Abstract:

Objective To investigate the effect of chloroquine on proliferation, apoptosis and cell cycle of human non-small cell lung cancer A549 cells and to explore the mechanism. Methods MTT assay was used to examin the A549 cells that were treated with chloroquine. The alteration of apoptosis rate and cell cycle was detected by flow cytometry. The expression of cell-cycle regulating proteins cyclin E1, cyclin dependent kinase (CDK2)，tumour suppressor protein PTEN and cell cycle inhibitory proteins P21 and P27 were examined with Western blotting. Results Chloroquine significantly inhibited cell proliferation of A549 cells in a time-and dose-dependent manner. Chloroquine also induced apoptosis. The rate of cell apoptosis was increased in a dose-dependent manner in A549 cells that were treated with various dose of chloroquine for 24 hours. Furthermore, chloroquine arrested the cell cycle at G₀/G₁ phase, decreased the protein expression level of cyclinE1 and CDK2, but significantly increased the protein expression level of PTEN, P21 and P27. Conclusion Chloroquine may inhibit the lung cancer cell proliferation, accelerate its apoptosis and arrest cell cycle processes. The mechanism may be related with the inhibition of expression of cyclinE1 and CDK2 and up-regulation of expression of PTEN, P21and P27.

Key words: Chloroquine, Non-small cell lung cancer, Proliferation, Cell cycle, Western blotting, Human