Abstract:

Objective To isolate CD133+A549 cells, and investigate the characteristics of cancer stemness and epithelial-mesenchymal transition (EMT). Methods A549 cells were isolated by immunomagnetic beads method, and were identified by Real-Time PCR and Western blotting. The expression of cancer stem cell markers (CXCR4, Oct4, CD44, Bmi1 and EpCam) and EMT markers (E-Cadherin and Zeb1) mRNA in CD133+A549 cells and CD133－A549 cells was detected by Real-Time PCR. The isolated CD133+A549 cells and CD133－A549 cells were treated with different concentrations (0, 0.25, 0.5 and 1.0 μg/mL) of adriamycin for 72 h, and the relative survival rates of cells were determined by cell viability assay. Results After isolation through CD133 antibody conjugated microbeads, CD133+ A549 cells and CD133－A549 cells were successfully obtained, and the expression of CD133 in CD133+A549 cells was significantly higher than that in CD133－A549 cells. Real-Time PCR revealed that the relative expression of Oct4, CD44, Bmi1 and EpCam mRNA in CD133+A549 cells was significantly higher than that in CD133－A549 cells [ (1±0.16) vs（0.66±0.12）,（1±0.07） vs （0.48±0.04）,（1±0.03） vs （0.49±0.06）, and (1±0.14） vs (0.38±0.12）; P<0.05], while there was no significant difference in the relative expression of CXCR4 mRNA between them [(1±0.13） vs (0.73±0.14），P>0.05]. The relative expression of Zeb1 mRNA in CD133+A549 cells was significantly higher than that in CD133－A549 cells [(1±0.09) vs (0.39±0.05），P<0.05], while the relative expression of E-Cadherin mRNA in CD133+A549 cells was significantly lower than that in CD133－A549 cells [(1±0.02) vs (4.98±0.04），P<0.05]. Cell viability assay indicated that the relative survival rate of CD133+A549 cells was significantly higher than that in CD133－A549 cells after treatment with 0.5 and 1.0 μg/mL adriamycin [(85±9.4）% vs (67±13.1）%，P<0.05；(80±14.9）% vs (56±6.3）%，P<0.01]. Conclusion CD133+ A549 cells and CD133－A549 cells can be successfully isolated by immunomagnetic beads method. There is expression of other cancer stem cell markers in CD133+A549 cells, which exhibit characteristics of EMT. CD133 may be a potential biomarker of cancer stemness and EMT in lung cancer.

Key words: CD133, cancer stem cells, epithelial-mesenchymal transition, lung cancer