Department of Otolaryngology Head and Neck Surgery, The First Affiliated Hospital of Bengbu Medical College, No. 287 Changhuai Road, Bengbu City, 233004, Anhui Province, China.
Genes Genomics. 2020 Aug;42(8):971-978. doi: 10.1007/s13258-020-00963-3. Epub 2020 Jul 9.
MicroRNA-34a (miR-34a) has been reported to inhibit TGF-β (transforming growth factor-β)-induced epithelial-mesenchymal transition (EMT) in nasopharyngeal carcinoma (NPC). However, the underlying mechanism remain unclear. Using the bioinformatics, we found that the AXL receptor tyrosine kinase (AXL) is a predicted target of miR-34a.
we aimed to reveal the relationship between miR-34a and AXL, and investigate the effect and mechanism of miR-34a in NPC progression.
The expression patterns of miR-34a and AXL in 30 paired NPC tissues and the adjacent tissues were examined by quantitative real time PCR (qRT-PCR). The target relationship between miR-34a and AXL was evaluated by the luciferase gene reporter assay. Cell migration and invasion were assessed by wound healing and transwell chamber assays, respectively.
miR-34a level was dramatically decreased in the NPC tissues compared to the adjacent tissues, while AXL expression was increased. Overexpression of miR-34a significantly reduced the luciferase activity of the luciferase vector of AXL (pGL3-AXL-WT), whereas this effect was abrogated when binding sites between miR-34a and AXL were mutated. In addition, ectopic expression of miR-34a dramatically inhibited Sune-1 cell migration and invasion abilities, decreased the levels of N-cadherin and Vimentin and increased E-cadherin and γ-catenin expressions, as well as induced significant reductions in the expressions of p-AKT and Snail. However, these effects were attenuated when the cells were treated with recombinant human AXL protein.
Our results demonstrate that miR-34a/AXL can inhibit NPC cell migration, invasion and EMT through inhibition of AKT/Snail signaling.
已有研究表明 microRNA-34a（miR-34a）可抑制转化生长因子-β（TGF-β）诱导的鼻咽癌细胞上皮间质转化（EMT）。然而，其具体机制仍不清楚。本研究通过生物信息学分析发现，AXL 受体酪氨酸激酶（AXL）是 miR-34a 的一个潜在靶点。
揭示 miR-34a 与 AXL 之间的关系，并探讨 miR-34a 在 NPC 进展中的作用及机制。
采用实时荧光定量 PCR（qRT-PCR）检测 30 对鼻咽癌组织及其相应癌旁组织中 miR-34a 和 AXL 的表达水平，通过荧光素酶基因报告实验验证 miR-34a 与 AXL 的靶向关系。采用划痕愈合实验和 Transwell 小室实验分别检测细胞迁移和侵袭能力。
与癌旁组织相比，鼻咽癌组织中 miR-34a 水平显著降低，而 AXL 表达水平升高。miR-34a 过表达可显著降低 AXL 野生型荧光素酶载体的荧光素酶活性，而当 miR-34a 与 AXL 结合位点发生突变时，这种作用则被消除。此外，过表达 miR-34a 可显著抑制 Sune-1 细胞的迁移和侵袭能力，降低 N-钙黏蛋白和波形蛋白的表达水平，增加 E-钙黏蛋白和 γ-连环蛋白的表达水平，并诱导 AKT 和 Snail 表达水平的显著降低。然而，当细胞用重组人 AXL 蛋白处理时，这些作用则被削弱。
本研究结果表明，miR-34a/AXL 可通过抑制 AKT/Snail 信号通路抑制 NPC 细胞的迁移、侵袭和 EMT。
