Ren Bo-Xue, Li Yang, Li Hong-Mei, Lu Tao, Wu Zhao-Qiu, Fu Rong
State Key Laboratory of Natural Medicines, School of Biopharmacy, China Pharmaceutical University, Nanjing, China.
State Key Laboratory of Natural Medicines, Laboratory of Molecular Design and Drug Discovery, School of Science, China Pharmaceutical University, Nanjing, China.
Br J Pharmacol. 2022 Jun;179(11):2659-2677. doi: 10.1111/bph.15763. Epub 2022 Mar 15.
The zinc finger transcription factor Snail is aberrantly activated in many human cancers and strongly associated with poor prognosis. As a transcription factor, Snail has been traditionally considered an 'undruggable' target. Here, we identified a potent small-molecule inhibitor of Snail, namely trimethoprim, and investigated its potential antitumour effects and the underlying mechanisms.
The inhibitory action of trimethoprim on Snail protein and the related molecular mechanisms were revealed by molecular docking, biolayer interferometry, immunoblotting, immunoprecipitation, qRT-PCR, pull-down and cycloheximide pulse-chase assays. The anti-proliferative and anti-metastatic effects of trimethoprim via targeting Snail were tested in multiple cell-based assays and animal models.
This study identified trimethoprim, an antimicrobial drug, as a potent antitumour agent via targeting Snail. Molecular modelling analysis predicted that trimethoprim directly binds to the arginine-174 pocket of Snail protein. We further discovered that trimethoprim strongly interrupts the interaction of Snail with CREB-binding protein (CBP)/p300, which consequently suppresses Snail acetylation and promotes Snail degradation through the ubiquitin-proteasome pathway. Furthermore, trimethoprim sufficiently inhibited the proliferation, epithelial-mesenchymal transition (EMT) and migration of cancer cells in vitro via specifically targeting Snail. More importantly, trimethoprim effectively reduced Snail-driven tumour growth and metastasis to vital organs such as lung, bone and liver.
These findings indicate, for the first time, that trimethoprim suppresses tumour growth and metastasis via targeting Snail. This study provides insights for a better understanding of the anticancer effects of trimethoprim and offers a potential anticancer therapeutic agent for clinical treatment.
锌指转录因子Snail在许多人类癌症中异常激活，并与不良预后密切相关。作为一种转录因子，Snail传统上被认为是一个“不可成药”的靶点。在此，我们鉴定出一种有效的Snail小分子抑制剂，即甲氧苄啶，并研究了其潜在的抗肿瘤作用及相关机制。
通过分子对接、生物膜干涉技术、免疫印迹、免疫沉淀、qRT-PCR、下拉实验和环己酰亚胺脉冲追踪实验，揭示了甲氧苄啶对Snail蛋白的抑制作用及其相关分子机制。通过多种基于细胞的实验和动物模型，测试了甲氧苄啶通过靶向Snail发挥的抗增殖和抗转移作用。
本研究确定抗菌药物甲氧苄啶是一种通过靶向Snail发挥作用的有效抗肿瘤药物。分子建模分析预测，甲氧苄啶直接结合到Snail蛋白的精氨酸-174口袋。我们进一步发现，甲氧苄啶强烈干扰Snail与CREB结合蛋白（CBP）/p300的相互作用，从而抑制Snail的乙酰化，并通过泛素-蛋白酶体途径促进Snail的降解。此外，甲氧苄啶通过特异性靶向Snail，在体外充分抑制癌细胞的增殖、上皮-间质转化（EMT）和迁移。更重要的是，甲氧苄啶有效减少了Snail驱动的肿瘤生长和向肺、骨和肝等重要器官的转移。
这些发现首次表明，甲氧苄啶通过靶向Snail抑制肿瘤生长和转移。本研究为更好地理解甲氧苄啶的抗癌作用提供了见解，并为临床治疗提供了一种潜在的抗癌治疗药物。
