[Reversal effect of 5-Aza-dc on cisplatin-resistance in human NSCLC cells in vitro].

Article Details

Citation

Copy to clipboard

Wu F, Hu CH

[Reversal effect of 5-Aza-dc on cisplatin-resistance in human NSCLC cells in vitro].

Zhonghua Zhong Liu Za Zhi. 2011 May;33(5):349-53.

PubMed ID

21875463 [ View in PubMed

]

Abstract

OBJECTIVE: The aim of this study was to investigate the effect of 5-aza-2'-deoxycytidine (5-Aza-dc), a methylation inhibitor, on cisplatin-resistance in non-small cell lung cancer cell line A549/DDP and to explore its possible mechanism. METHODS: MTT assay was used to test the cytotoxicity of 5-Aza-dc on A549/DDP cells, and the IC(50) and cisplatin resistance index of A540/DDP cells at 48 hours after 5-Aza-dc (0 micromol/L, 20 micromol/L, 40 micromol/L) treatment at different concentrations. MSP, fluorescence quantitative RT-PCR (real-time RT-PCR) and Western blot were used to detect the hMLH1 methylation status, mRNA and protein expressions, respectively. RESULTS: The IC(50) value of cisplatin in A549/DDP cells was 30.15 +/- 0.76 micromol/L. The MTT assay results demonstrated that during the 5-Aza-dc treatment for 48 hours, the dose of 20 micromol/L was non-toxic and 40 micromol/L was low-toxic. 5-Aza-dc at those two doses reduced IC(50) value of cisplatin to 16.54 +/- 0.35 micromol/L (RI = 1.82) and 6.82 +/- 0.16 micromol/L (RI = 4.42), respectively. MSP, real-time RT-PCR and Western blot showed that 5-Aza-dc at non-toxic and low-toxic doses removed the partial hMLH1-hypermethylation, and up-regulated hMLH1 mRNA and protein expressions. CONCLUSIONS: Low dose 5-Aza-dc can partially reverse the cisplatin-resistance in A549/DDP cells, which may be achieved through removal of hMLH1 hypermethylation and increased expression of hMLH1 gene. 5-Aza-dc may have a role in increasing the efficacy of chemotherapy for patients whose tumors are lack of hMLH1 expression because of hMLH1 promoter hypermethylation.