title: Immunomodulatory activity of SGI-110, a 5-aza-2'-deoxycytidine-containing demethylating dinucleotide.
abstract: OBJECTIVE
  Pharmacologic DNA hypomethylation holds strong promises in cancer immunotherapy due to its immunomodulatory activity on neoplastic cells. Searching for more efficient DNA hypomethylating agents to be utilized to design novel immunotherapeutic strategies in cancer, we investigated the immunomodulatory properties of the new DNA hypomethylating agent SGI-110, that is resistant to in vivo inactivation by cytidine deaminase.
  
  
  METHODS
  Cutaneous melanoma, mesothelioma, renal cell carcinoma, and sarcoma cells were treated in vitro with SGI-110. RT-PCR, quantitative RT-PCR, quantitative methylation-specific PCR, and flow cytometric analyses were performed to investigate changes induced by SGI-110 in the constitutive immune profile of cancer cells. The recognition by gp100-specific CTL of gp100-positive melanoma cells, treated or not with SGI-110, was tested by LDH release assays.
  
  
  RESULTS
  SGI-110 induced/up-regulated the expression of investigated cancer/testis antigens (CTA) (i.e., MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A10, GAGE 1-2, GAGE 1-6, NY-ESO-1, and SSX 1-5) in all cancer cell lines studied, both at mRNA and at protein levels. Quantitative methylation-specific PCR analyses identified a hypomethylation of MAGE-A1 and NY-ESO-1 promoters in SGI-110-treated neoplastic cells, demonstrating a direct role of pharmacologic DNA demethylation in CTA induction. SGI-110 also up-regulated the expression of HLA class I antigens and of ICAM-1, resulting in an improved recognition of cancer cells by gp100-specific CTL.
  
  
  CONCLUSIONS
  Our findings show that SGI-110 is a highly attractive therapeutic agent to comprehensively increase immunogenicity and immune recognition of neoplastic cells, and provide the scientific rationale for its clinical development to design novel chemo-immunotherapeutic approaches in cancer patients.
authors.affiliation: Cancer Bioimmunotherapy Unit, Centro di Riferimento Oncologico, Aviano, Italy.
authors.forename: Sandra
authors.initials: S
authors.lastname: Coral
authors.forename: Giulia
authors.initials: G
authors.lastname: Parisi
authors.forename: Hugues J M G
authors.initials: HJ
authors.lastname: Nicolay
authors.forename: Francesca
authors.initials: F
authors.lastname: Colizzi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Danielli
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Fratta
authors.forename: Alessia
authors.initials: A
authors.lastname: Covre
authors.forename: Pietro
authors.initials: P
authors.lastname: Taverna
authors.forename: Luca
authors.initials: L
authors.lastname: Sigalotti
authors.forename: Michele
authors.initials: M
authors.lastname: Maio
mesh_terms: D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic; D019175:DNA Methylation; D006801:Humans; D056747:Immunomodulation / Q000187:drug effects*; D016130:Immunophenotyping; D007167:Immunotherapy / Q000379:methods*; D008545:Melanoma / Q000276:immunology; D009369:Neoplasms / Q000276:immunology* / Q000628:therapy
chemical_list: D000951:Antigens, Neoplasm; C580831:guadecitabine; D001374:Azacitidine