The protein product of the fra-2 gene (Fra-2), a fos-family member, can compete with Fos protein for participation in activating protein-1 (AP-1) transcription factor complexes and each protein can contribute different transactivational consequences to an AP-1 complex. To date, there is limited characterization of fra-2 mRNA expression in the rat forebrain. We examined basal and restraint-induc...

Osteosarcoma (OS) is an aggressive bone tumor, and proto-oncogene c-Fos is involved in this lethal disease. However, the role and molecular mechanism of c-Fos in the development and progression of OS remain enigmatic. As one of the Wnt family members, Wnt2 is closely associated with the development of several malignant tumors. In the present study, the expression of c-Fos, Wnt2, and its recepto...

Photodynamic therapy (PDT) generates reactive oxygen species which initiate the cytotoxic events of this tumor treatment. We demonstrate that PDT mediated oxidative stress induced a transient increase in the early response genes c-fos, c-jun, c-myc, and egr-1 in murine radiation-induced fibrosarcoma cells. Incubation of exponentially growing cells with porphyrin based photosensitizers in the da...

The immediate early gene c-fos has long been known as a molecular marker of neural activity. The neuron's activity is transformed into intracellular calcium influx through NMDA receptors and L-type voltage sensitive calcium channels. For the transcription of c-fos, neural activity should be strong enough to activate mitogen-activated protein kinase (MAPK) signaling pathway which shows low calci...

We have recently observed that protein kinase C (PKC) was involved in the regulation of the accumulation of mRNAs of the AP-1 components in cultured Abelson-transformed murine fetal-liver-derived mast cells stimulated by exocytotic stimuli. Here we analyzed the probable regulatory effect of PKC on the synthesis and DNA-binding activity of AP-1 complexes in immunologic stimulated mast cells. In ...

OBJECTIVE To study the effect of cytokines on the transactivation of the c-fos gene in relation to the contribution of overexpression of c-fos/AP-1 in rheumatoid joint destruction. METHODS The promoter region (-447 to +109) of the human c-fos gene was integrated upstream of the chloramphenicol acetyltransferase (CAT) reporter gene, and the effect of cytokines on the expression of the c-fos ge...

Fibroblast growth factor-19 (FGF-19), a bile acid-responsive enterokine, is secreted by the ileum and regulates a variety of metabolic processes. These studies examined the signal transduction pathways operant in FGF-19-mediated repression of the apical sodium-dependent bile acid transporter (ASBT). Responses to FGF-19 were assessed in Caco-2 and CT-26 cells and in mice where c-fos was conditio...

We evaluated the mechanism of insulin and phorbol ester induction of the proto-oncogene c-fos in Chinese hamster ovary fibroblasts stably transformed with high levels of genes expressing normal or truncated human insulin receptors. Both insulin and the tumor-promoting phorbol ester phorbol 12-myristate 13-acetate (PMA) induced c-fos mRNA accumulation in cells expressing high numbers of normal h...

The proto-oncogene c-myc encodes a transcription factor that plays a pivotal role in cell proliferation, differentiation, and apoptosis. The signaling mechanism of c-Myc-induced apoptosis was investigated on the human hepatoma Huh7 cells under growth factor-deprived conditions. The apoptotic process did not involve p53. Rather it was dependent on the expression of c-Fos. Activation of caspases ...