Institute of Biotechnology, University of Lausanne, Lausanne, Switzerland.
PLoS One. 2011;6(8):e22895. doi: 10.1371/journal.pone.0022895. Epub 2011 Aug 18.
Cheap and massively parallel methods to assess the DNA-binding specificity of transcription factors are actively sought, given their prominent regulatory role in cellular processes and diseases. Here we evaluated the use of protein-binding microarrays (PBM) to probe the association of the tumor suppressor AP2α with 6000 human genomic DNA regulatory sequences. We show that the PBM provides accurate relative binding affinities when compared to quantitative surface plasmon resonance assays. A PBM-based study of human healthy and breast tumor tissue extracts allowed the identification of previously unknown AP2α target genes and it revealed genes whose direct or indirect interactions with AP2α are affected in the diseased tissues. AP2α binding and regulation was confirmed experimentally in human carcinoma cells for novel target genes involved in tumor progression and resistance to chemotherapeutics, providing a molecular interpretation of AP2α role in cancer chemoresistance. Overall, we conclude that this approach provides quantitative and accurate assays of the specificity and activity of tumor suppressor and oncogenic proteins in clinical samples, interfacing genomic and proteomic assays.
鉴于转录因子在细胞过程和疾病中的重要调节作用，人们积极寻求廉价且大规模并行的方法来评估其 DNA 结合特异性。在这里，我们评估了蛋白质结合微阵列 (PBM) 在探测肿瘤抑制因子 AP2α 与 6000 个人类基因组 DNA 调控序列之间的关联中的应用。我们表明，与定量表面等离子体共振测定法相比，PBM 提供了准确的相对结合亲和力。基于 PBM 的人类健康和乳腺癌组织提取物的研究允许鉴定先前未知的 AP2α 靶基因，并揭示了在病变组织中与 AP2α 直接或间接相互作用受影响的基因。在涉及肿瘤进展和对化疗药物耐药性的新型靶基因的人类癌细胞中，通过实验证实了 AP2α 结合和调节，为 AP2α 在癌症化疗耐药性中的作用提供了分子解释。总的来说，我们得出结论，这种方法为临床样本中肿瘤抑制因子和致癌蛋白的特异性和活性提供了定量和准确的检测，将基因组和蛋白质组检测相结合。
