Zhu Tingting, Xu Longjiang, Xu Xiukun, Wang Zheng, Zhu Jian, Xie Qing, Zhang Biyan, Wang Yanping, Ju Linling, He Yun, Ye Xinshan, Zhou Dapeng, Li Yunsen
Laboratory of Cellular and Molecular Tumor Immunology, Institutes of Biology and Medical Sciences, Jiangsu Laboratory of Infection Immunity, Soochow University, 199 Ren-Ai Road, Suzhou 215123, China.
The Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
Carbohydr Res. 2015 Jan 30;402:189-99. doi: 10.1016/j.carres.2014.10.006. Epub 2014 Oct 19.
Abnormal glycosphingolipids (GSLs) are expressed in many human tumors. These tumor-associated GSLs may have important roles in tumor progression. However, they are hard to be detected because of their low concentration and the limited availability of antibodies and lectins that recognize them. Thus, mass spectrometry is an effective method to analyze GSLs with high sensitivity. Here, we use electrospray ionization-linear ion trap quadrupole mass spectrometry (ESI-LTQ-MS) and liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) to determine the structure of a certain GSL in human breast cancer tissue. To obtain the breast cancer-associated GSLs, we applied relative abundance contrast of GSLs and signal-to-noise ratio (SNR) analyses. We also used α1,2 fucosidase and fucosyltransferases as tools in the structural analysis. Based on this analysis, we identified the ion with m/z 1184 molecular ion as fucosyl-lactoceramide (Fuc-LacCer) with a C16 fatty acid ceramide. Quantitative analysis of GSLs revealed both Fuc-LacCer and Globo-H increased in breast cancer tissues. However, these two breast cancer-associated GSLs had different roles. The results of SNR analysis suggested the abnormal Fuc-LacCer is specific to breast cancer. The GSL profiling of breast cancer cells showed fucosyltransferase 1 contributed to the biosynthesis of Globo-H and Fuc-LacCer. In conclusion, MS analysis identified an accumulation of Fuc-LacCer in breast cancer tissue. Our findings provide GSL profiles of human breast cancer and develop an MS method for the study of cancer-associated GSLs.
异常糖鞘脂（GSLs）在许多人类肿瘤中表达。这些肿瘤相关的GSLs可能在肿瘤进展中起重要作用。然而，由于它们的浓度低以及识别它们的抗体和凝集素的可用性有限，很难检测到它们。因此，质谱分析法是一种高灵敏度分析GSLs的有效方法。在这里，我们使用电喷雾电离-线性离子阱四极杆质谱仪（ESI-LTQ-MS）和液相色谱/电喷雾电离串联质谱仪（LC/ESI-MS/MS）来确定人乳腺癌组织中某一GSL的结构。为了获得与乳腺癌相关的GSLs，我们应用了GSLs的相对丰度对比和信噪比（SNR）分析。我们还使用α1,2岩藻糖苷酶和岩藻糖基转移酶作为结构分析的工具。基于此分析，我们鉴定出质荷比为1184的分子离子为带有C16脂肪酸神经酰胺的岩藻糖基乳糖神经酰胺（Fuc-LacCer）。GSLs的定量分析显示，Fuc-LacCer和Glob-H在乳腺癌组织中均增加。然而，这两种与乳腺癌相关的GSLs具有不同的作用。SNR分析结果表明，异常的Fuc-LacCer是乳腺癌特有的。乳腺癌细胞的GSL谱分析表明，岩藻糖基转移酶1有助于Glob-H和Fuc-LacCer的生物合成。总之，质谱分析确定了Fuc-LacCer在乳腺癌组织中的积累。我们的研究结果提供了人乳腺癌的GSL谱，并开发了一种用于研究癌症相关GSLs的质谱方法。
