RESUMO
Objective:To observe the effects of genistein on proliferation and apoptosis of human non -small cell lung cancer cell line A549/DDP.Methods:①MTT assay was applied to evaluate the resistance index of A 549/DDP cell line to cisplatin and half in-hibitory concentration ( IC50 ) .②Inhibition rate of A549/DDP cell proliferation and IC 50 value were evaluated by MTT assay after treat-ment with 0, 1.25, 2.5, 5.0, 10, 20, 40, 60, 80 μg/ml genistein for 48 hour respectively.③A549/DDP cell cycle and apoptosis were evaluated by flow cytometry after treatment with 6.25, 12.5, 25 μg/ml genistein for 24 hours respectively.Results:①In expo-sing to cisplatin, the IC50 of A549 and A549/DDP was 33.6 μmol/L and 76.9 μmol/L respectively.The resistance index was 2.3. Cell growth inhibition rate increased following the cisplatin concentration increasing gradually .②A549/DDP growth inhibition rate in-creased at first and later decreased gradually following treatment with the genistein dose increased .The IC50 of A549 and A549/DDP was about 85.1 μg/ml and 80.2μg/ml respectively.③After treatment with 6.25, 12.5, 25μg/ml genistein for 24 hours, there were more A549/DDP cells arresting and showing apoptosis along with the genistein dose increased .Conclusion: Genistein can inhibit A549/DDP proliferation, cause A549/DDP arresting in G2/M phase and induce A549/DDP cell apoptosis with dose dependently .