Since DNA methylation is considered an important mechanism for silencing of retroelements in the mammalian genome, hypomethylation in human tumours may lead to their reactivation. The methylation status of LINE-1 retroposons was determined in 73 samples of urinary bladder cancers, 34 specimens of renal cell carcinoma and in the corresponding normal tissues by Southern blot analysis. LINE-1 sequences were strongly methylated in normal tissues and were significantly hypomethylated in 69 (95%) urothelial carcinomas, but in none of the renal carcinomas. Hypomethylation in bladder cancers was independent of stage and tended to increase with grade. The methylation status of HERV-K proviral DNA in normal and transformed urothelial cells paralleled that of LINE-1 sequences (r2 = 0.87). It was shown by ligation-mediated polymerase chain reaction that hypomethylation also extended to the LINE-1 promoter sequence located at the 5′-ends of full-length elements which is repressed by methylation in somatic tissues. Accordingly, full-length LINE-1 transcripts were detected by Northern blot analysis in two urothelial carcinoma cell lines. In contrast, transcripts from HERV-K proviruses were restricted to teratocarcinoma cell lines. Our data indicate that genome-wide DNA hypomethylation is an early change in urothelial carcinoma, but is absent from renal cell carcinoma. The coordinate changes of LINE-1 and HERV-K DNA methylation suggest that hypomethylation in urothelial cancer affects a variety of different retroelements to similar extents. We speculate that decreased methylation of LINE-1 retroelements, in particular, may contribute to genomic instability in specific human tumours such as urothelial carcinoma by rendering these normally repressed sequences competent for transcription and recombination.
Alves, G., Tatro, A. & Fanning, T. (1996). Differential methylation of human LINE-1 retrotransposons in malignant cells. Gene 176: 39–44.
Baylin, S. B., Herman, J. G., Graff, J. R., Vertino, P. & Issa, J. P. (1998). Alterations in DNA methylation: a fundamental aspect of neoplasia. Adv Cancer Res 72: 141–196.
Bedford, M. T. & van Helden, P. D. (1987). Hypomethylation of DNA in pathological conditions of the human prostate. Cancer Res 47: 5274–5276.
Bratthauer, G. L. & Fanning, T. G. (1992). Active LINE-1 retrotransposons in human testicular cancer. Oncogene 7: 507–510.
Chen, R. Z., Petterson, U., Beard, C., Jackson-Grusby, L. & Jaehnisch, R. (1998). DNA hypomethylation leads to elevated mutation rates. Nature 395: 89–93.
Clifford, S. C., Prowse, A. H., Affara, N. A., Buys, CHCM & Maher, E. R. (1998). Inactivation of the von Hippel-Lindau (VHL) tumour suppressor gene and allelic losses at chromosome arm 3p in primary renal cell carcinoma. Genes Chromosomes Cancer 22: 200–209.
Dombroski, B. A., Scott, A. F. & Kazazian, H. H. (1993). Two additional potential retrotransposons isolated from a human L1 subfamily that contains an active retrotransposable element. Proc Natl Acad Sci USA 90: 6513–6517.
Feinberg, A. P., Gehrke, C. W., Kuo, K. C. & Ehrlich, M. (1988). Reduced genomic 5-methylcytosine content in human colonic neoplasia. Cancer Res 48: 1159–1161.
Feng, Q., Moran, J. V., Kazazian, H. H. & Boeke, J. D. (1996). Human L1 retrotransposon encodes a conserved endonuclease required for retrotransposition. Cell 87: 905–916.
Goelz, S. E., Vogelstein, B., Hamilton, S. R. & Feinberg, A. P. (1985). Hypomethylation of DNA from benign and malignant human colon neoplasms. Science 228: 187–190.
Gonzalez-Zulueta, M., Bender, C. M., Yang, A. S., Nguyen, T. T., Beart, R. W., van Tornout, J. M. & Jones, P. A. (1995). Methylation of the 5′CpG island of the p16/CDKN2 tumour suppressor gene in normal and transformed human tissues correlates with gene silencing. Cancer Res 55: 4531–4535.
Gotzinger, N., Sauter, M., Roemer, K. & Mueller-Lantzsch, N. (1996). Regulation of endogenous retrovirus-K Gag expression in teratocarcinoma cell lines and human tumours. J Gen Virol 77: 2983–2990.
Grimm, M. O., Jügens, B., Schulz, W. A., Decken, K., Makri, D. & Schmitz-Dräger, B. J. (1995). Inactivation of tumour suppressor genes and deregulation of the c-myc gene in urothelial cancer cell lines. Urol Res 23: 293–300.
Hata, K. & Sakaki, Y. (1997). Identification of critical CpG sites for repression of L1 transcription by DNA methylation. Gene 189: 227–234.
Herman, J. G., Latif, F., Weng, Y., Lerman, M. I., Zbar, B., Liu, S., Samid, D., Duan, D. S. R., Gnarra, J. R., Linehan, W. M. & Baylin, S. B. (1994). Silencing of the VHL tumor-suppressor gene by DNA methylation in renal carcinoma. Proc Natl Acad Sci USA 91: 9700–9704.
Herman, J. G., Merlo, A., Mao, L., Lapidus, R. G., Issa, J. P. J., Davidson, N. E., Sidransky, D. & Baylin, S. B. (1995). Inactivation of the CDKN2/p16/MTS1 gene is frequently associated with aberrant DNA methylation in all common human cancers. Cancer Res 55: 4525–4530.
Holmes, S. E., Dombroski, B. A., Krebs, C. M., Boehm, C. D. & Kazazian, H. H. (1994). A new retrotransposable human L1 element from the LRE2 locus on chromosome 1q produces a chimaeric insertion. Nat Genet 7: 143–148.
Jarrard, D. F., Bova, G. S., Ewing, C. M., Pin, S. S., Nguyen, S. H., Baylin, S. B., Cairns, P., Sidransky, D., Herman, J. G. & Isaacs, W. B. (1997). Deletional, mutational, and methylation analyses of CDKN2 (p16/MTSI) in primary and metastatic prostate cancer. Genes Chromosomes Cancer 19: 90–96.
Jürgens, B., Schmitz-Dräger, B. J. & Schulz, W. A. (1996). Hypomethylation of L1 LINE sequences prevailing in human urothelial carcinoma. Cancer Res 56: 5698–5703.
Kazazian, H. H. & Moran, J. V. (1998). The impact of L1 retrotransposons on the human genome. Nat Genet 19: 19–24.
Laird, P. W. (1996). The role of DNA methylation in cancer. Annu Rev Genet 30: 441–464.
Liu, J., Nau, M. M., Zucman-Rossi, J., Powell, J. I., Allegra, C. J. & Wright, J. J. (1997). LINE-I element insertion at the t(11;22) translocation breakpoint of a desmoplastic small round cell tumor. Genes Chromosomes Cancer 18: 232–239.
Löwer, R., Löwer, J., Tondera-Koch, C. & Kurth, R. (1993). A general method for the identification of transcribed retrovirus sequences (R-U5 PCR) reveals the expression of the human endogenous retrovirus loci HERV-H and HERV-K in teratocarcinoma cells. Virology 192: 501–511.
Löwer, R., Löwer, J. & Kurth, R. (1996). The viruses in all of us: characteristics and biological significance of human endogenous retrovirus sequences. Proc Natl Acad Sci USA 93: 5177–5184.
Löwer, R., Tönjes, R. R., Korbmacher, C., Kurth, R. & Löwer, J. (1995). Identification of a rev-related protein by analysis of spliced transcripts of the human endogenous retroviruses HDTV/HERV-K. J Virol 69: 141–149.
Makos, M., Nelkin, B. D., Reiter, R. E., Gnarra, J. R., Brooks, J., Isaacs, W., Linehan, M. & Baylin, S. B. (1993). Regional DNA hypermethylation at D17.5 precedes 17p structural changes in the progression of renal tumors. Cancer Res 53: 2719–2722.
Merlo, A., Herman, J. G., Mao, L., Lee, D. J., Gabrielson, E., Burger, P. C., Baylin, S. B. & Sidransky, D. (1995). 5′ CpG island methylation is associated with transcriptional silencing of the tumour suppressor p16/CDKN2/MTS1 in human cancers. Nat Med 7: 686–692.
Miki, Y., Nishisho, I., Horii, A., Miyoshi, Y., Utsunomiya, J., Kinzler, K. W., Vogelstein, B. & Nakamura, Y. (1992). Disruption of the APC gene by a retrotransposal insertion of L1 sequence in a colon cancer. Cancer Res 52: 643–645.
Miller, O. J., Schnedl, W., Allen, J. & Erlanger, B. F. (1974). 5-Methylcytosine localised in mammalian constitutive heterochromatin. Nature 251: 636–637.
Moran, J. V., Holmes, S. E., Naas, T. P., DeBerardinis, R. J., Boeke, J. D. & Kazazian, H. H. (1996). High frequency retrotransposition in cultured mammalian cells. Cell 87: 917–927.
Morse, B., Rothberg, P. G., South, V. J., Spandorfer, J. M. & Astrin, S. M. (1988). Insertional mutagenesis of the myc locus by a LINE-1 sequence in a human breast carcinoma. Nature 355: 87–90.
Nagarajan, L., Lange, B., Cannizzaro, L., Finan, J., Nowell, P. & Huebner, K. (1990). Molecular anatomy of a 5q interstitial deletion. Blood 75: 82–87.
Pomykala, H. M., Bohlander, S. K., Broeker, P. L., Olopade, O. I. & Diaz, M. O. (1994). Breakpoint junctions of chromosome 9p deletions in two human glioma cell lines. Mol Cell Biol 14: 7604–7610.
Santourlidis, S., Florl, A., Ackermann, R., Wirtz, H. C. & Schulz, W. A. (1999). High frequency of alterations in DNA methylation in adenocarcinoma of the prostate. Prostate 39: 166–174.
Schulz, W. A. (1998). DNA methylation in urological malignancies. Int J Oncol 13: 151–167.
Skowronski, J., Fanning, T. G. & Singer, M. F. (1988). Unit-length Line-1 transcripts in human teratocarcinoma cells. Mol Cell Biol 8: 1385–1397.
Steigerwald, S. D., Pfeifer, G. P. & Riggs, A. D. (1990). Ligation-mediated PCR improves the sensitivity of methylation analysis by restriction enzymes and detection of specific DNA strand breaks. Nucleic Acids Res 18: 1435–1439.
Swergold, G. D. (1990). Identification, characterization, and cell specificity of a human LINE-1 promoter. Mol Cell Biol 10: 6718–6729.
Tönjes, R. R., Loewer, R., Boller, K., Denner, J., Hasenmaier, B., Kirsch, H., Konig, H., Korbmacher, C., Limbach, C., Lugert, R., Phelps, R. C., Scherer, J., Thelen, K., Loewer, J. & Kurth, R. (1996). HERV-K: the biologically most active human endogenous retrovirus family. J AIDS & Hum Retrovirol 13: 261–267.
Woodcock, D. M., Lawler, C. B., Linsenmeyer, M. E., Doherty, J. P. & Warren, W. D. (1997). Asymmetric methylation in the hypermethylated CpG promoter region of the human L1 retrotransposon. J Biol Chem 272: 7810–7816.
Yoder, J. A., Walsh, C. P. & Bestor, T. H. (1997). Cytosine methylation and the ecology of intragenomic parasites. Trends Genet 13: 335–340.
About this article
Cite this article
Florl, A., Löwer, R., Schmitz-Dräger, B. et al. DNA methylation and expression of LINE-1 and HERV-K provirus sequences in urothelial and renal cell carcinomas. Br J Cancer 80, 1312–1321 (1999). https://doi.org/10.1038/sj.bjc.6690524
- bladder cancer
- renal cancer
- chromosome instability
Journal of Neuroimmune Pharmacology (2021)
Basic Hallmarks of Urothelial Cancer Unleashed in Primary Uroepithelium by Interference with the Epigenetic Master Regulator ODC1
Scientific Reports (2020)
Human endogenous retroviruses env gene expression and long terminal repeat methylation in colorectal cancer patients
Medical Microbiology and Immunology (2020)
Analysis of bovine leukemia virus integration sites in cattle under 3 years old with enzootic bovine leukosis
Archives of Virology (2020)
Mobile DNA (2019)