Carrier Marilyn, Joint Mathilde, Lutzing Régis, Page Adeline, Rochette-Egly Cécile
Department of Functional Genomics and Cancer, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), INSERM, U964, CNRS, UMR7104, Université de Strasbourg, 1 rue Laurent Fries, BP 10142, 67404 Illkirch Cedex, Strasbourg, France.
Proteomics Platform, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), INSERM, U964, CNRS, UMR7104, Université de Strasbourg, 1 rue Laurent Fries, BP 10142, 67404 Illkirch Cedex, Strasbourg, France.
PLoS One. 2016 Jun 30;11(6):e0157290. doi: 10.1371/journal.pone.0157290. eCollection 2016.
Retinoic acid (RA), the main active vitamin A metabolite, controls multiple biological processes such as cell proliferation and differentiation through genomic programs and kinase cascades activation. Due to these properties, RA has proven anti-cancer capacity. Several breast cancer cells respond to the antiproliferative effects of RA, while others are RA-resistant. However, the overall signaling and transcriptional pathways that are altered in such cells have not been elucidated. Here, in a large-scale analysis of the phosphoproteins and in a genome-wide analysis of the RA-regulated genes, we compared two human breast cancer cell lines, a RA-responsive one, the MCF7 cell line, and a RA-resistant one, the BT474 cell line, which depicts several alterations of the "kinome". Using high-resolution nano-LC-LTQ-Orbitrap mass spectrometry associated to phosphopeptide enrichment, we found that several proteins involved in signaling and in transcription, are differentially phosphorylated before and after RA addition. The paradigm of these proteins is the RA receptor α (RARα), which was phosphorylated in MCF7 cells but not in BT474 cells after RA addition. The panel of the RA-regulated genes was also different. Overall our results indicate that RA resistance might correlate with the deregulation of the phosphoproteome with consequences on gene expression.
视黄酸（RA）是维生素A的主要活性代谢产物，通过基因组程序和激酶级联激活来控制多种生物学过程，如细胞增殖和分化。由于这些特性，RA已被证明具有抗癌能力。几种乳腺癌细胞对RA的抗增殖作用有反应，而其他细胞则对RA耐药。然而，此类细胞中发生改变的整体信号传导和转录途径尚未阐明。在此，通过对磷酸化蛋白质的大规模分析以及对RA调控基因的全基因组分析，我们比较了两种人乳腺癌细胞系，一种是对RA有反应的MCF7细胞系，另一种是对RA耐药的BT474细胞系，后者表现出“激酶组”的几种改变。使用与磷酸肽富集相关的高分辨率纳米液相色谱-线性离子阱-轨道阱质谱法，我们发现几种参与信号传导和转录的蛋白质在添加RA前后磷酸化情况不同。这些蛋白质的典型代表是视黄酸受体α（RARα），在添加RA后，MCF7细胞中的RARα发生了磷酸化，而BT474细胞中则没有。RA调控的基因组合也不同。总体而言，我们的结果表明，RA耐药可能与磷酸化蛋白质组的失调有关，并对基因表达产生影响。
