CT10: A new cancer‐testis (CT) antigen homologous to CT7 and the MAGE family, identified by representational‐difference analysis

Assays relying on humoral or T‐cell‐based recognition of tumor antigens to identify potential targets for immunotherapy have led to the discovery of a significant number of immunogenic gene products, including cancer‐testis (CT) antigens predominantly expressed in cancer cells and male germ cells. The search for cancer‐specific antigens has been extended via the technique of representational‐difference analysis and SK‐MEL‐37, a melanoma cell line expressing a broad range of CT antigens. Using this approach, we have isolated CT antigen genes, genes over‐expressed in cancer, e.g., PRAME and KOC, and genes encoding neuro‐ectodermal markers. The identified CT antigen genes include the previously defined MAGE‐A6, MAGE‐A4a, MAGE‐A10, CT7/MAGE‐C1, as well as a novel gene designated CT10, which shows strong homology to CT7/MAGE‐C1 both at cDNA and at genomic levels. Chromosome mapping localized CT10 to Xq27, in close proximity to CT7/MAGE‐C1 and MAGE‐A genes. CT10 mRNA is expressed in testis and in 20 to 30% of various human cancers. A serological survey identified 2 melanoma patients with anti‐CT10 antibody, demonstrating the immunogenicity of CT10 in humans. Int. J. Cancer 85:726–732, 2000. © 2000 Wiley‐Liss, Inc.