Related Experiment Video
Updated: Aug 9, 2026
10:09
Methods for Evaluating the Role of c-Fos and Dusp1 in Oncogene Dependence
Published on: January 7, 2019
Transcription factors junB and c-jun are selectively up-regulated and functionally implicated in fibrosarcoma
E Bossy-Wetzel1, R Bravo, D Hanahan
1Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0534.
Genes & Development
|December 1, 1992
Summary
JunB and c-Jun proto-oncogenes drive tumor progression in bovine papillomavirus transgenic mice. These factors are crucial during intermediate fibromatosis stages, promoting cell shape changes and anchorage independence.
Area of Science:
- Oncology
- Molecular Biology
- Dermatology
Background:
- Bovine papillomavirus (BPV) induces skin tumors in transgenic mice.
- Tumor development progresses through mild fibromatosis, aggressive fibromatosis, and fibrosarcoma stages.
- Proto-oncogene expression patterns are critical in cancer progression.
Purpose of the Study:
- To investigate the role of junB, c-jun, junD, and fos proto-oncogenes in BPV-induced skin tumor development.
- To determine the functional significance of junB and c-jun in tumor progression.
Main Methods:
- Analysis of proto-oncogene expression in tumor tissue biopsies and cell lines.
- Assessment of AP-1 DNA-binding activity in fibrosarcoma cells.
- Gene transfection experiments to overexpress junB, c-jun, or junD in mild fibromatosis cells and normal fibroblasts.
Main Results:
- JunB and c-Jun were induced in aggressive fibromatosis and fibrosarcoma stages, unlike junD and fos.
- Fibrosarcoma cell lines exhibited elevated AP-1 DNA-binding activity.
- Overexpression of junB or c-jun in mild fibromatosis cells induced changes in cell shape and anchorage independence, while junD had no effect.
Conclusions:
- JunB and c-Jun act as progression factors in BPV-induced skin tumorigenesis.
- Their activity is essential during intermediate tumor development stages, following initial aberrant proliferation.
- These findings highlight specific jun genes as key mediators of tumor progression.
More Related Videos
Related Concept Videos
02:16Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
02:16Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
02:36RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
02:23Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
02:23Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
01:16TGF - β Signaling Pathway
The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...