Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA.
Arch Biochem Biophys. 2010 Feb 1;494(1):101-5. doi: 10.1016/j.abb.2009.11.023. Epub 2009 Nov 26.
The purpose of this study was to determine the sphingolipid (SL) profile in cells defective in autophagy protein ATG-7 and overall cell death after photodynamic therapy (PDT) with the photosensitizer Pc 4. MCF-7 human breast cancer cells with downregulated ATG-7 and their scrambled controls (Scr) were used. Exposure of ATG-7 knockdown cells to PDT led to increased cell killing. PDT evoked an early (2h) greater global increase in ceramides in ATG-7 defective cells compared to Scr cells. The total increases in dihydroceramide (DHceramide) were significant at 2 and 24h in both cell types post-PDT. The levels of sphingosine-1-phosphate (S1P) and sphingosine were decreased below resting levels at both time points irrespective of the cell type. The data imply that ceramide might be a marker of ATG-7 deficiency in cells sensitized to PDT.
本研究旨在确定自噬蛋白 ATG-7 缺陷细胞中的鞘脂(SL)谱以及光动力疗法(PDT)后细胞的总体死亡情况,该研究使用了下调 ATG-7 的 MCF-7 人乳腺癌细胞及其对照(Scr)。与 Scr 细胞相比,ATG-7 敲低细胞暴露于 PDT 会导致细胞杀伤增加。PDT 引发了早期(2 小时)ATG-7 缺陷细胞中神经酰胺的更大全局增加。两种细胞类型在 PDT 后 2 和 24 小时,二氢神经酰胺(DHceramide)的总增加均具有统计学意义。S1P 和神经酰胺的水平均低于静息水平,与细胞类型无关。数据表明,神经酰胺可能是对 PDT 敏感的细胞中 ATG-7 缺陷的标志物。