Phenotypic and functional changes of human melanoma xenografts induced by DNA hypomethylation: immunotherapeutic implications

J Cell Physiol. 2006 Apr;207(1):58-66. doi: 10.1002/jcp.20540.


Emerging in vitro evidence points to an immunomodulatory activity of DNA hypomethylating drugs in human malignancies. We investigated the potential of 5-aza-2'-deoxycytidine (5-AZA-CdR) to modulate the expression of cancer testis antigens (CTA) and of HLA class I antigens by melanoma xenografts, and the resulting modifications in immunogenicity of neoplastic cells. Three primary cultures of melanoma cells, selected for immune phenotype and growth rate, were grafted into BALB/c nu/nu mice that were injected intraperitoneally with different dose- and time-schedules of 5-AZA-CdR. Molecular analyses demonstrated a de novo long-lasting expression of the CTA MAGE-1, -2, -3, -4, -10, GAGE 1-6, NY-ESO-1, and the upregulation of MAGE-1, MAGE-3, and NY-ESO-1 levels in melanoma xenografts from 5-AZA-CdR-treated mice. Serological and biochemical analyses identified a de novo expression of NY-ESO-1 protein and a concomitant and persistent upregulation of HLA class I antigens and of HLA-A1 and -A2 alleles. Immunization of BALB/c mice with 5-AZA-CdR-treated melanoma cells generated high titer circulating anti-NY-ESO-1 antibodies. Altogether, the data obtained identify an immunomodulatory activity of 5-AZA-CdR in vivo and strongly suggest for its clinical use to design novel strategies of CTA-based chemo-immunotherapy for melanoma patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibody Formation / immunology
  • Antigens, Neoplasm / genetics
  • Antigens, Neoplasm / immunology
  • Antigens, Neoplasm / metabolism
  • Antimetabolites, Antineoplastic / administration & dosage
  • Antimetabolites, Antineoplastic / pharmacology
  • Antimetabolites, Antineoplastic / therapeutic use
  • Azacitidine / administration & dosage
  • Azacitidine / analogs & derivatives*
  • Azacitidine / pharmacology
  • Azacitidine / therapeutic use
  • DNA Methylation / drug effects*
  • Decitabine
  • Female
  • Gene Expression / drug effects
  • Gene Expression / genetics
  • HLA-A1 Antigen / metabolism
  • HLA-A2 Antigen / metabolism
  • Histocompatibility Antigens Class I / metabolism
  • Humans
  • Immunotherapy / methods*
  • Melanoma, Experimental / genetics
  • Melanoma, Experimental / pathology
  • Melanoma, Experimental / therapy*
  • Melanoma-Specific Antigens
  • Membrane Proteins / genetics
  • Membrane Proteins / immunology
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Neoplasm Proteins / genetics
  • Tumor Cells, Cultured
  • Vaccination
  • Xenograft Model Antitumor Assays*


  • Antigens, Neoplasm
  • Antimetabolites, Antineoplastic
  • CTAG1B protein, human
  • HLA-A1 Antigen
  • HLA-A2 Antigen
  • Histocompatibility Antigens Class I
  • MAGEA1 protein, human
  • MAGEA3 protein, human
  • Melanoma-Specific Antigens
  • Membrane Proteins
  • Neoplasm Proteins
  • Decitabine
  • Azacitidine