性肿瘤形成中的PIK3CA激活，以及与低分化恶性肿瘤相关的RUNX1缺失。
To gain insight into the role of genomic alterations in breast cancer progression, we conducted a comprehensive genetic characterization of a series of four cell lines derived from MCF10A. MCF10A is an immortalized mammary epithelial cell line (MEC); MCF10AT is a premalignant cell line generated from MCF10A by transformation with an activated HRAS gene; MCF10CA1h and MCF10CA1a, both derived from MCF10AT xenografts, form well-differentiated and poorly-differentiated malignant tumors in the xenograft models, respectively. We analyzed DNA copy number variation using the Affymetrix 500 K SNP arrays with the goal of identifying gene-specific amplification and deletion events. In addition to a previously noted deletion in the CDKN2A locus, our studies identified MYC amplification in all four cell lines. Additionally, we found intragenic deletions in several genes, including LRP1B in MCF10CA1h and MCF10CA1a, FHIT and CDH13 in MCF10CA1h, and RUNX1 in MCF10CA1a. We confirmed the deletion of RUNX1 in MCF10CA1a by DNA and RNA analyses, as well as the absence of the RUNX1 protein in that cell line. Furthermore, we found that RUNX1 expression was reduced in high-grade primary breast tumors compared to low/mid-grade tumors. Mutational analysis identified an activating PIK3CA mutation, H1047R, in MCF10CA1h and MCF10CA1a, which correlates with an increase of AKT1 phosphorylation at Ser473 and Thr308. Furthermore, we showed increased expression levels for genes located in the genomic regions with copy number gain. Thus, our genetic analyses have uncovered sequential molecular events that delineate breast tumor progression. These events include CDKN2A deletion and MYC amplification in immortalization, HRAS activation in transformation, PIK3CA activation in the formation of malignant tumors, and RUNX1 deletion associated with poorly-differentiated malignant tumors.