Published in:
01-06-2010 | Original Article
Immunohistochemical expression of retinoblastoma and phospho-retinoblastoma protein in lung sheep exposed to fluoro-edenite fibers
Authors:
Giuseppe Musumeci, Carla Loreto, Venera Cardile, Maria Luisa Carnazza, Giuseppina Martinez
Published in:
Anatomical Science International
|
Issue 2/2010
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Abstract
The immunohistochemical expression of retinoblastoma protein (Rb) and its phosphorylated form (pRb) was investigated in an in vivo sheep model, i.e., lung tissue exposed to asbestos-like fibers. Rb is a phosphoprotein with a central role in controlling the cell cycle, cell growth regulation, differentiation, and apoptosis. pRb functions as a checkpoint in the G1 phase, favoring cell growth, while the hypophosphorylated form (Rb) not only promotes cell-cycle arrest and a return to the G1 phase, but also appears to be a key player in most instances of apoptosis. pRb overexpression was detected in alveolar epithelium and the interstitium, especially close to the fluoro-edenite fibers, whereas Rb immunostaining was faint or absent. The data suggest that the altered balance between pRb and Rb expression may be a programmed response to protect the organism against uncontrolled cell proliferation.