Induction of MAGE genes in lymphoid cells by the demethylating agent 5-aza-2'-deoxycytidine.

MAGE genes encoding tumor antigens recognized by cytotoxic T lymphocytes are appropriate target molecules for specific immunotherapy of cancer. We have investigated whether the demethylating agent 5-aza-2'-deoxycytidine (DAC) induces MAGE-1, -2, -3, and -6 in normal and malignant lymphoid cells. DAC induced these MAGE genes in both PHA/interleukin-2 (IL-2)-activated T cells from healthy donors and MAGE-negative T and B cell leukemias in most cases. It also induced MAGE-1 in IL-2-dependent T cell clones and all MAGE genes tested in Epstein-Barr virus-transformed B cell lines. Expression of MAGE-1 protein in the cells was confirmed by western blot analysis with anti-MAGE-1 polyclonal antibody. Therefore, demethylation is a potent stimulus to induce MAGE genes in both normal and malignant lymphoid cells.