scholarly journals A SCANNING ELECTRON MICROSCOPE STUDY OF SURFACE FEATURES OF VIRAL AND SPONTANEOUS TRANSFORMANTS OF MOUSE BALB/3T3 CELLS

1973 ◽  
Vol 59 (3) ◽  
pp. 633-642 ◽  
Author(s):  
Keith R. Porter ◽  
George J. Todaro ◽  
Virginia Fonte
Keyword(s):  
Parent Cell ◽  
Cell Of Origin ◽  
3T3 Cells ◽  
Scanning Electron Microscope Study ◽  
Murine Sarcoma Virus ◽  
Sarcoma Virus ◽  
Surface Morphologies ◽  
Murine Sarcoma ◽  
Scanning Electron

Cells of the mouse line Balb/3T3 as well as three virus-induced transformants and two spontaneous transformants grown in vitro have been studied for their topography by scanning electron microscopy. The parent cell in confluent culture closely resembles an endothelial cell in its form and in the structure of its association with adjacent cells. The tumorigenic transformants produced by SV40, murine sarcoma virus, or polyoma viruses are fusiform to pleomorphic and distinctly different from the cell of origin. They show relatively smooth surfaces except for blebs and marginal microvilli. Perhaps most surprising is the similarity they bear to one another. This is made the more singular by the very different form shown by the tumorigenic transformants of spontaneous origin. One of these, S2-4, possesses a thickened rather than the lamellar form of the parent A31 cell and is covered by long microvilli and many spherical blebs. The other, TuT3, more closely resembles the cell of origin but shows extensive ruffling at its margins. All transformants grow without evidence of contact inhibition. The significance of the surface morphologies and the factors influencing cell form are discussed.

scholarly journals LACK OF DISTINCTIVE SURFACE ANTIGEN ON CELLS TRANSFORMED BY MURINE SARCOMA VIRUS

1972 ◽  
Vol 136 (2) ◽  
pp. 344-352 ◽  
Author(s):  
Vladimir Strouk ◽  
Gertrud Grundner ◽  
Eva Maria Fenyö ◽  
Ed Lamon ◽  
Henryk Skurzak ◽  
...  
Keyword(s):  
Surface Antigen ◽  
Leukemia Virus ◽  
Target Cells ◽  
3T3 Cells ◽  
L Cells ◽  
C57bl Mice ◽  
Murine Sarcoma Virus ◽  
Sarcoma Virus ◽  
Murine Sarcoma

Some murine sarcoma virus (MSV)-transformed mouse 3T3 cells contain the MSV genome in the absence of infectious helper murine leukemia virus (MuLV) and MSV production. These cells, designated S+L- (sarcoma positive, leukemia negative), were analyzed for the presence of a possible MSV-determined membrane antigen by the mixed hemadsorption test and in vitro lymphocyte cytotoxicity assay. Two different serological approaches were used: (a) isoantibody-free sera were obtained by immunizing with MSV of syngeneic origin or by allowing primary, autologous MSV sarcomas to regress, or (b) alloantisera obtained by immunizing C57BL mice with S+L- cells were absorbed with the corresponding nontransformed 3T3 cells until all activity against 3T3 had been removed. While MuLV-superinfected S+L- cells and a culture line of an MSV sarcoma known to produce both MSV and MLV were highly reactive, normal 3T3 and S+L- cells were negative. Similarly, lymph node cells from MSV immune mice or rats did not kill S+L- cells, although they were cytotoxic against target cells known to carry MuLV-associated antigens. Thus, the present study gives no positive evidence for the existence of any MSV-induced new surface antigen in the transformed target cell, known to carry the viral genome.

scholarly journals Nucleotide sequence of the two rat cellular rasH genes.

1986 ◽  
Vol 6 (5) ◽  
pp. 1706-1710 ◽  
Author(s):  
M Ruta ◽  
R Wolford ◽  
R Dhar ◽  
D Defeo-Jones ◽  
R W Ellis ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nucleotide Sequence ◽  
Coding Region ◽  
3T3 Cells ◽  
Ras Gene ◽  
P21 Protein ◽  
Murine Sarcoma Virus ◽  
Sarcoma Virus ◽  
Nih 3T3 ◽  
Murine Sarcoma

We present the nucleotide sequence of the coding region of the rat c-rasH-1 gene and a partial sequence analysis of the rat c-rasH-2 gene. By comparing these sequences with the Harvey murine sarcoma virus ras gene, we predict that the p21 protein encoded by the Harvey virus differs from the cellular c-rasH-1-encoded p21 at only two amino acids; those at positions 12 and 59. Alterations at each of these positions may play a role in activating the viral p21 protein. The c-rasH-2 gene is likely to be a nonfunctional pseudogene because it lacks introns, cannot be activated to transform NIH 3T3 cells, and differs in sequence from both c-rasH-1 and v-rasH at several base pair positions.

Mouse cells contain two distinct ras gene mRNA species that can be translated into a p21 onc protein

1982 ◽  
Vol 2 (11) ◽  
pp. 1339-1345
Author(s):  
R W Ellis ◽  
D DeFeo ◽  
M E Furth ◽  
E M Scolnick
Keyword(s):  
Normal Mouse ◽  
Velocity Sedimentation ◽  
Ras Gene ◽  
Mrna Species ◽  
P21 Ras ◽  
Murine Sarcoma Virus ◽  
Sarcoma Virus ◽  
Mouse Cells ◽  
Murine Sarcoma

The Kirsten (Ki) and Harvey (Ha) strains of murine sarcoma virus encode a 21,000-dalton protein (p21 ras) which is the product of the transforming gene of these viruses. Normal cells express low levels of p21 ras encoded by cellular genes (Ki-ras and Ha-ras) homologous to the Ki and Ha murine sarcoma virus transformation genes. A bone marrow-derived mouse cell line, 416B, has been shown to express unusually high levels of p21 ras. In this manuscript, we investigated the molecular biology of p21 ras gene expression in 416B and other normal mouse cells. We identified four distinct polyadenylated and polysome-associated RNAs, two related to Ki-ras and two to Ha-ras. The levels in 416B cells of the two Ki-ras RNAs, sized 5.2 and 2.0 kilobases, were both elevated approximately 25-fold over levels found in normal mouse cells; there was no corresponding change in 416B cells in the levels of the two Ha-ras RNAs. We partially purified the two Ki-ras mRNAs and separated them by velocity sedimentation in sucrose density gradients. Both the 5.2- and 2.0-kilobase mRNAs could be translated in vitro into p21 ras. These results show that a cellular onc protein can be translated from two distinct cellular mRNA species.

In Vivo and In Vitro Studies on the Morphogenesis of Tumors Induced by Murine Sarcoma Virus (Harvey) 2

1973 ◽  
Vol 51 (5) ◽  
pp. 1541-1549 ◽  
Author(s):  
W. R. Thomas ◽  
E. J. Aw ◽  
J. M. Papadimitriou ◽  
P. J. Simons
Keyword(s):  
In Vitro Studies ◽  
Murine Sarcoma Virus ◽  
Sarcoma Virus ◽  
Murine Sarcoma
Sign in / Sign up

Export Citation Format

Share Document