Key Laboratory of Shanghai Gastric Neoplasms, Department of Surgery, Ruijin Hospital, Shanghai Jiao Tong University, Shanghai 200025, PR China.
Clin Chim Acta. 2012 Jul 11;413(13-14):1098-106. doi: 10.1016/j.cca.2012.03.003. Epub 2012 Mar 13.
Early diagnosis and treatment of gastric cancer patients is essential for improving prognosis. However, no available serum-based test provides sufficient sensitivity or specificity for widespread use. Therefore, in this study we aimed to identify cancer biomarkers in human sera using 2-dimensional difference gel electrophoresis (2D-DIGE), and to characterize protein biomarkers with tandem mass spectrometry.
We compared the serum proteomic profiles of 20 gastric cancer patients and 10 healthy volunteers. Serum samples were first chromatographed using an immunoaffinity high-performance liquid chromatography (HPLC) column to selectively remove albumin, immunoglobulins, transferrin, haptoglobin, and antitrypsin. Differential protein analysis was then performed using DIGE. Significantly increased and decreased protein spot features were excised, trypsin digested, and analyzed by tandem matrix-assisted laser desorption/ionization (MALDI) time of flight (TOF)/TOF and a linear trap quadrupole (LTQ) mass spectrometer.
Seventeen protein spot features were significantly increased and 7 were significantly decreased in cancer serum samples compared to healthy controls. We identified 7 unique proteins that were upregulated, including plasminogen, apolipoprotein A-IV, Kininogen-1, complex-forming glycoprotein HC, complement component C4A, apolipoprotein J, and clusterin, and 5 that were decreased.
These results suggest that the combination of multi-dimensional HPLC and 2D-DIGE provides a valuable tool for serum proteomics in gastric cancer.
早期诊断和治疗胃癌患者对于改善预后至关重要。然而，目前尚无基于血清的检测方法能够提供足够的敏感性和特异性以供广泛应用。因此，在本研究中，我们旨在使用二维差异凝胶电泳（2D-DIGE）鉴定人血清中的癌症生物标志物，并使用串联质谱法对蛋白质生物标志物进行鉴定。
我们比较了 20 例胃癌患者和 10 例健康志愿者的血清蛋白质组图谱。首先使用免疫亲和高效液相色谱（HPLC）柱对血清样本进行色谱分离，以选择性去除白蛋白、免疫球蛋白、转铁蛋白、触珠蛋白和α-1 抗胰蛋白酶。然后使用 DIGE 进行差异蛋白分析。选择明显增加和减少的蛋白质斑点特征进行酶切，然后通过串联基质辅助激光解吸/电离（MALDI）飞行时间（TOF）/TOF 和线性阱四极杆（LTQ）质谱仪进行分析。
与健康对照组相比，癌症血清样本中 17 个蛋白质斑点特征明显增加，7 个蛋白质斑点特征明显减少。我们鉴定出 7 种上调的独特蛋白质，包括纤溶酶原、载脂蛋白 A-IV、激肽原-1、形成复合物的糖蛋白 HC、补体成分 C4A、载脂蛋白 J 和簇蛋白，以及 5 种下调的蛋白质。
这些结果表明，多维 HPLC 和 2D-DIGE 的组合为胃癌的血清蛋白质组学提供了一种有价值的工具。
