Cancer Program, Biomedicine Discovery Institute, Monash University, Melbourne, Australia.
Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia.
Mol Cancer Ther. 2018 May;17(5):931-942. doi: 10.1158/1535-7163.MCT-17-0377. Epub 2018 Feb 12.
The small-molecule drug NT157 has demonstrated promising efficacy in preclinical models of a number of different cancer types, reflecting activity against both cancer cells and the tumor microenvironment. Two known mechanisms of action are degradation of insulin receptor substrates (IRS)-1/2 and reduced Stat3 activation, although it is possible that others exist. To interrogate the effects of this drug on cell signaling pathways in an unbiased manner, we have undertaken mass spectrometry-based global tyrosine phosphorylation profiling of NT157-treated A375 melanoma cells. Bioinformatic analysis of the resulting dataset resolved 5 different clusters of tyrosine-phosphorylated peptides that differed in the directionality and timing of response to drug treatment over time. The receptor tyrosine kinase AXL exhibited a rapid decrease in phosphorylation in response to drug treatment, followed by proteasome-dependent degradation, identifying an additional potential target for NT157 action. However, NT157 treatment also resulted in increased activation of p38 MAPK α and γ, as well as the JNKs and specific Src family kinases. Importantly, cotreatment with the p38 MAPK inhibitor SB203580 attenuated the antiproliferative effect of NT157, while synergistic inhibition of cell proliferation was observed when NT157 was combined with a Src inhibitor. These findings provide novel insights into NT157 action on cancer cells and highlight how globally profiling the impact of a specific drug on cellular signaling networks can identify effective combination treatments. .
小分子药物 NT157 在多种不同癌症类型的临床前模型中表现出有希望的疗效，这反映了它对癌细胞和肿瘤微环境都有活性。两种已知的作用机制是胰岛素受体底物 (IRS)-1/2 的降解和 Stat3 激活的减少，尽管可能存在其他机制。为了以无偏倚的方式研究该药物对细胞信号通路的影响，我们对 NT157 处理的 A375 黑色素瘤细胞进行了基于质谱的全局酪氨酸磷酸化谱分析。对所得数据集的生物信息学分析解析了 5 个不同的酪氨酸磷酸化肽簇，它们在药物处理时的响应方向和时间上有所不同。受体酪氨酸激酶 AXL 对药物处理的反应表现出快速的磷酸化减少，随后是蛋白酶体依赖性降解，这确定了 NT157 作用的另一个潜在靶点。然而，NT157 处理还导致 p38 MAPKα 和γ以及 JNKs 和特定的Src 家族激酶的激活增加。重要的是，用 p38 MAPK 抑制剂 SB203580 共处理可减弱 NT157 的抗增殖作用，而当 NT157 与 Src 抑制剂联合使用时，观察到协同抑制细胞增殖。这些发现为 NT157 对癌细胞的作用提供了新的见解，并强调了如何通过全局分析特定药物对细胞信号网络的影响来确定有效的联合治疗方法。
