Yang Ting, Xu Feifei, Zhao Yi, Wang Shui, Yang Mi, Chen Yun
School of Pharmacy, Nanjing Medical University, Nanjing, China.
Proteomics Clin Appl. 2014 Oct;8(9-10):773-82. doi: 10.1002/prca.201300109. Epub 2014 Jun 25.
Overexpression of human transferrin receptor (TfR) has been described qualitatively in various cancers, including breast cancer. Since TfR is also expressed to some extent under normal physiological conditions, increase of specificity and reproducibility in TfR quantification could improve the early detection and prognostic evaluation of cancers.
A LC-MS/MS-based targeted proteomics assay was developed for the determination of TfR in human breast cells and tissue samples.
We selected the tryptic peptide 681VEYHFLSPYVSPK693 as the surrogate peptide for quantification and used a stable isotope-labeled synthetic peptide with this sequence as an internal standard. Quality control data indicated acceptable accuracy and precision. Finally, this assay was successfully applied to the quantitative analysis of TfR in three breast cell lines and 36 matched pairs of breast tissue samples. The experimental values were compared with those obtained from conventional analytical methods, including immunofluorescence microscopy, Western blotting, flow cytometry, and immunohistochemistry.
Not only is the LC-MS/MS-based targeted proteomics assay a more accurate method for the determination of TfR levels, but may afford more reliable quantification of TfR at low concentrations in clinical practice.
人类转铁蛋白受体（TfR）的过表达已在包括乳腺癌在内的多种癌症中得到定性描述。由于TfR在正常生理条件下也有一定程度的表达，提高TfR定量的特异性和可重复性可能会改善癌症的早期检测和预后评估。
开发了一种基于液相色谱-串联质谱（LC-MS/MS）的靶向蛋白质组学分析方法，用于测定人乳腺细胞和组织样本中的TfR。
我们选择胰蛋白酶肽段681VEYHFLSPYVSPK693作为定量的替代肽段，并使用具有该序列的稳定同位素标记合成肽作为内标。质量控制数据表明准确性和精密度可接受。最后，该分析方法成功应用于三种乳腺癌细胞系和36对匹配的乳腺组织样本中TfR的定量分析。将实验值与通过传统分析方法获得的值进行比较，这些传统方法包括免疫荧光显微镜、蛋白质印迹法、流式细胞术和免疫组织化学。
基于LC-MS/MS的靶向蛋白质组学分析方法不仅是测定TfR水平更准确的方法，而且在临床实践中可能能够更可靠地定量低浓度的TfR。
