Electron microscopic observation of simian sarcoma virus transformed NIH 3T3 cells in vitro

1989 ◽  
Vol 1 (3) ◽  
pp. 13-15
Author(s):  
Jingsheng Tian ◽  
Shuyun Su
1987 ◽  
Vol 7 (10) ◽  
pp. 3582-3590 ◽  
Author(s):  
D Shalloway ◽  
P J Johnson ◽  
E O Freed ◽  
D Coulter ◽  
W A Flood

pp60c-src, the cellular homolog of the Rous sarcoma virus transforming protein, does not completely transform cells even when present at high levels, but has been shown to be involved in polyomavirus-induced transformation when activated by polyomavirus middle T (pmt)-antigen binding. Here we show that cotransfection, but not solo transfection, of expression plasmids for c-src and either adenovirus E1A, v-myc, c-myc, or the 5' half of polyomavirus large T (pltN) antigen into NIH 3T3 cells induces anchorage-independent growth, enhanced focus formation, and, for pltN cotransfection, tumorigenicity in adult NFS mice. Enhancement of transformation was not observed with polyomavirus small t (pst) antigen. Cotransfection of c-src with pltN induced modification of pp60c-src that altered its electrophoretic mobility and in vivo phosphorylation state and stimulated its in vitro kinase activity. Similar alterations were not seen after c-src-E1A cotransfection, suggesting that at least two different mechanisms of enhancement are involved.


1987 ◽  
Vol 7 (10) ◽  
pp. 3582-3590
Author(s):  
D Shalloway ◽  
P J Johnson ◽  
E O Freed ◽  
D Coulter ◽  
W A Flood

pp60c-src, the cellular homolog of the Rous sarcoma virus transforming protein, does not completely transform cells even when present at high levels, but has been shown to be involved in polyomavirus-induced transformation when activated by polyomavirus middle T (pmt)-antigen binding. Here we show that cotransfection, but not solo transfection, of expression plasmids for c-src and either adenovirus E1A, v-myc, c-myc, or the 5' half of polyomavirus large T (pltN) antigen into NIH 3T3 cells induces anchorage-independent growth, enhanced focus formation, and, for pltN cotransfection, tumorigenicity in adult NFS mice. Enhancement of transformation was not observed with polyomavirus small t (pst) antigen. Cotransfection of c-src with pltN induced modification of pp60c-src that altered its electrophoretic mobility and in vivo phosphorylation state and stimulated its in vitro kinase activity. Similar alterations were not seen after c-src-E1A cotransfection, suggesting that at least two different mechanisms of enhancement are involved.


2019 ◽  
Vol 7 (22) ◽  
pp. 3733-3736
Author(s):  
Dian Ika Perbina Meliala ◽  
Jansen Silalahi ◽  
Yuandani Yuandani ◽  
Linda Margata ◽  
Denny Satria

AIM: The objective of the study was to evaluate protein expression in NIH 3T3 cells that are treated with virgin coconut oil (VCO) and hydrolysed of virgin coconut oil (HVCO) in vitro. METHODS: Coconut oil used in this study was virgin coconut oil (VCO) and VCO hydrolysed by Rhizomucor miehei (HVCO). NIH 3T3 cells (5x105 cells/well) were seeded in nine wells and incubated for overnight, then divided into three groups. Each group consisted of three wells. Group one without treatment, group two added VCO, and group three added HVCO and then incubated for overnight. One well in each group was added MMP-9, PDGF-BB, and TGF-β1 and incubated one hour. Finally, expressions of MMP-9, PDGF-BB, and TGF-β1 were detected using immunocytochemistry method. RESULTS: The results of the study showed that VCO and HVCO increased protein expressions of MMP-9, PDGF-BB, and TGF-β1. Percentage of MMP-9 expressions treated by VCO increased from 2.89 ± 0.07 to 28.16 ± 0.34, PDGF-BB from 28.11 ± 0.13 to 48.53 ± 0.49, and TGF-β1 from 4.19 ± 0.08 to 18.41 ± 0.54. Percentage of MMP-9 expressions treated by HVCO increased from 2.89 ± 0.07 to 55.40 ± 0.94, PDGF-BB from 28.11 ± 0.13 to 61.65 ± 0.42, and TGF-β1 from 4.19 ± 0.08 to 36.35 ± 0.67. CONCLUSION: VCO and HVCO increase the expression of MMP-9, PDGF-BB, dan TGF-β1 in NIH3T3 cells and therefore, coconut oil active in the wound healing process. HVCO is more than active than VCO.


1988 ◽  
Vol 8 (2) ◽  
pp. 704-712
Author(s):  
S Reddy ◽  
P Yaciuk ◽  
T E Kmiecik ◽  
P M Coussens ◽  
D Shalloway

Previous studies have shown that carboxyl-terminal mutation of pp60c-src can activate its transforming ability. Conflicting results have been reported for the transforming ability of pp60c-src mutants having only mutations outside its carboxyl-terminal region. To clarify the effects of such mutations, we tested the activities of chimeric v(amino)- and c(carboxyl)-src (v/c-src) proteins at different dosages in NIH 3T3 cells. The focus-forming activity of Rous sarcoma virus long terminal repeat (LTR)-src expression plasmids was significantly reduced when the v-src 3' coding region was replaced with the corresponding c-src region. This difference was masked when the Rous sarcoma virus LTR was replaced with the Moloney murine leukemia virus LTR, which induced approximately 20-fold more protein expression, but even focus-selected lines expressing v/c-src proteins were unable to form large colonies in soft agarose or tumors in NFS mice. This suggests that pp60c-src is not equally sensitive to mutations in its different domains and that there are at least two distinguishable levels of regulation, the dominant one being associated with its carboxyl terminus. v/c-src chimeric proteins expressed with either LTR had high in vitro specific kinase activity equal to that of pp60v-src but, in contrast, were phosphorylated at both Tyr-527 and Tyr-416. Total cell protein phosphotyrosine was enhanced in cells incompletely transformed by v/c-src proteins to the same extent as in v-src-transformed cells, suggesting that the carboxyl-terminal region may affect substrate specificity in a manner that is important for transformation.


2003 ◽  
Vol 77 (23) ◽  
pp. 12617-12629 ◽  
Author(s):  
Derek E. Dimcheff ◽  
Srdjan Askovic ◽  
Audrey H. Baker ◽  
Cedar Johnson-Fowler ◽  
John L. Portis

ABSTRACT FrCasE is a mouse retrovirus that causes a fatal noninflammatory spongiform neurodegenerative disease with pathological features strikingly similar to those induced by transmissible spongiform encephalopathy (TSE) agents. Neurovirulence is determined by the sequence of the viral envelope protein, though the specific role of this protein in disease pathogenesis is not known. In the present study, we compared host gene expression in the brain stems of mice infected with either FrCasE or the avirulent virus F43, differing from FrCasE in the sequence of the envelope gene. Four of the 12 disease-specific transcripts up-regulated during the preclinical period represent responses linked to the accumulation of unfolded proteins in the endoplasmic reticulum (ER). Among these genes was CHOP/GADD153, which is induced in response to conditions that perturb endoplasmic reticulum function. In vitro studies with NIH 3T3 cells revealed up-regulation of CHOP as well as BiP, calreticulin, and Grp58/ERp57 in cells infected with FrCasE but not with F43. Immunoblot analysis of infected NIH 3T3 cells demonstrated the accumulation of uncleaved envelope precursor protein in FrCasE- but not F43-infected cells, consistent with ER retention. These results suggest that retrovirus-induced spongiform neurodegeneration represents a protein-folding disease and thus may provide a useful tool for exploring the causal link between protein misfolding and the cytopathology that it causes.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Dinesh Gajamange ◽  
Seung-Hyeon Kim ◽  
Kwang-Sik Choi ◽  
Carlos Azevedo ◽  
Kyung-Il Park

An amendment to this paper has been published and can be accessed via the original article.


Science ◽  
1992 ◽  
Vol 257 (5075) ◽  
pp. 1404-1407 ◽  
Author(s):  
P Dent ◽  
W Haser ◽  
T. Haystead ◽  
L. Vincent ◽  
T. Roberts ◽  
...  

1994 ◽  
Vol 14 (2) ◽  
pp. 906-913 ◽  
Author(s):  
E Gulbins ◽  
K M Coggeshall ◽  
C Langlet ◽  
G Baier ◽  
N Bonnefoy-Berard ◽  
...  

We recently identified Vav, the product of the vav proto-oncogene, as a guanine nucleotide exchange factor (GEF) for Ras. Vav is enzymatically activated by lymphocyte antigen receptor-coupled protein tyrosine kinases or independently by diglycerides. To further evaluate the physiological role of Vav, we assessed its GDP-GTP exchange activity against several Ras-related proteins in vitro and determined whether Vav activation in transfected NIH 3T3 fibroblasts correlates with the activity status of Ras and mitogen-activated protein (MAP) kinases. In vitro translated purified Vav activated by phorbol myristate acetate (PMA) or phosphorylation with recombinant p56lck displayed GEF activity against Ras but not against recombinant RacI, RacII, Ral, or RhoA proteins. Expression of vav or proto-vav in stably transfected NIH 3T3 cells led to a approximately 10-fold increase in basal or PMA-stimulated Ras exchange activity, respectively, in total-cell lysates and Vav immunoprecipitates. Elevated GEF activity was paralleled in each case by a significant increase in the proportion of active, GTP-bound Ras. PMA had a minimal effect on the low Ras. GTP level in untransfected control fibroblasts but increased it from 20 to 37% in proto-vav-transfected cells. vav-transfected cells displayed a constitutively elevated Ras. GTP level (35%), which was not increased further by PMA treatment. MAP kinases, known downstream intermediates in Ras-dependent signaling pathways, similarly exhibited increased basal or PMA-stimulated activity in Vav-expressing cells by comparison with normal NIH 3T3 cells. These results demonstrate a physiologic interaction between Vav and its target, Ras, leading to MAP kinase activation.


2019 ◽  
Vol 35 (3) ◽  
pp. 239-247 ◽  
Author(s):  
Runan Qin ◽  
Yue Wang ◽  
Shengyuan Wang ◽  
Bing Xia ◽  
Rui Xin ◽  
...  

Nickel (Ni) is a metal known to be a human carcinogen that occupational workers can be exposed to during the process of Ni refining. We investigated the molecular mechanism of inflammation that is induced by Ni-refining dust in a factory, using concentrations of 0, 25, 50, and 100 µg/mL for 24 h and 48 h, in vitro. Quantitative real-time polymerase chain reactions (qRT-PCR), Western blot analysis, and enzyme-linked immunosorbent assays (ELISA) were used to detect the transcriptional expression levels of nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Results showed that Ni-refining dust decreased the secretion of IL-6 under the experimental conditions. In contrast, Ni-refining dust activated NF-κB expression and stimulated the secretion of TNF-α, IL-1β, iNOS, and COX-2 in a dose- and time-dependent manner. To summarize, we demonstrated that exposure to Ni-refining dust can induce the expression of NF-κB in NIH/3T3 cells and the secretion of inflammation related factors. This provides a new basis for further study of the inflammatory effects of Ni-refining dust.


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