Cellular toxicity induced by different pH levels on the R3230AC rat mammary tumour cell line.: An in vitro model for investigation of the tumour destructive properties of electrochemical treatment of tumours
Cellular toxicity induced by different pH levels on the R3230AC rat mammary tumour cell line.: An in vitro model for investigation of the tumour destructive properties of electrochemical treatment of tumours
复制标题
DOI：
10.1016/s1567-5394(02)00154-8
复制
发表时间：
2002-12-01
影响因子：
5
通讯作者：
Yongqing, G
中科院分区：
文献类型：
--
作者：
von Euler, H;Söerstedt, A;Yongqing, G
前言：本研究的目的是在体外评估不同pH水平对R3230AC乳腺肿瘤细胞系（克隆d）的细胞毒性，并确定pH对肿瘤细胞的影响方式。研究结果可以用来解释肿瘤电化学治疗（EChT）中的细胞损伤效应，其中组织中的pH改变是主要事件。方法：分别用pH为3.5、5、7、9、10、I、I处理肿瘤细胞10、20、30 min，然后进行3-（4,5-二甲基噻唑-2-基）-2,5，-二苯基溴化四唑（methyltetrazolium， MTT）活力测定、相差显微镜（PCM）和光镜下形态学观察、核苷酸类似物整合（BrdU; 5- brdmo -2'-脱氧尿苷）、Caspase-3活性测定和琼脂糖凝胶电泳检测DNA片段。结果：在细胞活力测定中，发现不同的pH水平有细胞毒作用；这些影响取决于pH值和在给定pH下暴露的时间。从形态学上看，pH值为3.5和5的细胞收缩，呈圆形，染色质浓缩，而pH值为9和10的细胞明显肿胀和细胞核扩张。pH值为11时细胞明显溶解。BrdU掺入实验表明，随着pH值的升高和降低，细胞增殖速率均受到明显抑制。在pH值为3.5和5时，Caspase-3活性显著。暴露在碱性环境中的Caspase-3水平等于或低于正常对照。DNA阶梯形成是细胞凋亡的一个特征，仅在pH 3.5处理30分钟时可见。结论：pH变化抑制细胞增殖，降低细胞活力。在低pH下，肿瘤细胞的杀伤途径可能至少有凋亡和细胞坏死两个方向，而高pH只导致细胞坏死。本研究提示低pH环境在非生理性条件下可诱导细胞凋亡，与EChT下的组织pH值相当。此外，R3230AC乳腺肿瘤细胞似乎对高pH值的耐受性强于对酸性变化的耐受性。这支持了阳极EChT应该比阴极EChT更有效的理论。(C) 2002 Elsevier Science b.v.版权所有
Introduction: The aim of this study was to evaluate the cellular toxicity of different pH levels on the R3230AC mammary tumour cell line (clone-D) in vitro and to determine in what way the pH affects the tumour cells. The results could be used to interpret the cell damaging effects seen in electrochemical treatment of tumours (EChT),-where pH alteration in tissue is the major event. Methods: Tumour cells were treated with pH 3.5, 5, 7, 9, 10 and I I for 10, 20 or 30 min, respectively, followed by studies with the viability assay 3-(4,5-dimethylthiazol-2-yl)-2,5,-diphenyl tetrazolium bromide (methyltetrazolium (MTT)), morphological observation in phase contrast microscope (PCM) and light microscope, nucleotide analogue incorporation (BrdU; 5-Brdmo-2'-deoxyuridine), Caspase-3 activity measurement and detection of DNA fragmentation by an agarose gel electrophoresis. Results: In the viability assay, it was found that different pH levels had cytotoxic effects; these effects were dependent on the pH value and on the time of exposure at a given pH. Morphologically, cells in pH 3.5 and 5 had shrunk, were rounded and had condensed chromatin, whereas prominent cell swelling and nuclear expansion were seen in the pH 9- and 10- treated cells. Gross cytolysis was found in pH 11. A BrdU incorporation assay indicated that proliferation rate is inhibited markedly both with decreasing and increasing pH. Significant Caspase-3 activity was found in pH 3.5 and 5 groups. Caspase-3 levels for the alkaline exposure were equal or below the normal control. DNA ladder formation, a characteristic of apoptosis, was only visualised in the treatment of pH 3.5 for 30 min. Conclusions: pH changes inhibit cell proliferation and decrease cell viability. The pathway of killing tumour cell in low pH probably has at least two directions: apoptosis and cell necrosis, whereas high pH results in only cell necrosis. The study suggests that low pH environment can induce apoptosis in unphysiological condition comparable with tissue pH at EChT. In addition, it seems that R3230AC mammary tumour cells are more tolerant to high pH than to acidic changes. This supports the theory that anodic EChT should be more efficient than cathodic. (C) 2002 Elsevier Science B.V All rights reserved.