4-hydroxy-2-nonenal and citric-acid--iron--sorbitol-drug-combination

We described before that iron-containing, anti-anaemic drug, ferric-sorbitol-citrate complex (FSC) inhibited proliferation of various murine cancer cells in vitro and caused tumour regression in vivo, but did not affect proliferation of the non-malignant cells. The aim of this study was to evaluate further the anticancer activity mechanism of FSC using human colon cancer cell line CaCo2. After treatment with FSC for 72 hours impaired proliferative ability and viability of CaCo2 cells as observed. Growth modification caused by FSC involved diminished expression of Bcl-2, and over-expression of mp53 proto-oncogenes, accompanied by increased incidence of apoptosis. Immunostaining the cells applying monoclonal antibodies for lipid peroxidation product 4-hydroxynonenal (HNE) showed that FSC-iron increased intracellular HNE, but did not induce severe HNE-mediated oxidative stress. Thus, antitumorous mechanism of FSC involves modulation of oncogene expression and induction of apoptosis apparently not triggered by lipid peroxidation-mediated oxidative stress, although FSC might restore endogenous HNE production in the CaCo2 cells to level resembling physiological for various non-malignant cells and tissues. Higher dose of FSC increased also number of intracellular ferritin positive CaCo2 cells.

Topics: Aldehydes; Antineoplastic Agents; Apoptosis; Caco-2 Cells; Citric Acid; Drug Combinations; Ferric Compounds; Genes, p53; Humans; Lipid Peroxidation; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogenes; Sorbitol

Anti-anaemic drug, ferric-sorbitol-citrate complex (FSC), inhibit tumour cell growth through the mechanisms which are complex and not entirely understood. The probable mechanisms of described effects of iron is iron-induced oxidative stress of the treated cells. Hence, the effects of FSC on HeLa cell growth in vitro were compared with the biological activity of one of the major mediators of the oxygen free radicals--aldehyde 4-hydroxinonenal (HNE), to see if the effects of FSC and of HNE resemble each other. Impaired proliferative ability and DNA synthesis of HeLa cells was observed after treatment with anti-anaemic drug FSC for 24 hours. After treatment with FSC and culturing of HeLa cells in fresh medium for 24 or 96 hours the cells did not proliferate at all, DNA synthesis was transiently recovered and then diminished again. HNE blocked cell proliferation during the time the aldehyde was present in culture and 24 h later. Afterwards, the cells proliferated as control non-treated cells. HNE did not inhibit DNA synthesis during treatment, but intensity of 3H-thymidine incorporation was lower after preincubation. Thus, both FSC and HNE interfere with the basic mechanisms of the cell growth regulation, while antitumour activity of FSC resembles, but does not necessarily include iron induced lipid peroxidation.

Topics: Aldehydes; Cell Division; Citric Acid; DNA; Drug Combinations; Ferric Compounds; HeLa Cells; Humans; Kinetics; Lipid Peroxidation; Sorbitol; Thymidine; Time Factors