Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Minin and Pozharsky Square, 10/1, 603005 Nizhny Novgorod, Russia.
N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Kosygin st. 4, 119991 Moscow, Russia.
Methods Appl Fluoresc. 2022 Aug 25;10(4). doi: 10.1088/2050-6120/ac89cd.
The investigations reported here were designed to determine whether the bulk plasma membrane is involved in mechanisms of acquired resistance of colorectal cancer cells to 5-fluorouracil (5-FU). Fluorescence lifetime imaging microscopy (FLIM) of live cultured cells stained with viscosity-sensitive probe BODIPY 2 was exploited to non-invasively assess viscosity in the course of treatment and adaptation to the drug. In parallel, lipid composition of membranes was examined with the time-of-flight secondary ion mass spectrometry (ToF-SIMS). Our results showed that a single treatment with 5-FU induced only temporal changes of viscosity in 5-FU sensitive cells immediately after adding the drug. Acquisition of chemoresistance was accompanied by persistent increase of viscosity, which was preserved upon treatment without any changes. Lipidomic analysis revealed that the resistant cells had a lower level of monounsaturated fatty acids and increased sphingomyelin or decreased phosphatidylcholine in their membranes, which partly explain increase of the viscosity. Thus, we propose that a high membrane viscosity mediates the acquisition of resistance to 5-FU.
本研究旨在探讨结直肠癌细胞获得性耐氟尿嘧啶（5-FU）的机制是否与质膜整体有关。本研究利用对粘度敏感的 BODIPY 2 荧光探针对活细胞进行荧光寿命成像显微镜（FLIM）检测，以在治疗和适应药物的过程中无创性地评估粘度。同时，利用飞行时间二次离子质谱（ToF-SIMS）来检测膜的脂质组成。我们的结果表明，5-FU 单次处理仅在添加药物后立即引起敏感细胞的粘度短暂变化。获得化疗耐药性伴随着粘度的持续增加，而在没有任何变化的情况下继续处理时，这种增加的粘度得以保留。脂质组学分析表明，耐药细胞的膜中不饱和脂肪酸水平较低，鞘磷脂增加或磷脂酰胆碱减少，这部分解释了粘度的增加。因此，我们提出高膜粘度介导了结直肠癌细胞对 5-FU 的耐药性的获得。
