Abstract
To isolate novel molecular targets for treatment of testicular germ cell tumor (TGCT), we performed genome‐wide expression profile analysis of testicular seminomas using a cDNA microarray. We here report identification of NACHT, leucine‐rich repeat and PYD containing 7 (NALP7), that was significantly transactivated in testicular seminomas. Subsequent semi‐quantitative RT‐PCR and northern blot analyses confirmed an approximately 3.3‐kb transcript that was expressed exclusively in testis, although the expression level of this gene in normal testis was much lower than in tumor cells, suggesting an important role of this gene in germ‐cell proliferation. Immunohistochemical analysis using anti‐NALP7 polyclonal antibody detected the endogenous NALP7 protein in the cytoplasm of embryonal carcinoma cells and testicular seminoma tissues. Transfection of small interfering RNA (siRNA) for NALP7 significantly reduced the NALP7 expression and resulted in growth suppression of testicular germ‐cell tumors. These findings imply that NALP7 may play a crucial role in cell proliferation, as well as testicular tumorigenesis, and it appears to be a promising candidate for development of targeted therapy for TGCTs.
References
- 1. Zheng T, Holford TR, Ma Z, Ward BA, Flannery J, Boyle P. Continuing increase in incidence of germ‐cell testis cancer in young adults: experience from Connecticut, USA, 1935–1992. Int J Cancer 1996; 65: 723–9. [DOI] [PubMed] [Google Scholar]
- 2. Bergstrom R, Adami HO, Mohner M, Zatonski W, Storm H, Ekbom A, Tretli S, Teppo L, Akre O, Hakulinen T. Increase in testicular cancer incidence in six European countries: a birth cohort phenomenon. J Natl Cancer Inst 1996; 88: 727–33. [DOI] [PubMed] [Google Scholar]
- 3. Chaganti RSK, Houldsworth J. Genetics and biology of adult human male germ cell tumors. Cancer Res 2000; 60: 1475–82. [PubMed] [Google Scholar]
- 4. Richie JP. Urology. J Am. Coll Surg 1999; 188: 198–201. [DOI] [PubMed] [Google Scholar]
- 5. Smiraglia DJ, Szymanska J, Kraggerud SM, Lothe RA, Peltomaki P, Plass C. Distinct epigenetic phenotypes in seminomatous and nonseminomatous testicular germ cell tumors. Oncogene, 2002; 21: 3909–16. [DOI] [PubMed] [Google Scholar]
- 6. Jones RH, Vasey PA. Part I: testicular cancer‐management of early disease. Lancet Oncol 2003; 4: 730–7. [DOI] [PubMed] [Google Scholar]
- 7. Petricoin EF 3rd, Hackett JL, Lesko LJ, Puri RK, Gutman SI, Chumakov K, Woodcock J, Feigal DW Jr, Zoon KC, Sistare FD. Medical applications of microarray technologies: a regulatory science perspective. Nat Genet 2002; 32 Suppl: 474–9. [DOI] [PubMed] [Google Scholar]
- 8. Okabe H, Satoh S, Kato T, Kitahara O, Yanagawa R, Yamaoka Y, Tsunoda T, Furukawa Y, Nakamura Y. Genome‐wide analysis of gene expression in human hepatocellular carcinomas using cDNA microarray: identification of genes involved in viral carcinogenesis and tumor progression. Cancer Res 2001; 61: 2129–37. [PubMed] [Google Scholar]
- 9. Lin YM, Furukawa Y, Tsunoda T, Yue CT, Yang KC, Nakamura Y. Molecular diagnosis of colorectal tumors by expression profiles of 50 genes expressed differentially in adenomas and carcinomas. Cancer Res 2002; 21: 4120–8. [DOI] [PubMed] [Google Scholar]
- 10. Nagayama S, Katagiri T, Tsunoda T, Hosaka T, Nakashima Y, Araki N, Kusuzaki K, Nakayama T, Tsuboyama T, Nakamura T, Imamura M, Nakamura Y, Toguchida J. Genome‐wide analysis of gene expression in synovial sarcomas using a cDNA microarray. Cancer Res 2002; 62: 5859–66. [PubMed] [Google Scholar]
- 11. Okutsu J, Tsunoda T, Kaneta Y, Katagiri T, Kitahara O, Zembutsu H, Yanagawa R, Miyawaki S, Kuriyama K, Kubota N, Kimura Y, Kubo K, Yagasaki F, Higa T, Taguchi H, Tobita T, Akiyama H, Takeshita A, Wang YH, Motoji T, Ohno R, Nakamura Y. Prediction of chemosensitivity for patients with acute myeloid leukemia, according to expression levels of 28 genes selected by genome‐wide complementary DNA microarray analysis. Mol Cancer Ther 2002; 1: 1035–42. [PubMed] [Google Scholar]
- 12. Hasegawa S, Furukawa Y, Li M, Satoh S, Kato T, Watanabe T, Katagiri T, Tsunoda T, Yamaoka Y, Nakamura Y. Genome‐wide analysis of gene expression in intestinal‐type gastric cancers using a complementary DNA microarray representing 23,040 genes. Cancer Res 2002; 62: 7012–7. [PubMed] [Google Scholar]
- 13. Kaneta Y, Kagami Y, Tsunoda T, Ohno R., Nakamura Y, Katagiri T. Genome‐wide analysis of gene‐expression profiles in chronic myeloid leukemia cells using a cDNA microarray. Int J Oncol 2003; 23: 681–91. [PubMed] [Google Scholar]
- 14. Kikuchi T, Daigo Y, Katagiri T, Tsunoda T, Okada K, Kakiuchi S, Zembutsu H, Furukawa Y, Kawamura M, Kobayashi K, Imai K, Nakamura Y. Expression profiles of non‐small cell lung cancers on cDNA microarrays: identification of genes for prediction of lymph‐node metastasis and sensitivity to anti‐cancer drugs. Oncogene 2003; 22: 2192–205. [DOI] [PubMed] [Google Scholar]
- 15. Okada K, Katagiri T, Tsunoda T, Mizutani Y, Suzuki Y, Kamada M, Fujioka T, Shuin T, Miki T, Nakamura Y. Analysis of gene‐expression profiles in testicular seminomas using a genome‐wide cDNA microarray. Int J Oncol 2003; 23: 1615–35. [PubMed] [Google Scholar]
- 16. Nakamura T, Furukawa Y, Nakagawa H, Tsunoda T, Ohigashi H, Murata K, Ishikawa O, Ohgaki K, Kashimura N, Miyamoto M, Hirano S, Kondo S, Katoh H, Nakamura Y, Katagiri T. Genome‐wide cDNA microarray analysis of gene expression profiles in pancreatic cancers using populations of tumor cells and normal ductal epithelial cells selected for purity by laser microdis‐section. Oncogene 2004; 23: 2385–400. [DOI] [PubMed] [Google Scholar]
- 17. Nagayama S, Liizumi M, Katagiri T, Toguchida J, Nakmaura Y. Identification of PDZK4, a novel human gene with PDZ domains, that is upregulated in synovial sarcomas. Oncogene 2004; 23: 5551–7. [DOI] [PubMed] [Google Scholar]
- 18. Shimokawa T, Furukawa Y, Sakai M, Li M, Miwa N, Lin YM, Nakamura Y. Involvement of the FGF18 gene in colorectal carcinogenesis, as a novel downstream target of the beta‐catenin/T‐cell factor complex. Cancer Res 2003; 63: 6116–20. [PubMed] [Google Scholar]
- 19. Tschopp J, Martinon F, Burns K. NALPs: a novel protein family involved in inflammation. Nat Rev Mol Cell Biol 2002; 4: 95–104. [DOI] [PubMed] [Google Scholar]
- 20. Kobe B, Kajava AV. The leucine‐rich repeat as a protein recognition motif. Curr Opin Struct Biol 2001; 11: 725–31. [DOI] [PubMed] [Google Scholar]
- 21. 1 Cutting edge: CATERPILLER: a large family of mammalian genes containing CARD, pyrin, nucleotide‐binding, and leucine‐rich repeat domains. J Immunol 2002; 169: 4088–93. [DOI] [PubMed] [Google Scholar]
- 22. Chu ZL, Pio F, Xie Z, Welsh K, Krajewska M, Krajewski S, Godzik A, Reed JC. A novel enhancer of the Apafl apoptosome involved in cytochrome c‐dependent caspase activation and apoptosis. J Biol Chem 2001; 276: 9239–45. [DOI] [PubMed] [Google Scholar]
- 23. Pathan N, Marusawa H, Krajewska M, Matsuzawa S, Kim H, Okada K, Torii S, Kitada S, Krajewski S, Welsh K, Pio F, Godzik A, Reed JC. TUCAN, an antiapoptotic caspase‐associated recruitment domain family protein overexpressed in cancer. J Biol Chem. 2001; 276: 32220–9. [DOI] [PubMed] [Google Scholar]