Serine protease 2 (PRSS2) is upregulated in gastric cancer tissues, correlates with poor prognosis and promotes migration and invasion of gastric cancer cells. However, the exact mechanism by which PRSS2 promotes metastasis in gastric cancer is unclear. We examined serum PRSS2 levels in healthy controls and gastric cancer patients by enzyme linked immunosorbent assay (ELISA) and analyzed the correlation between PRSS2 serum level with the clinicopathological characteristics of gastric cancer patients and matrix metalloproteinase-9 (MMP-9) expression. A lentiviral MMP-9 overexpression vector was constructed and used to transfect gastric cancer cells with stable silencing of PRSS2, and migration, invasion and epithelial-mesenchymal transition (EMT) of gastric cancer cells were examined. High serum PRSS2 levels were detected in gastric cancer patients and associated with lymphatic metastasis and TNM stage. Serum PRSS2 was positively correlated with serum MMP-9 level. PRSS2 silencing inhibited EMT, and knock-down of PRSS2 partially abrogated cell metastasis and EMT caused by overexpression of MMP-9. These results suggest that PRSS2 promotes the migration and invasion of gastric cancer cells through EMT induction by MMP-9. Our findings suggest that PRSS2 may be a potential early diagnostic marker and therapeutic target of gastric cancer.

丝氨酸蛋白酶2（PRSS2）在胃癌组织中表达上调，与不良预后相关，并促进胃癌细胞的迁移和侵袭。然而，PRSS2促进胃癌转移的确切机制尚不清楚。我们通过酶联免疫吸附试验（ELISA）检测了健康对照和胃癌患者血清中PRSS2的水平，并分析了PRSS2血清水平与胃癌患者临床病理特征和基质金属蛋白酶9（MMP-9）表达的相关性。构建慢病毒MMP-9过表达载体，转染稳定沉默PRSS2的胃癌细胞，检测胃癌细胞的迁移、侵袭和上皮间质转化（EMT）。在胃癌患者中检测到高血清 PRSS2 水平，并与淋巴转移和 TNM 分期相关。血清PRSS2与血清MMP-9水平呈正相关。PRSS2 沉默抑制 EMT，PRSS2 的敲除部分消除了 MMP-9 过表达引起的细胞转移和 EMT。这些结果表明PRSS2通过MMP-9诱导EMT促进胃癌细胞的迁移和侵袭。我们的研究结果表明PRSS2可能是胃癌潜在的早期诊断标志物和治疗靶点。