Abstract:

Objective

To investigate the effects of 5-aza-2′-deoxycitydine (5-Aza-CdR) on apoptosis and expression of Runt-related transcription factor 3 (RUNX3) in breast cancer MCF-7 cell line.

Methods

MCF-7 cells were cultured with different concentrations (0.4、1.6、6.4、25.6、102.4 μmol/L) of 5-Aza-CdR in vitro. MCF-7 cells cultured with no 5-Aza-cdR served as control. MTT assay was used for analyzing the growth inhibitory effect of 5-Aza-CdR in MCF-7 cells. The apoptosis rate was detected by flow cytometric analysis. The RUNX3 mRNA and protein levels were measured by reverse transcription-polymerase chain reaction (RT-PCR)and Western blot analysis. Data were analyzed with Student Newman Keuls (SNK) test of one-way analysis of variance (ANOVA) using SPSS 13.0 software.

Results

5-Aza-CdR effectively inhibited MCF-7 cells in a dose- and time-dependent manner. Flow cytometric analysis showed that the apoptosis ratio was 15.33%,25.35%, 27.95%, 32.39%, 39.27% in the experimental groups with different concentrations of 0.4-102.4 μmol/L 5-Aza-CdR respectively after 48 h treatment. Except 0.4 μmol/L group, the apoptosis ratio in other experiment groups was higher than that in control group(P＜0.05). RT-PCR and Western-blot results showed that the expressions of RUNX3 on both mRNA and protein levels were increased.

Conclusion

5-Aza-CdR can induce the apoptosis of breast cancer MCF-7 cells, which may be due to that 5-Aza-CdR can promote the demethylation and the expressions of RUNX3 mRNA and protein.

Key words: breast neoplasms, apoptosis, 5-Aza-CdR, RUNX3, MCF-7 cells