Bateman L A, Nguyen T B, Roberts A M, Miyamoto D K, Ku W-M, Huffman T R, Petri Y, Heslin M J, Contreras C M, Skibola C F, Olzmann J A, Nomura D K
Departments of Chemistry and Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
Chem Commun (Camb). 2017 Jun 29;53(53):7234-7237. doi: 10.1039/c7cc01480e.
Chemical genetics has arisen as a powerful approach for identifying novel anti-cancer agents. However, a major bottleneck of this approach is identifying the targets of lead compounds that arise from screens. Here, we coupled the synthesis and screening of fragment-based cysteine-reactive covalent ligands with activity-based protein profiling (ABPP) chemoproteomic approaches to identify compounds that impair colorectal cancer pathogenicity and map the druggable hotspots targeted by these hits. Through this coupled approach, we discovered a cysteine-reactive acrylamide DKM 3-30 that significantly impaired colorectal cancer cell pathogenicity through targeting C1101 on reticulon 4 (RTN4). While little is known about the role of RTN4 in colorectal cancer, this protein has been established as a critical mediator of endoplasmic reticulum tubular network formation. We show here that covalent modification of C1101 on RTN4 by DKM 3-30 or genetic knockdown of RTN4 impairs endoplasmic reticulum and nuclear envelope morphology as well as colorectal cancer pathogenicity. We thus put forth RTN4 as a potential novel colorectal cancer therapeutic target and reveal a unique druggable hotspot within RTN4 that can be targeted by covalent ligands to impair colorectal cancer pathogenicity. Our results underscore the utility of coupling the screening of fragment-based covalent ligands with isoTOP-ABPP platforms for mining the proteome for novel druggable nodes that can be targeted for cancer therapy.
化学遗传学已成为一种识别新型抗癌药物的有力方法。然而，这种方法的一个主要瓶颈是确定筛选出的先导化合物的靶点。在这里，我们将基于片段的半胱氨酸反应性共价配体的合成与筛选与基于活性的蛋白质谱分析（ABPP）化学蛋白质组学方法相结合，以识别损害结直肠癌致病性的化合物，并绘制这些命中靶点的可药物化热点区域。通过这种联合方法，我们发现了一种半胱氨酸反应性丙烯酰胺DKM 3-30，它通过靶向网织蛋白4（RTN4）上的C1101显著损害了结直肠癌细胞的致病性。虽然关于RTN4在结直肠癌中的作用知之甚少，但该蛋白已被确定为内质网管状网络形成的关键介质。我们在此表明，DKM 3-30对RTN4上C1101的共价修饰或RTN4的基因敲低会损害内质网和核膜形态以及结直肠癌的致病性。因此，我们提出RTN4作为一种潜在的新型结直肠癌治疗靶点，并揭示了RTN4内一个独特的可药物化热点区域，可被共价配体靶向以损害结直肠癌的致病性。我们的结果强调了将基于片段的共价配体筛选与isoTOP-ABPP平台相结合用于在蛋白质组中挖掘可作为癌症治疗靶点的新型可药物节点的实用性。
