亚砷酸钠致人支气管上皮细胞恶性转化过程中氧化应激指标变化

Changes of oxidative stress indicators in malignant transformation of human bronchial epithelial cells induced by sodium arsenite

目的探讨在亚砷酸盐致人支气管上皮(HBE)细胞恶性转化过程中氧化应激指标的变化趋势,初步探讨其对细胞恶性转化的作用。方法用1μmol/L亚砷酸钠连续染毒HBE细胞。通过形态学观察、基质金属蛋白酶-9(MMP-9)以及软琼脂克隆实验鉴定细胞恶性转化情况,分别于暴露1、8、15、22、29、36、43代,以流式细胞仪检测细胞活性氧(ROS)水平,检测细胞丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力。结果亚砷酸钠长期染毒HBE细胞至43代时,细胞生长速度明显加快,且呈浸润型生长,MMP-9分泌量升高,细胞集落数量增多。与正常对照(0代)比较,22代及以前HBE细胞内ROS、MDA及SOD的水平均呈先升高后下降的波浪形趋势;29代及以后,ROS、MDA水平逐渐下降,且以ROS表现更为明显,而SOD水平呈逐渐升高趋势。结论细胞内氧化-抗氧化平衡失调可能在低剂量砷化合物诱导HBE细胞恶性转化过程中发挥重要作用。

Objective To analyze the changes and the possible roles of oxidative stress indicators in the process of malignant transformation of human bronchial epithelial（HBE） cells induced by sodium arsenite. Methods HBE cells were continuously treated with 1 μmol/L sodium arsenite. The phenotype of malignant transformation of HBE cells was identified by the morphological observation, matrix metalloproteinases 9（MMP-9） activity and soft agar cloning assay. Further, the flow cytometry was used to detect the levels of reactive oxygen species（ROS） and determine malondialdehyde（MDA） and superoxide dismutase（SOD） activity respectively at passage 1, 8, 15, 22, 29, 36 and 43. Results After treatment with 1 μmol/L sodium arsenite for43 passages,HBE cells grew significantly faster and showed invasive growth,the secretion of MMP-9 was higher and the colonies were significantly increased. Compared with the control groups（passage 0）, the levels of ROS, MDA and SOD all displayed a wavy tendency of up-regulation first and down-regulation second before passage 22. After passage 29, however, the levels of ROS and MDA were declined to a much lower level gradually, particularly for ROS. Moreover,the activity of SOD was constantly increased. Conclusion The intracellular imbalance between oxidation and anti-oxidation may be involved in the malignant transformation of HBE cells induced by low concentration of sodium arsenite.