Effect of reversing methylation of SARI gene by 5-azacytidine on proliferation and invasion of human breast cancer cells

AIM: To observe whether reversing methylation of SARI (suppressor of activator protein-1 regulated by interferon) gene by 5-azacytidine (5-Aza) inhibits the proliferation and invasion of human breast cancer MDA-MB-231 cells. METHODS: MDA-MB-231 cells were treated with 5-Aza at 5 and 10 μmol/L. The methylation of SARI gene promoter was detected by methylation-specific PCR (MSP), and the mRNA expression of SARI was detected by RT-PCR. The protein expression of SARI was determined by Western blot. The cell growth was detected by MTT assay and colony formation assay. The cell invasion ability was detected by Transwell invasion assay. RESULTS: The results of MSP detection showed that the methylation levels of SARI promoter were significantly decreased after 5-Aza treatment (P<0.01). The results of RT-PCR and Western blot showed that the expression of SARI were significantly increased after 5-Aza treatment (P<0.05). The results of MTT and colony formation assays showed that the cell proliferation was significantly decreased after 5-Aza treatment (P<0.05). The results of Transwell invasion test showed that the invasive ability of the cells was significantly decreased after 5-Aza treatment (P<0.05). CONCLUSION: 5-Aza reverses the methylation status of SARI promoter in MDA-MB-231 cells, up-regulates the expression of SARI, and restores its ability to inhibit tumor cell growth and invasion.