Waki Michihiko, Ide Yoshimi, Ishizaki Itsuko, Nagata Yasuyuki, Masaki Noritaka, Sugiyama Eiji, Kurabe Nobuya, Nicolaescu Dan, Yamazaki Fumiyoshi, Hayasaka Takahiro, Ikegami Koji, Kondo Takeshi, Shibata Kiyoshi, Hiraide Takanori, Taki Yumiko, Ogura Hiroyuki, Shiiya Norihiko, Sanada Noriaki, Setou Mitsutoshi
Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, 1-20-1, Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan.
Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, 1-20-1, Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan; Department of Surgery I, Hamamatsu University School of Medicine, 1-20-1, Handayama, Higashi-ku, Hamamatsu, Shizuoka, Japan.
Biochimie. 2014 Dec;107 Pt A:73-7. doi: 10.1016/j.biochi.2014.10.003. Epub 2014 Oct 13.
Lipids comprise the primary component of cell membranes. Imaging mass spectrometry is increasingly being used to visualize membranous lipids in clinical specimens, and it has revealed that abnormal lipid metabolism is related to the development of diseases. To characterize cell populations which are rare and sparsely localized in tissues, we conducted time-of-flight secondary ion mass spectrometry (TOF-SIMS) analyses of individual cells sorted by fluorescence activated cell sorting (FACS) and applied the method to analyze breast cancer stem cells (CSCs). TOF-SIMS analyses visualized phosphoric acids and four fatty acid (FA) species in the sorted CD45(-)/CD44(+)/CD24(-) CSCs, and these ions are suspected to have originated from membranous phospholipids as they were uniformly detected from the locus where the cells attached. Integrated ion intensity of palmitoleic acids [FA(16:1)] normalized by phosphoric acid signals were decreased significantly in CSCs as compared to that of CD45(-)/CD44(-)/CD24(+) non-stem cancer cells (NSCCs). This finding was supported by liquid chromatography coupled electrospray ionization-tandem mass spectrometry analysis, which revealed phosphatidylcholine (PC)(16:0/16:1) to be less abundant and PC(16:0/16:0) to be more abundant in CSCs as compared to NSCCs. Therefore, our novel method successfully provided lipid composition analysis of individual cells classified by the expression of a complex combination of cell-surface markers. The lipid compositions of CSCs originating from the heterogeneous cellular populations of clinical specimens were successfully characterized by this method.
脂质是细胞膜的主要成分。成像质谱技术越来越多地用于可视化临床标本中的膜脂，并且已经揭示异常脂质代谢与疾病的发展有关。为了表征在组织中罕见且分布稀疏的细胞群体，我们对通过荧光激活细胞分选（FACS）分选的单个细胞进行了飞行时间二次离子质谱（TOF-SIMS）分析，并将该方法应用于分析乳腺癌干细胞（CSCs）。TOF-SIMS分析可视化了分选的CD45(-)/CD44(+)/CD24(-) CSCs中的磷酸和四种脂肪酸（FA）种类，并且这些离子被怀疑源自膜磷脂，因为它们是从细胞附着的位点均匀检测到的。与CD45(-)/CD44(-)/CD24(+)非干细胞癌细胞（NSCCs）相比，CSCs中棕榈油酸[FA(16:1)]的积分离子强度经磷酸信号归一化后显著降低。液相色谱-电喷雾电离串联质谱分析支持了这一发现，该分析显示与NSCCs相比，CSCs中磷脂酰胆碱（PC）(16:0/16:1)含量较低，而PC(16:0/16:0)含量较高。因此，我们的新方法成功地提供了通过细胞表面标志物复杂组合表达分类的单个细胞的脂质组成分析。通过该方法成功表征了源自临床标本异质细胞群体的CSCs的脂质组成。
