1,721,013 research outputs found
Felis catus papillomavirus type 2 E6 oncogene enhances mitogen-activated protein kinases and Akt activation but not EGFR expression in an in vitro feline model of viral pathogenesis
No full textA possible causative role of Felis catus papillomavirus type 2 (FcaPV2) in the development of feline oral and cutaneous squamous cell carcinomas (SCC) has been recently suggested by demonstrating viral gene expression in vivo and transforming properties by its putative oncogenes E6 and E7 in vitro. The activated molecules MEK (pMEK), ERK (pERK) and Akt (pAkt) are signaling transduction effectors regulating cell proliferation and inhibition of apoptosis, which are critical steps towards tumour formation. Here, we show by Western blotting (WB) that expression of FcaPV2 E6 in feline epithelial cells enhances pMEK, pERK and pAkt levels compared to control cells. Additionally, we demonstrated by real-time quantitative PCR on epidermal growth factor receptor (EGFR) transcripts and WB that activation of these signaling routes is independent from EGFR differential gene expression, total protein levels or phosphorylation, unlike in human papillomavirus associated tumours. This study contributes to define the molecular scenario underlying FcaPV2-triggered pathogenesis of feline SCC
Proliferative index evaluated by immunohistochemistry in bovine cutaneous fibropapillomas
No full textBiogenesis of VGF secretory granules in epithelial thyroid cells.
No full textVGF is a granin that is sorted to a regulated and polarized pathway of secretion when expressed in FRT epithelial cells. We are investigating the role of aggregation and interaction with lipid rafts in VGF protein sorting. We demonstrated that a fraction of the intracellular protein is associated to GM1 rafts and that in a low pH and high calcium buffer VGF aggregates. Since only the intracellular protein, not the one secreted in the culture medium, is capable to aggregate, we hypothesized that VGF aggregation might be due to its interaction with some other molecule. We have excluded that the interaction of VGF to GM1 rafts is relevant for VGF aggregation since it is not affected by the inhibition of glycosphyngolipid synthesis. We have then looked for proteins capable to interact with VGF by gel filtration and by SDS-PAGE analysis of proteins that co-aggregated with VGF. We found a 40 kDa protein that is co-eluted with VGF and we demonstrated that it is not flotillin 2, which also forms aggregates but has an intracellular distribution distinct from that of VGF. FRT-VGF cells were treated with bafilomycin A1 that alters the proton gradient of the secretory compartment. A dramatic reduction in VGF secretion and granule formation, and lack of response to PMA were observed. The secretion of thyroglobulin, that we have stably expressed in FRT cells and that is also secreted through the apical cell domain but by a constitutive pathway, was unaffected.Overall our data support the hypothesis that VGF aggregation does not depend on rafts association and possibly occurs in the presence of a 40 kDa protein. Proton gradient perturbation affects granule formation and VGF secretion
Bovine papillomavirus E5 and E7 oncoproteins in naturally occurring tumors: are two better than one?
No full textProliferative index evaluated by immunoistochemistry in bovine cutaneous fibropapillomas
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Phosphatidylinositol-3-kinase-AKT pathway, phospho-JUN and phospho-JNK expression in spontaneously arising bovine urinary bladder tumours.
No full textPathways molecolari alla base della cancerogenesi uroteliale indotta dal papillomavirus bovino
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