Effect of dimethyl amiloride on proliferation and expression of cell cycle-related proteins of human lung carcinoma cell lines

【Objective】To study the effect of dimethyl amiloride(DMA) on the proliferation and the expression of cell cycle-related proteins of PGCL3 cells from a human highly metastatic giant-cell lung carcinoma cell line in vitro.【Methods】PGCL3 cells were incubated with DMA at various concentration, MTT assay was used to determine the growth inhibition by DMA in PGCL3 cells; flow cytometry was applied to detect the change in cell cycle; the expression level of p21, cyclinA, CDK2 (cell cycle depend on kinase 2), cyclinB1 and Cdc25B (cell divide cycle 25B) protein and the activity of CDK1 and Cdc25B were assessed by Western blot.【Results】DMA inhibited the proliferation of human lung carcinoma cells PGCL3 on a time-and concentration-dependent manner; DMA treatment arrested cell cycle in G2/M phase and S phase; after 24h treatment, DMA up-regulated the expression of p21 protein, down-regulated the expression of cyclinB1 protein, reduced the activity of CDK2 and Cdc25B, but did not affect the the expression of cyclinA, CDK2 and Cdc25. 【Conclusion】DMA can inhibite the proliferation of PGCL3 cells, the effect of DMA on changing the expression and activity of cell cycle-related proteins might be one of the mechanisms underlying tumor suppressive effeccts of DMA.