目的 通过研究胃癌患者血清和组织中miRNA21的表达情况，了解其在胃癌发病过程中的意义。方法 选取胃癌患者 及正常健康对照组各20例，采用原位杂交的方法检测和实时定量PCR检测miRNA21的水平。结果 胃癌组组织和血清 中的miRNA21表达水平均较正常组升高，且差异具有统计学意义(P＜0.05)。结论 胃癌患者组织和血清中的miRNA21 表达升高，可能为胃癌的诊断以及治疗提供新的方向。

Objective To investigate the significance of the detection of miRNA21 expression in the serum and tissues of the patients with gastric cancer. Methods 20 patients with gastric cancer and 20 healthy controls were detected. And the expression of miRNA21 was evaluated by using the method of in situ hybridization and realtime quantitative polymerase chain reaction(PCR). Results miRNA21 in the serum and tissues of patients with gastric cancer was higher than that in the healthy control group, the difference had statistical significance (P<0.05). Conclusion The upregulated expression of miRNA21 in the serum and tissues of the patients with gastric cancer might provide a new direction of diagnosis and therapy for gastric cancer.