Effects of 5-Aza-CdR on proliferation and apoptosis of human non-small cell lung cancer A549 cells and the expression of Apaf-1 gene

Objective To explore the effect of DNA methyltransferase inhibitor 5-Aza-2\u0027 -deoxy-cytidine (5-Aza-CdR) on the growth of human lung cancer cell line A549 and study the effect of 5-Aza-CdR on the expression of Apaf-1 gene in A549 cell line.Methods A549 ceils were treated with 5-Aza-CdR at different concentrations.The growth inhibition rate of A549 ceils was detected by MTT assay.Chan-ges in cell cycle distribution and apoptosis rate were detected by flow eytometry 72 h after treatment with 5-Aza-CdR.The expression of methyltransferase mRNA and Apaf-1 mRNA was observed by RT-PCR, and the expression of Apaf-1 protein detected by Western blot respectively.Results The growth inhibition rate of A549 cells was increased in a concentration-and time-independent manner.The proportion of apoptotie ceils and the ceils in G1 phase were significantly increased 72 h after treatment with 5-Aza-CdR, while the cells in S phase were reduced.The expression of Apaf-1 mRNA and protein was increased,while the ex-pression of methyhransferase mRNA decreased after treatment with 5-Aza-CdR.Conclusion 5-Aza-CdR could reduce the growth of tumor ceils by inhibiting DNA methltransferase and reactivating tumor suppres-sor Apaf-1 gene in A549 cell line.\r\n\r\nKey words: \r\nLung carcinoma;  Apaf 1 gene;  DNA methylation;  Gene expression