Cancer Immunity, Vol. 8, p. 15 (13 November 2008) Submitted: 18 September 2008. Accepted: 27 October 2008.
Toshiaki Ishida1,2, Yuichi Obata3, Nobuya Ohara4, Hirokazu Matsushita1, Shuichiro Sato1, Akiko Uenaka1, Takashi Saika5, Takako Miyamura2, Kosuke Chayama2, Yurika Nakamura6, Hisashi Wada6, Toshiharu Yamashita7, Tsuneo Morishima2, Lloyd J. Old8 and Eiichi Nakayama1
1Department of Immunology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
2Department of Pediatrics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
3RIKEN Bioresource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
4Department of Pathology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
5Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
6Department of Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
7Department of Dermatology, Sapporo Medical University School of Medicine, S1W16 Chuo-ku, Sapporo, Hokkaido 060-8543, Japan
8Ludwig Institute for Cancer Research, New York Branch at Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA
Contributed by: LJ Old
The prostate cancer HERV-K gag-related NGO-Pr-54 antigen was identified by SEREX analysis using autologous patient serum. NGO-Pr-54 mRNA was observed to be faintly expressed in normal prostate and strongly expressed in a variety of cancers, including ovarian cancer (5/8), prostate cancer (6/9), and leukemia (5/14). A phage plaque assay showed that a strong reaction was constantly observed with clone ZH042 in which the 5' end of NGO-Pr-54 is deleted, suggesting that it contained the sequence coding for the protein product. A TI-35 mAb was produced using a recombinant protein (438 aa) deduced from the sequence of ZH042. Transfection of clone ZH042 into 293T cells resulted in the production of an approximately 50-kDa molecule visualized by Western blotting. Natural production of the molecule was confirmed in a SK-MEL-23 melanoma cell line. An indirect immunofluorescence assay showed that NGO-Pr-54 protein was expressed on the cell surface as well as in the cytoplasm. Cell surface expression was confirmed by flow cytometry using the TI-35 mAb. The antibody response against NGO-Pr-54 was observed in patients with bladder (5.1%), liver (4.1%), lung (3.4%), ovarian (5.6%), and prostate (4.2%) cancer, as well as with malignant melanoma (13.2%).
Copyright © 2008 by Eiichi Nakayama