As the critical components of tumor microenvironment, cancer-associated fibroblasts (CAFs) support the development of various type of cancers, including laryngeal squamous cell carcinoma (LSCC), but the detailed molecular mechanisms by which cancer-associated fibroblasts interact with LSCC cells to facilitate its progression have not been fully uncovered. In the present study, by analyzing the contents from normal fibroblasts (NFs) and cancer-associated fibroblasts-derived extracellular vesicles (EVs) with Real-Time qPCR analysis, we found that the tumor-initiating LncRNA TUC338 was significantly upregulated in the cancer-associated fibroblasts-derived extracellular vesicles, compared to the normal fibroblasts-secreted extracellular vesicles. Further experiments confirmed that cancer-associated fibroblasts-derived extracellular vesicles promoted cell proliferation, colony formation abilities, epithelial-mesenchymal transition (EMT) and tumorigenesis of LSCC cells via delivering LncRNA TUC338. The mechanical experiments verified that LncRNA TUC338 was stabilized by METTL3/YTHDF1-mediated N6-methyladenosine (m6A) modifications, and elevated LncRNA TUC338 sponged miR-8485 to upregulate chromobox homolog 2 (CBX2) in LSCC cells in a competing endogenous RNA mechanisms-dependent manner. Moreover, our rescue experiments evidenced that cancer-associated fibroblasts-derived LncRNA TUC338-containing extracellular vesicles-induced supportive effects in LSCC aggressiveness were all abrogated by overexpressing miR-8485 and silencing CBX2. Collectively, this study is the first to identify a novel m6A/LncRNA TUC338/miR-8485/CBX2 axis in CAFs-EVs-mediated LSCC development, and to show its potential as a diagnostic biomarker for LSCC.

作为肿瘤微环境的关键组成部分，癌症相关成纤维细胞（CAF）支持多种类型癌症的发展，包括喉鳞状细胞癌（LSCC），但癌症相关成纤维细胞与LSCC细胞相互作用的详细分子机制促进其进展尚未完全揭示。在本研究中，通过实时定量PCR分析正常成纤维细胞（NF）和癌症相关成纤维细胞衍生的细胞外囊泡（EV）的含量，我们发现肿瘤启动LncRNA TUC338在癌症中显着上调。相关成纤维细胞衍生的细胞外囊泡，与正常成纤维细胞分泌的细胞外囊泡相比。进一步的实验证实，癌症相关成纤维细胞来源的细胞外囊泡通过传递 LncRNA TUC338 促进细胞增殖、集落形成能力、上皮间质转化 (EMT) 和 LSCC 细胞的肿瘤发生。机械实验验证了 LncRNA TUC338 通过 METTL3/YTHDF1 介导的 N6-甲基腺苷 (m6A) 修饰而稳定，并且升高 LncRNA TUC338 海绵 miR-8485 以竞争性内源性 RNA 机制依赖的方式上调 LSCC 细胞中的染色体盒同源物 2 (CBX2)方式。此外，我们的救援实验证明，癌症相关成纤维细胞衍生的含有 TUC338 的 LncRNA TUC338 细胞外囊泡诱导的 LSCC 侵袭性支持作用均通过过度表达 miR-8485 和沉默 CBX2 而消除。总的来说，这项研究首次在 CAFs-EVs 介导的 LSCC 发展中鉴定出一种新型 m6A/LncRNA TUC338/miR-8485/CBX2 轴，并显示其作为 LSCC 诊断生物标志物的潜力。