大气中细颗粒物对肺癌细胞A549迁移和侵袭作用的影响

采集大连城区大气中可吸入性细颗粒物(PM_(2.5)),研究其对肺癌A549细胞迁移、黏附和侵袭力的影响,利用明胶酶谱法检测细胞分泌的基质金属蛋白酶活性,利用Western blot法测定A549细胞中转移相关蛋白的表达。结果表明,在无明显细胞毒性浓度下,PM_(2.5)可增加A549细胞的迁移速率;细胞与细胞外基质的黏附率增加;细胞侵袭实验结果表明PM_(2.5)可增加A549细胞穿透基底膜的能力;用明胶酶谱法检测发现PM_(2.5)可使A549细胞分泌的基质金属蛋白酶-2(MMP-2)和基质金属蛋白酶-9(MMP-9)活性增强。转移相关蛋白——细胞钙粘蛋白-N(N-cadherin)的表达量升高,而钙粘蛋白-E(E-cadherin)的表达量下降,实验结果表明,PM_(2.5)可增强A549细胞的侵袭性,大气中的可吸入性颗粒可能导致肺癌转移发生率增加。

Effect of Ambient PM2.5 on Migration and Invasion in Human A549 Lung Cancer Cells

Tumor metastasis is the major cause of mortality in patients with lung cancer. To explore the effects of PM2.5 on tumor metastasis, the cultured human lung cancer cells A549 were exposed to 10 and 20 μg·mL-1 of PM2.5(which was collected in Dalian) for 24 hours. The adhesion of A549 cells was studied by cell-matrix adhesion assay.Cell invasion and migration assay was used to determine the changes in invasion and migration of A549 cells respectively.The gelatinolytic activity was detected in the conditioned medium from cells treated with PM2.5. The effect of PM2.5 on the protein expression of metastasis-related proteins were also detected. After incubation with dif-ferent concentrations of PM2.5 for 24 h, higher concentration (20 μg·mL-1 ) of PM2.5 led to significantly increased migration in A549 cells. Cell invasion analysis showed A549 cells invaded from the upper to the lower chamber, which was increased in the presence of PM2.5 . The adhesion of A549 cells was gradually enhanced with the in-creasing concentration of PM2.5 . The gelatinolytic activity of MMP-2 and MMP-9 was markedly higher in PM2.5 treatment groups. E-cadherin was down-regulated and N-cadherin was up-regulated. The results presented in this study suggest PM2.5 enhance the adhesion,invasion and migration of A549 cells probably through regulating the expression of cadherins.