A yeast two-hybrid system using Sp17 identified Ropporin as a novel cancer–testis antigen in hematologic malignancies
Article first published online: 5 JUN 2007
Copyright © 2007 Wiley-Liss, Inc.
International Journal of Cancer
Volume 121, Issue 7, pages 1507–1511, 1 October 2007
How to Cite
Li, Z., Li, W., Meklat, F., Wang, Z., Zhang, J., Zhang, Y. and Lim, S. H. (2007), A yeast two-hybrid system using Sp17 identified Ropporin as a novel cancer–testis antigen in hematologic malignancies. Int. J. Cancer, 121: 1507–1511. doi: 10.1002/ijc.22842
- Issue published online: 24 JUL 2007
- Article first published online: 5 JUN 2007
- Manuscript Accepted: 17 APR 2007
- Manuscript Received: 22 FEB 2007
- National Institute of Health/National Cancer Institute. Grant Numbers: RO1 CA 088434, RO1 CA 106283
- yeast two-hybrid;
- ropporin 1;
- CT antigen
Since most intracellular proteins are expressed with their ligands, ligands of cancer–testis (CT) antigens may also be CT in their distribution. Applying Sperm protein 17 (Sp17) as the bait in a yeast 2-hybrid system of a testicular cDNA library, 17 interacting clones were isolated and all encoded Ropporin, a spermatogenic cell-specific protein that serves as an anchoring protein for the A-kinase anchoring protein, AKAP110. Ropporin showed a very restricted normal tissue gene expression, detected only in testis and fetal liver. Ropporin mRNA could also be detected in tumor cells from patients with multiple myeloma, chronic lymphocytic leukemia and acute myeloid leukemia. Interestingly, expression of Sp17 did not necessarily predict for the expression of Ropporin suggesting that their coexpression in these tumor cells was random rather than coordinated. Ropporin gene expression in tumor cells is associated with the presence of high titer IgG antibodies against Ropporin, suggesting the in vivo translation of the mRNA into protein and the immunogenicity of the protein to the autologous hosts. Using a CT antigen as the bait in a yeast 2-hybrid system may, therefore, identify novel tumor antigen. Our results also suggest that Ropporin is a novel CT antigen in hematologic malignancies. © 2007 Wiley-Liss, Inc.