Lu Baocai, Li Xiao, Miao Wenjie, Liu Qi, Li Ruixue, Cui Can, Gao Qingzu, Lian Rong
Department of Otolaryngology, the First Affiliated Hospital of Xinxiang Medical University, No. 88, Jiankang Road, Xinxiang, Henan, 453100, China.
Department of Pathology, the First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan, China.
Naunyn Schmiedebergs Arch Pharmacol. 2025 Jan 7. doi: 10.1007/s00210-024-03779-0.
High levels of the N7 methylguanosine (m7G) methyltransferase WD repeat domain 4 (WDR4) are associated with the progression of multiple tumors, including head and neck squamous cell carcinoma. Laryngeal cancer (LC) is the second most common malignant tumor of the head and neck. However, the role of WDR4 in LC remains unclear. Here, we found that WDR4 expression was significantly upregulated in LC tissues and cells. Silencing WDR4 inhibited proliferation, invasion, and epithelial-mesenchymal transition (EMT, manifested by an increase in E-cadherin protein levels and a decrease in N-cadherin and Vimentin protein levels) in TU177 and M4E cells. Furthermore, the levels of m7G and ZFAS1 were significantly upregulated in LC tissues and cells. Mechanistic studies revealed that WDR4 upregulated the levels of ZFAS1 and RBFOX2 proteins by promoting the stability of ZFAS1 in an m7G-dependent manner, and RBFOX2 promoted WDR4 expression by binding to WDR4 mRNA. Overexpression of WDR4 increased m7G and ZFAS1 levels, whereas overexpression of WDR4 with m7G catalytic site mutation had no effect on m7G and ZFAS1 levels in TU177 and M4E cells. Silencing ZFAS1 or RBFOX2 counteracted the promoting effect of WDR4 overexpression on the malignant proliferation of TU177 and M4E cells. TU177 cells transfected with sh-WDR4 lentiviral vectors were intraperitoneally injected into nude mice to construct xenograft tumor models. Knockdown of WDR4 significantly inhibited LC tumor growth in vivo. In conclusion, RBFOX2-mediated upregulation of WDR4 promoted LC progression through the WDR4/m7G/ZFAS1/RBFOX2 axis.
高水平的N7甲基鸟苷（m7G）甲基转移酶WD重复结构域4（WDR4）与包括头颈部鳞状细胞癌在内的多种肿瘤进展相关。喉癌（LC）是头颈部第二常见的恶性肿瘤。然而，WDR4在喉癌中的作用仍不清楚。在此，我们发现WDR4在喉癌组织和细胞中表达显著上调。沉默WDR4可抑制TU177和M4E细胞的增殖、侵袭及上皮-间质转化（EMT，表现为E-钙黏蛋白水平升高以及N-钙黏蛋白和波形蛋白水平降低）。此外，m7G和ZFAS1水平在喉癌组织和细胞中显著上调。机制研究表明，WDR4通过以m7G依赖的方式促进ZFAS1的稳定性上调ZFAS1和RBFOX2蛋白水平，且RBFOX2通过与WDR4 mRNA结合促进WDR4表达。WDR4过表达增加m7G和ZFAS1水平，而WDR4的m7G催化位点突变过表达对TU177和M4E细胞中的m7G和ZFAS1水平无影响。沉默ZFAS1或RBFOX2可抵消WDR4过表达对TU177和M4E细胞恶性增殖的促进作用。将转染sh-WDR4慢病毒载体的TU177细胞腹腔注射到裸鼠体内构建异种移植瘤模型。敲低WDR4可显著抑制体内喉癌肿瘤生长。总之，RBFOX2介导的WDR4上调通过WDR4/m7G/ZFAS1/RBFOX2轴促进喉癌进展。
