Nitric oxide and acid induce double-strand DNA breaks in Barrett's esophagus carcinogenesis via distinct mechanisms
Nitric oxide and acid induce double-strand DNA breaks in Barrett's esophagus carcinogenesis via distinct mechanisms
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DOI：
10.1053/j.gastro.2007.06.061
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发表时间：
2007-10-01
期刊：
影响因子：
29.4
通讯作者：
Fitzgerald, Rebecca C.
中科院分区：
文献类型：
--
作者：
Clemons, Nicholas J.;Mccoll, Kenneth E. L.;Fitzgerald, Rebecca C.
背景与目的：包括酸和一氧化氮（NO）在内的管腔微环境与Barrett食管癌的发生有关。我们研究了酸和NO诱导食管细胞DNA损伤的能力。研究方法：将转化的和原代Barrett食管和腺癌细胞暴露于酸（pH 3.5）、+/-抗氧化剂或来自供体的NO或通过在抗坏血酸+/-NO清除剂存在下酸化亚硝酸盐产生的NO。采用组蛋白H2AX磷酸化和中性彗星试验检测DNA双链断裂。用荧光染料检测细胞内活性氧和NO水平。用罗丹明染料测定线粒体活力。通过克隆形成试验评估长期存活率。结果如下：酸（pH3.5）作用≥ 15分钟，所有细胞系（P <25 μ mol/L）和细胞依赖性方式（腺癌> Barrett食管，P
Background & Aims: The luminal microenvironment including acid and nitric oxide (NO) has been implicated in Barrett's esophagus carcinogenesis. We investigated the ability of acid and NO to induce DNA damage in esophageal cells. Methods: Transformed and primary Barrett's esophagus and adenocarcinoma cells were exposed to either acid, (pH 3.5), +/- antioxidant or NO from a donor or generated by acidification of nitrite in the presence of ascorbate +/- NO scavenger. Phosphorylation of histone H2AX and the neutral comet assay were used to detect DNA double-strand breaks (DSBs). Intracellular levels of reactive oxygen species and NO were detected with fluorescent dyes. Mitochondrial viability was measured with a rhodamine dye. Long-term survival was assessed by clonogenic assay. Results: Exposure to acid (pH 3.5) for >= 15 minutes induced DSBs in all cell lines (P 25 mu mol/L) and cell-dependent manner (adenocarcinoma >Barrett's esophagus, P