scholarly journals Interferon-induced revertants of ras-transformed cells: resistance to transformation by specific oncogenes and retransformation by 5-azacytidine.

1987 ◽  
Vol 7 (6) ◽  
pp. 2196-2200 ◽  
Author(s):  
D Samid ◽  
D M Flessate ◽  
R M Friedman

Prolonged alpha/beta interferon (IFN-alpha/beta) treatment of NIH 3T3 cells transformed by a long terminal repeat-activated Ha-ras proto-oncogene resulted in revertants that maintained a nontransformed phenotype long after IFN treatment had been discontinued. Cloned persistent revertants (PRs) produced large amounts of the ras-encoded p21 and were refractile to transformation by EJras DNA and by transforming retroviruses which carried the v-Ha-ras, v-Ki-ras, v-abl, or v-fes oncogene. Transient treatment either in vitro or in vivo with cytidine analogs that alter gene expression by inhibiting DNA methylation resulted in transformation of PR, but not of NIH 3T3, cells. The PR retransformants reverted again with IFN, suggesting that DNA methylation is involved in IFN-induced persistent reversion.

1987 ◽  
Vol 7 (6) ◽  
pp. 2196-2200
Author(s):  
D Samid ◽  
D M Flessate ◽  
R M Friedman

Prolonged alpha/beta interferon (IFN-alpha/beta) treatment of NIH 3T3 cells transformed by a long terminal repeat-activated Ha-ras proto-oncogene resulted in revertants that maintained a nontransformed phenotype long after IFN treatment had been discontinued. Cloned persistent revertants (PRs) produced large amounts of the ras-encoded p21 and were refractile to transformation by EJras DNA and by transforming retroviruses which carried the v-Ha-ras, v-Ki-ras, v-abl, or v-fes oncogene. Transient treatment either in vitro or in vivo with cytidine analogs that alter gene expression by inhibiting DNA methylation resulted in transformation of PR, but not of NIH 3T3, cells. The PR retransformants reverted again with IFN, suggesting that DNA methylation is involved in IFN-induced persistent reversion.


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 19 (5) ◽  
pp. 326-334
Author(s):  
Lu Huang ◽  
Marco Tjakra ◽  
Desha Luo ◽  
Lin Wen ◽  
Daoxi Lei ◽  
...  

Background: In vertebrates, cilium is crucial for Hedgehog signaling transduction. Forkhead box transcriptional factor FoxF1 is reported to be associated with Sonic Hedgehog (Shh) signaling in many cases. However, the role of FoxF1 in cilium remains unknown. Here, we showed an essential role of FoxF1 in the regulation of ciliogenesis and in the distribution of Shh signaling components in cilium. Methods: NIH/3T3 cells were serum starved for 24h to induce cilium. Meanwhile, shRNA was used to knockdown the FoxF1 expression in the cells and CRISPR/Cas9 was used to generate the FoxF1 zebrafish mutant. The mRNA and protein expression of indicated genes were detected by the qRT-PCR and western blot, respectively. Immunofluorescence staining was performed to detect the cilium and Shh components distribution. Results: FoxF1 knockdown decreased the cilium length in NIH/3T3 cells. Meanwhile, the disruption of FoxF1 function inhibited the expression of cilium-related genes and caused an abnormal distribution of Shh components in the cilium. Furthermore, homozygous FoxF1 mutants exhibited defective development of pronephric cilium in early zebrafish embryos. Conclusion: Together, our data illustrated that FoxF1 is required for ciliogenesis in vitro and in vivo and for the proper localization of Shh signaling components in cilium.


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.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 18054-18054
Author(s):  
W. J. Petty ◽  
W. R. Voelzke ◽  
V. A. Memoli ◽  
K. H. Dragnev ◽  
J. J. Urbanic ◽  
...  

18054 Background: Transcriptional repression of cyclin D1 occurs during responses to erlotinib (E) both in vitro and in vivo. Cyclin D3 has overlapping function with cyclin D1 but has distinct transcriptional regulation. Methods: The expression of cyclin D3 was compared in E sensitive cell lines (H358, H441) and an E resistant cell line (A549). Cyclins D1, D2, and D3 were independently overexpressed in E sensitive NIH 3T3 cells by plasmid transfection. Biopsy tissues from a proof-of-principal clinical trial of E were assessed for cyclin D3 expression. Results: A549 cells were resistant to E and expressed high levels of cyclin D3 RNA and protein compared to E sensitive cell lines. Overexpression of cyclin D1 and cyclin D3 conferred partial resistance to E in NIH 3T3 cells while cyclin D2 had no significant effect. Comparison of cyclin D3 immunostaining in tumor biopsies from patients before and after treatment with E revealed an increase in the percentage of cyclin D3 expressing cells following treatment with E. Conclusions: Cyclin D3 confers resistance to E in vitro and in vivo. Drugs such as retinoids and rexinoids that target cyclin D3 expression may prove useful for enhancing sensitivity to E. No significant financial relationships to disclose.


2007 ◽  
Vol 27 (13) ◽  
pp. 4980-4990 ◽  
Author(s):  
Masahiro Morita ◽  
Toru Suzuki ◽  
Takahisa Nakamura ◽  
Kazumasa Yokoyama ◽  
Takashi Miyasaka ◽  
...  

ABSTRACT The stability of mRNA influences the abundance of cellular transcripts and proteins. Deadenylases play critical roles in mRNA turnover and thus are important for the regulation of various biological events. Here, we report the identification and characterization of CCR4b/CNOT6L, which is homologous to yeast CCR4 mRNA deadenylase. CCR4b is localized mainly in the cytoplasm and displays deadenylase activity both in vitro and in vivo. CCR4b forms a multisubunit complex similar to the yeast CCR4-NOT complex. Suppression of CCR4b by RNA interference results in growth retardation of NIH 3T3 cells accompanied by elevation of both p27 Kip1 mRNA and p27Kip1 protein. Reintroduction of wild-type CCR4b, but not mutant CCR4b lacking deadenylase activity, restores the growth of CCR4b-depleted NIH 3T3 cells. The data suggest that CCR4b regulates cell growth in a manner dependent on its deadenylase activity. We also show that p27 Kip1 mRNA is stabilized and its poly(A) tail is preserved in CCR4b-depleted cells. Our findings provide evidence that CCR4b deadenylase is a constituent of the mammalian CCR4-NOT complex and regulates the turnover rate of specific target mRNAs. Thus, CCR4b may be involved in various cellular events that include cell proliferation.


2001 ◽  
Vol 10 (2) ◽  
pp. 209-221 ◽  
Author(s):  
Roberto Del Bo ◽  
Yvan Torrente ◽  
Stefania Corti ◽  
Maria Grazia D'angelo ◽  
Giacomo Pietro Comi ◽  
...  

1989 ◽  
Vol 9 (6) ◽  
pp. 2453-2463
Author(s):  
P Yaciuk ◽  
J K Choi ◽  
D Shalloway

The product of the c-src proto-oncogene, pp60c-src, is phosphorylated at Ser-17 by cyclic AMP-dependent protein kinase A and at Ser-12 by calcium-phospholipid-dependent protein kinase C (when stimulated by 12-O-tetradecanoyl phorbol acetate). We tested the effects of Ser----Ala and Ser----Glu mutations at these sites in pp60c-src and in pp60c-src(F527) (a mutant whose transforming activities are enhanced by Tyr-527----Phe mutation) by transfecting single-, double-, and triple-mutant src expression plasmids into NIH 3T3 cells. Tryptic phosphopeptide analyses of the mutant proteins confirmed prior biochemical identifications of the phosphorylation sites and showed that neither separate nor coordinate mutations at Ser-12 and Ser-17 affected Tyr-416, Tyr-527, or Ser-48 phosphorylation or prevented mitosis-specific phosphorylations of either pp60c-src or pp60c-src(F527). Ser-12 mutation did not affect phosphorylation of the Ser-17-containing peptide, but mutation of Ser-17 significantly increased phosphorylation at Ser-12. Specific kinase activities (both with and without in vivo 12-O-tetradecanoyl phorbol acetate treatment) and the abilities of pp60c-src and pp60c-src(F527) to induce foci, transformed morphologies, and anchorage-independent growth were unaffected by any of the serine mutations. Thus, pp60c-src transforming activity in NIH 3T3 cells is relatively insensitive to phosphorylation at these sites, but there is a suggestion that Ser-17 phosphorylation may have a subtle regulatory effect.


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.


2004 ◽  
Vol 24 (8) ◽  
pp. 3227-3237 ◽  
Author(s):  
Kazuhiro Maki ◽  
Honoka Arai ◽  
Kazuo Waga ◽  
Ko Sasaki ◽  
Fumihiko Nakamura ◽  
...  

ABSTRACT TEL is an ETS family transcription factor that possesses multiple putative mitogen-activated protein kinase phosphorylation sites. We here describe the functional regulation of TEL via ERK pathways. Overexpressed TEL becomes phosphorylated in vivo by activated ERK. TEL is also directly phosphorylated in vitro by ERK. The inducible phosphorylation sites are Ser213 and Ser257. TEL binds to a common docking domain in ERK. In vivo ERK-dependent phosphorylation reduces trans-repressional and DNA-binding abilities of TEL for ETS-binding sites. A mutant carrying substituted glutamates on both Ser213 and Ser257 functionally mimics hyperphosphorylated TEL and also shows a dominant-negative effect on TEL-induced transcriptional suppression. Losing DNA-binding affinity through phosphorylation but heterodimerizing with unmodified TEL could be an underlying mechanism. Moreover, the glutamate mutant dominantly interferes with TEL-induced erythroid differentiation in MEL cells and growth suppression in NIH 3T3 cells. Finally, endogenous TEL is dephosphorylated in parallel with ERK inactivation in differentiating MEL cells and is phosphorylated through ERK activation in Ras-transformed NIH 3T3 cells. These data indicate that TEL is a constituent downstream of ERK in signal transduction systems and is physiologically regulated by ERK in molecular and biological features.


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