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 h 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).
Conclusion: Our findings reveal for the first time the impact of SNE on the methylation of breast