Wei Zihao, Wang Ying, Peng Jiakuan, Li Honglin, Gu Junjie, Ji Ning, Li Taiwei, Zhou Xikun, Zeng Xin, Li Jing, Chen Qianming
State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, P.R. China.
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, China.
Cell Death Discov. 2022 Jun 11;8(1):285. doi: 10.1038/s41420-022-01066-6.
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer in the world, the 5-year survival rate of patients with HNSCC is still about 50% due to frequent metastasis and recurrence. Circular RNAs (circRNAs) have been characterized as key regulators of gene expression in numerous malignancies. However, the role of circRNA in HNSCC metastasis remains largely unknown. Here, we demonstrated that the circRFWD3 was significantly upregulated in HNSCC tissues and cell lines by circRNA microarray analysis and qPCR. Notably, high expression of circRFWD3 is related to highly aggressive HNSCC cell lines and lymph node metastasis in HNSCC patients. After that, Sanger sequencing, RNase R, and actinomycin D assay were performed to verify the ring structure of circRFWD3. Then functional experiments found it could promote the metastasis of HNSCC cells both in vitro and in vivo. Mechanistically, a dual-luciferase reporter assay, FISH, RIP, RNA pull-down, RNA-seq, and western blot experiments were employed and found that circRFWD3 served as a miRNAs sponge for miR-27a/27b, leading to the upregulation of PPARγ, and then promoted HNSCC metastasis via NF-κB/MMP13 pathway. Finally, ISH and IHC were carried out to determine the expression levels and clinical significances of circRFWD3 and PPARγ in clinical cohorts of HNSCC. According to the analysis results from two independent HNSCC cohorts, upregulated expression of circRFWD3 and PPARγ were positively associated with worse survival in patients with HNSCC. Overall, our results uncover that circRFWD3 acts a critical role in promoting the aggressiveness of HNSCC cells and is a prognostic marker for the disease, indicating that circRFWD3 may act as a potential therapeutic target in HNSCC.
头颈部鳞状细胞癌（HNSCC）是全球第六大常见癌症，由于频繁转移和复发，HNSCC患者的5年生存率仍约为50%。环状RNA（circRNAs）已被证明是多种恶性肿瘤中基因表达的关键调节因子。然而，circRNA在HNSCC转移中的作用仍 largely未知。在此，我们通过circRNA微阵列分析和qPCR证明circRFWD3在HNSCC组织和细胞系中显著上调。值得注意的是，circRFWD3的高表达与HNSCC患者中高侵袭性的HNSCC细胞系和淋巴结转移相关。之后，进行了桑格测序、RNase R和放线菌素D试验以验证circRFWD3的环状结构。然后功能实验发现它能在体外和体内促进HNSCC细胞的转移。机制上，采用双荧光素酶报告基因试验、FISH、RIP、RNA下拉、RNA测序和蛋白质印迹实验，发现circRFWD3作为miR-27a/27b的miRNAs海绵，导致PPARγ上调，进而通过NF-κB/MMP13途径促进HNSCC转移。最后，进行ISH和IHC以确定circRFWD3和PPARγ在HNSCC临床队列中的表达水平和临床意义。根据两个独立的HNSCC队列的分析结果，circRFWD3和PPARγ的上调表达与HNSCC患者较差的生存率呈正相关。总体而言，我们的结果揭示circRFWD3在促进HNSCC细胞侵袭性方面起关键作用，是该疾病的一个预后标志物，表明circRFWD3可能作为HNSCC的一个潜在治疗靶点。
