Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Guangdong Institute of Gastroenterology, Guangzhou, Guangdong, China.
J Clin Lab Anal. 2022 Oct;36(10):e24678. doi: 10.1002/jcla.24678. Epub 2022 Aug 29.
The inhibitor of β-catenin and T-cell factor (ICAT) is a direct negative regulator of the canonical Wnt signaling pathway, which is an attractive therapeutic target for colorectal cancer (CRC). Accumulating evidence suggests that ICAT interacts with other proteins to exert additional functions, which are not yet fully elucidated.
The overexpression of ICAT of CRC cells was conducted by lentivirus infection and plasmids transfection and verified by quantitative real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) and Western blotting. The effect of ICAT on the mobility of CRC cells was assessed by wound healing assay and transwell assay in vitro and lung metastasis in vivo. New candidate ICAT-interacting proteins were explored and verified using the STRING database, silver staining, co-immunoprecipitation mass spectrometry analysis (Co-IP/MS), and immunofluorescence (IF) staining analysis.
Inhibitor of β-catenin and T-cell factor overexpression promoted in vitro cell migration and invasion and tumor metastasis in vivo. Co-IP/MS analysis and STRING database analyses revealed that junction plakoglobin (JUP), a homolog of β-catenin, was involved in a novel protein interaction with ICAT. Furthermore, JUP downregulation impaired ICAT-induced migration and invasion of CRC cells. In addition, ICAT overexpression activated the NF-κB signaling pathway, which led to enhanced CRC cell migration and invasion.
Inhibitor of β-catenin and T-cell factor promoted CRC cell migration and invasion by interacting with JUP and the NF-κB signaling pathway. Thus, ICAT could be considered a protein diagnostic biomarker for predicting the metastatic ability of CRC.
β-连环蛋白和 T 细胞因子（ICAT）抑制剂是经典 Wnt 信号通路的直接负调节剂，是结直肠癌（CRC）有吸引力的治疗靶点。越来越多的证据表明，ICAT 与其他蛋白质相互作用以发挥额外的功能，这些功能尚未完全阐明。
通过慢病毒感染和质粒转染过表达 CRC 细胞的 ICAT，并通过实时定量逆转录聚合酶链反应（real-time RT-PCR）和 Western blot 验证。体外划痕愈合实验和 Transwell 实验以及体内肺转移实验评估 ICAT 对 CRC 细胞迁移能力的影响。使用 STRING 数据库、银染、免疫共沉淀质谱分析（Co-IP/MS）和免疫荧光（IF）染色分析探索和验证新的候选 ICAT 相互作用蛋白。
ICAT 过表达促进了 CRC 细胞的体外迁移和侵袭以及体内肿瘤转移。Co-IP/MS 分析和 STRING 数据库分析表明，桥粒斑蛋白（JUP），β-连环蛋白的同源物，参与了与 ICAT 的新型蛋白相互作用。此外，JUP 下调削弱了 ICAT 诱导的 CRC 细胞迁移和侵袭。此外，ICAT 过表达激活了 NF-κB 信号通路，导致 CRC 细胞迁移和侵袭增强。
ICAT 通过与 JUP 和 NF-κB 信号通路相互作用促进 CRC 细胞迁移和侵袭。因此，ICAT 可被视为预测 CRC 转移能力的蛋白质诊断生物标志物。
