Abstract
Human endogenous retroviral sequences recently have been shown to be associated with breast cancer and some leukemias. These retroviral sequences have similarities to an endogenous retrovirus expressed in guinea pigs. The conditions for activation of this guinea pig retrovirus (GPRV) in cultured guinea pig embryo (GPE) cells using 5-bromo-2′-deoxyuridine (BrdU) was investigated. These studies employed the reverse transcriptase activity (RT) assay and electron microscopy (EM), in conjunction with Northern blot analysis that utilized a 2.6 kb GPRV-specific cDNA probe. Contrary to published studies, dexamethasone at concentrations ranging from 10−8 to 10−5 M appeared to play a minimal role in enhancing the production of GPRV. Following a 6 hr incubation with BrdU, GPRV mRNA was present in cultured GPE cells. Extracellular virion release was also observed by EM 12 hr later, although RT activity was not detected. All three methods detected viral expression at 48 hr after the addition of the drug. Additionally, after 6 hr exposure to BrdU, detectable RT and mRNA levels were maintained through 44 days after the removal of BrdU in a stationary culture condition and through 31 days in cultures that were subcultured weekly in media not containing BrdU. Low levels of extracellular viruses were detected in these cultures by electron microscopy through 49 days. Therefore, after only a 6 hr exposure to BrdU was extracellular GPRV detected 12 hr after drug removal and virus production continued for up to 49 days. This study provides information about an animal endogenous retroviral system that may be used as a model for the study of human endogenous retroviruses.
Similar content being viewed by others
References
Hutchison C.A., Hardies S.C., Loeb D.D., Shehee W.R., and Edgell M.H., in Berg D.E. and Howe M.M. (eds).Mobile DNA, Vol. 1. American Society for Microbiology, Washington, D.C., 1989, pp. 593–617.
Ono M., Yasunaga T., Miyata T., and Ushikubo H., J Virol60 589–598, 1986.
Lower R., Boller K., Hasenmaier B., Korbmacher C., Muller-Lantzsch N., Lower J., and Kurth R., Proc Natl Acad Sci USA90 4480–4484, 1993.
Brodsky I., Fuscaldo A.A., Erlick B.J., Kingsbury E.W., Schultz G.M., and Fuscado K.E., J Natl Cancer Inst55 1069–1074, 1975.
Viola M.V., Frazier M., Wiernick P.H., McCredie K.B., and Spiegelman S., N Engl J Med294 75–80, 1976.
Brodsky I., Foley B., Haines D., Johnson J., Cuddy K., and Gillespie D., Blood81 2369–2374, 1993.
Ono M., Kawakami M., and Ushikubo H., J Virol61 2059–2062, 1987.
Hsiung G.D., J Natl Cancer Inst49 567–570, 1972.
Dahlberg J.E., Perk K., and Dalton A.J., Nature249 828–830, 1974.
Michalides R., Schlom J., Dahlberg J., and Perk K., J Virol16 1039–1050, 1975.
Murray P.R. and Nayak D.P., J Virol14 679–688, 1974.
Nayak D.P. and Murray P.R., J Virol12 177–187, 1973.
Putnam D.L. and Rhim J.S., Fed Proc36 2316–2319, 1977.
Davis A.R., Nayak D.P., and Lofgren J., J Virol26 603–614, 1978.
Feldman D.G. and Gross L., Cancer Res30 2702–2711, 1970.
Hsiung G.D., Fong C.K.Y., and Evans C.H., Intervirology3 319–331, 1974.
Nadel E., Banfield W., Burnstein S., and Tousimis A.J., J Natl Cancer Inst38 979–981, 1967.
Opler S.R., J Natl Cancer Inst38 979–800, 1967.
Lerner-Tung M.B., Crouch J.Y., and Hsiung G.D., Virology180 826–830, 1991
Lerner-Tung M.B. and Hull B.E., J Burn Care Rehabil10 151–155, 1989.
Chromczynski P. and Sacchi N., Analyt Biochem162 156–159, 1987.
Sambrook J., Fritsch E.F., and Maniatis T.,Molecular Cloning, A Laboratory Manual, 2nd ed. Cold Spring Harbor Laboratory Press. Cold Spring Harbor, NY, 1989.
Teich N., Lowy D.R., Hartley J. W., and Rowe, P.W., Virology51 163–173, 1973.
Besmer P., Smotkin D., Haseltine W., Fan H, Wilson A.T., Paskind M., Weinberg R., and Baltimore D., Cold Spring Harb Symp Quant Biol2 1103–1107, 1975.
Boyd M.T., Bax C.M.R., Bax B.E., Bloxam D.L., and Weiss R.A., Virology196 905–909, 1993.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lerner-Tung, M.B., Doong, SL., Cheng, YC. et al. Characterization of conditions for the activation of endogenous guinea pig retrovirus in cultured cells by 5-bromo-2′-deoxyuridine. Virus Genes 9, 201–209 (1995). https://doi.org/10.1007/BF01702876
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01702876