Background: Long noncoding RNAs (lncRNAs) are potential biomarkers that are very important for the development of cancer. Studies show that lncRNAs are significantly correlated with the carcinogenesis and progression of bladder cancer (BLCA). In this research, we aimed at probing into the role of lncRNA MAFG-AS1 in the tumorigenesis of BLCA. Methods: RT-qPCR was employed to detect MAFG-AS1 expression in BLCA tissues and cells. MAFG-AS1 siRNA and overexpression plasmid were transfected into 5637 and T24 BLCA cell lines to inhibit or upregulate MAFG-AS1 expression, respectively, and then the regulatory functions of MAFG-AS1 on BLCA cell proliferation, migration, and invasion were assessed using cell counting kit-8 (CCK-8) assay, EdU method, and Transwell experiments, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation were conducted to validate the targeting relationships between MAFG-AS1 and miR-143-3p, and miR-143-3p and COX-2. In addition, miR-143-3p was repressed in MAFG-AS1-silenced 5637 and T24 cell lines, and the function of MAFG-AS1/miR-143-3p axis in BLCA cells was further evaluated. The regulatory effects of MAFG-AS1 and miR-143-3p on the expression of COX-2 protein were detected by Western blot. Results: MAFG-AS1 was remarkably upregulated in BLCA patient tissues and cell lines, and its high expression was closely related to histological grade, tumor size, and lymph node metastasis. Silencing of MAFG-AS1 inhibited BLCA cell proliferation, metastasis, and invasion, while overexpression of MAFG-AS1 in BLCA cells had opposite biological effects. MAFG-AS1 was proved to target miR-143-3p to repress its expression. Moreover, it was confirmed that MAFG-AS1 and miR-143-3p could modulate COX-2 expression. Conclusion: The MAFG-AS1/miR-143-3p/COX-2 axis contributes to BLCA progression.

中文翻译：

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LncRNA MAFG-AS1 通过靶向 miR-143-3p/COX-2 轴促进膀胱癌的进展

背景：长链非编码 RNA (lncRNA) 是潜在的生物标志物，对癌症的发展非常重要。研究表明，lncRNAs与膀胱癌（BLCA）的癌变和进展显着相关。在本研究中，我们旨在探讨 lncRNA MAFG-AS1 在 BLCA 肿瘤发生中的作用。方法：采用RT-qPCR检测BLCA组织和细胞中MAFG-AS1的表达。将MAFG-AS1 siRNA和过表达质粒分别转染到5637和T24 BLCA细胞系中，分别抑制或上调MAFG-AS1的表达，然后通过细胞计数评估MAFG-AS1对BLCA细胞增殖、迁移和侵袭的调节作用分别是 kit-8 (CCK-8) 检测、EdU 方法和 Transwell 实验。进行双荧光素酶报告基因检测和 RNA 免疫沉淀以验证 MAFG-AS1 和 miR-143-3p 以及 miR-143-3p 和 COX-2 之间的靶向关系。此外，miR-143-3p 在 MAFG-AS1 沉默的 5637 和 T24 细胞系中被抑制，并进一步评估了 MAFG-AS1/miR-143-3p 轴在 BLCA 细胞中的功能。Western blot检测MAFG-AS1和miR-143-3p对COX-2蛋白表达的调控作用。结果：MAFG-AS1在BLCA患者组织和细胞系中显着上调，其高表达与组织学分级、肿瘤大小、淋巴结转移密切相关。MAFG-AS1 的沉默抑制了 BLCA 细胞的增殖、转移和侵袭，而 MAFG-AS1 在 BLCA 细胞中的过表达具有相反的生物学效应。MAFG-AS1 被证明靶向 miR-143-3p 以抑制其表达。此外，已证实 MAFG-AS1 和 miR-143-3p 可以调节 COX-2 的表达。结论：MAFG-AS1/miR-143-3p/COX-2 轴有助于 BLCA 进展。