探讨微RNA-129（miR-129）是否通过靶向阳离子氨基酸转运蛋白（CAT-1）调控结肠癌细胞精氨酸代谢，从而影响其增殖行为。

收集上海市东方医院2022年1月至2023年12月93对结肠癌及癌旁组织样本，采用实时荧光定量PCR（qPCR）、组织芯片与免疫组织化学检测CAT-1和miR-129的表达。通过生物信息学分析预测miR-129与CAT-1的靶向关系。选用RKO细胞，分别转染miR-129 mimic和sh-miR-129构建过表达与低表达模型，运用蛋白质印迹法（Western blotting）、酶联免疫吸附分析（ELISA）和CCK-8法检测CAT-1蛋白水平、细胞内精氨酸浓度及细胞增殖能力。

结肠癌组织中CAT-1在mRNA和蛋白水平均显著高表达，而miR-129明显低表达。生物信息学分析提示，miR-129与CAT-1的3’-UTR存在结合位点。功能实验显示结肠癌细胞增殖具有精氨酸浓度依赖性：过表达miR-129可抑制CAT-1表达，减少细胞内精氨酸蓄积，并抑制细胞增殖；干扰miR-129则呈现相反的效应。

miR-129在结肠癌中作为抑癌因子，可通过靶向CAT-1负调控精氨酸摄取，影响肿瘤细胞增殖。本研究揭示了“miR-129/CAT-1/精氨酸代谢”轴在结肠癌中的重要作用，为代谢靶向治疗提供了新思路。

To determine whether microRNA (miR)-129 regulating colon cancer cell proliferation by targeting the cationic amino acid transporter 1(CAT-1) and thus modulating arginine metabolism.

Expression of CAT-1 and miR-129 was examined in 93 paired colon cancer tissues using real-time fluorogenic quantitative PCR (qPCR) and immunohistochemistry (tissue microarray) from Shanghai East Hospital. Bioinformatics predicted their targeting relationship. In RKO cells, gain-and loss-of-function models for miR-129 were established. Western blotting, enzyme-linked immunosorbent assay (ELISA), and CCK-8 assays were used to assess CAT-1 protein, intracellular arginine, and proliferation.

CAT-1 was upregulated and miR-129 downregulated in tumors. miR-129 was bioinformatically predicted to bind the 3'-UTR of CAT-1. Functionally, cell proliferation was arginine-dependent. Overexpression of miR-129 suppressed CAT-1, decreased intracellular arginine, and inhibited proliferation, while miR-129 knockdown had opposing effects.

miR-129 functions as a tumor suppressor in colon cancer by targeting CAT-1, thereby negatively regulating arginine uptake and cell proliferation. This defines a critical miR-129/CAT-1/arginine metabolic axis.