Background: DNA methylation plays an important role in the regulation of gene expression in mammalian cells and often occurs at CpG islands in the genome. It is more reversible than genetic variations and has therefore attracted much attention for the treatment of many diseases, especially cancer. In the present study, we investigated the effect of Solanum Nigrum Extract (SNE) on the methylation status of the VIM and CXCR4 genes in breast cancer cell lines.
Methods: The Trypan blue assay was used to study the effect of SNE at various concentrations of 0, 0.1, 1.5, 2.5, 3.5 and 5 mg/ml for 48 hrs on the survival of three human breast cancer cell lines MCF7, MDA-MB-468, MDA-MB-231. Methylation status of VIM and CXCR4 genes in breast cancer cell lines was assessed by Methylation-Specific PCR (MSP) method. Also, methylation changes of VIM and CXCR4 genes in breast cancer cell lines after treatment with 0.1 mg/ml of SNE for 6 days were analyzed by MSP method. To confirm the effect of SNE on methylation of VIM and CXCR4 genes, Real-Time PCR was performed.
Results: The Trypan blue assay results indicated that treatment with SNE reduced cell viability in a dose dependent manner in breast cancer cells. Our results showed that treatment of breast cancer cells with 0.1 mg/ml of SNE hypermethylated the VIM, CXCR4 genes and significantly reduced the expression levels of their mRNA (P<0.05).
Conclusions: Our findings reveal for the first time the impact of SNE on the methylation of breast cancer cells.