Systematic analysis of synergistic proteome modulations in a drug combination of cisplatin and MLN4924

Chemotherapeutic treatment regimens often take advantage of synergistic effects of drug combinations. Anticipating that synergistic effects on cell biological level likely manifest on proteome level, the analysis of proteome modulations represents an appropriate strategy to study drug combinations on molecular level. More specifically, the detection of single proteins exhibiting synergistic abundance changes could be helpful to shed light on key molecules, which contribute in mechanisms facilitating the synergistic interaction and therefore represent potential target for specific therapeutic approaches. In the reported study, we investigated the drug combination of cisplatin and the neddylation inhibitor MLN4924 in HCT-116 cells via cell biological analyses and mass spectrometry-based quantitative proteomics. From 1,789 proteins quantified with two unique peptides, activated RNA polymerase II transcriptional coactivator p15 (SUB1) was highlighted as most synergistically regulated protein using a synergistic scoring approach. Western blotting and analyses of cellular processes associated with this protein (DNA damage, oxidative stress and apoptosis) revealed supporting evidence for the synergistic regulation. Whereas the distinct role of SUB1 in the investigated drug combination needs to be elucidated in future studies, the presented results demonstrated the benefit and feasibility of synergistic scoring of proteome alterations to highlight proteins that likely contribute to the underlying molecular mechanisms of synergistic effects.

化疗方案常借助药物联合的协同效应发挥治疗作用。本研究推测，细胞生物学层面的协同效应大概率会在蛋白质组（proteome）层面有所体现，因此对蛋白质组调控模式的分析，是在分子层面研究药物联合方案的合理策略。更具体而言，检测呈现协同丰度变化的单个蛋白质，有助于阐明参与协同作用机制的关键分子，进而为针对性治疗手段提供潜在靶点。在本研究中，我们通过细胞生物学分析与基于质谱的定量蛋白质组学（mass spectrometry-based quantitative proteomics）技术，探究了顺铂（cisplatin）与诺丁化抑制剂（neddylation inhibitor）MLN4924在HCT-116细胞中的联合作用。在通过2条唯一肽段（unique peptides）定量得到的1789种蛋白质中，我们采用协同评分法将激活型RNA聚合酶II转录辅激活因子p15（activated RNA polymerase II transcriptional coactivator p15，SUB1）鉴定为协同调控效应最显著的蛋白质。通过蛋白质印迹法（Western blotting）以及针对该蛋白相关细胞过程——DNA损伤（DNA damage）、氧化应激（oxidative stress）与细胞凋亡（apoptosis）——的分析，我们获得了支持其协同调控特性的实验证据。尽管SUB1在本次药物联合研究中的具体作用仍需后续实验阐明，但本研究结果证实了对蛋白质组变化进行协同评分的优势与可行性，可用于筛选可能参与协同效应分子机制的关键蛋白质。