转移是一个多步骤的过程，涉及癌细胞的迁移和侵袭，是癌症恶性的标志。长链非编码RNA（lncRNA）在转移调控中发挥关键作用。本研究旨在阐明长链非编码RNA溶质载体有机阴离子转运蛋白家族成员4A1-反义1（SLCO4A1-AS1）在转移中的作用及其潜在调控机制。通过对基因表达坊（GEO）数据库的综合分析，选择了与转移相关的lncRNAs。通过Transwell迁移和侵袭实验以及尾静脉注射小鼠模型来评估癌细胞的体外和体内迁移和侵袭情况。采用高通量筛选方法，包括质谱分析和RNA测序（RNA-seq），鉴定了SLCO4A1-AS1的下游靶点。通过反转录定量聚合酶链式反应（RT-qPCR）、蛋白质印迹、RNA pull-down、RNA免疫沉淀（RIP）、原位杂交（FISH）和染色质免疫沉淀（ChIP）实验来鉴定并验证SLCO4A1-AS1的潜在调控机制。SLCO4A1-AS1通过破坏细胞骨架丝降低癌细胞的迁移和侵袭，并与肺腺癌患者的总体生存期延长有关。SLCO4A1-AS1直接与DNA结合蛋白TOX High Mobility Group Box Family Member 4（TOX4）相互作用，抑制TOX4诱导的迁移和侵袭。此外，RNA-seq揭示了神经肽承受体1（NTSR1）是SLCO4A1-AS1和TOX4的一个新的汇合下游靶点。机制上，SLCO4A1-AS1充当TOX4的诱骗物，中断其与NTSR1启动子的相互作用，阻止NTSR1的转录。功能上，NTSR1通过细胞骨架重塑促进癌细胞的迁移和侵袭，并且NTSR1的敲低显著抑制了TOX4诱导的迁移和侵袭。这些发现表明SLCO4A1-AS1在对抗TOX4/NTSR1信号传导方面起到了重要作用，突出了其在肺癌细胞迁移和侵袭中的关键作用。这些发现为针对SLCO4A1-AS1/TOX4/NTSR1轴的新型治疗策略开发提供了希望，作为肺癌有效干预的潜在途径。© 2023. 中华民国（台湾）国家科学委员会。

Metastasis is a multistep process involving the migration and invasion of cancer cells and is a hallmark of cancer malignancy. Long non-coding RNAs (lncRNAs) play critical roles in the regulation of metastasis. This study aims to elucidate the role of the lncRNA solute carrier organic anion transporter family member 4A1-antisense 1 (SLCO4A1-AS1) in metastasis and its underlying regulatory mechanisms.A comprehensive analysis of the Gene Expression Omnibus (GEO) database were used to identify metastasis-associated lncRNAs. Transwell migration and invasion assays, and a tail vein-injection mouse model were used to assess the migration and invasion of cancer cells in vitro and in vivo, respectively. High-throughput screening methods, including MASS Spectrometry and RNA sequencing (RNA-seq), were used to identify the downstream targets of SLCO4A1-AS1. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), western blotting, RNA pull-down, RNA immunoprecipitation (RIP), fluorescence in situ hybridization (FISH), and chromatin immunoprecipitation (ChIp) assays were conducted to identify and validate the underlying regulatory mechanisms of SLCO4A1-AS1.SLCO4A1-AS1 reduced cancer cell migration and invasion by disrupting cytoskeleton filaments, and was associated with longer overall survival in patients with lung adenocarcinoma. SLCO4A1-AS1 directly interacted with the DNA-binding protein, TOX High Mobility Group Box Family Member 4 (TOX4), to inhibit TOX4-induced migration and invasion. Furthermore, RNA-seq revealed that neurotensin receptor 1 (NTSR1) is a novel and convergent downstream target of SLCO4A1-AS1 and TOX4. Mechanistically, SLCO4A1-AS1 functions as a decoy of TOX4 by interrupting its interaction with the NTSR1 promoter and preventing NTSR1 transcription. Functionally, NTSR1 promotes cancer cell migration and invasion through cytoskeletal remodeling, and knockdown of NTSR1 significantly inhibits TOX4-induced migration and invasion.These findings demonstrated that SLCO4A1-AS1 antagonizes TOX4/NTSR1 signaling, underscoring its pivotal role in lung cancer cell migration and invasion. These findings hold promise for the development of novel therapeutic strategies targeting the SLCO4A1-AS1/TOX4/NTSR1 axis as a potential avenue for effective therapeutic intervention in lung cancer.© 2023. National Science Council of the Republic of China (Taiwan).