Guo Yuduo, He Xin, Zhang Mingshan, Qu Yanming, Gu Chunyu, Ren Ming, Wang Haoran, Ning Weihai, Li Junfa, Yu Chunjiang, Zhang Hongwei
Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing, 100093, People's Republic of China.
Department of Neurosurgery, The Third Medical Center of the General Hospital of the People's Liberation Army, Beijing, 100039, People's Republic of China.
J Neurooncol. 2020 Apr;147(2):327-337. doi: 10.1007/s11060-020-03453-4. Epub 2020 Mar 13.
Glioblastoma multiforme (GBM) is one of the most devastating brain malignancies worldwide and is considered to be incurable. However, the mechanisms underlying its aggressiveness remain unclear.
The expression of ADAM17 in tissue samples was detected by immunohistochemistry. Knockdown and rescue experiments were used to demonstrate the regulatory effect of ADAM17 on the invasion ability of GBM cells. Western Blot and qPCR were used to detect the expression of related proteins and RNAs. Moreover, a luciferase reporter assay was performed to verify whether miR-145 directly binds to the 3'-UTR of ADAM17.
We revealed that ADAM17 was overexpressed in GBM tissues and correlated positively with poor prognosis. The knockdown of ADAM17 obviously suppressed the invasiveness of GBM cell lines. Furthermore, we found that knockdown of ADAM17 decreased activation of EGFR/Akt/C/EBP-β signaling, and consequently upregulated miR-145 expression in GBM cell lines. Notably, miR-145 directly targeted the ADAM17 3'-UTR and suppressed expression levels of ADAM17.
Our findings define an ADAM17/EGFR/miR-145 feedback loop that drives the GBM invasion. Reciprocal regulation between ADAM17 and miR-145 results in aberrant activation of EGFR signaling, suggesting that inhibition of ADAM17 expression can be an ideal therapeutic strategy for the treatment of GBM.
多形性胶质母细胞瘤（GBM）是全球最具毁灭性的脑恶性肿瘤之一，被认为无法治愈。然而，其侵袭性的潜在机制仍不清楚。
采用免疫组织化学法检测组织样本中ADAM17的表达。通过敲低和挽救实验来证明ADAM17对GBM细胞侵袭能力的调节作用。采用蛋白质免疫印迹法（Western Blot）和定量聚合酶链反应（qPCR）检测相关蛋白质和RNA的表达。此外，进行荧光素酶报告基因检测以验证miR-145是否直接与ADAM17的3'-非翻译区（3'-UTR）结合。
我们发现ADAM17在GBM组织中过表达，且与预后不良呈正相关。敲低ADAM17明显抑制了GBM细胞系的侵袭性。此外，我们发现敲低ADAM17可降低GBM细胞系中表皮生长因子受体（EGFR）/蛋白激酶B（Akt）/CCAAT增强子结合蛋白β（C/EBP-β）信号通路的激活，从而上调miR-145的表达。值得注意的是，miR-145直接靶向ADAM17的3'-UTR并抑制ADAM17的表达水平。
我们的研究结果确定了一个驱动GBM侵袭的ADAM17/EGFR/miR-145反馈环。ADAM17与miR-145之间的相互调节导致EGFR信号通路异常激活，这表明抑制ADAM17的表达可能是治疗GBM的理想治疗策略。
