目的：探讨RNA干扰 Med19 的表达对结肠癌Caco-2细胞增殖和凋亡的影响。 方法: 构建靶向 Med19 的干扰质粒pSilencer-Med19-siRNA，转染Caco-2细胞后，RT-PCR检测Caco-2细胞中 Med19 mRNA的表达，Western blotting检测Caco-2细胞中Med19蛋白的表达，MTT检测pSilencer-Med19-siRNA转染后Caco-2细胞的增殖，流式细胞术分析Caco-2细胞的凋亡。 结果: RT-PCR及Western blotting检测结果显示，pSilencer-Med19-siRNA转染后Caco-2细胞中 Med19 mRNA及蛋白表达水平上均显著下降（P<0.01）；MTT及流式细胞术检测结果表明，与pSilencer对照组相比，pSilencer-Med19-siRNA组Caco-2细胞的增殖明显受到抑制\[7 d时：（0.86±0.09）% vs（1.38±1.10）%，P<0.01\]，且细胞凋亡比例明显升高\[（22.72±2.85）% vs（7.23±1.29）%，P<0.01\]。 结论: RNA干扰沉默 Med19 的表达可抑制结肠癌Caco-2细胞的增殖，促进其凋亡，提示 Med19 可作为结肠癌治疗的潜在靶点。

Objective: To explore the effect of the down-regulation of Med19 expression by RNAi on the proliferation and apoptosis of colon cancer Caco-2 cells. Methods: The pSilencer-Med19-siRNA interference plasmid targeting Med19 was constructed, which was transfected into Caco-2 cells. The level of Med19 mRNA in transfected Caco-2 cells was detected by RT-PCR and the level of Med19 protein was determined by Western blotting. Flow cytometry and MTT were performed to detect the proliferation and apoptosis of Caco-2 cells after pSilencer-Med19-siRNA transfection. Results: The results of RT-PCR and Western blotting showed that the mRNA and protein levels of Med19 declined markedly in Caco-2 cells that were transfected by pSilencer-Med19-siRNA vector (P<0.01). Compared with the control pSilencer group, flow cytometry and MTT assay demonstrated that pSilencer-Med19-siRNA significantly suppressed proliferation （7 d: \[086±0.09\]% vs \[1.38±1.10\]%, P<0.01) and induced the apoptosis of Caco-2 cells (\[22.72±2.85\]% vs \[723±1.29\]%, P<0.01) in the pSilencer-Med19-siRNA group. Conclusion: Silence Med19 expression by interference RNA can inhibit the proliferation and induce apoptosis of colon cancer Caco-2 cells, so Med19 may act as a potential therapeutic target in colon cancer.