asbestos--amosite and Cell-Transformation--Neoplastic

asbestos--amosite has been researched along with Cell-Transformation--Neoplastic* in 5 studies

Other Studies

5 other study(ies) available for asbestos--amosite and Cell-Transformation--Neoplastic

ArticleYear
Persistent effects of Libby amphibole and amosite asbestos following subchronic inhalation in rats.
    Particle and fibre toxicology, 2016, Apr-15, Volume: 13

    Human exposure to Libby amphibole (LA) asbestos increases risk of lung cancer, mesothelioma, and non-malignant respiratory disease. This study evaluated potency and time-course effects of LA and positive control amosite (AM) asbestos fibers in male F344 rats following nose-only inhalation exposure.. Rats were exposed to air, LA (0.5, 3.5, or 25.0 mg/m(3) targets), or AM (3.5 mg/m(3) target) for 10 days and assessed for markers of lung inflammation, injury, and cell proliferation. Short-term results guided concentration levels for a stop-exposure study in which rats were exposed to air, LA (1.0, 3.3, or 10.0 mg/m(3)), or AM (3.3 mg/m(3)) 6 h/day, 5 days/week for 13 weeks, and assessed 1 day, 1, 3, and 18 months post-exposure. Fibers were relatively short; for 10 mg/m(3) LA, mean length of all structures was 3.7 μm and 1% were longer than 20 μm.. Ten days exposure to 25.0 mg/m(3) LA resulted in significantly increased lung inflammation, fibrosis, bronchiolar epithelial cell proliferation and hyperplasia, and inflammatory cytokine gene expression compared to air. Exposure to 3.5 mg/m(3) LA resulted in modestly higher markers of acute lung injury and inflammation compared to AM. Following 13 weeks exposure, lung fiber burdens correlated with exposure mass concentrations, declining gradually over 18 months. LA (3.3 and 10.0 mg/m(3)) and AM produced significantly higher bronchoalveolar lavage markers of inflammation and lung tissue cytokines, Akt, and MAPK/ERK pathway components compared to air control from 1 day to 3 months post-exposure. Histopathology showed alveolar inflammation and interstitial fibrosis in all fiber-exposed groups up to 18 months post-exposure. Positive dose trends for incidence of alveolar epithelial hyperplasia and bronchiolar/alveolar adenoma or carcinoma were observed among LA groups.. Inhalation of relatively short LA fibers produced inflammatory, fibrogenic, and tumorigenic effects in rats which replicate essential attributes of asbestos-related disease in exposed humans. Fiber burden, inflammation, and activation of growth factor pathways may persist and contribute to lung tumorigenesis long after initial LA exposure. Fiber burden data are being used to develop a dosimetry model for LA fibers, which may provide insights on mode of action for hazard assessment.

    Topics: Adenocarcinoma, Bronchiolo-Alveolar; Adenoma; Animals; Apoptosis; Asbestos, Amosite; Asbestos, Amphibole; Cell Proliferation; Cell Transformation, Neoplastic; Cytokines; Dose-Response Relationship, Drug; Epithelial Cells; Hyperplasia; Inflammation Mediators; Inhalation Exposure; Lung; Lung Neoplasms; Male; Pneumonia; Pulmonary Fibrosis; Rats, Inbred F344; Risk Assessment; Signal Transduction; Time Factors

2016
Establishment of a human in vitro mesothelial cell model system for investigating mechanisms of asbestos-induced mesothelioma.
    The American journal of pathology, 1989, Volume: 134, Issue:5

    Normal human mesothelial (NHM) cells were transfected with a plasmid containing SV40 early region DNA. Individual colonies of transformed cells from several donors were subcultured for periods of 5 to 6 months and 60 to 70 population doublings (PDs) before senescence, in contrast to a culture lifespan of approximately 1 month and 15 PDs for NHM cells. One such culture, designated MeT-5A, escaped senescence and has been passaged continuously for more than 2 years. These cells had a single integrated copy of SV40 early region DNA in their genome, expressed SV40 large T antigen, and exhibited features of mesothelial cells including sensitivity to the cytotoxic effects of asbestos fibers. One year after injection subcutaneously or intraperitoneally in athymic nude mice, these cells remain nontumorigenic, and therefore are a potential model system for in vitro fiber carcinogenesis studies.

    Topics: Animals; Antigens, Polyomavirus Transforming; Asbestos; Asbestos, Amosite; Carcinogenicity Tests; Cell Survival; Cell Transformation, Neoplastic; Cell Transformation, Viral; Cells, Cultured; Glycoproteins; Growth Substances; Humans; Karyotyping; Mesothelioma; Mice; Mice, Nude; Plasmids; Plasminogen Activators; Plasminogen Inactivators; Pleural Neoplasms; RNA, Messenger; Simian virus 40; Transfection

1989
Correlation of in vitro genotoxicity and oncogenicity induced by radiation and asbestos fibres.
    British journal of cancer, 1985, Volume: 52, Issue:4

    The in vitro cytotoxicity and oncogenic potential of both native and acid leached asbestos fibres were studied using the C3H 10T1/2 cell model. Both native and leached fibres induced a dose-dependent toxicity. At high fibre concentrations, acid leached fibres were significantly less toxic than their untreated counterparts. While asbestos fibres alone do not induce oncogenic transformation at the concentration examined, it was found that both leached and native fibres substantially enhanced the oncogenicity of gamma-irradiation in a more than additive fashion. Although no significant chromosomal aberrations or sister chromatid exchanges (SCE) were found in asbestos treated cultures, a significantly higher number of SCEs was observed in cells treated with both asbestos and radiation compared to cells receiving radiation alone. The results suggest that the enhancement in radiation induced oncogenicity by asbestos fibres may be attributed to the mere physical presence of the fibres rather than any chemical contaminants the fibres may contain. Furthermore, the carcinogenicity of asbestos may be unrelated to genotoxicity.

    Topics: Animals; Asbestos; Asbestos, Amosite; Asbestos, Crocidolite; Cell Survival; Cell Transformation, Neoplastic; Cells, Cultured; Chromosome Aberrations; Fibroblasts; Gamma Rays; Mice; Mice, Inbred C3H; Mitosis; Neoplasms, Radiation-Induced; Sister Chromatid Exchange

1985
The influence of asbestos dust on the oncogenic transformation of C3H10T 1/2 cells.
    Cancer letters, 1983, Volume: 18, Issue:2

    The cell transforming ability of asbestos dust was investigated using C3H10T 1/2 murine fibroblasts. In a series of experiments both crocidolite and amosite caused no increase in the number of transformed foci over that seen in cultures from untreated cells. The dusts, were, however, capable of augmenting the oncogenic effect of benzo[a]pyrene (BP). This putative synergistic effect was evident when fibres and chemicals were added to cultures as simple mixtures and when BP was adsorbed to the surface of the fibres.

    Topics: Animals; Asbestos; Asbestos, Amosite; Asbestos, Crocidolite; Cell Transformation, Neoplastic; Cells, Cultured; Mice

1983
Study of the cell-transforming ability of amosite and crocidolite asbestos and the ability to induce changes in the metabolism and macromolecular binding of benzo(a)pyrene in C3H10T1/2 cells.
    Environmental health perspectives, 1983, Volume: 51

    The cell transforming ability of asbestos dusts was investigated using C3H10T1/2 murine fibroblasts. In a series of experiments, crocidolite and amosite caused no increase in the number of transformed colonies over that seen in cultures from untreated cells. The dusts were, however, capable of augmenting the oncogenic effect of benzo(a)pyrene. This synergistic effect was evident when fibers and chemicals were added to cultures as simple mixtures and when benzo(a)pyrene was adsorbed to the surface of fibers. Asbestos dust did not, however, appear to exert its oncogenic enhancing effect by modifying the metabolism of benzo(a)pyrene in C3H10T1/2 cells.

    Topics: Animals; Asbestos; Asbestos, Amosite; Asbestos, Crocidolite; Benzo(a)pyrene; Benzopyrenes; Cell Line; Cell Transformation, Neoplastic; DNA; Embryo, Mammalian; Fibroblasts; Mice; Mice, Inbred C3H; Protein Binding

1983