Multinucleation and pro-inflammatory cytokine release promoted by fibrous fluoro-edenite in lung epithelial A549 cells (original) (raw)
Related papers
Behaviour of the new asbestos amphibole fluoro-edenite in different lung cell systems
The International Journal of Biochemistry & Cell Biology, 2004
The aim of the present research was to determine whether the recently identified and characterized new fibrous amphibole fluoro-edenite may induce a cytopathic response in cultured cells. The final goal was to gain suggestions on the potentiality of fluoro-edenite to be harmful to human beings. Epidemiological studies, in fact, have shown an excess of developing mesothelioma among residents in Biancavilla, a town in eastern Sicily located in the Etna volcanic area. Therefore, we treated human lung fibroblasts, human lung alveolar epithelial cancer cell line A549 and monocyte-macrophage cell line J774 with fluoro-edenite or crocidolite; the latter used as a highly toxic amphibole asbestos reference. Our results show that fluoro-edenite may induce functional modifications and affects some biochemical parameters in tested cell cultures in a concentration and time dependent manner. However, the observed functional modifications induced by fluoro-edenite are generally less dramatic than those induced by crocidolite and more evident on human lung alveolar epithelial cancer cell line A549 with respect to those obtained on human lung fibroblasts or monocyte-macrophage cell line J774. The sequence of the damage is hypothesised to be as follows: at increasing fluoro-edenite concentrations, and/or treatment times, the increase in reactive oxygen species (ROS) production could trigger significant DNA damage in cell cultures, concomitantly with drop in cell metabolism and increase in lactic dehydrogenase release. In conclusion, according to our data, fluoro-edenite appears as a probable carcinogenic agent, responsible for the high incidence of malignant pleural mesothelioma in Biancavilla.
Effects of the new-identified amphibole fluoro-edenite in lung epithelial cells
Toxicology in vitro : an international journal published in association with BIBRA
An epidemiological survey on mortality for malignant pleural neoplasm in Italy evidenced a number of patients in Biancavilla, a village located in a volcanic area of eastern Sicily, none of which had been significantly exposed to asbestos during their professional lives. Environmental studies suggested the involvement of the material derived from stone quarries in the disease onset. A detailed crystal-chemical analysis of amphiboles contained in this material allowed the discovery and the identification of a new fiber that was named fluoro-edenite. In order to define the mode of action of fluoro-edenite at a subcellular level, we have conducted a study by using A549 cells, a tumor-cell line from a human lung carcinoma with properties of alveolar epithelial cells. The results obtained showed a remarkable tropism of A549 cells toward fluoro-edenite fibers. In fact, these epithelial cells contacted the fibers via the extension of membrane ruffles and filopodia that allowed the capture ...
In vitro study of biofunctional indicators after exposure to asbestos-like fluoro-edenite fibres
Cellular and molecular biology (Noisy-le-Grand, France)
The in vitro biological response to fluoro-edenite (FE) fibres, an asbestos-like amphibole, was evaluated in lung alveolar epithelial A549, mesothelial MeT-5A and monocyte-macrophage J774 cell lines. The mineral has been found in the vicinity of the town of Biancavilla (Catania, Sicily), where an abnormal incidence of mesothelioma has been documented. Cell motility, distribution of polymerized actin, and synthesis of vascular endothelial growth factor (VEGF) and of beta-catenin, critical parameters for tumour development, progression and survival, were investigated in A549 and MeT-5A cells exposed to 50 microg/ml FE fibres for 24 hr and 48 hr. The levels of cyclooxygenase (COX-2) and prostaglandin (PGE2), two molecules involved in cancer pathogenesis by affecting mitogenesis, cell adhesion, immune surveillance and apoptosis, were measured in J774 cells treated with FE fibres under the same experimental conditions. Finally, FE fibres were studied by SEM and EDS analysis to investigat...
Erionite and asbestos differently cause transformation of human mesothelial cells
… journal of cancer, 2007
Malignant Mesothelioma (MMe) is an aggressive tumor associated with environmental or occupational exposure to asbestos fibers. Erionite is a fibrous Zeolite, morphologically similar to asbestos and assumed even more carcinogenic. Onset and progression of MMe has been suggested as the result of the cooperation between asbestos and other cofactors, like SV40 virus infection. Nevertheless, several cases of MMe were associated with environmental exposure to Erionite in Turkey, where SV40 was never isolated in MMe specimens. We show here that Erionite is poorly cytotoxic, induces proliferative signals and high growth rate in Human Mesothelial Cells (HMC). Long term exposure to Erionite, but not to Asbestos fibers transforms HMC in vitro, regardless the presence of SV40 sequences, leading to foci formation in cultured monolayers. Cells derived from foci display constitutive activation of Akt, NF-kB and Erk1/2, show prolonged survival and a deregulated cell cycle, involving cyclin D1 and E overexpression. Our results reveal that Erionite is able per se to turn HMC into transformed highly proliferating cells and disclose the carcinogenic properties of Erionite prompting for a careful evaluation of environmental exposure to these fibers.
Toxicology and Applied Pharmacology, 1997
By using a colony-forming efficiency (CFE) assay, the cytotoxicity and proliferative potential of three mineral samples containing various proportions of fibrous talc were compared to NIEHS samples of crocidolite and chrysotile asbestos in cell types giving rise to tracheobronchial carcinomas, i.e., hamster tracheal epithelial (HTE) cells, and mesotheliomas, i.e., rat pleural mesothelial (RPM) cells. Characterization of mineralogical composition, surface area, and size distributions as well as proportions of fibers in all mineral samples allowed examination of data by various dose parameters including equal weight concentrations, numbers of fibers >5 m in length, and equivalent surface areas. Exposure to samples of asbestos caused increased numbers of colonies of HTE cells, an indication of proliferative potential, but fibrous talc did not. RPMs did not exhibit increased CFE in response to either asbestos or talc samples. Decreased numbers of colonies, an indication of cytotoxicity, were observed in both cell types and were more striking at lower weight concentrations of asbestos in comparison to talc samples. However, all samples of fibrous minerals produced comparable dose-response effects when dose was measured as numbers of fibers greater than 5 m or surface area. The unique proliferative response of HTE cells to asbestos could not be explained by differences in fiber dimensions or surface areas, indicating an important role of mineralogical composition rather than size of fibers.
2004
A total of 17 cases of pleural mesothelioma were ascertained in the town of Biancavilla (Sicily, Italy), on the southwest slopes of the volcano Etna, from 1980 to 1997. Occupational exposure to asbestos was considered possible in only 2 of them, though it could not be excluded in 5 other cases: for the remaining 10 cases the hypothesis of environmental exposure was deemed reasonable. On the basis of this evaluation, a mineralogic study was started in the area of Biancavilla, where incohesive volcanic material has largely been used in the building industry and road paving since the 1960s-1970s. This study led to the identification of the new fluoro-edenite amphibole with prismatic, acicular and fibrous asbestiform morphologies. With a view to acquiring more detailed information on the possible causal relationship between exposure to this mineral and the onset of mesotheliomas, the mineral was tested, by a single intraperitoneal or intrapleural injection, on groups of 80 Sprague-Dawley rats (40 males and 40 females) (fibrous fluoroedenite) and on a group of 30 rats (15 males and 15 females) (powdered prismatic fluoro-edenite), 8 weeks old at the start of the study, at a dose of 25 mg in 1 cc of water; 1 cc of water was administered by intraperitoneal injection to 80 rats (controls). One hundred and nine weeks after the treatment, a high incidence of peritoneal and, to a lesser extent, pleural mesotheliomas was observed in the animals treated with fibrous fluoroedenite; this incidence is comparable to that obtained with various kinds of asbestos. Up to now no cases of mesothelioma have been observed in the group treated with prismatic fluoro-edenite, or in the control group. Eur.
Spontaneous and asbestos-induced transformation of mesothelial cells in vitro
Birth Defects Research, 1998
The processes of spontaneous and asbestos-induced transformation of rat mesothelium were studied using cell cultures obtained in the laboratory. The same changes in cell properties were established in both spontaneous and asbestos-induced transformation: change in epidermal growth factor (EGF) response, in some cases appearance of fibroblast-like cells instead of polygonal ones, appearance of multilayer cell growth foci, and ability to grow in semisolid agar. The response to fibroblast growth factor, insulin-like growth factor 1, and insulin did not change during transformation as well as the P450 system activity measured by benz(a)pyrene (BP) and 7,12dimethylbenzanthracene (DMBA) cytotoxicity. The asbestos-induced transformation began earlier than the spontaneous one. EGF began to stimulate mesothelium proliferation instead of its inhibition at 6-7 passages in the case of asbestos-induced transformation, whereas during spontaneous transformation this change began at 9-10 passages. Elongated rather than polygonal cells appeared at 10-11 instead of 17-18 passages (this morphological change did not take place at all lines studied). The ability to grow in semisolid agar was found at 14-16 passages with asbestos and at 22-24 passages without it. The results allow us to propose the necessity of a positive EGF response for mesothelial cell transformation and the similarity of mechanisms of spontaneous and asbestos-induced transformation.
Toxicology and Industrial Health, 2010
The present investigations correlate the potentials of the reactive oxygen species (ROS) generation and the cyto-genotoxicity of amphibole asbestos fibers (amosite, crocidolite and tremolite) with their surface iron, under in vitro controlled conditions, using A549 cells (human lung epithelial cell line). The mobilizable surface iron was measured by Atomic Absorption Spectroscopy; the production of ROS was investigated using 2, 7 dichloro-dihydrofluorescein-diacetate (DCFH-DA) dye; for cytotoxicity assessment, the intracellular organelles specific damages were measured, using 3-(4, 5 dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide salt (MTT) assay; and, the genotoxic potential of amphibole fibers was determined by cytokinesis block micronucleus (CBMN) assay. In the study, highest amount of ROS was generated by crocidolite followed by tremolite and minimum with amosite. In MTT assay, the time- and concentration-dependent decrease in percent cell viability was recorded with all...