Lin Yanling, Wang Lingzhi, Luo Wenxiao, Zhou Xiaohan, Chen Yuting, Yang Kaifan, Liao Jinrong, Wu Dehua, Cai Longmei
Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China.
First Clinical Medical College, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China.
Cancer Manag Res. 2020 Oct 27;12:10639-10649. doi: 10.2147/CMAR.S268216. eCollection 2020.
Nasopharyngeal carcinoma (NPC) is among the most common malignancies derived from the epithelium of the nasopharynx. To date, the regulatory networks involved in NPC have not been fully identified. Previous studies revealed multiple loss-of-function mutations in NPC and specifically in cylindromatosis lysine 63 deubiquitinase (); however, the exact role of CYLD in NPC progression and its potential mechanism remains unclear.
We performed immunohistochemical (IHC) staining and real-time quantitative polymerase chain reaction (qPCR) to measure expression in NPC tissues, and Western blot was conducted to determine CYLD levels in NPC cell lines. Cell proliferation was detected by CCK8 assay and colony formation analysis, and apoptosis was determined by Annexin V/propidium iodide staining. Potential targets of CYLD were verified by co-immunoprecipitation and mass spectrometry. Xenograft assay was conducted to confirm the role of in vivo.
We found that CYLD levels were significantly decreased in both NPC tissues and cell lines, and that overexpression inhibited NPC cell proliferation and promoted apoptosis. Additionally, we revealed that CYLD bound and upregulated N-Myc downstream regulated 1 (NDRG1), and that silencing abolished the tumor-suppressor effect of CYLD on NPC cells. Furthermore, CYLD suppressed tumor growth in xenograft mice models.
These results suggest CYLD as a tumor suppressor, potential biomarker for diagnosing NPC, and therapeutic target.
鼻咽癌（NPC）是源自鼻咽上皮的最常见恶性肿瘤之一。迄今为止，参与鼻咽癌的调控网络尚未完全明确。先前的研究揭示了鼻咽癌中存在多个功能丧失突变，特别是在圆柱瘤赖氨酸63去泛素化酶（CYLD）中；然而，CYLD在鼻咽癌进展中的确切作用及其潜在机制仍不清楚。
我们进行了免疫组织化学（IHC）染色和实时定量聚合酶链反应（qPCR）以检测鼻咽癌组织中CYLD的表达，并进行蛋白质免疫印迹法以测定鼻咽癌细胞系中CYLD的水平。通过CCK8法和集落形成分析检测细胞增殖，通过膜联蛋白V/碘化丙啶染色确定细胞凋亡。通过免疫共沉淀和质谱法验证CYLD的潜在靶点。进行异种移植试验以证实CYLD在体内的作用。
我们发现CYLD水平在鼻咽癌组织和细胞系中均显著降低，并且CYLD过表达抑制鼻咽癌细胞增殖并促进细胞凋亡。此外，我们发现CYLD与N-Myc下游调节因子1（NDRG1）结合并上调其表达，并且沉默NDRG1消除了CYLD对鼻咽癌细胞的肿瘤抑制作用。此外，CYLD在异种移植小鼠模型中抑制肿瘤生长。
这些结果表明CYLD是一种肿瘤抑制因子、鼻咽癌诊断的潜在生物标志物和治疗靶点。
