Kumar Naveen, Gupta Sonal, Dabral Surbhi, Singh Shailja, Sehrawat Seema
Brain Metastasis and NeuroVascular Disease Modeling Lab, Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, NCR, India.
Host Pathogen Interactions and Disease Modeling Group, Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, NCR, India.
Mol Cell Biochem. 2017 Jun;430(1-2):115-125. doi: 10.1007/s11010-017-2959-3. Epub 2017 Feb 16.
Despite the current progress in cancer research and therapy, breast cancer remains the leading cause of mortality among half a million women worldwide. Migration and invasion of cancer cells are associated with prevalent tumor metastasis as well as high mortality. Extensive studies have powerfully established the role of prototypic second messenger cAMP and its two ubiquitously expressed intracellular cAMP receptors namely the classic protein kinaseA/cAMP-dependent protein kinase (PKA) and the more recently discovered exchange protein directly activated by cAMP/cAMP-regulated guanine nucleotide exchange factor (EPAC/cAMP-GEF) in cell migration, cell cycle regulation, and cell death. Herein, we performed the analysis of the Cancer Genome Atlas (TCGA) dataset to evaluate the essential role of cAMP molecular network in breast cancer. We report that EPAC1, PKA, and AKAP9 along with other molecular partners are amplified in breast cancer patients, indicating the importance of this signaling network. To evaluate the functional role of few of these proteins, we used pharmacological modulators and analyzed their effect on cell migration and cell death in breast cancer cells. Hence, we report that inhibition of EPAC1 activity using pharmacological modulators leads to inhibition of cell migration and induces cell death. Additionally, we also observed that the inhibition of EPAC1 resulted in disruption of its association with the microtubule cytoskeleton and delocalization of AKAP9 from the centrosome as analyzed by in vitro imaging. Finally, this study suggests for the first time the mechanistic insights of mode of action of a primary cAMP-dependent sensor, Exchange protein activated by cAMP 1 (EPAC1), via its interaction with A-kinase anchoring protein 9 (AKAP9). This study provides a new cell signaling cAMP-EPAC1-AKAP9 direction to the development of additional biotherapeutics for breast cancer.
尽管目前癌症研究和治疗取得了进展，但乳腺癌仍是全球五十万女性死亡的主要原因。癌细胞的迁移和侵袭与普遍存在的肿瘤转移以及高死亡率相关。广泛的研究有力地证实了原型第二信使cAMP及其两种普遍表达的细胞内cAMP受体，即经典的蛋白激酶A/cAMP依赖性蛋白激酶（PKA）和最近发现的由cAMP直接激活的交换蛋白/cAMP调节的鸟嘌呤核苷酸交换因子（EPAC/cAMP-GEF）在细胞迁移、细胞周期调节和细胞死亡中的作用。在此，我们对癌症基因组图谱（TCGA）数据集进行了分析，以评估cAMP分子网络在乳腺癌中的重要作用。我们报告，EPAC1、PKA和AKAP9以及其他分子伴侣在乳腺癌患者中发生扩增，表明该信号网络的重要性。为了评估其中一些蛋白质的功能作用，我们使用了药理学调节剂，并分析了它们对乳腺癌细胞迁移和细胞死亡的影响。因此，我们报告使用药理学调节剂抑制EPAC1活性会导致细胞迁移受到抑制并诱导细胞死亡。此外，我们还观察到，通过体外成像分析，抑制EPAC1会导致其与微管细胞骨架的结合被破坏，以及AKAP9从中心体上脱离。最后，本研究首次提出了一种主要的cAMP依赖性传感器，即由cAMP激活的交换蛋白1（EPAC1），通过其与A激酶锚定蛋白9（AKAP9）相互作用的作用机制见解。本研究为开发用于乳腺癌的其他生物疗法提供了新的细胞信号cAMP-EPAC1-AKAP9方向。
