Effects of microcystins on cell cycle and expressions of c-fos and c-jun / 中华预防医学杂志

<p><b>OBJECTIVES</b>To investigate the effects of microcystins on cell cycle and expressions of c-fos and c-jun, and explore the potential carcinogenic mechanisms of Microcystins.</p><p><b>METHODS</b>Microcystic cyanobacteria extraction (MCE) purified by Sep-Pak C(18) cartridge was added into the media and co-incubated with SHE cell for various periods. Immunohistochemistry assay was applied to detect the expressions of c-fos and c-jun at 1, 3, 6 hr time point, and cell cycle at 6, 12, 24 hr point were analyzed by flow cytometry respectively.</p><p><b>RESULTS</b>Sustained up-regulated expression of c-fos and c-jun were induced by MCE during the experimental period, and 5 - 6 folds increased expression were observed at 6 hour point after treatment. As much as 44.8 per cent of cells were induced to entry S-phase from resting G(0)/G(1).</p><p><b>CONCLUSION</b>Up-regulating the expression of transcript factor such as c-fos and c-jun thus to induce cell abnormal proliferation may be the potential carcinogenic mechanisms of microcystins.</p>

Progress on Carcinogenicity of Alga Toxins / 环境与健康杂志

Three aspects of advances in study on the carcinogenicity of alga toxins are reviewed in this paper. Water pollution by alga toxins has become a worldwide environmental problem, and special attention has been paid to the potential carcinogenicity of microcystins, the main alga toxin. Results from the study on structure_activity relationship, short_term screening assay in vitro and long_term rodent carcinogenesis bioassay all showed that alga toxins possessed tumor_promoting activities. It suggested that inhibition of protein phosphatase activities, induction of expression changes of cell proliferation_related genes, dysregulations of signal transduction and cell proliferation might be the mechanisms of the carcinogenesis effect of alga toxins.