title: Cytotoxicity induced by exposure to natural and synthetic tremolite asbestos: an in vitro pilot study.
abstract: Mineral fibers are potential carcinogens to humans. In order to help clarify the etiology of the pathological effects of asbestos, cellular reactions to natural and synthetic asbestos fibers were compared using a lung alveolar cancer cell line (A549 epithelial cells), considered the first target of inhaled micro-environmental contaminants. Natural asbestos tremolite (NAT) fibers were collected from rocks in NW Italy. Synthetic asbestos tremolite (SAT) was iron-free and therefore considered as standard tremolite. Both fibers, subjected to mineralogical characterization by X-ray powder diffractometry, electron microscopy and energy dispersive spectrometry, fell within the definition of respirable and potentially carcinogenic fibers. Several signs of functional and structural cell damage were found after treatment with both fibers, documented by viability, motility, and morphological perturbations. Phalloidin labeling showed irregular distribution of cytoskeletal F-actin, whereas immunohistochemical investigations showed abnormal expression of VEGF, Cdc42, β-catenin, assessed as risks indicators for cancer development. Both fibers caused significant loss of viability, even compared to UICC crocidolite, but, while SAT fibers exerted a more direct cytotoxic effect, survival of damaged cells expressing high VEGF levels was detected after NAT contact. This in vitro pilot study outlines potential health risks of NAT fibers in vivo related to their iron content, which could trigger signaling networks connected with cell proliferation and neoplastic transformation.
authors.affiliation: Dipartimento di Scienze Cliniche e Molecolari-Istologia, Università Politecnica delle Marche, Via Tronto 10/A 60020 Torrette, Ancona, Italy. armanda.pugnaloni@univpm.it
authors.forename: Armanda
authors.initials: A
authors.lastname: Pugnaloni
authors.forename: Federica
authors.initials: F
authors.lastname: Giantomassi
authors.forename: Guendalina
authors.initials: G
authors.lastname: Lucarini
authors.forename: Silvana
authors.initials: S
authors.lastname: Capella
authors.forename: Andrea
authors.initials: A
authors.lastname: Bloise
authors.forename: Roberto
authors.initials: R
authors.lastname: Di Primio
authors.forename: Elena
authors.initials: E
authors.lastname: Belluso
mesh_terms: D000199:Actins / Q000378:metabolism; D017209:Apoptosis; D001194:Asbestos / Q000633:toxicity*; D017636:Asbestos, Amphibole / Q000633:toxicity*; D017638:Asbestos, Crocidolite / Q000633:toxicity; D045744:Cell Line, Tumor; D002470:Cell Survival; D003599:Cytoskeleton / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007501:Iron / Q000737:chemistry; D008854:Microscopy, Electron; D008938:Mitosis; D009336:Necrosis; D010590:Phalloidine / Q000737:chemistry; D010865:Pilot Projects; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014965:X-Rays; D051176:beta Catenin / Q000378:metabolism; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism
chemical_list: D000199:Actins; D017636:Asbestos, Amphibole; D013778:Tetrazolium Salts; D013844:Thiazoles; D042461:Vascular Endothelial Growth Factor A; D051176:beta Catenin; D017638:Asbestos, Crocidolite; D001194:Asbestos; C005846:tremolite; D010590:Phalloidine; D007501:Iron; D020764:cdc42 GTP-Binding Protein; C022616:thiazolyl blue