背景：石斛（Dendrobium nobile, D. nobile）是一种传统中药，近年来作为抗肿瘤药物备受关注，但其机制仍不清楚。本研究采用网络药理学、生物信息学和体外实验，探讨D. nobile中活性成分石斛素A对胰腺导管腺癌（PDAC）的作用和机制。 方法：利用SwissTargetPrediction和PharmMapper数据库获取石斛素A的潜在靶点，从The Cancer Genome Atlas和Genotype-Tissue Expression数据库获取PDAC与正常胰腺组织的差异表达基因（DEGs）。基于STRING数据库构建了石斛素A抗PDAC靶点的蛋白质相互作用（PPI）网络，采用分子对接评估石斛素A与抗PDAC靶点的结合情况。在临床组织芯片上免疫组化染色PLAU，其中PLAU是石斛素A抗PDAC的关键靶点之一。最后，利用体外实验验证石斛素A对PDAC细胞的PLAU表达、增殖、凋亡、细胞周期、迁移和侵袭的影响。 结果：筛选出90个石斛素A抗PDAC的基因，构建了石斛素A抗PDAC靶点的PPI网络。值得注意的是，PPI中的一个无标度模块包含19个基因，表明PPI非常可信。在这19个基因中，PLAU与癌性恶病质状态呈正相关，与PDAC患者总体生存率呈负相关。分子对接表明，石斛素A与PLAU结合，石斛素A处理导致PDAC细胞PLAU表达下降。基于临床组织芯片，PLAU蛋白在PDAC细胞中高表达，与PDAC分化和淋巴结转移状态有关。体外实验进一步显示，石斛素A处理显著抑制PDAC细胞的增殖、迁移和侵袭，诱导凋亡，阻滞PDAC细胞在G2/M期的细胞周期。 结论：石斛素A是D. nobile中有效的抗PDAC活性成分，通过靶向PLAU来抗击PDAC。我们的结果为基于D. nobile的未来PDAC治疗提供了基础。Copyright © 2023 Xu，Yu，Yang，Wang，Fan，Ruan，Zhang，Dai，Mei，Jie和Zheng。

Background: Dendrobium nobile (D. nobile), a traditional Chinese medicine, has received attention as an anti-tumor drug, but its mechanism is still unclear. In this study, we applied network pharmacology, bioinformatics, and in vitro experiments to explore the effect and mechanism of Dendrobin A, the active ingredient of D. nobile, against pancreatic ductal adenocarcinoma (PDAC). Methods: The databases of SwissTargetPrediction and PharmMapper were used to obtain the potential targets of Dendrobin A, and the differentially expressed genes (DEGs) between PDAC and normal pancreatic tissues were obtained from The Cancer Genome Atlas and Genotype-Tissue Expression databases. The protein-protein interaction (PPI) network for Dendrobin A anti-PDAC targets was constructed based on the STRING database. Molecular docking was used to assess Dendrobin A anti-PDAC targets. PLAU, one of the key targets of Dendrobin A anti-PDAC, was immunohistochemically stained in clinical tissue arrays. Finally, in vitro experiments were used to validate the effects of Dendrobin A on PLAU expression and the proliferation, apoptosis, cell cycle, migration, and invasion of PDAC cells. Results: A total of 90 genes for Dendrobin A anti-PDAC were screened, and a PPI network for Dendrobin A anti-PDAC targets was constructed. Notably, a scale-free module with 19 genes in the PPI indicated that the PPI is highly credible. Among these 19 genes, PLAU was positively correlated with the cachexia status while negatively correlated with the overall survival of PDAC patients. Through molecular docking, Dendrobin A was found to bind to PLAU, and the Dendrobin A treatment led to an attenuated PLAU expression in PDAC cells. Based on clinical tissue arrays, PLAU protein was highly expressed in PDAC cells compared to normal controls, and PLAU protein levels were associated with the differentiation and lymph node metastatic status of PDAC. In vitro experiments further showed that Dendrobin A treatment significantly inhibited the proliferation, migration, and invasion, inducing apoptosis and arresting the cell cycle of PDAC cells at the G2/M phase. Conclusion: Dendrobin A, a representative active ingredient of D. nobile, can effectively fight against PDAC by targeting PLAU. Our results provide the foundation for future PDAC treatment based on D. nobile.Copyright © 2023 Xu, Yu, Yang, Wang, Fan, Ruan, Zhang, Dai, Mei, Jie and Zheng.