Low-dose decitabine induces MAGE-A expression and inhibits invasion via suppression of NF-κB2 and MMP2 in Eca109 cells.

Decitabine, a demethylating drug, is the first-line treatment for myelodysplastic syndromes and gains better overall survival, which is based on epigenetic mechanism. Activated by promoter demethylation, melanoma-associated antigens-A (MAGE-A), cancer-testis antigens are attractive targets for immunotherapy. Our purpose was to investigate whether decitabine could show anti-tumor effects for esophageal cancer and explore its mechanism. In addition, we aimed to examine its modulation for most MAGE-A members. The results showed the baseline expression were MAGE-A2, -3,-9, and -10 in Eca109 cells and decitabine (0.5 µM) could induce MAGE-A8 and -A4 whereas reduce MAGE-A9 and -A10. Moreover, decitabine (0.5 µM) inhibited cell proliferation, migration and invasive ability by 15%, 34% and 47.2%, respectively and decreased expressions of NF-κB2 and MMP2. Our results demonstrated that low-dose decitabine induced the expression of MAGE-A8 and -A4, and inhibited cell invasion through decreasing expression of MMP2 and NF-κB2, which provides possibilities for combing decitabine with immunotherapy targeting MAGE-A to treat advanced esophageal squamous cell carcinoma.

Expressions of MAGE-A9 and MAGE-A11 in breast cancer and their expression mechanism.

BACKGROUND AND AIMS: The MAGE gene encodes cancer/testis antigens that are selectively expressed in various types of human neoplasms but not in normal tissues other than testis and placenta. However, the expression pattern of MAGE-A9 and MAGE-A11 in breast cancer patients is still unclear. The purpose of our study is to investigate the expression pattern and mechanism of MAGE-A9 and MAGE-A11 in breast cancer patients. METHODS: The expression of MAGE-A9 and MAGE-A11 was investigated in 60 breast benign diseases specimens, 60 tumor-free breast specimens and 60 breast cancer specimens by RT-PCR, and their correlation with clinicopathological parameters was elucidated. We examined the influence of the DNA methylase inhibitor 5-aza-2'-deoxycytidine (5-aza-CdR) together with the histone deacetylase inhibitor trichostatin A (TSA) on the expression of MAGE-A9 and MAGE-A11 genes in two breast cancer cell lines. RESULTS: The expression rates of MAGE-A9 and MAGE-A11 in breast cancer specimens were 45 and 66.7%, respectively. MAGE-A9 and MAGE-A11 expression was positively associated with estrogen-receptor (ER) and HER-2 expression (p <0.05). 5-Aza-CdR treatment alone could induce the expression of MAGE-A9 and MAGE-A11 in cell lines that did not express this antigen. TSA treatment alone had no influence on MAGE-A9 and MAGE-A11 gene expression. However, TSA was able synergistically to enhance 5-aza-CdR-mediated MAGE-A transcription (p <0.05). CONCLUSIONS: Our data show that MAGE-A9 and MAGE-A11 are tumor-specific antigens and not only DNA hypermethylation but also histone deacetylation is responsible for the mechanism underlying MAGE-A9 and MAGE-A11 gene silencing.