Li Miao, Qi Yonghao, Wei Jing, Lu Lulu, Zhao Xuan, Zhou Lijun
Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, P.R. China.
Tumour Biol. 2017 Mar;39(3):1010428317695966. doi: 10.1177/1010428317695966.
N6-Isopentenyladenosine, a member of the family of plant hormones, possesses anti-cancer activities on a number of cancer cell lines. However, its mode of action in cervical cancer cell remains poorly understood. Our computational docking studies showed that N6-Isopentenyladenosine could bind with the really interesting new gene domain of tumor necrosis factor receptor-associated factor 6, which is an ubiquitination E3 ligase. Tumor necrosis factor receptor-associated factor 6-mediated ubiquitination is known to activate both protein kinase B (also known as AKT) and transforming growth factor β-activated kinase 1, and the really interesting new gene domain comprises the core of the ubiquitin ligase catalytic domain. First, we evaluated the effects of iPA on cervical cancer cell line HeLa using MTT and flow cytometry. Second, we examined the effects of iPA on activation of tumor necrosis factor receptor-associated factor 6-mediated downstream targets using western blot or immunoprecipitation. iPA could reduce HeLa cell proliferation through apoptosis, and such anti-cancer activity is associated with inhibitions of both AKT and transforming growth factor β-activated kinase 1 signaling pathways. In addition, suppression of the anti-apoptotic protein Bcl-2 and elevation of the pro-apoptotic protein Bax were also observed. Anti-proliferation properties of iPA are likely due to its binding at the really interesting new gene domain of tumor necrosis factor receptor-associated factor 6 and loss of AKT and transforming growth factor β-activated kinase 1 activities as a result of functional modulations of tumor necrosis factor receptor-associated factor 6. These results support the emerging notion that tumor necrosis factor receptor-associated factor 6 could serve as a viable target for developing new cancer therapeutics.
N6-异戊烯基腺苷是植物激素家族的一员，对多种癌细胞系具有抗癌活性。然而，其在宫颈癌细胞中的作用模式仍知之甚少。我们的计算机对接研究表明，N6-异戊烯基腺苷可与肿瘤坏死因子受体相关因子6的真核生物有趣新基因结构域结合，该结构域是一种泛素化E3连接酶。已知肿瘤坏死因子受体相关因子6介导的泛素化可激活蛋白激酶B（也称为AKT）和转化生长因子β激活激酶1，而真核生物有趣新基因结构域包含泛素连接酶催化结构域的核心。首先，我们使用MTT法和流式细胞术评估了iPA对宫颈癌细胞系HeLa的影响。其次，我们使用蛋白质印迹法或免疫沉淀法检测了iPA对肿瘤坏死因子受体相关因子6介导的下游靶点激活的影响。iPA可通过凋亡减少HeLa细胞增殖，这种抗癌活性与抑制AKT和转化生长因子β激活激酶1信号通路有关。此外，还观察到抗凋亡蛋白Bcl-2的抑制和促凋亡蛋白Bax的升高。iPA的抗增殖特性可能是由于其在肿瘤坏死因子受体相关因子6的真核生物有趣新基因结构域处结合，以及由于肿瘤坏死因子受体相关因子6的功能调节导致AKT和转化生长因子β激活激酶1活性丧失。这些结果支持了一种新出现的观点，即肿瘤坏死因子受体相关因子6可作为开发新型癌症治疗药物的可行靶点。
