Department of Gastroenterology and Hepatology, The 309 Hospital of People's Liberation Army, Beijing, China.
Braz J Med Biol Res. 2012 Mar;45(3):273-83. doi: 10.1590/s0100-879x2012007500026. Epub 2012 Mar 1.
Chronic atrophic gastritis (CAG) is a very common gastritis and one of the major precursor lesions of gastric cancer, one of the most common cancers worldwide. The molecular mechanism underlying CAG is unclear, but its elucidation is essential for the prevention and early detection of gastric cancer and appropriate intervention. A combination of two-dimensional gel electrophoresis and mass spectrometry was used in the present study to analyze the differentially expressed proteins. Samples from 21 patients (9 females and 12 males; mean age: 61.8 years) were used. We identified 18 differentially expressed proteins in CAG compared with matched normal mucosa. Eight proteins were up-regulated and 10 down-regulated in CAG when compared with the same amounts of proteins in individually matched normal gastric mucosa. Two novel proteins, proteasome activator subunit 1 (PSME1), which was down-regulated in CAG, and ribosomal protein S12 (RPS12), which was up-regulated in CAG, were further investigated. Their expression was validated by Western blot and RT-PCR in 15 CAG samples matched with normal mucosa. The expression level of RPS12 was significantly higher in CAG than in matched normal gastric mucosa (P < 0.05). In contrast, the expression level of PSME1 in CAG was significantly lower than in matched normal gastric mucosa (P < 0.05). This study clearly demonstrated that there are some changes in protein expression between CAG and normal mucosa. In these changes, down-regulation of PSME1 and up-regulation of RPS12 could be involved in the development of CAG. Thus, the differentially expressed proteins might play important roles in CAG as functional molecules.
慢性萎缩性胃炎（CAG）是一种非常常见的胃炎，也是胃癌的主要前体病变之一，胃癌是全球最常见的癌症之一。CAG 的分子机制尚不清楚，但阐明这一机制对于胃癌的预防和早期发现以及适当的干预至关重要。本研究采用二维凝胶电泳和质谱联用技术分析差异表达蛋白。共检测了 21 例患者（9 例女性，12 例男性；平均年龄：61.8 岁）的标本。与匹配的正常黏膜相比，CAG 中鉴定出 18 种差异表达蛋白。与单独匹配的正常胃黏膜相比，CAG 中有 8 种蛋白上调，10 种蛋白下调。PSME1（下调）和 RPS12（上调）这两种新的差异表达蛋白在 CAG 中进一步研究。通过 Western blot 和 RT-PCR 验证了 15 例 CAG 样本与其匹配的正常黏膜中的表达情况。与匹配的正常胃黏膜相比，RPS12 在 CAG 中的表达水平明显升高（P < 0.05）。相反，PSME1 在 CAG 中的表达水平明显低于匹配的正常胃黏膜（P < 0.05）。本研究清楚地表明，CAG 与正常黏膜之间存在一些蛋白表达变化。在这些变化中，PSME1 的下调和 RPS12 的上调可能与 CAG 的发生有关。因此，差异表达蛋白可能作为功能分子在 CAG 中发挥重要作用。
