Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.37 (DNA methyltransferase)
 4,983 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Melanoma-associated antigen-A11 (MAGE-A11) is frequently expressed in breast cancer and is associated with poor prognosis. Therefore, MAGE-A11 is a potential immunotherapy target in breast cancer. MAGE-A11 expression, however, is downregulated in many patients, thus constraining the application of immunotherapy. The induction of MAGE-A11 expression is crucial for the recognition and killing of breast cancer cells by cytotoxic T lymphocytes (CTL). In this study, a series of HLA-A2-restricted candidate MAGE-A11 peptides were predicted, synthesized, and tested. Of the selected peptides, p350 (FLFGEPKRL) elicited peptide-specific CTLs from healthy HLA-A*0201-positive donors. The induced CTLs can lyse MAGE-A11-expressing breast cancer cells but not MAGE-A11-negative tumor cells. To improve antitumor immune response, zebularine, a DNA methyltransferase inhibitor, was used to induce MAGE-A11 expression and upregulate the cytotoxicity of antigen-specific T cells in breast cancer cell lines and primary breast cancer cells. The present findings suggested that peptide p350 induces peptide-specific cytolytic activity and is thus a potential candidate for tumor vaccination or T-cell therapy. Epigenetic modulation by zebularine can induce MAGE-A11 expression in breast cancer cells and facilitate cytotoxicity via MAGE-A11-specific CTL.
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PMID:Zebularine Treatment Induces MAGE-A11 Expression and Improves CTL Cytotoxicity Using a Novel Identified HLA-A2-restricted MAGE-A11 Peptide. 2848 73

Recently, we have reported that the product of Melanoma Antigens Genes (MAGE) family member MAGE-A11 is an independent poor prognostic marker for esophageal squamous cell carcinoma (ESCC). However, the reason how MAGE-A11 is activated in ESCC progression still remains unclear. In the current study, we demonstrated that DNA methylation and the subsequent histone posttranslational modifications play crucial roles in the regulation of MAGE-A11 in ESCC progression. We found that the methylation rate of TFCP2/ZEB1 binding site on MAGE-A11 promoter in ESCC tissues and cells is higher than the normal esophageal epithelial tissues and cells. Transcription factors TFCP2 and ZEB1 directly bind MAGE-A11 promoter and regulate the endogenous MAGE-A11 expression in a methylation-dependent manner in ESCC cells. Following MAGE-A11 promoter methylation, the methyl-CpG-binding protein MeCP2 was found to bind the methylated MAGE-A11 promoter to mediate histone deactylation by recruiting HDAC1 and HDAC2. Simultaneously, histone inactivation marks including H3K27me3 as well as H3K9me3 were increased, whereas histone activation mark H3K4me3 was decreased. HDAC inhibitor Trichostatin A (TSA) increased DNA methylase inhibitor Decitabine (DAC)-induced MAGE-A11 expression. siRNA-mediated knockdown of histone methltransferase EZH2 or DZNep (a EZH2 inhibitor) treatment increased DAC-induced MAGE-A11 expression. Our results indicate that MAGE-A11 is activated through DNA demethylation, histone acetylation and histone methylation in ESCC, and its activation promotes ESCC tumor growth.
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PMID:MAGE-A11 is activated through TFCP2/ZEB1 binding sites de-methylation as well as histone modification and facilitates ESCC tumor growth. 2942 52

Cancer testis antigens (CTAs) are promising targets for T cell-based immunotherapy and studies have shown that certain CT genes are epigenetically depressed in cancer cells through DNA demethylation. Melanoma-associated antigen A11 (MAGE-A11) is a CTA that is frequently expressed in esophageal cancer and is correlated with a poor esophageal cancer prognosis. Consequently, MAGE-A11 is a potential immunotherapy target. In this study, we evaluated MAGE-A11 expression in esophageal cancer cells and found that it was downregulated in several tumor cell lines, which restricted the effect of immunotherapy. Additionally, the specific recognition and lytic potential of cytotoxic T lymphocytes (CTLs) derived from the MAGE-A11 was determined. Specific CTLs could kill esophageal cancer cells expressing MAGE-A11 but rarely lysed MAGE-A11-negative tumor cells. Therefore, induction of MAGE-A11 expression is critical for CTLs recognition and lysis of esophageal cancer cells. Treatment with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine increased MAGE-A11 expression in esophageal cancer cells and subsequently enhanced the cytotoxicity of MAGE-A11-specific CD8+T cells against cancer cell lines. Furthermore, we found that PD-L1 expression in esophageal cancer cells affected the antitumor function of CTLs. programmed death-1 (PD-1)/PD-L1 blockade could increase the specific CTL-induced lysis of HLA-A2+/MAGE-A11+ tumor cell lines treated with 5-aza-2'-deoxycytidine. These findings indicate that the treatment of tumor cells with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine augments MAGE-A11 expression in esophageal cancer cells. The combination of epigenetic modulation by 5-aza-2'-deoxycytidine and PD-1/PD-L1 blockade may be useful for T cell-based immunotherapy against esophageal cancer.
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PMID:Epigenetic modulation combined with PD-1/PD-L1 blockade enhances immunotherapy based on MAGE-A11 antigen-specific CD8+T cells against esophageal carcinoma. 3252 60