ABSTRACT
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.