scholarly journals The Mos/MAP kinase pathway stabilizes c-Fos by phosphorylation and augments its transforming activity in NIH 3T3 cells.

1995 ◽  
Vol 14 (20) ◽  
pp. 5048-5059 ◽  
Author(s):  
K. Okazaki ◽  
N. Sagata
Keyword(s):  
Map Kinase ◽  
3T3 Cells ◽  
Transforming Activity ◽  
Map Kinase Pathway ◽  
Nih 3T3 ◽  
Kinase Pathway ◽  
Nih 3T3 Cells

scholarly journals Complementation of Defective Colony-Stimulating Factor 1 Receptor Signaling and Mitogenesis by Raf and v-Src

1999 ◽  
Vol 19 (2) ◽  
pp. 1101-1115 ◽  
Author(s):  
Natasha Aziz ◽  
Holly Cherwinski ◽  
Martin McMahon
Keyword(s):  
Map Kinase ◽  
Cyclin D1 ◽  
Colony Stimulating Factor ◽  
3T3 Cells ◽  
Mitogenic Response ◽  
Induced Expression ◽  
Map Kinase Pathway ◽  
Nih 3T3 ◽  
Kinase Pathway ◽  
Stimulating Factor

ABSTRACT Ras-activated signal transduction pathways are implicated in the control of cell proliferation, differentiation, apoptosis, and tumorigenesis, but the molecular mechanisms mediating these diverse functions have yet to be fully elucidated. Conditionally active forms of Raf, v-Src, and MEK1 were used to identify changes in gene expression that participate in oncogenic transformation, as well as in normal growth control. Activation of Raf, v-Src, and MEK1 led to induced expression of c-Myc and cyclin D1. Induction of c-Myc mRNA by Raf was an immediate-early response, whereas the induction of cyclin D1 mRNA was delayed and inhibited by cycloheximide. Raf activation also resulted in the induction of an established c-Myc target gene, ornithine decarboxylase (ODC). ODC induction by Raf was mediated, in part, by tandem E-boxes contained in the first intron of the gene. Activation of the human colony-stimulating factor 1 (CSF-1) receptor in NIH 3T3 cells leads to activation of the mitogen-activated protein (MAP) kinase pathway and induced expression of c-Fos, c-Myc, and cyclin D1, leading to a potent mitogenic response. By contrast, a mutated form of this receptor fails to activate the MAP kinases or induce c-Myc and cyclin D1 expression and fails to elicit a mitogenic response. The biological significance of c-Myc and cyclin D1 induction by Raf and v-Src was confirmed by the demonstration that both of these protein kinases complemented the signaling and mitogenic defects of cells expressing this mutated form of the human CSF-1 receptor. Furthermore, the induction of c-Myc and cyclin D1 by oncogenes and growth factors was inhibited by PD098059, a specific MAP kinase kinase (MEK) inhibitor. These data suggest that the Raf/MEK/MAP kinase pathway plays an important role in the regulation of c-Myc and cyclin D1 expression in NIH 3T3 cells. The ability of oncogenes such as Raf and v-Src to regulate the expression of these proteins reveals new lines of communication between cytosolic signal transducers and the cell cycle machinery.

Specific activation of the cellular Harvey-ras oncogene in dimethylbenzanthracene-induced mouse mammary tumors

1986 ◽  
Vol 6 (11) ◽  
pp. 4104-4108
Author(s):  
S Dandekar ◽  
S Sukumar ◽  
H Zarbl ◽  
L J Young ◽  
R D Cardiff
Keyword(s):  
Mammary Tumors ◽  
3T3 Cells ◽  
Mouse Mammary Tumor ◽  
Mouse Mammary Tumors ◽  
Transforming Activity ◽  
Radiation Induced ◽  
Genomic Dnas ◽  
Nih 3T3 ◽  
Adenosine Nucleotide ◽  
Nih 3T3 Cells

Genomic DNAs from dimethylbenzanthracene-induced BALB/c mouse mammary tumors arising from the transplantable hyperplastic outgrowth (HPO) line designated DI/UCD transformed NIH 3T3 cells upon transfection. Transforming activity was attributed to the presence of activated Harvey ras-1 oncogenes containing an A----T transversion at the middle adenosine nucleotide in codon 61. DNAs from untreated DI/UCD HPO cells and radiation-induced and spontaneous mammary tumors from the DI/UCD HPO line failed to transform NIH 3T3 cells. The results indicated that the mutation activation of Harvey ras-1 oncogenes was specific to dimethylbenzanthracene treatment in the mouse mammary tumor system.

scholarly journals A transforming activity not detected by DNA transfer to NIH 3T3 cells is detected by JB6 mouse epidermal cells.

1985 ◽  
Vol 5 (4) ◽  
pp. 890-893 ◽  
Author(s):  
N H Colburn ◽  
M I Lerman ◽  
G A Hegamyer ◽  
T D Gindhart
Keyword(s):  
Tumor Cell ◽  
Cell Lines ◽  
Tumor Cell Lines ◽  
3T3 Cells ◽  
Anchorage Independence ◽  
Transforming Activity ◽  
Mouse Epidermal Cell ◽  
Nih 3T3 ◽  
Transforming Genes ◽  
Nih 3T3 Cells

Transfection of four different mouse epidermal tumor cell DNAs into NIH 3T3 cells yielded neither morphologically altered foci nor anchorage independence. However, promotion-sensitive, but not promotion-insensitive, JB6 mouse epidermal cell lines were permissive for the expression of anchorage independence after transfection of DNA from three of these tumor cell lines. This transforming activity and the promotion-sensitive activity that confers sensitivity to promotion of transformation show differences in restriction enzyme sensitivity. In view of this difference and the differences in both recipient cells and 12-O-tetradecanoyl-phorbol-13-acetate dependence of expression, it appears that the transforming activity and the promotion-sensitive activity are specified by different genes. The JB6 promotion-sensitive cell lines may be useful for detecting and cloning transforming genes that escape detection in the NIH 3T3 cell focus assay.

scholarly journals B-raf, a new member of the raf family, is activated by DNA rearrangement.

1988 ◽  
Vol 8 (6) ◽  
pp. 2651-2654 ◽  
Author(s):  
S Ikawa ◽  
M Fukui ◽  
Y Ueyama ◽  
N Tamaoki ◽  
T Yamamoto ◽  
...  
Keyword(s):  
Ewing Sarcoma ◽  
Dna Rearrangement ◽  
Terminal Portion ◽  
3T3 Cells ◽  
Complementary Dna ◽  
Amino Terminal ◽  
Transforming Activity ◽  
Nih 3T3 ◽  
Transforming Gene ◽  
Nih 3T3 Cells

Complementary DNA clones of a putative transforming gene were isolated from NIH 3T3 cells transformed with human Ewing sarcoma DNA. The gene was termed B-raf because it is related to but distinct from c-raf and A-raf. It appears that substitution in the amino-terminal portion of the normal B-raf protein confers transforming activity to the gene.

scholarly journals Mechanism of activation of the ret proto-oncogene by multiple endocrine neoplasia 2A mutations.

1995 ◽  
Vol 15 (3) ◽  
pp. 1613-1619 ◽  
Author(s):  
N Asai ◽  
T Iwashita ◽  
M Matsuyama ◽  
M Takahashi
Keyword(s):  
Cell Surface ◽  
Multiple Endocrine Neoplasia ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
3T3 Cells ◽  
Endocrine Neoplasia ◽  
Transforming Activity ◽  
Nih 3T3 ◽  
Men 2A ◽  
Nih 3T3 Cells

Transforming activity of the c-ret proto-oncogene with multiple endocrine neoplasia (MEN) 2A mutations was investigated by transfection of NIH 3T3 cells. Mutant c-ret genes driven by the simian virus 40 or cytomegalovirus promoter induced transformation with high efficiencies. The 170-kDa Ret protein present on the cell surface of transformed cells was highly phosphorylated on tyrosine and formed disulfide-linked homodimers. This result indicated that MEN 2A mutations induced ligand-independent dimerization of the c-Ret protein on the cell surface, leading to activation of its intrinsic tyrosine kinase. In addition to the MEN 2A mutations, we further introduced a mutation (lysine for asparaginic acid at codon 300 [D300K]) in a putative Ca(2+)-binding site of the cadherin-like domain. When c-ret cDNA with both MEN 2A and D300K mutations was transfected into NIH 3T3 cells, transforming activity drastically decreased. Western blot (immunoblot) analysis revealed that very little of the 170-kDa Ret protein with the D300K mutation was expressed in transfectants while expression of the 150-kDa Ret protein retained in the endoplasmic reticulum was not affected. This result also demonstrated that transport of the Ret protein to the plasma membrane is required for its transforming activity.

Potent transforming activity of the small GTP-binding protein Rit in NIH 3T3 cells: evidence for a role of a p38γ-dependent signaling pathway

FEBS Letters ◽  
2001 ◽  
Vol 511 (1-3) ◽  
pp. 15-20 ◽  
Author(s):  
Kaoru Sakabe ◽  
Hidemi Teramoto ◽  
Muriel Zohar ◽  
Babak Behbahani ◽  
Hiroshi Miyazaki ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Binding Protein ◽  
3T3 Cells ◽  
Gtp Binding Protein ◽  
Gtp Binding ◽  
Transforming Activity ◽  
Nih 3T3 ◽  
Dependent Signaling Pathway ◽  
Nih 3T3 Cells

scholarly journals The Carboxyl Terminus of v-Abl Protein Can Augment SH2 Domain Function

2000 ◽  
Vol 74 (10) ◽  
pp. 4495-4504 ◽  
Author(s):  
David Warren ◽  
Andrew J. Heilpern ◽  
Kent Berg ◽  
Naomi Rosenberg
Keyword(s):  
Map Kinase ◽  
Protein Interactions ◽  
Leukemia Virus ◽  
Sh2 Domain ◽  
Carboxyl Terminus ◽  
Abl Tyrosine Kinase ◽  
Mitogen Activated Protein ◽  
Map Kinase Pathway ◽  
Nih 3T3 ◽  
Kinase Pathway

ABSTRACT Abelson murine leukemia virus (Ab-MLV) transforms NIH 3T3 and pre-B cells via expression of the v-Abl tyrosine kinase. Although the enzymatic activity of this molecule is absolutely required for transformation, other regions of the protein are also important for this response. Among these are the SH2 domain, involved in phosphotyrosine-dependent protein-protein interactions, and the long carboxyl terminus, which plays an important role in transformation of hematopoietic cells. Important signals are sent from each of these regions, and transformation is most likely orchestrated by the concerted action of these different parts of the protein. To explore this idea, we compared the ability of the v-Src SH2 domain to substitute for that of v-Abl in the full-length P120 v-Abl protein and in P70 v-Abl, a protein that lacks the carboxyl terminus characteristic of Abl family members. Ab-MLV strains expressing P70/S2 failed to transform NIH 3T3 cells and demonstrated a greatly reduced capacity to mediate signaling events associated with the Ras-dependent mitogen-activated protein (MAP) kinase pathway. In contrast, Ab-MLV strains expressing P120/S2 were indistinguishable from P120 with respect to these features. Analyses of additional mutants demonstrated that the last 162 amino acids of the carboxyl terminus were sufficient to restore transformation. These data demonstrate that an SH2 domain with v-Abl substrate specificity is required for NIH 3T3 transformation in the absence of the carboxyl terminus and suggest that cooperativity between the extreme carboxyl terminus and the SH2 domain facilitates the transmission of transforming signals via the MAP kinase pathway.

Loss of the amino-terminal helix-loop-helix domain of the vav proto-oncogene activates its transforming potential

1991 ◽  
Vol 11 (4) ◽  
pp. 1912-1920
Author(s):  
S Katzav ◽  
J L Cleveland ◽  
H E Heslop ◽  
D Pulido
Keyword(s):  
Leucine Zipper ◽  
Ectopic Expression ◽  
Cdna Clones ◽  
3T3 Cells ◽  
Amino Terminal ◽  
Helix Loop Helix ◽  
Transforming Activity ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

vav, a novel human oncogene, was originally generated in vitro by replacement of its normal 5' coding sequences with sequences from pSV2neo DNA, cotransfected as a selectable marker (S. Katzav, D. Martin-Zanca, and M. Barbacid, EMBO J. 8:2283-2290, 1989). The vav proto-oncogene is normally expressed in cells of hematopoietic origin. To determine whether the 5' rearrangement of vav or its ectopic expression in NIH 3T3 cells contributes to its transforming potential, we isolated murine and human proto-vav cDNA clones as well as human genomic clones corresponding to the 5' end of the gene. Normal proto-vav was poorly transforming in NIH 3T3 cells, whereas truncation of its 5' end greatly enhanced its transforming activity. The relative failure of full-length proto-vav cDNA clones to transform NIH 3T3 cells indicates that the transforming activity of vav is not simply due to ectopic expression. Analysis of the predicted amino terminus of the vav proto-oncogene shows that it contains a helix-loop-helix domain and a leucine zipper motif similar to that of myc family proteins, though it lacks a basic region that is usually found adjacent to helix-loop-helix domains. Loss of the helix-loop-helix domain of proto-vav, either by truncation or by rearrangement with pSV2neo sequences, activates its oncogenic potential.

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