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.

TG/DSC study of the thermal behaviour of hazardous mineral fibres

“…Furthermore, since both asbestos samples and asbestiform erionite are used for in vitro studies to test their cyto-toxicity [30,31], the determination of the presence of impurities may be crucial as such contaminants may adversely affect the experimental results. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 with a Netzsch STA 449 C Jupiter in a 25 -1000 and 25 -1100 °C temperature range, with a heating rate of 10 °C/min.…”

“…The study was performed on eight selected fibrous minerals including chrysotile, crocidolite (asbestiform riebeckite), tremolite asbestos, anthophyllite asbestos, amosite (grunerite asbestos) and fibrous erionite object of many important biomedical studies [30,31]. Four fibrous species (chrysotile, crocidolite, amosite, and anthophyllite asbestos) were distributed by the International Union Against Cancer (UICC).…”

Raw and thermally treated cement asbestos exerts different cytotoxicity effects on A549 cells in vitro

“…Suspensions were prepared with 50 g/ml of each material (equal to 14 g/cm 2 ) per ml of culture medium by vortexing at maximum speed for 1 min. 50 g/ml was the selected concentration that produces welldefined cell responses to compare the mineral cytotoxic action and their effects on cells at experimental points as assessed in our previous studies Pugnaloni et al, 2010Pugnaloni et al, , 2013.…”

“…The number of p53, p73, TRAIL and iNOS positive cells was evaluated by quantitative immunoassays (Pugnaloni et al, 2013). All counts were performed simultaneously by two investigators blinded to the treatment (G.L.…”

Multi-Analytical Approach for Identifying Asbestos Minerals In Situ

“…Previous studies [15,42,43] [28]. The toxicology of chrysotile, such as tremolite asbestos, is associated with size, durability, and chemical composition [27,44,45].…”