Examine the effect of 5-Azacitidine on expression levels of TLR2, 4 in Human breast cancer cells (MCF-7)

Introduction: Despite advances in treatment of breast cancer, the operative control of metastasis remains a complex problem. Toll-like receptors (TLRs) have garnered an extraordinary amount of interest in cancer research due to their role in tumor progression. Toll-like receptor (TLR)-mediated signaling has been associated in tumor cell invasion, survival, and metastasis in a variety of cancers. Recent studies showed that in addition to genetic disorders, the development of cancer is triggered by epigenetic changes. DNA methylation is a key epigenetic modification that often leads to silencing on the gene transcription. Cancer cells are characterized by abnormal DNA methylation arrangements. This study examined the expression of TLR2 and TLR4 in human breast cancer after treatment by epi-drug 5-azacitidin in MCF-7 as humanbreast cancer cell lines with low metastatic potential Methods: Human breast cancer cell lines MCF-7 were cultured and the experiment was designed in 2 groups: Control and 5-aza: for 5-aza treatment, at various concentrations. After RNA extraction and cDNA synthesis, Real-time PCR was performed to detect TLR2 and TLR4 gene expression.Results: Expression of TLR2 and TLR4 on MCF-7 human breast cancer cell line was analyzed by RTPCR, real time-PCR. The increased expression of TLR 2 and 4 was clearly observed in control group. Quantitative analysis of the increased expression of TLR2 and TLR4 mRNA by real time-PCR showed that, at the mRNA level, TLR2 and TLR4 expression in MCF-7 cells in the treated group(5-aza treated) was lower than in the controls (P<0.05). Conclusion: It was revealed that use of Epi-drug such as 5-aza can down-regulated the expression of TLR2 and TLR4 in breast cancer cells. The Epi-drugs such as 5-aza not only possess the demetylation effect, but also by changes in expression of innate immunity component that involved in inflammation, metastasis and tumor cell proliferation

Keywords:

TLR2 , TLR4 , epi-drug , MCF-7