Subcellular localization of Photofrin® determines the death phenotype of human epidermoid carcinoma A431 cells triggered by photodynamic therapy:: When plasma membranes are the main targets
Subcellular localization of Photofrin® determines the death phenotype of human epidermoid carcinoma A431 cells triggered by photodynamic therapy:: When plasma membranes are the main targets
复制标题
DOI：
10.1002/jcp.10273
复制
发表时间：
2003-03-01
影响因子：
5.6
通讯作者：
Yu, JS
中科院分区：
文献类型：
--
作者：
Hsieh, YJ;Wu, CC;Yu, JS
光动力疗法(PDT)是一种主要通过诱导细胞死亡来发挥作用的光化学疗法。不同的光动力疗法可能会引起不同类型的细胞死亡。在这项研究中，研究了PDT与Photofrin(R)(一种临床批准的光敏剂)触发人表皮样癌A431细胞死亡的机制。PHOTOFRIN在A431细胞中动态分布，短时间(3h)和长时间(24h)孵育后，质膜和高尔基复合体是其主要靶点。具有不同定位的Photofrin的细胞对PDT的反应显示出不同的死亡表型。进一步研究了PDT对质膜定位的Photofrin细胞的影响。当Photofrin剂量为7µg/ml时，细胞在PDT后停止增殖，而在较高剂量(28µg/ml)时，细胞在PDT后即刻出现质膜断裂和细胞肿胀。在Photofrin(R)-PDT后的A431细胞中检测到几个重要的信号事件的戏剧性变化，包括：(I)立即形成活性氧物种(ROS)，(Ii)c-jun氨基末端激酶的快速激活，(Iii)caspase-3的延迟激活和多ADP-核糖聚合酶和p21-激活的激酶2的裂解，以及(Iv)线粒体膜电位的丧失。有趣的是，在这种PDT引起的细胞死亡过程中，没有检测到典型的细胞凋亡特征，如磷脂酰丝氨酸外化和DNA片段化。综上所述，我们的结果表明，当质膜为主要靶点时，Photofrin-PDT可以导致瞬时ROS的形成和随后的下游信号事件的激活，类似于许多凋亡刺激所引发的信号事件，但质膜的破坏使死亡表型更像坏死型。(C)2003年Wiley-Liss，Inc.
Photodynamic therapy (PDT) is a kind of photochemo-therapeutic treatment that exerts its effect mainly through the induction of cell death. Distinct types of cell death may be elicited by different PDT regimes. In this study, the mechanisms involved in the death of human epidermoid carcinoma A431 cells triggered by PDT with Photofrin(R) (a clinically approved photosensitizer) were characterized. Photofrin distributes dynamically in A431 cells; the plasma membranes and Golgi complex are the main target sites of Photofrin after a brief (3 h) and prolonged (24 h) incubation, respectively. Cells with differentially localized Photofrin displayed distinct death phenotypes in response to PDT. The effects of PDT on cells with plasma membrane-localized Photofrin were further studied in details. Cells stopped proliferating post PDT at Photofrin dose >7 mug/ml, and at higher dose (28 mug/ml) plasma membrane disruption and cell swelling were observed immediately after PDT. Dramatic alterations of several important signaling events were detected in A431 cells post Photofrin(R)-PDT, including (i) immediate formation of reactive oxygen species (ROS), (ii) rapid activation of c-Jun N-terminal kinase, (iii) delayed activation of caspase-3 and cleavage of polyADP-ribose polymerase and p21-activated kinase 2, and (iv) loss of mitochondrial membrane potential. Intriguingly, the characteristics of typical apoptosis such as phosphatidylserine externalization and DNA fragmentation were not detected in the cell death process caused by this PDT regime. In conclusion, our results show that when plasma membranes are the main targets, Photofrin-PDT can lead to instant ROS formation and subsequent activation of downstream signaling events similar to those elicited by many apoptotic stimuli, but the damage of plasma membranes renders the death phenotype more necrosis like. (C) 2003 Wiley-Liss, Inc.