The change of intracellular pH is involved in the cisplatin-resistance of human lung adenocarcinoma A549/DDP cells
The change of intracellular pH is involved in the cisplatin-resistance of human lung adenocarcinoma A549/DDP cells
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DOI：
10.1081/cnv-200046353
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发表时间：
2005-01-01
影响因子：
2.4
通讯作者：
Huang, YG
中科院分区：
文献类型：
--
作者：
Huang, ZH;Huang, YG
我们曾报道，对顺铂敏感的人肺腺癌A549细胞的细胞内pH（pH(i)）比顺铂耐药的A549/DDP细胞更呈酸性。通过改变培养箱内CO2浓度改变pHi，进一步研究A549/DDP细胞pHi变化与顺铂耐药的相关性。使用BCECF-AM荧光探针监测细胞的pHi变化。结果表明，与正常条件下 5% CO2 培养的 A549 和 A549/DDP 细胞相比，A549 和 A549/DDP 细胞的 pHi 在较低 CO2 浓度（培养箱中为 2% CO2）时呈碱性，在较高 CO2 浓度（培养箱中为 8% CO2）时呈酸性。与 A549/DDP 细胞相比，在 2%、5% 和 8% CO2 孵育的 A549 细胞中，bodipy-cisplatin（一种用于耐药性测定的荧光探针）的积累分别增加了 8.4%、17.4% 和 23.5%。通过激光扫描共聚焦显微镜成像的 bodipy-cisplatin 的细胞内隔离和分布表明 bodipy-cisplatin 更多地封装在 A549/DDP 细胞的酸性区室中，如吖啶橙（一种专门标记细胞中酸性细胞器的染料）所示。这些结果可以在不同pH梯度的脂质体系统中得到进一步证实。从以上结果推测，A549/DDP细胞中特别是酸性区室中pH(i)的变化涉及其顺铂耐药性。
We had reported that the intracellular pH (pH(i)) of human lung adenocarcinoma A549 cells, which is sensitive to cisplatin, was more acidic than that of cisplatin-resistant A549/DDP cells. The correlation between the change of the pHi and cisplatin-resistance of A549/DDP cells was further studied by altering pHi in consequence of the change of CO2 concentration of the incubator. The pHi alterations of the cells were monitored by using the fluorescence probe of BCECF-AM. The results indicated that the pHi was more alkaline at lower CO2 concentration (2% CO2 in the incubator) and more acidic at higher CO2 concentration (8% CO2 in the incubator) for both A549 and A549/DDP cells compared with those of both A549 and A549/DDP cells cultured at 5% CO2 as the normal condition. Accumulation of bodipy-cisplatin, a fluorescence probe used for drug resistance assays, in A549 cells incubated at 2%, 5%, and 8% CO2 was increased 8.4%, 17.4%, and 23.5% compared to A549/DDP cells, respectively. Intracellular sequestration and distribution of bodipy-cisplatin imaged by laser scanning confocal microscopy indicated that bodipy-cisplatin was more encapsulated in acidic compartments of A549/DDP cells as shown with acridine orange, a dye that specifically labels acidic organelles in the cells. These results can be further confirmed in liposome systems with different pH gradients. It is proposed from the above results that the change of pH(i) in especially more acidic compartments in A549/DDP cells involves their cisplatin resistance.