结直肠腺癌（COAD）是全世界癌症相关死亡的一个重要原因，因此需要确定新的治疗靶点和治疗方法。本研究旨在探讨ARL3在COAD进展中的作用，并探讨胡椒碱对ARL3表达、细胞增殖、上皮间质转化（EMT）和内质网（ER）应激的影响。对癌症基因组图谱 (TCGA)-COAD、GSE39582 和 GSE44861 数据集的生物信息学分析评估了 ARL3 表达水平。来自人类蛋白质图谱 (HPA) 数据库的免疫组织化学数据证实了 COAD 中 ARL3 过度表达。还检查了 ARL3 与 COAD 临床参数和预后的关联。 COAD 细胞用胡椒碱处理，体外测定评估了细胞增殖、凋亡、EMT 标志物表达和 ER 应激反应。 COAD 中 ARL3 过度表达与不良预后相关，并且在不同病理阶段存在差异。胡椒碱处理以浓度和时间依赖性方式抑制 COAD 细胞增殖，如 Ki-67 水平降低和集落形成能力降低所示。胡椒碱诱导 COAD 细胞 S 期细胞周期停滞并促进细胞凋亡，Bax、Bcl-2、裂解的 caspase-3 和裂解的聚 (ADP-核糖) 聚合酶 (PARP) 水平的变化证明了这一点。此外，胡椒碱下调 COAD 细胞中 ARL3 的表达，从而抑制转化生长因子 β (TGF-β) 诱导的 EMT。此外，胡椒碱还可减弱 ARL3 介导的 ER 应激反应，显着减少结合免疫球蛋白 (BiP)、肌醇需求酶 1 α (p-IRE1α)、激活转录因子 6 (ATF6) 和 C/EBP 同源蛋白 (CHOP)水平。胡椒碱通过调节 ARL3 表达、破坏细胞周期进程、抑制 EMT 途径和调节 ER 应激在 COAD 中发挥抗癌作用。这些发现表明，胡椒碱通过靶向 ARL3 有望成为 COAD 的治疗剂。

Colorectal adenocarcinoma (COAD) is a significant cause of cancer-related mortality worldwide, necessitating the identification of novel therapeutic targets and treatments. This research aimed to investigate the role of ARL3 in COAD progression and to explore the effects of Piperine on ARL3 expression, cell proliferation, epithelial-mesenchymal transition (EMT), and endoplasmic reticulum (ER) stress. Bioinformatics analysis of The Cancer Genome Atlas (TCGA)-COAD, GSE39582, and GSE44861 datasets assessed ARL3 expression levels. Immunohistochemical data from the Human Protein Atlas (HPA) database confirmed ARL3 overexpression in COAD. The association of ARL3 with COAD clinical parameters and prognosis was also examined. COAD cells were treated with Piperine, and in vitro assays evaluated cell proliferation, apoptosis, EMT marker expression, and ER stress responses. ARL3 overexpression in COAD correlated with poor prognosis and varied across pathological stages. Piperine treatment inhibited COAD cell proliferation in a concentration- and time-dependent manner, as indicated by reduced Ki-67 levels and decreased colony-forming ability. Piperine induced S-phase cell cycle arrest and facilitated apoptosis in COAD cells, evidenced by changes in Bax, Bcl-2, cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase (PARP) levels. Moreover, Piperine downregulated ARL3 expression in COAD cells, thereby suppressing transforming growth factor beta (TGF-β)-induced EMT. Additionally, Piperine attenuated the ARL3-mediated ER stress response, significantly reducing binding immunoglobulin protein (BiP), inositol-requiring enzyme 1 alpha (p-IRE1α), activating transcription factor 6 (ATF6), and C/EBP homologous protein (CHOP) levels. Piperine exerted anti-cancer effects in COAD by modulating ARL3 expression, disrupting cell cycle progression, inhibiting the EMT pathway, and regulating ER stress. These findings suggest that Piperine holds promise as a therapeutic agent for COAD through its targeting of ARL3.