Exposure to
asbestos is associated with the development of
mesothelioma. In addition to
asbestos, other fibers have been identified as risk factors for malignant and non-malignant diseases of the lungs. Among these,
fluoro-edenite (FE) was found in patients from Biancavilla (Sicily, Italy) with pleural and
lung disease, suggesting its role for
tumor expansion. In this context, the identification of early
biomarkers useful for the diagnosis of
cancer is mandatory. Fibulin-3 represents an important marker for the diagnosis of
mesothelioma. However, it remains to be determined whether it is directly associated with exposure to
asbestos-like fibers. In the present study, peripheral blood levels of fibulin-3 from 40
asbestos-exposed workers were compared with those detected in 27 street cleaners from Biancavilla. Intriguingly, the results showed that fibulin-3 levels were higher in the group of street cleaners compared with those of the
asbestos-exposed workers, suggesting that these workers used the
personal protective equipment according to the current regulations. These data suggest that subjects exposed to FE should be monitored for the risk of
mesothelioma. FE and volcanic particulates are probably contained within dust inhaled by street cleaners from Biancavilla during their work activities. Based on these criteria, in this study, such fibers were used to treat mesothelial cells (MeT5A) in order to verify whether fibulin-3 levels are affected by these treatments. The results showed that only treatment with FE was associated with fibulin-3 overexpression at both the transcript and
protein levels. It was previously demonstrated that mesothelial cells exhibited low levels of p27 following treatment with FE. Notably, p27 downregulation is associated with
stathmin upregulation in
cancer, conferring an aggressive phenotype of
tumor cells. This observation prompted us to perform a computational evaluation demonstrating the activation of
stathmin in
lung cancer in patients exposed to
asbestos. Overall, it can be speculated that both fibulin-3 and
stathmin overexpression may be associated with the malignant transformation of mesothelial cells following exposure to
asbestos-like fibers.