Effect of indomethacin on E-cadherin and beta-catenin expression in HT-29 colon cancer cells.
ABSTRACT Nonsteroidal anti-inflammatory drugs (NSAIDs) lower the incidence of and mortality from colon cancer. Although there is much evidence from epidemiological and laboratory studies that NSAIDs have antitumor activity and reduce the incidence of colon cancer, the mechanism of action remains unknown. In this paper, we present the effect of indomethacin on growth inhibition, induction of apoptosis, and alterations in the expression of several genes involved in Wnt signaling in HT-29 colon cancer cells. We have shown that indomethacin reduces the proliferation rate of HT-29 colon cancer cells and induces apoptosis. Concentrations of indomethacin from 10(-4) to 10(-3) M strongly inhibited the growth of HT-29 cells. The inhibition of growth, as well as induction of apoptosis was dose and time dependent. The treatment of cells with 4 x 10(-4) M indomethacin caused strong inhibition of cell growth (about 70%), enhanced expression of APC, decreased expression of beta-catenin and induced expression of E-cadherin proteins. Expression of beta-catenin was not markedly reduced instead, beta-catenin was translocated from the nucleus and cytoplasm to the plasma membrane. These results were confirmed by real-time RT-PCR analysis on mRNA level. At a concentration of 4 x 10(-4) M indomethacin there was increased expression of APC gene (10.9-fold induction; DeltaDeltaCt = 3.43) and E-cadherin gene (3.5-fold induction; DeltaDeltaCt = 1.79). These results suggest the antiproliferative effect of indomethacin may contribute to enhanced cell adhesion through increased expression of E-cadherin and translocation of beta-catenin from the nucleus to the cell membrane.
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ABSTRACT: A laboratory study was conducted to determine whether the concentration of heavy metals, zinc (Zn), lead (Pb), and cadmium (Cd), in leachate from mine tailings could be affected by the presence of organic acids exuded by plant roots and microbes in the rhizosphere. Geochemical modeling predicted that some organic ligands found in the rhizosphere have the capability to complex and increase the solubility of Zn. These results were confirmed by batch and column studies in which mine tailings were exposed to 0–10000 μM organic acids. The leachate was analyzed for Zn, Pb, and Cd content and for organic acid concentration.Journal of Hazardous Materials. 01/1995;
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ABSTRACT: Summary The behavior of cadmium labeled with 109Cd in different depth horizons of arable and forest soils were studied under static (batch) conditions in three interconnected processes, which consist of sorption, desorption and extraction. In the sorption, Cd2+ was applied in the aqueous calcium nitrate solution. Both untreated soils and peroxide treated soils were used in order to remove organic matter from some of the soil samples used in parallel. The influence of the V/m ratio on the sorption coefficients was investigated in preliminary experiments with untreated soils. Contrary to the usually short-term sorption, a long-term sorption of cadmium was investigated in untreated and treated soil horizons, which lasted more than fortnight. Kinetic studies of sorption were carried out and cadmium concentration dependence in aqueous phase of the second order kinetic constants was observed. For evaluation of sorption and desorption processes Freundlich isotherms were used. It was found that the Freundlich adsorption intensity coefficient is more time dependent than the absorption capacity coefficient, and the sorption itself consists of rapid and slow processes according to the soil constituents. Desorption and extraction processes revealed the possibility of cadmium recovery from various soil horizons. Based on the obtained results two- or three-stage theory of cadmium retention in soils was proposed. Some new insight into the role of organic matter in the sorption/desorption process of cadmium is also presented.Journal of Radioanalytical and Nuclear Chemistry 01/2006; 269(1):103-113. · 1.47 Impact Factor
- Journal of Environmental Engineering-asce - J ENVIRON ENG-ASCE. 01/2005; 131(2).