Dai Changyuan, Li Qingwen, Wang Lili, Zhang Jiajun, Yang Shuai, Zhang Xiaole
Department of Urology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, 233000, Anhui, China.
Department of Emergency Medicine, The First Affiliated Hospital of Bengbu Medical College, No.287 Zhihuai Road, Bengbu, 233000, Anhui, China.
Biochem Genet. 2024 Nov 21. doi: 10.1007/s10528-024-10944-w.
Bladder cancer (BC) is the most prevalent malignancy of the urinary tract and ranks among the most common tumors globally due to its high recurrence and fatality rates. Evidence suggests that long noncoding RNAs (lncRNAs) may serve as novel biomarkers for cancer therapy. The study aimed to investigate the functions of lncRNA fetal-lethal non-coding developmental regulatory RNA (FENDRR) in regulating malignant phenotypes of BC cell lines (T24 and RT-4) and the underlying mechanism. RT-qPCR was used to measure FENDRR, miR-18a-5p, and AF4/FMR2 family member 4 (AFF4) expression in BC tissue samples and cell lines. Subcellular fractionation assay and fluorescence in situ hybridization were conducted to determine the localization of FENDRR in T24 and RT-4 cell. EdU, sphere formation, Transwell invasion, and wound healing assays were carried out to detect the changes in BC cell proliferation, stemness, invasion, and migration in response to FENDRR or AFF4 dysregulation. Protein levels of epithelial-mesenchymal transition (EMT) markers were quantified by western blotting. The interaction between miR-18a-5p and FENDRR (or AFF4) was verified by luciferase reporter assays. Experimental results revealed that FENDRR expression was downregulated in BC tissue samples and cell lines, with primary localization in cytoplasm of T24 and RT-4 cells. FENDRR overexpression inhibited BC cell proliferation, migration, invasion, stemness, and EMT process. FENDRR was shown to bind with miR-18a-5p, and AFF4 is a direct target of miR-18a-5p. In addition, AFF4 knockdown partially counteracted the effect of FENDRR on malignant phenotypes of BC cells. In summary, FENDRR represses BC cell proliferation, migration, invasion, stemness, and EMT process by targeting the miR-18a-5p/AFF4 axis.
膀胱癌（BC）是泌尿系统中最常见的恶性肿瘤，因其高复发率和死亡率而位居全球最常见肿瘤之列。有证据表明，长链非编码RNA（lncRNA）可能作为癌症治疗的新型生物标志物。本研究旨在探讨lncRNA胎儿致死性非编码发育调控RNA（FENDRR）在调节膀胱癌细胞系（T24和RT-4）恶性表型中的作用及其潜在机制。采用RT-qPCR检测BC组织样本和细胞系中FENDRR、miR-18a-5p和AF4/FMR2家族成员4（AFF4）的表达。进行亚细胞分级分离试验和荧光原位杂交以确定FENDRR在T24和RT-4细胞中的定位。进行EdU、成球、Transwell侵袭和伤口愈合试验，以检测BC细胞在FENDRR或AFF4失调时增殖、干性、侵袭和迁移的变化。通过蛋白质印迹法定量检测上皮-间质转化（EMT）标志物的蛋白质水平。通过荧光素酶报告基因试验验证miR-18a-5p与FENDRR（或AFF4）之间的相互作用。实验结果显示，BC组织样本和细胞系中FENDRR表达下调，主要定位于T24和RT-4细胞的细胞质中。FENDRR过表达抑制BC细胞增殖、迁移、侵袭、干性和EMT过程。结果表明，FENDRR与miR-18a-5p结合，AFF4是miR-18a-5p的直接靶标。此外，敲低AFF4可部分抵消FENDRR对BC细胞恶性表型的影响。总之，FENDRR通过靶向miR-18a-5p/AFF4轴抑制BC细胞增殖、迁移、侵袭、干性和EMT过程。
