Ramamurthy Vidya P, Ramalingam Senthilmurugan, Gediya Lalji, Kwegyir-Afful Andrew K, Njar Vincent C O
Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA.
Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD, USA.
Oncotarget. 2015 Feb 20;6(5):3195-210. doi: 10.18632/oncotarget.3084.
Androgen receptor (AR) and MNK activated eIF4E signaling promotes the development and progression of prostate cancer (PCa). In this study, we report that our Novel Retinamides (NRs) target both AR signaling and eIF4E translation in androgen sensitive and castration resistant PCa cells via enhancing AR and MNK degradation through ubiquitin-proteasome pathway. Dual blockade of AR and MNK initiated eIF4E activation by NRs in turn induced cell cycle arrest, apoptosis, and inhibited cell proliferation. NRs also inhibited cell migration and invasion in metastatic cells. Importantly, the inhibitory effects of NRs on AR signaling, eIF4E translation initiation and subsequent oncogenic program were more potent than that observed with clinically relevant retinoids, established MNK inhibitors, and the FDA approved PCa drugs. Our findings provide the first preclinical evidence that simultaneous inhibition of AR and eIF4E activation is a novel and efficacious therapeutic approach for PCa, and that NRs hold significant promise for treatment of advanced prostate cancer.
雄激素受体(AR)和MNK激活的eIF4E信号传导促进前列腺癌(PCa)的发生和发展。在本研究中,我们报告了我们的新型视黄酰胺(NRs)通过泛素-蛋白酶体途径增强AR和MNK的降解,从而在雄激素敏感和去势抵抗性PCa细胞中靶向AR信号传导和eIF4E翻译。NRs对AR和MNK的双重阻断引发eIF4E激活,进而诱导细胞周期停滞、凋亡并抑制细胞增殖。NRs还抑制转移性细胞的迁移和侵袭。重要的是,NRs对AR信号传导、eIF4E翻译起始及随后致癌程序的抑制作用比临床相关视黄酸、已确立的MNK抑制剂及FDA批准的PCa药物所观察到的作用更强。我们的研究结果提供了首个临床前证据,即同时抑制AR和eIF4E激活是一种针对PCa的新型有效治疗方法,并且NRs在治疗晚期前列腺癌方面具有巨大潜力。