Acidification and apoptosis of human lung cancer cells induced with antisense nucleotides against NHE-1 gene

To explore the role of Na+/H+ exchanger-1 (NHE-1 ) gene expression in intracellular PH (pHi) regulation and the modulation of apoptosis of human lung cancer cells. Methods: After the human lung cell line A549 cells were incubated with a 21-mer antisense phosphorothioate oligodeoxynucleotide (ASODN) complementary to NHE-1 gene, the acidification effects of AS-ODN on A549 cells was investigated with fluorescent probe labeling and the apoptotic rate of these cells determined with in situ cell apoptosis detection. Results: Intracellular acidification (pHi from 7. 12 to 6. 55) and cell apoptosis of A549 cells induced by AS-ODN were correlated to dose of the agent. The apoptotic rate was found to be 30. 1 %, 91. 2% and 99. 6% respectively at the end of incubation time of 24, 48 and 72 h with 20μmol/L AS--ODN. Under the electron microscope, morphological changes of cell apoptosis were seen. Conclusion: Intracellular acidification (pHi<6. 55) can trigger apoptosis of human lung cancer cells and NHE-1 gene expression plays an important role in the regulation of apoptosis of the human lung cancer cells through preventing intracellular acidification.

人肺癌组织细胞NHE-1 mRNA表达及其意义的研究

目的 :研究人肺癌组织细胞NHE - 1基因表达水平 ;探讨人肺癌细胞在整体条件下PHi调节的分子机制及其生物学意义。方法 :以半定量逆转录PCR研究了 1 4例人肺癌组织手术新鲜标本的NHE - 1mRNA的表达水平。结果 :人肺癌组织细胞NHE - 1mRNA表达水平非常显著地高于正常肺组织 (p <0 0 0 1 ) ,系正常肺组织的 1 1 81倍。结论 :人肺癌组织细胞通过上调NHE - 1基因超表达 ,以增强Na+ /H+ 交换 ,可能是其在整体条件下PHi调节的主要分子机制和特点。