MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University , Guangzhou 510631, P. R. China.
Anal Chem. 2017 Aug 15;89(16):8238-8243. doi: 10.1021/acs.analchem.7b00140. Epub 2017 Aug 2.
Mass spectrometry imaging (MSI) is an innovative and powerful tool in biomedical research. It is well-known that folic acid (FA) has a high affinity for folic acid receptor (FR), which is overexpressing in epithelial cancer. Herein, we propose a novel method to diagnose cancer through direct mapping of the label-free FA spatial distribution in tissue sections by state-of-the-art laser desorption postionization-mass spectrometry imaging (LDPI-MSI). Compared with other tumor imaging methods, such as fluorescence imaging, photoacoustic imaging (PAI), magnetic resonance imaging (MRI), and micro-SPECT/CT, complicated synthesis and labeling processes are not required. The LDPI-MSI was performed on 30 μm thick sections from a murine model of breast cancer (inoculation of 4T1 cells) that were predosed with 20 mg/kg of FA. The image obtained from the characteristic mass spectrometric signature of FA at m/z 265 illustrated that FA was concentrated primarily in tumor tissue and displayed somewhat lower retention in adjacent normal controls. The results suggest that the proposed method could be used potentially in cancer diagnosis.
质谱成像（MSI）是生物医学研究中一种创新且强大的工具。众所周知，叶酸（FA）与叶酸受体（FR）具有高亲和力，而 FR 在上皮癌中过度表达。在此，我们提出了一种通过最先进的激光解吸/场解吸-质谱成像（LDPI-MSI）直接对组织切片中无标记 FA 空间分布进行定位来诊断癌症的新方法。与其他肿瘤成像方法（如荧光成像、光声成像（PAI）、磁共振成像（MRI）和微 SPECT/CT）相比，这种方法不需要复杂的合成和标记过程。在预先给予 20mg/kg FA 的乳腺癌（接种 4T1 细胞）小鼠模型的 30μm 厚切片上进行了 LDPI-MSI。从 FA 的特征质谱特征 m/z 265 获得的图像表明，FA 主要集中在肿瘤组织中，在相邻的正常对照组织中的保留量略低。结果表明，该方法可能可用于癌症诊断。
