MacDonald Julie A, Bradshaw Gary A, Jochems Fleur, Bernards René, Letai Anthony
Dana Farber Cancer Institute, Boston, MA, USA.
Department of Systems Biology, Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA, USA.
Cell Death Differ. 2025 May;32(5):802-817. doi: 10.1038/s41418-024-01431-1. Epub 2025 Jan 6.
Cellular senescence contributes to a variety of pathologies associated with aging and is implicated as a cellular state in which cancer cells can survive treatment. Reported senolytic drug treatments act through varying molecular mechanisms, but heterogeneous efficacy across the diverse contexts of cellular senescence indicates a need for predictive biomarkers of senolytic activity. Using multi-parametric analyses of commonly reported molecular features of the senescent phenotype, we assayed a variety of models, including malignant and nonmalignant cells, using several triggers of senescence induction and found little univariate predictive power of these traditional senescence markers to identify senolytic drug sensitivity. We sought to identify novel drug targets in senescent cells that were insensitive to frequently implemented senolytic therapies, such as Navitoclax (ABT-263), using quantitative mass spectrometry to measure changes in the senescent proteome, compared to cells which acquire an acute sensitivity to ABT-263 with senescence induction. Inhibition of the antioxidant GPX4 or the Bcl-2 family member MCL-1 using small molecule compounds in combination with ABT-263 significantly increased the induction of apoptosis in some, but not all, previously insensitive senescent cells. We then asked if we could use BH3 profiling to measure differences in mitochondrial apoptotic priming in these models of cellular senescence and predict sensitivity to the senolytics ABT-263 or the combination of dasatinib and quercetin (D + Q). We found, despite being significantly less primed for apoptosis overall, the dependence of senescent mitochondria on BCL-XL was significantly correlated to senescent cell killing by both ABT-263 and D + Q, despite no significant changes in the gene or protein expression of BCL-XL. However, our data caution against broad classification of drugs as globally senolytic and instead provide impetus for context-specific senolytic targets and propose BH3 profiling as an effective predictive biomarker.
细胞衰老促成了与衰老相关的多种病理状况，并且被认为是癌细胞能够在治疗后存活的一种细胞状态。报道的衰老细胞溶解药物治疗通过不同的分子机制起作用，但在细胞衰老的不同背景下疗效各异，这表明需要衰老细胞溶解活性的预测性生物标志物。通过对衰老表型常见报道分子特征的多参数分析，我们使用多种衰老诱导触发因素检测了包括恶性和非恶性细胞在内的多种模型，发现这些传统衰老标志物在单变量分析中几乎没有预测衰老细胞溶解药物敏感性的能力。我们试图在对常用的衰老细胞溶解疗法（如Navitoclax，ABT - 263）不敏感的衰老细胞中鉴定新的药物靶点，通过定量质谱法测量衰老蛋白质组的变化，并与在衰老诱导后对ABT - 263产生急性敏感性的细胞进行比较。使用小分子化合物抑制抗氧化剂GPX4或Bcl - 2家族成员MCL - 1，并与ABT - 263联合使用，在一些但并非所有先前不敏感的衰老细胞中显著增加了细胞凋亡的诱导。然后我们询问是否可以使用BH3分析来测量这些细胞衰老模型中线粒体凋亡启动的差异，并预测对衰老细胞溶解剂ABT - 263或达沙替尼和槲皮素组合（D + Q）的敏感性。我们发现，尽管总体上衰老细胞凋亡启动明显较少，但衰老线粒体对BCL - XL的依赖性与ABT - 263和D + Q诱导的衰老细胞杀伤显著相关，尽管BCL - XL的基因或蛋白质表达没有显著变化。然而，我们的数据提醒不要将药物广泛分类为全局衰老细胞溶解剂，而是为特定背景的衰老细胞溶解靶点提供了动力，并提出BH3分析作为一种有效的预测性生物标志物。
