Anti-apoptosis competence and drug-resistance protein expression of tumor spheres from lung cancer cell line A549 / 肿瘤

ABSTRACT

Objective: To investigate the anti-apoptosis competence and the expression of glutathione- S-transferase-π (GST-π) of tumor spheres from lung cancer cell line A549. Methods: The tumor spheres were achieved from lung cancer cell line A549 cultured in serum-free medium. The apoptosis rates of both tumor spheres and primary A549 cells after treatment with cisplatin were detected by immunofluorescence assay with Annexin V-FITC+PI and JC-1 stainings, and the expressions of GST-π protein were also examined in the tumor spheres and the primary A549 cells as well as their grafted tumors in nude mice by Western blotting and fluorescence immunohistochemistry, respectively. Results: Immunofluorescence assay showed that the apoptosis rate was significantly higher in tumor spheres than that in primary A549 cells. Compared with the primary A549 cells and their corresponding grafted tumors, the expression levels of GST-π protein were significantly higher in the tumor spheres and their corresponding grafted tumors. Conclusion: Tumor spheres from lung cancer cell line A549 have a strong capability of drug-resistance, which is probably associated with the up-regulated expressions of drug-resistance proteins in these tumor spheres.