Immunologic selection against simian virus-40 transformed cells: Concomitant loss of viral antigens and early viral gene sequences

Kuster, J M; Mora, Peter T.; Brown, M.; Khoury, George

doi:10.1073/pnas.74.11.4796

Cited by 12 publications

(19 citation statements)

References 30 publications

(28 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The immunological selection against the SV40 T antigen-positive cells resulted in the rare revertant T antigen-negative cells growing out as tumors; the origin and the phenotypic properties of these T antigen-negative tumor lines and clones were described (23). The loss of the early viral gene sequences, but the retention of late SV40 sequences, in some of these lines and clones was also described (11).…”

Section: Methodsmentioning

confidence: 99%

“…cells were injected into immunologically competent syngeneic mice and the resulting tumors were put back into culture, the cells of the resulting tumor lines (e.g., 124CSCT and 127CSCT) were T antigen and TSTA negative (23). The 124CSCT and 127CSCT cells are also negative for the early half of the SV40 DNA (11). The early half of the SV40 DNA encodes the T antigen.…”

Section: Methodsmentioning

confidence: 99%

“…The following designations were used in earlier publications (11,23): the 104C clone was referred to as T AL/N CL3; 106CSC, subclone 1; 124CSCT and 127CSCT, tumor lines 124 and 127; and 130CSCTC, tumor clone 130. The clone 140CSCTCSC and its sister clone 138CSCTCSC were obtained from 130CSCTC after retransformation by SV40 and recloning; 153CSCTCSCT is a tumor line from 138CSCTCSC (to be published).…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Quantitation of a 55K cellular protein: similar amount and instability in normal and malignant mouse cells.

Mora¹,

Chandrasekaran²,

Hoffman³

et al. 1982

Mol. Cell. Biol.

View full text Add to dashboard Cite

Quantitative expression of a specific 55,000 (55K)-molecular-weight cellular protein was studied in two groups of mouse embryo fibroblast (clonal) cells originating from two parent clones, one of which possessed high tumorigenicity and the other of which possessed very low tumorigenicity. From the clone with low tumorigenicity, tumor lines and clones were obtained by selecting rare spontaneously transformed highly tumorigenic (mutant) (4,10,15,21,22,(26)(27)(28). It is intriguing that similar 53 to 56K cellular proteins were also found in mouse cells transformed in diverse other ways, such as in chemically induced sarcomas, in RNA virus-induced sarcomas and leukemias, and in a spontaneously transformed fibroblast (6). Also, similar 53 to 55K proteins were found in the human B-cell lymphomas and in many other established human tumor cell lines (5, 17). These observations led to an impression that the 53 to 55K protein is a "tumor antigen" and that it may be a correlate of the tumorigenic transformation of the cells (6,9). However, the 55K protein was also observed in small amounts in normal mouse embryo fibroblast cells, such as 3T3 cells not transformed by SV40 (14,15,25). In the 3T3 cells, the 55K protein was found to be rapidly degraded once it was synthesized, but it was stable in the SV40-transformed 3T3 cells (25).In the last few years we have developed and partially characterized closely related mouse cells with or without SV40 transformation and have determined quantitatively their cellular tumorigenicity in the syngeneic mouse.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Quantitation of a 55K cellular protein: similar amount and instability in normal and malignant mouse cells.

Mora¹,

Chandrasekaran²,

Hoffman³

et al. 1982

Mol. Cell. Biol.

View full text Add to dashboard Cite

show abstract

“…First, injected to observe the same frequency of tumors. Furthermore, tumor cells derived from those T-antigen-positive spontaneous transformants did not contain T antigen, had lost the early region of SV40 coding for the T proteins, and had regained their initial tumorigenic potential (9,14). Because the cells before SV40 infection were transformed and highly tumorigenic, those studies did not have an implication on the role of SV40 proteins in transformation.…”

Section: Methodsmentioning

confidence: 81%

“…When BK virus was isolated from humans and was later shown to be widespread and very similar to SV40, several investigators looked for BK virus-related material (proteins and DNA) in a large number of human tumors. Because the results were largely negative, it was concluded that BK virus has a minor role, if any, in the induction of human cancer (3,6,8,9,11,13,25,28,30,34,35). The finding that transformed cells induced by SV40 lose all viral proteins, and probably ultimately all viral DNA, during their development into tumors is good reason to reconsider SV40-like viruses as potentially important factors in the genesis of human cancer.…”

Section: Methodsmentioning

confidence: 99%

Rat cells transformed by simian virus 40 give rise to tumor cells which contain no viral proteins and often no viral DNA.

Seif¹,

Seif²,

Wantyghem³

1983

Mol. Cell. Biol.

View full text Add to dashboard Cite

Rat 3T3 cells transformed by simian virus 40 were injected into rats to examine their capacity to develop into tumors. Both large T-dependent (N) transformants and large T-independent (A) transformants were used. All the transformed cell lines contained large T and small t and could multiply efficiently in agar. Only some transformants could develop into tumors. All tumor cells examined had lost both large T and small t. Tumor cells in which the viral genome could still be detected were found together with tumor cells in which the simian virus 40 DNA could no longer be detected. N transformants which displayed the transformed phenotype in a temperature-sensitive manner became temperature insensitive during tumor formation.Cells capable of limiting their growth under certain conditions in vitro can suffer a permanent loss of growth control when infected with simian virus 40 (SV40). The virus codes for two proteins involved in cell transformation, large T and small t, and is able to integrate its genome into the cellular DNA (4,33).Both large T and small t are required for the establishment of transformation in resting cells (27). However, transformed cells obtained from resting cells do not require large T for the maintenance of transformation; they are referred to as large T-independent (A) transformants (26). On the other hand, only large T is sufficient for the establishment of transformation in growing cells (27) and transformants obtained from growing cells do depend on large T, but not small t, for the maintenance of transformation; they are referred to as large Tdependent (N) transformants (26). When cultivated under conditions which induce the resting state in normal cells, large T-dependent transformants did not become large T independent at a high frequency (26). N and A transformants are also obtained by infection with polyoma virus (18,23,24). To investigate further the nature of and the relationship between N and A transformants, several rat cell lines of each type were injected into rats. The resulting tumor cells were examined for the presence of SV40 DNA and SV40-coded proteins, and their growth properties in vitro were studied. MATERIALS AND METHODSCells, medium, and animals. Normal Fisher rat 3T3 cells were previously described (24). N and A transformants induced by the tsA mutant of SV40, tsA209, were also previously described (26). The medium used for growing cells was Dulbecco modified Eagle medium supplemented with 10% fetal bovine serum. The animals used were Fisher rats (an inbred family of rats) purchased from Microbiological Associates. They were injected with cells when 6 to 8 weeks old.Isolation of tumor cell lines. The tumor was removed from the animal when it reached at least 5 cm in diameter. The entire tumor was first cut with scissors for 20 min and then treated with trypsin. The tumor cells were seeded at a very low density, and independent clones which developed 10 days later were isolated and grown.Detection of viral proteins. The cells were grown to confluence in a 25-cm2 flas...

show abstract

Anti‐tumor potential of retinoic acid: Stimulation of immune mediated effectors

Patek

Collins

Yogeeswaran

et al. 1979

Intl Journal of Cancer

View full text Add to dashboard Cite

Data are presented on the effects of retinoic acid (RA) treatment on the in vivo growth of tumors in two mouse strains. Inhibition of tumor growth as a result of systemic RA injection was observed in three out of seven tumor models. Using adult thymectomized, lethally irradiated and fetal liver (A x TFL) reconstituted mice, we found that inhibition of tumor growth is not due to direct toxic effects of RA but rather appears to be the result of stimulation of thymus-dependent immune-mediated effectors to suppress tumor growth. Results suggest that only strongly immunogenic tumors are sensitive to in vivo retinoid inhibition.

show abstract

Immunologic selection against simian virus-40 transformed cells: Concomitant loss of viral antigens and early viral gene sequences

Cited by 12 publications

References 30 publications

Quantitation of a 55K cellular protein: similar amount and instability in normal and malignant mouse cells.

Quantitation of a 55K cellular protein: similar amount and instability in normal and malignant mouse cells.

Rat cells transformed by simian virus 40 give rise to tumor cells which contain no viral proteins and often no viral DNA.

Anti‐tumor potential of retinoic acid: Stimulation of immune mediated effectors

Contact Info

Product

Resources

About