Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy.
Department of Biochemical Sciences, Sapienza, University of Rome, 00185 Rome, Italy.
Int J Mol Sci. 2019 Dec 19;21(1):32. doi: 10.3390/ijms21010032.
Among natural products under investigation for their additive potential in cancer prevention and treatment, the flavonoid quercetin has received attention for its effects on the cell cycle arrest and apoptosis. In the past, we addressed this issue in K562 cells, a cellular model of the human chronic myeloid leukemia. Here, we applied stable isotope labeling by amino acids in cell culture (SILAC) proteomics with the aim to increase knowledge on the regulative and metabolic pathways modulated by quercetin in these cells. After 24 h of quercetin treatment, we observed that apoptosis was not completely established, thus we selected this time range to capture quantitative data. As a result, we were able to achieve a robust identification of 1703 proteins, and to measure fold changes between quercetin-treated and untreated cells for 1206 proteins. Through a bioinformatics functional analysis on a subset of 112 proteins, we propose that the apoptotic phenotype of K562 cells entails a significant modulation of the translational machinery, RNA metabolism, antioxidant defense systems, and enzymes involved in lipid metabolism. Finally, we selected eight differentially expressed proteins, validated their modulated expression in quercetin-treated K562 cells, and discussed their possible role in flavonoid cytotoxicity. This quantitative profiling, performed for the first time on this type of tumor cells upon treatment with a flavonoid, will contribute to revealing the molecular basis of the multiplicity of the effects selectively exerted by quercetin on K562 cells.
在研究用于癌症预防和治疗的添加潜力的天然产物中，类黄酮槲皮素因其对细胞周期停滞和细胞凋亡的影响而受到关注。过去，我们在 K562 细胞中研究了这个问题，K562 细胞是人类慢性髓性白血病的细胞模型。在这里，我们应用了稳定同位素标记的氨基酸在细胞培养中的应用 ( SILAC ) 蛋白质组学，旨在增加对槲皮素在这些细胞中调节和代谢途径的了解。在槲皮素处理 24 小时后，我们观察到细胞凋亡并没有完全建立，因此我们选择这个时间范围来获取定量数据。结果，我们能够实现对 1703 种蛋白质的稳健鉴定，并对 1206 种蛋白质进行了槲皮素处理和未处理细胞之间的倍数变化测量。通过对 112 种蛋白质中的一小部分进行生物信息学功能分析，我们提出 K562 细胞的凋亡表型需要对翻译机制、RNA 代谢、抗氧化防御系统和参与脂质代谢的酶进行显著调节。最后，我们选择了 8 种差异表达的蛋白质，验证了它们在槲皮素处理的 K562 细胞中的表达变化，并讨论了它们在黄酮类化合物细胞毒性中的可能作用。这种在这种类型的肿瘤细胞上首次进行的定量分析，将有助于揭示槲皮素对 K562 细胞选择性发挥的多种作用的分子基础。
