目的:探讨miR-429 靶向PTEN并通过PI3K/AKT信号通路调控胰腺癌PANC-1 细胞对卡培他滨的耐药性及其作用机制。方法：建立胰腺癌卡培他滨耐药细胞株PANC-1/CAP后，采用qRT-PCR和Western blotting 实验检测miR-429 和PTEN在胰腺癌细胞中的表达情况，平板克隆形成实验、CCK-8 法和Annexin V-FITC/PI 双染流式细胞术检测敲降miR-429 对胰腺癌卡培他滨耐药细胞株PANC-1/CAP 细胞增殖、凋亡和卡培他滨耐药性的影响，双荧光素酶报告基因验证miR-429 与PTEN 的靶向关系，Western blotting 实验进一步检测miR-429 对PTEN-PI3K/AKT信号通路的调控作用。结果：miR-429 在胰腺癌PANC-1 细胞和PANC-1/CAP细胞中的表达水平高于人胰腺导管上皮细胞（HPDE6-C7）（P<0.05 或P<0.01），敲降miR-429 可显著抑制PANC-1/CAP细胞增殖活力、促进细胞凋亡及下调细胞卡培他滨耐药性，且双荧光素酶报告基因证实miR-429 靶向作用PTEN并下调其表达水平（P<0.05 或P<0.01）；敲降miR-429 可通过靶向上调PTEN并阻断PI3K/AKT信号通路进而显著抑制PANC-1/CAP细胞增殖活力，从而下调PANC-1/CAP细胞对卡培他滨的耐药性（P<0.05 或P<0.01）。结论：miR-429/PTEN-PI3K、AKT信号通路与胰腺癌卡培他滨耐药性存在调控关系，且敲降miR-429 可逆转PANC-1/CAP对卡培他滨的耐药性。

Objective: To explore the mechanism of miR-429 targeting PTEN to affect capecitabine-resistance in pancreatic cancer PANC-1 cells though the PI3K/AKT signaling pathway. Methods: Capecitabine-resistant pancreatic cancer cell line PANC-1/CAP was constructed, and the expression of miR-429 and PTEN were detected by quantitative Real-time polymerase chain reaction (qRT-PCR)and Western blotting. The effect of miR-429 knock-down on cell proliferation viability, apoptosis and capecitabine-resistance was measured by colony formation assay, CCK-8 assay and Annexin V-FITC/PI double staining flow cytometry assay, respectively. Subsequently,dual luciferase reporter assay verified that PTEN was a target gene of miR-429. Furthermore, the effect of miR-429 on PTEN-PI3K/AKT signaling pathway was measured by Western blotting. Results: miR-429 was found to be up-regulated in PANC-1 cells and PANC-1/CAP cells compared with the non-malignant pancreatic ductal cell line (HPDE6-C7) (P<0.05 or P<0.01). Moreover, silencing of miR-429 significantly decreased cell proliferation viability, capecitabine-resistance and enhanced apoptosis of PANC-1/CAP cells;additionally, dual luciferase reporter assay confirmed that PTEN was a target of miR-429 (P<0.05 or P<0.01). Suppression of miR-429 up-regulated PTEN and blocked the PI3K / AKT signaling pathway to decrease cell proliferation viability and further reduce the capecitabine-resistance of PANC-1/CAP cells (P<0.05 or P<0.01). Conclusion: miR-429/PTEN-PI3K/AKT signaling pathway plays a certain role in regulating the capecitabine-resistance of pancreatic cancer, and inhibition of miR-429 expression may reverse the resistance of PANC-1/CAP to capecitabine.