Zhu Weihong, Mao Xinzhan, Wang Wanchun, Chen You, Li Ding, Li Hui, Dou Pengcheng
Pharmazie. 2018 Feb 1;73(2):80-86. doi: 10.1691/ph.2018.7836.
Cisplatin is an effective chemotherapeutic agent for osteosarcoma (OS) and has been shown to induce endoplasmic reticulum (ER) stress-associated apoptosis in human cancer cells. Ganglioside GD2-specific antibodies can inhibit tumor cell viability without involvement of the immune system. A recent study has shown that antiGD2 monoclonal antibody (mAb) 14G2a effectively inhibits the viability and invasiveness of human OS cells. In this study, we explored the effect of anti-GD2 mAb and cisplatin alone and in combination on ER stress-associated apoptosis in osteosarcoma cells. MG-63 and Saos-2 human OS cells were treated with cisplatin and/or an-GD2 mAb 14G2a for 48 hours. Cisplatin and 14G2a dose-dependently induced apoptosis in MG-63 and Saos-2 cells. They in combination induced 70%-77% of apoptosis in MG-63 cells and 79%-85% of apoptosis in Saos-2 cells, exhibiting a synergistic effect stronger than addition of their individual effects over the control level. Showing no significant effect on the expression of protein kinase RNA-like ER kinase (PERK), cisplatin and 14G2a exhibited a marked synergistic effect on inducing phosphorylation/activation of PERK, phosphorylation/inactivation of eukaryotic translation initiation factor 2α (eIF2α), expression of CHOP, in parallel to inducing the caspase-3 activity and apoptosis in MG-63 and Saos-2 cells. The effects were abolished by lentivirus-mediated knockdown of PERK. Particularly, PERK knockdown abolished 63% and 65% of the combined apoptotic effect of cisplatin and 14G2a on MG-63 and Saos-2 cells, respectively. In conclusion, this study provides the first evidence supporting that cisplatin and 14G2a synergize to induce ER stress-associated apoptosis in human OS cells through activating the PERK ER stress pathway by synergistically inducing phosphorylation/activation of PERK. Our findings add new insights into the pharmacologic effects of anti-GD2 mAb in anticancer treatment and suggest that cisplatin plus anti-GD2 mAb could be a new effective therapeutic strategy for OS.
顺铂是一种治疗骨肉瘤（OS）的有效化疗药物，已被证明可诱导人癌细胞内质网（ER）应激相关的凋亡。神经节苷脂GD2特异性抗体可在不涉及免疫系统的情况下抑制肿瘤细胞活力。最近一项研究表明，抗GD2单克隆抗体（mAb）14G2a可有效抑制人骨肉瘤细胞的活力和侵袭性。在本研究中，我们探究了抗GD2单克隆抗体和顺铂单独及联合使用对骨肉瘤细胞内质网应激相关凋亡的影响。用顺铂和/或抗GD2单克隆抗体14G2a处理MG-63和Saos-2人骨肉瘤细胞48小时。顺铂和14G2a在MG-63和Saos-2细胞中剂量依赖性地诱导凋亡。它们联合使用时，在MG-63细胞中诱导70%-77%的凋亡，在Saos-2细胞中诱导79%-85%的凋亡，与单独作用相比，在对照水平上表现出更强的协同效应。顺铂和14G2a对蛋白激酶RNA样内质网激酶（PERK）的表达无显著影响，但在诱导PERK磷酸化/激活、真核翻译起始因子2α（eIF2α）磷酸化/失活、CHOP表达方面表现出显著的协同效应，同时诱导MG-63和Saos-2细胞中的半胱天冬酶-3活性和凋亡。慢病毒介导的PERK敲低消除了这些效应。特别是，PERK敲低分别消除了顺铂和14G2a联合作用对MG-63和Saos-2细胞63%和65%的凋亡效应。总之，本研究提供了首个证据支持顺铂和14G2a通过协同诱导PERK磷酸化/激活激活PERK内质网应激途径，协同诱导人骨肉瘤细胞内质网应激相关凋亡。我们的发现为抗GD2单克隆抗体在抗癌治疗中的药理作用提供了新见解，并表明顺铂加抗GD2单克隆抗体可能是骨肉瘤的一种新的有效治疗策略。
