Unique expression signatures of circular RNAs in response to DNA tumor virus SV40 infection

The life cycles of the tumor virus SV40 and polyoma are discussed with particular emphasis on the role of the viral coded proteins which mediate the transformation of normal cells into their cancerous equivalents. One or more of these proteins possibly act by stimulating directly the synthesis of cellular DNA, while others may mimic the action of polypeptide mitogens that act at the cell surface.

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Transformation of Astrocytes and Destruction of Spongioblasts Induced by a Simian Tumor Virus (SV40) in Cultures of Human Fetal Neuroglia*†‡

Journal of Neuropathology & Experimental Neurology ◽

10.1097/00005072-196701000-00005 ◽

1967 ◽

Vol 26 (1) ◽

pp. 60-76 ◽

Cited By ~ 35

Author(s):

H. M. Shein

Keyword(s):

Tumor Virus ◽

Virus Sv40

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Simian Vacuolating Virus (SV40) infection in Cell Cultures Derived From Adult Human Thyroid Tissue

JNCI Journal of the National Cancer Institute ◽

10.1093/jnci/29.6.1123 ◽

1962 ◽

Keyword(s):

Cell Cultures ◽

Thyroid Tissue ◽

Human Thyroid ◽

Adult Human ◽

Human Thyroid Tissue ◽

Sv40 Infection ◽

Virus Sv40

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Human Diploid Cell Transformation by DNA Extracted from the Tumor Virus SV40

Science ◽

10.1126/science.166.3903.390 ◽

1969 ◽

Vol 166 (3903) ◽

pp. 390-391 ◽

Cited By ~ 21

Author(s):

S. A. Aaronson ◽

G. J. Todaro

Keyword(s):

Cell Transformation ◽

Diploid Cell ◽

Human Diploid Cell ◽

Tumor Virus ◽

Virus Sv40

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Electron Microscopy of the Nucleic Acid of Mouse Mammary Tumor Virus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100099854 ◽

1968 ◽

Vol 26 ◽

pp. 22-23

Author(s):

N. H. Sarkar ◽

Dan H. Moore

Keyword(s):

Mammary Tumor ◽

Mouse Mammary Tumor Virus ◽

Ammonium Acetate ◽

Dry Weight ◽

Mouse Tumor ◽

Mammary Tumor Virus ◽

Rna Molecules ◽

Mouse Mammary Tumor ◽

Tumor Virus ◽

The Subject

Mouse mammary tumor virus (MTV) is believed to contain about 0.8% single stranded ribonucleic acid (RNA). This value of RNA content was estimated on a dry weight basis. The subject of this report is an attempt to visualize the RNA molecules of MTV particles.MTV particles were isolated from RIII mouse (tumor incidence approximately 80%) milk according to the method described by Lyons and Moore. Purified virions from 5 ml of milk were finally suspended in 0.2 ml of PBS, pH 7.4 and was mixed with an equal volume of pronase (5 mg/ml). This mixture was incubated at 37°C for an hour. RNA was extracted three times using freshly prepared cold phenol. It was then treated three times with cold ethyl ether to remove any trace of phenol. The RNA thus extracted was divided into two parts. One part was diluted four fold with 8M urea to avoid aggregation of the molecules. The other part was left untreated. Both samples were then mixed with an equal volume of 1M ammonium acetate, adjusted to pH 8.0 with NH3 containing chymotrypsin at a concentration of 0.01%.

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Electron Immunochemical Labeling of Ultrathin Sections of Murine Tumor Viruses and Cell Cultures using the Unlabeled Antibody Enzyme Technique

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091317 ◽

1976 ◽

Vol 34 ◽

pp. 266-267

Author(s):

W. J. Hamilton

Keyword(s):

Mammary Tumor ◽

Leukemia Virus ◽

Parallel Methods ◽

Tumor Viruses ◽

Mouse Mammary Tumor ◽

Tumor Virus ◽

Antibody Conjugates ◽

Rauscher Leukemia ◽

Antigen Localization ◽

Unlabeled Antibody

The study of RNA tumor viruses has been greatly facilitated by the use of immunochemical tagging methods. In the past these methods have been constrained to antibody conjugates with ferritin or peroxidase. In order to avoid the disadvantages of using conjugated antisera, investigators have applied the unlabeled antibody enzyme method of Sternberger to mammary tumor derived mouse cells prior to embedding for electron microscopy. The current study has successfully applied the Sternberger method to virusproducing cells and purified virus pellets after epoxy-embedding and ultrathin sectioning. The results demonstrate the distinct advantages of this “post-embedding” method for viral antigen localization.Purified Rauscher leukemia virus (RLV) and mouse mammary tumor virus (MMTV) were pelleted, fixed in buffered 2% paraformaldehyde and washed thoroughly. These were dehydrated in acetone, infiltrated and embedded in Spurr resin according to common procedures. A tumor derived cell line, Mm5mt, producing MMTV was embedded by parallel methods.

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Lectin Binding Studies on RNA Tumor Virus-Infected Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100115250 ◽

1975 ◽

Vol 33 ◽

pp. 326-327

Author(s):

D. C. Hixson

Keyword(s):

Binding Sites ◽

Lectin Binding ◽

Culture Conditions ◽

3T3 Cells ◽

Binding Studies ◽

Con A ◽

Microscopic Studies ◽

Tumor Virus ◽

Infected Cells ◽

Cell Culture Conditions

The abilities of plant lectins to preferentially agglutinate malignant cells and to bind to specific monosaccharide or oligosaccharide sequences of glycoproteins and glycolipids make them a new and important biochemical probe for investigating alterations in plasma membrane structure which may result from malignant transformation. Electron and light microscopic studies have demonstrated clustered binding sites on surfaces of SV40-infected or tryp- sinized 3T3 cells when labeled with concanavalin A (con A). No clustering of con A binding sites was observed in normal 3T3 cells. It has been proposed that topological rearrangement of lectin binding sites into clusters enables con A to agglutinate SV40-infected or trypsinized 3T3 cells (1). However, observations by other investigators have not been consistent with this proposal (2) perhaps due to differences in reagents used, cell culture conditions, or labeling techniques. The present work was undertaken to study the lectin binding properties of normal and RNA tumor virus-infected cells and their associated viruses using lectins and ferritin-conjugated lectins of five different specificities.

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