The purpose of this study was to elucidate the role that the miR-18a-5p/THBD regulatory pathway plays in endometrial cancer (EC), which could provide a theoretical basis for potential therapeutic targets. Differentially expressed genes in EC tissue and normal tissue were determined by bioinformatics analysis. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to compare the expression of miR-18a-5p and THBD mRNA in normal human endometrial cells and human EC cells. CCK-8 assay was used to compare the proliferative ability of EC cells in different treatment groups. Transwell assay was used to detect the migratory and invasive abilities of EC cells in different treatment groups. Dual-luciferase assay was used to verify the targeting relationship between miR-18a-5p and THBD. Western blot assay was used to detect THBD protein expression level. qRT-PCR results showed that miR-18a-5p was significantly upregulated in EC cells, and expression of its target gene, THBD, was significantly downregulated. CCK-8 and transwell assays showed that miR-18a-5p could enhance the proliferative, migratory, and invasive abilities of EC cells, whereas THBD could weaken those abilities. Dual-luciferase assay confirmed that miR-18a-5p could negatively regulate THBD expression. In addition, rescue experiments revealed that the oncogenic effect of miR-18a-5p on EC cells was inhibited by THBD overexpression. We conclude that miR-18a-5p could promote the proliferation, migration, and invasion of EC cells by targeting and downregulating THBD expression, and the miR-18a-5p/THBD regulatory pathway might be a therapeutic target. The results of this study may serve as a theoretical basis for related drug development.

中文翻译：

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MiR-18a-5p 通过靶向 THBD 促进子宫内膜癌细胞的增殖、迁移和侵袭。

本研究旨在阐明miR-18a-5p/THBD调控通路在子宫内膜癌（EC）中的作用，为潜在的治疗靶点提供理论依据。通过生物信息学分析确定EC组织和正常组织中差异表达的基因。定量逆转录聚合酶链反应（qRT-PCR）用于比较正常人子宫内膜细胞和人EC细胞中miR-18a-5p和THBD mRNA的表达。CCK-8测定用于比较不同处理组中EC细胞的增殖能力。Transwell测定用于检测不同治疗组中EC细胞的迁移和侵袭能力。双荧光素酶测定用于验证 miR-18a-5p 和 THBD 之间的靶向关系。Western印迹法用于检测THBD蛋白表达水平。qRT-PCR结果显示miR-18a-5p在EC细胞中显着上调，其靶基因THBD的表达显着下调。CCK-8 和 transwell 检测表明 miR-18a-5p 可以增强 EC 细胞的增殖、迁移和侵袭能力，而 THBD 可以削弱这些能力。双荧光素酶测定证实 miR-18a-5p 可以负调节 THBD 表达。此外，拯救实验表明 miR-18a-5p 对 EC 细胞的致癌作用受到 THBD 过表达的抑制。我们得出结论，miR-18a-5p可以通过靶向和下调THBD表达来促进EC细胞的增殖、迁移和侵袭，miR-18a-5p/THBD调节通路可能是一个治疗靶点。