Comert Onder Ferah, Kahraman Nermin, Bellur Atici Esen, Cagir Ali, Kandemir Hakan, Tatar Gizem, Taskin Tok Tugba, Kara Goknur, Karliga Bekir, Durdagi Serdar, Ay Mehmet, Ozpolat Bulent
Department of Experimental Therapeutics, The University of Texas, MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 422, Houston, Texas 77030, United States.
Department of Medical Biology, Çanakkale Onsekiz Mart University, Faculty of Medicine, 17020 Canakkale, Turkey.
ACS Pharmacol Transl Sci. 2021 Mar 30;4(2):926-940. doi: 10.1021/acsptsci.1c00030. eCollection 2021 Apr 9.
Eukaryotic elongation factor 2 kinase (eEF-2K) is an unusual alpha kinase involved in protein synthesis through phosphorylation of elongation factor 2 (EF2). eEF-2K is highly overexpressed in breast cancer, and its activity is associated with significantly shortened patient survival and proven to be a potential molecular target in breast cancer. The crystal structure of eEF-2K remains unknown, and there is no potent, safe, and effective inhibitor available for clinical applications. We designed and synthesized several generations of potential inhibitors. The effect of the inhibitors at the binding pocket of eEF-2K was analyzed after developing a 3D target model by using a domain of another α-kinase called myosin heavy-chain kinase A (MHCKA) that closely resembles eEF-2K. studies showed that compounds with a coumarin-chalcone core have high predicted binding affinities for eEF-2K. Using studies in highly aggressive and invasive (MDA-MB-436, MDA-MB-231, and BT20) and noninvazive (MCF-7) breast cancer cells, we identified a lead compound that was highly effective in inhibiting eEF-2K activity at submicromolar concentrations and at inhibiting cell proliferation by induction of apoptosis with no toxicity in normal breast epithelial cells. systemic administration of the lead compound encapsulated in single lipid-based liposomal nanoparticles twice a week significantly suppressed growth of MDA-MB-231 tumors in orthotopic breast cancer models in nude mice with no observed toxicity. In conclusion, our study provides a highly potent and effective novel small-molecule eEF-2K inhibitor that may be used as a molecularly targeted therapy breast cancer or other eEF-2K-dependent tumors.
真核生物延伸因子2激酶（eEF - 2K）是一种独特的α激酶，通过对延伸因子2（EF2）进行磷酸化参与蛋白质合成。eEF - 2K在乳腺癌中高度过表达，其活性与患者生存期显著缩短相关，并且已被证明是乳腺癌潜在的分子靶点。eEF - 2K的晶体结构尚不清楚，目前尚无有效、安全且适用于临床的抑制剂。我们设计并合成了几代潜在抑制剂。利用与eEF - 2K高度相似的另一种α激酶肌球蛋白重链激酶A（MHCKA）的一个结构域构建三维靶点模型后，分析了这些抑制剂在eEF - 2K结合口袋处的作用效果。研究表明，具有香豆素 - 查尔酮核心结构的化合物对eEF - 2K具有较高的预测结合亲和力。通过对高侵袭性（MDA - MB - 436、MDA - MB - 231和BT20）及非侵袭性（MCF - 7）乳腺癌细胞的研究，我们确定了一种先导化合物，该化合物在亚微摩尔浓度下能高效抑制eEF - 2K活性，并通过诱导凋亡抑制细胞增殖，对正常乳腺上皮细胞无毒性。每周两次将该先导化合物封装在单脂质体纳米颗粒中进行全身给药，可显著抑制裸鼠原位乳腺癌模型中MDA - MB - 231肿瘤的生长，且未观察到毒性。总之，我们的研究提供了一种高效且有效的新型小分子eEF - 2K抑制剂，可作为乳腺癌或其他eEF - 2K依赖性肿瘤的分子靶向治疗药物。
